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Home My WebLink AboutAPA1380.. '' ~.. . ... ~ ;·-~-·· ', ' ......_ ____ ,_,.,_ ______ ... -----~-----~------------~-·----·--~ Please Return To 1360 -------...-..--------------------·--l ---·--·-...... :JI ~ . DOCUMENT CONT~OL __ _ ';·-: l ( r 1 ! . ' SUSITNA H\'DROEL.E.CTRiC PROJECT { '4 ' ~ ' ~ .<p r L; [ ·-~ ,I .. '; l 1 .-_ [; u 0 [~.·r I .:!# . 0 i I ! I I I l l I I 1 l ~ ' I I t . I 1 I j . -1 1 I I I ' l I . . . .. ._._ . ,. ... .. . _..... "" .... ~ . ~ . I j • I LIB Ptepar~ by; llltli·: .1 .. , .· . .. •. :1 1 I f . i ., ,'· ' .. ·. . .. ' .·' . . . ' . . .. . . . . . . . . . . •. t'· .. . . . . . ··~ ~ AtAS~A.:.p:ovJ~R AUTHORITY .. LIBRARY COPY PLEASE, DO HOT REf10VE FROt1 OFFICE!! . ' INFORMATION PACKAGE IJCTOBER 6-8, 1981 PFlOPERTY OF: . Al(il$~a ·Power Authority · · .~ W. 5th Ave, . An.e~~r~g~, Alaska ~5P1 --~--~~~~--.~. ~------- ! I l J I i I I I I l f I l ' l ~ ··. -· ¥"""·-. ···.A t··A· ·s.-·. ·K··· A· f"'r'\'w· · ···E·R· Au··TH·o· ·RI.TY· --..-·----F~~l·<· ... ~ n.... . I •. . i""''..) . . . . . . . • . . . ___ __,_____. • I 4 . r,: . : 2·· g· .o·· . . ~ , :: ''I~ •• ' -{ j• ' .. ~.~.:.-... # .......... ---~-,"""""" '. . J i ' l . ~ i + i ! . ' ! l ! ' { i· l. ' ; r l '· ' ' : 1 '·· , I I ( ! I ! ~ I I I I L. lt I l • ..,,..o; I • I ........ I I .... -...: I [ -[ -~:'.' r l INTRODUCTION SUSITNA HYDROELECTRIC PROJECT EXTERNAL REVIEW PANEL REPORT NO. 3 October 8, 1981 The third meeting of the External Review Panel for the Susitna Hydro- electric Proj~ct was convened on October 6-8, 1981 at the Acres American office in Buffalo. In addition to Panel Members, representatives of the Alaska Power Authority and Acres American were present. Various members of the Acres American staff presented discussions regarding progress in geotechnical areass seismicity, hydraulics, hydrology, and design. The discussions were well prepared and presented in such a manner as to give a maximum amount of information in a reasonable time. Prior to the meeting Panel Members received a document entitled 11 Susitna Hydroelectric Project, External Review Board, Meeting #3, Information Package, October 6-8, 1981 11 • During the meeting other printed information was presented to the Panel as required. The Panel appreciates the efforts of the Acres American Staff in planning and preparing for this very informative and successful meeting. SEISMICITY AND SEISMIC GEOLOGY Excellent progress has been made during the summer months in resolving most of the uncertainties regarding the possible presence of active faults in the vicinity of the dam sites, in developing an adequate model of the seismic geology of the region, and in assessing the maximum levels of earthquake shaking which could result from events occurring along the major seismic sources. These studies have led to the following preliminary conclusions: WATANA DAM SITE Four major lineaments were originally identified as being possible faults in the vicinity of the dam: (1) The Talkeetna Thrust Fault (2) The Fins Feature (3) The Susitna Feature (4) The Watana River Feature Field geologic studies during the past several months have developed evidence indicating that: ( 1 ) (2) (3) and ( 4) The Talkeetna Thrust Fault is not an active fault. The Watana River Feature is not a fault. The Susitna Feature is not a fault. The Fins Feature may well be a fault but it is relatively short in length and, since there are apparently no other active faults in the area, it is very unlikely that it could be active. In any case its length would preclude the possibility of it being the source of a significant earthquake. In consequence, there are apparently no active faults crossing the site and the major sources of earthquake shaking at the site may be attributed to earthquakes occurring on tl1e Benioff Zone underlying the site at depth, the Denali fault, the Castle Mountain Fault, and smaller local earthquakes occurring with no apparent surface expression in the crust of the Talkeetna terrain. Considerations of fault distances and possible earthquake mag- nitudes leads to the coQclusion that the approximate maximum levels of shaking will be due to the following sources: .. \~:~ 3 Source Benioff Zone Benioff Zone Dena 1 i Fault Local Event Closest Distance ::::: 63 km Magnitude (Ms) ~ 8~ Peak Ace. (Mean) ~ 0.35g ~ 48 km ~ 7~ !:! 0.32g ~ 70 km ~ 8+ !:! 0.22g * * * Seismic geology considerations have led Woodward-Clyde consultants to suggest that the maximum local earthqu3ke which needs to be considered is a Magnitude 5~ to 6 event occurring at a distance of about 10 km from the site. Such an event would produce a peak acceleration (mean value) of about 0.35g and would therefore not be a controlling event. However, the Panel believes that in view of the past seismic history and other con- siderations it would probably be prudent to ccn~ider the possibility of a somewhat larger event at a slightly shorter distance. In which case the local earthquake would be responsible for the maximum accelerations likely to develop at the dam site. This does not mean however, that it will necessarily control the design. For the Benioff Zone event, which seems to be controlling at this stage, the motions recommended by Woodward-Clyde Consultants for preliminary design evaluations appear to be entirely appropriate. DEVIL CANYON SITE At the end of 1980, nine lineaments were identified in the vicinity of the Devil Canyon site which could possibly be active faults. Field geologic studies during the past 6 months have led to the conclusion that only 3 of these features are faults, that the three features recog- nized as faults are inactive, and that in any case they are so short in length that they could not generate earthquakes which would be controlling events with regard to earthquake motions at the dam site. Thus since there are no active faults in the vicinity of the dam site, the design earthquake motions will be determined b~ similar considerations to those applicable for the Watana site. The Panel agrees with those conclusions. * Information to be provided in Final WCC Report 4 Consideration of the most significant seismic sources of ground shaking leads to the fo 11 owing: Source Closest Distance Magnitude (Ms) Peak Ace. (Mean) Benioff Zone !:: 90 km ~ Bl2 !:: 0.3g Benioff Zone ~ 58 km ~ '7!.,: I 2 ~ 0. 3g Denali Fault !:: 64 km ~ 8+ ~ 0.24g Local Event * * * As for the Watana site, there is a need to establish very soon the signi- ficant characteristics of the local earthquake (in the crust of the Talkeetna Terrain) in order to finalize the seismic criteria to be used for project design. In the light of the information presented at this meeting and on the basis of past experience, the Panel believes that through the use of appropriate design and construction procedures, dams with ample margins of seismic safety can be constructed at both sites. The Panel believes, however, that the question of seismic effects due to local crusted earthquakes should be resolved in the next few weeks so that more definitive design studies can be completed. ROCK ENGINEERING CONSIDERATIONS As a result of discussions during this meeting as well as observations made in the field by Panel member Merritt during the period of 23-25 September, we have the following comments regarding present designs. WATANA Every effort should be made to t'educe the height of the cut slope at the inlet to the diversion tunnel. The structures can probably be moved closer to the river and perhaps shifted slightly in a downstream direction. The surface excavation at the outlets of the tailrace tunnels and spillway structures is likewise very extensive. Further detailed examination is warranted to minimize possible slope stability problems. * To be provided in final WCC Report .Jc • " : 5 -If :'-;~: ~,...,-: Recent borings in the proposed underground powerhouse site encountered a zone of soft hydrothermally altered diorite. This is not acceptable material to have in a major underground excavation. Some shifting of these openings is required. Considering all borings made in the right abutment, the general quality of the diorite is quite high and we .foresee that acceptable rock can be found for the proposed structures. DEVIL CANYON The graywacke and argillite at this site appear to be of acceptable quality for the proposed underground structures. No major shear zones have been recognized in these areas. The underground openings have been oriented with respect to the major known joint systems and bedding planes. The present layout is acceptable and it is recognized that some slight shift could result based upon the results of future exploration. The axis of the proposed surface spillway on the right abutment will nearly parallel the strike of the bedding of the rock. The required cuts will daylight the bedding which dips at about 50 deg_rees into the excavation. Potential major rock stability problems could result which might not be solved by simple rock bolting measures. This design likewise requires t your review. BURIED CHANNEL The results of all geophysical surveys completed to date have defined a major channel beneath the plateau on the tight abutment at the Watana Site. The channel is approximately 15,000 fi wide when measured with respect to that portion of the bedro~k channel below the proposed reservoir pool level. The deepest portion of the channel li~s about 450 ft below pool level; however, perhaps as much as 60-70% of the channel lies 100ft or less below maximum pool level._, ·. · ,. The borings completed during the Corps of Engineers study indicated that the channel is filled with glacial till,, outwash; and. perhaps lacustrine deposits. The boring_.logs show that boulders {'s-ome as large as 12ft) can be expected in these heterogeneous deposits, either as individual units or as thick layers. Contour maps ~ade of th~ bedrock surface suggest a 6 wide entrance channel or channnels upstream of the damsite and a relatively narrow exit into Tsusena Creek downstream of the damsite. The buried channel on the north slope of the reservoir at Watana Dam is much greater in extent than was anticipated a year ago and represents one of the greatest uncertainties associated with the Watana Dam project. Major problems posed by the presence and extent of this channel are (1) The magnitude of possible seepage losses through the channel. (2) The possibility of piping within the channel resulting from seepage from the reservoir towards Tsusena Creek. (3) The possibility of seismic instability in the soils comprising the buried channel under s:rong earthquake shaking. It appears that proqlems (1) and (2) above could be eliminated by construc- tion of a cut-off wall and grout curtain through the soils filling the channel. However, the provision of such a cut-off would not solve any problems of seismic instability on the upstream side of the wall. Since very little information is available concerning the nature of the soils forming the channel fill it is not possible to assess the magnitude of the seismic instability problem, if indeed it exists at all, or the need for an extensive cut-off wall, currently projected to be about 15,000 feet long and varying from a few feet to 450 feet in depth. However, it is clear that both the possibility of seismic instability and the cost of a cut-off would be dramatically reduced if the reservoir level ·were about 100 feet lower than currently planned. Such a lowering could reduce the length of the cut-off to about 4,000 feet, facilitate its construction and by lowering the water table in the soils, increase their seismic sta- bility. In view of these advantages, together with the fact that economic advantages associated with the top 50 to 80 feet of Watana Dam do not appear to be very great, the Panel believes that careful consideration should be given to the potential benefits of reducing the height of Watana Dam by 50 to 100 feet. Such a reduced height might also facilitate layout problems for the dam. The Panel cannot be sure that a reduction in dam height would be advanta- geous but believes that a careful study of the question is warranted in the next several months. ... . . ~ \< .. '-· "'..:l ··~~· ~ 7 WATANA DAM EMBANKMENT The Panel believes that the preliminary design section selected for Watana Dam is satisfactory and will produce a stable and economical structure. It is suggested however, that consideration be given to the following items: "(1) If the shells are constructed of densely compacted gravel and/or or rockfill and the core of a much more compressible sandy- silky-clay, there is a danger of deleterious stress redistribu- tion due to differential settlements. Thus consideration should be given to minimizing this possibility by: (a) inclining the core slightly upstream, providing this can be done without jeopardizing stability. (b) locating a relatively incompressible core material which is adequately impervious. Such a material appears to be available as a GC material in one of the -borrow areas. (2) Deformations of the upstream shell of the dam due to strong earthquake shaking can be minimized either by densifying the shell material to such extent that high pore pressures cannot develop or by using highly pervious rock-fill which will dissipate any pore pressures resulting from earthquake shaking almost as rapidly as they develop. Consideration should be given to using gravel-fill and rock-fill in the upstream shell in such a way as to optimize their use from a seismic design point of view. (3) There is apparently ice in the rock joints in the abutments at Watana dam site and this will have to be thawed before grouting. It would be desirable to determine whether construction costs have allowed for this. (4) It appears that there may well be permafrost in the foundation soils for the saddle-dam. When this melts it could leave the soils in a very loose condition which may be adequate for static stability but inadequate for seismic stability. It would be desirable to explore this possibility further and examine the need for exacavation of frozen foundations soils prior to saddle- dam or dike construction. DEVIL CANYON DAM Sufficient study has been completed to adequately support the present arch • J:.* 4lr .. .. 8 dam design for feasibility purposes. However, the linear feature through the pond areas where the wing dam will be located should be further explored in the near futureo Similar considerations to those discussed for the Watana Site should be given to the foundation soils under the Devil Canyon wing damo WATANA DAM DIVERSION TUNNELS Two diversion tunnels are proposed for diverting up to a 1 in 50-year flood during construction of Watana Dam. One tunnel would be located at a low level so that it would flow full at all times. The second tunnel, located at a higher level, would have free flow. After diversion the lower tunnel would be plugged. Two plugs would be constructed in the upper tunnel with gated outlets through them to permit release of low flows until Devil Canyon is completed and serve to lower the reservoir in case of an emergency. The Panel concurs in the general concept of the diversion tunnels and modification of the high level tunnel for use as a low-flow and emergency release outlet, subject to refinements discussed by Acres. WATANA DAM SPILLWAY Spillway f1ows at Watana Dam would be handled by three separate flow release structures. Discharges corresponding up to a 1 in 100-year flood, would be released through a low-level tunnel controlled by three or more Hewell- Bunger or similar valves located at the dowr.stream end of the tunnel. Discharges corresponding to floods in excess of 1 in 100-years and up to 1 in 10,000-years would flow through an open chute spillway with a flip bucket. Discharges in excess of the 1 in 10,000-year flood up to the PMF would pass through a bypass channel controlled by a fuse 'plug. The Panel concurs in the proposed concept of handling spillway flows. Release of floods up to 1 in 100-years by low level valves would maintain the nitrogen supersaturation level to an acceptable limit. The Panel suggests that fixed cone valves, as installed by the Corps of Engineers at New Melones Dam be used, since its greater rigidity makes it more suitable for high-head operation. The smaller spillway/chute flows reduce erosion in the downstream river channel. Hydraulic model tests wi11 be required 9 •' to determine the extent of material that should be pre-excavated in the plunge pool area. In view of the infrequency and short duration of spillway operation and the relatively high quality of rock in the steep river banks, the Panel is of the opinion that excessive erosion would not occur due to service spillway operation. With respect to the emergency spillway bypass channel, the Panel is concerned over the 45-ft height of the fuse plug. This high plug would need to be designed as a small earth dam to retain the power pool at maximum levels and also be capable of failure as a fuse plug when it is overtopped. It is suggested that the entrance to the bypass channel be widened, thereby requiring a smaller height of fuse plug. This would also reduce the amount of reservoir lowering in the event of fuse plug failure. DEVIL CANYON DIVERSION TUNNEL One diversion tunnel is proposed for Devil Canyon Dam to divert flows up to a 1 in 50-year flood during dam construction. The tunnel would be plugged after it is no longer needed for diversion. The Panel suggests that this tunnel could be used for spillway flow releases in an alternative spillway design discussed hereinafter. DEVIL CANYON SPILLWAYS As for Watana Dam, spillway flows at Devil Canyon would be handled by three separate flow release structures. Flows up to the 1 in 100-year flood would be released by four or five outlets through the base of the concrete arch dam controlled by Hewell-Bunger or other type high pressure valves. Discharges in excess of 1 in 100-years and up to 1 in 10,000-years would flow through an open chute spillway with a high level flip bucket. Dis- charges in excess of the 1 in lO,OQQ.year flood up to the PMF would pass through a bypass channel c9ntrolled by a fuse plug. The Panel concurs in the concept of handling the spillway flows subject to one question discussed below. Release of small flows through valves at the base of the dam will prevent excessive nitrogen supersaturation in the downstream river channel, as well as reduce discharges and flow fre- quency and duration in the chute/flip bucket spillway, thereby reducing plunge pool erosion. Based on a ground and air inspection of the river channel at the Devil Canyon Site by Panel member Douma and Acres repre- ... ~ 10 ·~-.. ·~· sentatives on September 17, 1981, the Panel is of the opinion that the very high quality rock in the canyon walls should not experience excessive erosion due to spillway operation. In this case, pre-excavation of streamed material and weathered rock is probably not required. The Panel is con- cerned, however, over the deep sidehill rock cut required for construction of the spillway chute. It suggests that consideration be given to an alternate plan of providing spillway tunnels, as required, instead of the chute spillway. In this alternate plan, the diversion tunnel and probably only one addi-~ tional tunnel would be required. With respect to the emergency bypass channel spillway, the Panel is concerned over the 57-foot high fuse p1ug for the reasons stated for the Watana fuse plug. Consideration should be given to increasing the length and reducing the height of this fuse plug as described for Watana. DEVIL CANYON POWERHOUSE TAILRACE The Panel concurs in extending the tailrace for the Devil Canyon powerhouse about 1 l/4 mile to take advantage of the additional approximately 30 feet of head. CLOSING REMARKS The Panel requests that the topics raised in this report be thoroughly discussed in the next External Review Board Meeting tentatively scheduled for the week of January 11,1982 in Anchorage. The Panel greatly appreciates the many courtesies extended to it by the staff of the Alaska Power Authority and the staff of Acres American, Inc. Merlin D. Copen Andrew H. Merritt Jacob H. Douma H. Bolton Seed TABLE OF CONTENTS -PROJECT STATUS REPORT, SEPTEMBER 1981 -SUPPORT MATERIAL TO TASK 3 -HYDROLOGY -SUPPORT MATERIAL TO TASK 4 -SEISMIC STUDIES -SUPPORT MATERIAL TO TASK 5 -GEOTECHNICAL STUDIES -SUPPORT MATERIAL TO TASK 6 -DESIGN DEVELOPMENT ·WATANA LAYOUT STUDIES aWATANA DAM DESIGN ·oEVIL CANYON LAYOUT STUDIES ·o~J!L CANYON ARCH DAM DESIGN -MEETING AGENDA I . I ' ! 1t I I' r~ .! ll r1 f1 ~ . i . !} 1 :] ~ . ~ f] L1 :·I ·~ ~.L ~·~ \ .ty r; [~ []ij q~ l• ~~ f ·~ u ~ . ' ~ PROJECT STATUS REPORT, SEPT. 1981 -·. I "' ' ·a .I ~~ -fl.·. . » ' ,, 'lj . ; ;-.. II 'illl -~~· i ~ . ' . r--".1. ' . i ! .. ,, r·J· ! ' i .. ..._ ,ifll ·g ,__ ,...· m1 •• ...... :I I \.! .. """"' !I ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT PROJECT STATUS REPORT, OCTOBER 1981 The third meeting of the Powe.r Authority • s. External Review B~ard for trye Susitna Project will take place at the off1ces of Acres Amer1can Inc. 1n Buffalo October 6, 7 and 8, 1981. The objective of this meeting is to review the status of field work and engineering studies in hydrology, seismic and geotechnical aspects and in the development of layouts and 'designs for the main structures at the Watana and Devil Canyon sites. This Project Status Report is intended to summarize the current status of all project activities, on a Task by Task basis . Task 1 -Power Studies This activity is complete., and the results were incorporated in the Project Development Selection Report issued in June 1981. Current studies of power alternatives by Battelle for the State of Alaska include an update of the load forecast for the Railbelt region. The results of these studies will be incorporated into the Acres feasibility assessment later this year. No major changes in the size or scale of the Susitna Project are anticipated at this time • Task 2 -Surveys and Site Facilities Operation of the Watana camp has continued in support of field activities. Surveys of dam and reservoir areas for each site have been completed and recent activity has been concentrated on completion of surveys of aiternative access and transmission corridors. Work is currently being completed to provide a basis for selection of an access route before · the end of the year. Task 3 -Hydrology Collection of stream gauge, snow course, climatological, bedload and water quality data at the stations set up for this purpose throughout the project area, has continued in support of the feasibility study and licensing requirements. Engineering activities in support of project flood, energy yield, river morphology, ice and hydraulic design studies have continued to the point where the design requirements for hydraulic structures can be established . Task 4 -Seismic Studies The 1981 field program of geologic mapping and trenching has been completed. Evaluation of data is continuing and preliminary findings indic~te no major concerns relative to project feasibility. The results of th1s work are discussed elsewhere in this document. ' -~ ~-~ .. -·- . 1 ~··1.· -:. l ;·I r·~ , I 1 ~ ~ 1 nl • I .. ~~g·. . ' • ! 1 1 . I t. •. r'l' ; I . '' L. , .... 1 i ; • I I ! \--* rll ~ rJ .. l l w rt l·· L. r.l L. ~u ! .. '-- Jfl ,·_m. ;I .. . '"-- •• Task 5 -Geotechnical Investigations The 1981 program of geologic mapping, seismic refraction surveys, drilling and testing at the Devil Canyon and Watana sites is continuing . Preliminary results of this work are presented elsewhere in this document. Sufficient data has been obtained to support with reasonable confidence the design requirements for major structures at each site such that the locations and scale of such structures can be establi~hed for feasibility study purposes. The final detailed report on the 1980 field exploration activities is currently being distributed$ Task 6 -Design Development The Project Development Selection Report issued in June 1981 recommended that the feasibility study be continued to refine and optimize the Susitna Project on the basis of the following components: Watana: 880 feet high earth-and rockfill dam 400 MW 1993 400 MW 1996 Devil Canyon: 675 feet high thin arch dam 400 MvJ 2000 Under Task 6, engineering studies have continued at each site on the basis of the additional survey, hydrologic, geotechnical, seismic and environ- mental data which is becoming available. The studies havP included ~t each site: establishment of design assumptions and/or criteria -consideration of alternative types of dam -optimization of reservoir levels and dam centerline -selection of power plant installed capacity -preliminary spillway design concepts consideration of alternative spillway types -development of optimum diversi.·on schemes -development of reservoir release facili.ties .. consideration of alternative project layouts preliminary desi·gn of aams The currently favored general arrangements at each site are illustrated in the attached Plates 8~1 and 8'!4 (Watana} and 9'!1 (.Devtl Canyon}. Results of these studies to date are summarized elsewhere i.n th.is document. Task 7 -Environmental Wildlife, fisheries and all other environmental studies to establish current c~ryditions in the project area are continuing at full pace. Water qua 1 1ty studies parti.cularly as they relate to sedi.ment tran.s- portat1on, th~ ~otential for nitrogen supersaturati.on and f:ish.eri,es are also rece1v1ng considerable attention. These studies will form -, •.. . .. ' ' ,-.•... · . ' ; ,J! -1' . ' . . . . ~ .. g ' . j rD ril t, .. ~ ~"""'".a· ~ ~ . : ! .. i . :11 ~~~ .. L .... rfJ•· ' ' i:- J . \. .: r~u L_ dl L 9 [!I r.JI [ltl i....:: r~l L . the basis of assessments of the environmental impact of the project and the ultimate development of appropriate mitigation measures for the license application • The socioeconomic impacts resulting from construction and operation of the project and its associated recreational potential are also being assessed. Task 8 -Transmission A report on transmission corridor selection is currently being distributed. Two 345 kv transmission lines from the Watana site will initially be installed with a third line to be added when Devil Canyon is constructed. The three lines will ultimately be used to transmit power to the Anchorage area and two lines to the Fairbanks area. Route selection studies within the proposed corridor are continuing on the basis of ongoing environmental and access studies. Studies are also continuing to optimize and advance the design of these lines and to examine the future development of the total transmission system for the Railbelt region with the Susitna Project incorporated. Task 9 -Construction Cost Estimates and Schedules Data gathering to provide labor, equipment and materials costs as a basis for cost estimates has been initiated. An "upper limit" magnitude cost estimate for the project was developed under Task 6 for purposes of ensuring the economic feasibility of the selected project. The currently preferred project layouts are being used as the basis of refined preliminary cost estimates which will be completed by November 30. These estimates will be further refined in parallel with continuing development of designs up to issue of the feasibility report which is scheduled for March 15, 1982. Task 10 -Licensing Activities under this Task have continued in terms of coordination with the various federal and state agencies involved and an assess- ment of the recent proposed changes in licensing requirements and fonnat. Task 11 -Marketing and Financing Activities in this area have been limited pending clarification of recent State legislation concerning financing of the project. · Task 12 -Public Participation Involvement of the public in the development of project concepts has been and continues to be actively encouraged through public meetings, workshops, the issue of newsletters and an action list program. 1-..... , !~' ·, ... ~. :-· "I ..... -· . , . ~,_,_,... .~ ... 'I --• .. .. rl ll • t! I ~ ·l i[ ,, :l • • "-·i :~. 7' ... , ... ~ ... -.--.. ... ~, -110 liil ' liiJ ,. "'i liiilli t-,.,~--1..;~~ . •• lrfi~ WATANA· VALVE 1Yf'£ SPillWAY AllERHMI\IE r.£NEJW. ARRANGEMENT • ,-~, r-~· ;-~····'] ... ~ ..,_,'7'-.~t _,_ -., .... _, .. ··"I .-.... ,~-1 ·-·, . ...... ---~ --1 ' '. ' '1 ! ... t .. l -l'lfd I ---' ---' llfjJ . -. .. ~ ·-' ., D c • too•: 1 mz-"" ' ..... , ! . . ~-. L; r·.l ! ., If Cl u 1: .·~ ~· . .------.. / I ,.,, Cl u • ~~ ~ a~ ~~~~ ~~~4!.1 ..o....i...l..lb..I...J..J .... _______ . --· + • . .. ·- . ,·-· '1 \'~. r .. :-lr : ~ . . - 11 l-· •:. ,_, r,. , ' ' ' ~ . ~ . ... " ·I i: i . ;I . ·- 1 I ~-"". ·-· ; ~ l ~ -'" ' -DEADLINES - -FINAL DEVELOPMENT SELECTION REPORT-SEP.1 81 -REVIEW OF WCC FIELD WORK-SEP.'81 -REVIEW OF ACRES/R&M FIELD WORK-SEP.'81 -APA EXTERNAL PANEL REVIEW-OCT.'81 -PRELIMINARY DEVIL CANYON ESTIMATE-OCT.'81 -PRELIMINARY WATANA ESTIMATE-NOV.'81 -FINAL GEOTECH. REPORT-FEB.'82 -FIRST DRAFT FEASIBILITY REPORT-FEB.'82 -FINAL DRAFT FEASIBILITY REPORT -MAR. 15, '82 -FERC LICENSE DOCUMENTS -MAY '82 f ~· ... -qr_, "1 -. . . r . .. ; 1 -Sll· ······~ r ·-·~. ..... r --~·~ -- 10 8 • II 7 ' Cl I II ACTIVITIES PRIOR TO LIC£NSE APPLICATION TASK tfO. DESCRIPTION 1900 1991 JIFIMIAIMIJIJ A I S I 0 I N I 0 J IF MIAIMIJIJIAISIOINIDIJIF ._.,u l .. .,. -1 l -•• -I!I!U i lfl&l -- ' .. • i :t ACTIVITIES PRIOR TO A*RO ~ C:OHSTRUCTIOtl t.a:NSII'«J 19P2 19115 1984 1185 MIAIMIJIJ A I I o I H 0 I ~,Ill I AIMIJ·I JIAI't i 01111'11 JIFIII I 11/llt.l I JIAfl I 0/111111 JtP/111 A/Mil I ""' I 0/11111 1-1--·--·-- 2.16 I HYOOOGRAPtte SURVElS I 1 ·1 -~--~ll;rntil-f'iifi!i~illf"fmf=l-rt=r-=-~ I I I I I-t-I I 1-J-1-1 I I 1-1-1 I I E 300 lfYDROLOGY I I I I j-t-+-1-1-t-·1!!~ * ~ !!!-'-~~ .. !f!!-\;-.;;;~-* .. ~ -~-* -·~ I! 301 'REVIEW OF AM.A8t.E MATERIAl. 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SUPPORT MATERIAL TO TASK 3 HYDROLOGY I I I I I I· I I ·- ' :1, I I I I I I I .; Water Resources of the Susitna River Basin I I I I I I I I I I I I I I I I I I II Water Resources of the Susitna River Basin Streamflow data has been recorded by the USGS for a number of years at a total of 12 gaging stations on the Susitna River and its tributaries. The length of these records varies from 30 years at Gold Creek to about five years at the Susitna station. There are no historical records of streamflow at any of the proposed dam sites. For current study purposes, available streamflow records have been extended to cover the full 30 year period using a multisite correlation technique to fill the gaps in flow data at each of the stations. Fiow sequences at the dam sites have subsequently been generated for the same 30 year period by extrapolation on the basis of drainage basin areas. A gaging station was estab 1 i shed at the vlatana dam site in June 1980 and continuous river stage data is being collected. It is proposed to develop a rating curve at the station with streamflow measurements taken during the 1980 and 1981 seasons. River flows will be calculated and used to check the extrapolated streamflow data at the Watana site. Seasonal variation of flows is extreme and ranges from very low values in winter (October to April) to high summer values (May to September). For the Susitna River at Gold Creek, the average winter and summer flows are 2100 and 20,250 cfs respectively, i.e., a 1 to 10 ratio. On average, approximately 88 percent of the streamflow recorded at Gold Creek station occurs during the summer months. At higher elevations in the basin, the distri.bution of flows is concentrated even more in the summer months. For the Maclaren River near Paxson (El 4520 ft) the average winter and summer flows are 144 and 2100 cfs respectively, i.e., a 1 to 15 ratio. The Susitna River above the confluence with the Chulitna River contributes only approximately 20 percent of the mean annual flow measured near Cook Inlet (at Susitna station). Attached figure shows how the mean annual flow of the Susitna increases towards the mouth of the river at Cook Inlet. Flow duration curves for the Watana and Devil Canyon dam sites for natural and post-project conditions are attached along with natural streamflow in the river at Gold Creek gaging station. I I I I I I 1- I I •• . . I I ·-· I L: ,. I ·- I I I ,I CHULITNA RIVER YENTNA RIVER 39 °/o SUSITNA RIVER DEVIL WATANA CANYON SITE SITE 20°/0 GOLD CREEK ::::~ :•:•: r:; COOK INLET TALKEETNA RIVER ·o;~~ .•;-;--::J=·: PARKS HIGHWAY BRIDGE GAGING STATION SUSITNA GAGING STATION AVERAGE ANNUAL FLOW DISTRIBUTION WlTHIN THE SUSITNA RIVER BASIN liiiii --riiWJ '' ' -r• r ... ' .. ~·-:-~--·-·--"-·-- l. 50.000 LEGEND -0 40,000t-I I I I WETTEST YEAR • 1962 z 0 u I I I rtl/111~ AVERAGE YEAR w (/) 0:: w a.. I I I 1::::::::::::::::::::::::::::1 DRIEST YEAR -1969 :::::::::::::::::::::::::::: .__ 30,000 w w lL () -m ::::> () -3: 20,000 0 _J lL ~ <{ w 0::: 1- (f) 10,000 0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MONTHLY AVERAGE FLOWS IN THE SUSITNA RIVER AT GOLD CREEK FIGURE 7.3 (i) I I I I I I I I • I '-• I '-·' I \ .. I ._ I L •. I I I •• I. I -· .., .. _: . . ~ .. -'-• ·~ : ·-·-' -· . ,_-,_ ·.C .. .. ... . f; :. . MEAN MONTHLY INFLOW AT WATANA PRE/POST PROJECT ;::· r: ,..... :-. ~. -... I I I I I I :} I r' I I •. · I \.... II I I I ...... , .. I I I .. . ---. to.i'. ! • .. -~ ~. . .'0 I " ·• .. '-. ...;; c ~: ·i -; i ~ .! -· .1 .. -. ;I \ -' . L:' ::.. . \ (·. . < ;;~ . . . . . .. i - c.-. ~..:-._ .... c "" .... ,, \, i:..--... -~,---., L-··t..&---~ 1-~' .., .. . r-~ ... ~ .. _ '-· .. .I - -,_ .. MEAN MONTHLY INFLOW AT DEVIL DANYON PRE-PROJECT 1-'· ~ .. · c: ,-:· .. ~ ... ~ ;""' . . ..... r· '"l .... r : r ... ""-· (" ~ .. -"'-· _. - - ' M 1-.. ,,.. ... . ~ I I •• I . I I I I .. I I . •• l I i •,...,_·. I .. ' . ....... :1· i. • ....... I '-· I ........:. il: ~- 1 I -. ·--. . '.- :) . ('":- . I .. . ·• .. "--· (--· ~· c: ~ ....--~-.1 ~\ I '-' -. . --\ . ... -· '-.. -~ ...... -'·. ·.: . -. • ·-1 I \ I i ' ' \ ~--·.· -... -. r . ;: ~ - -,... .. r r~ ~ . ' r .. ·-·-. \. ..... ' . · .. MEAN MONTHLY OUTFLOW AT WATANA POST PROJECT I I I I I I I I· I ... I ,. ' .. · •• !.... I '· I I I I I I • .. :~ l --. . _: ~ .. ~ : :\ .. · .. .. _. . ' ... ~ : ~ """ -.-.. -\..• ' ,.-.... ,_ . ~ ,..., : '! .:.: : -·• -' _,., ~ .- c: '"': . .... . -. \ -.. "'\ ,. "• <.J -..; .J \ \ \ ~=.-.• -.. r ~=~:.-· ....... = --·" - -... - . MEAN MONTHLY INFLOW AT DEVIL CANYON POST PROJECT r· . -• . ,.. . ~ (. r : / --~ ~ .. .:. i • ·-~ I· ' .. ., ... I ,_ I L I L~ I \ .. ' . ~ I 'I . . ~ '1:. \--· I I I ·-. ..... ,.• ' ~~ ' . I .. . \ .. ·~ : . ' -~J. : . i ~' ~~ ... ~~ r-..:-\ ---·..;.-\ --· -\ - ... ·-........ •.: t . ~ ~~- -· .... 4'.; - ·- .-,. -~ \ r · ~ f:. ..,.. ~ -• ~ · r= .. ~---. ·-.._ ... ··- MEAN MONTHLY OUTFLOW AT DEVIL CANYON POST PROJECT -"\ \ ·:---~---:--~---,--------~--~--~---:--~ -"'.. '"'1. ... .. - ::. c; r ;. ... ·- I •• ' 1- i I· ~ ; I I I I I_ .... · I t.~ ... a~ . •,. Regtonal Flood Frequency Analysis I- I I I I· I ' I I· '·' I t I • <,, ' I I I I I I I Regional Flood Frequency Analysis The objective of this study is to provide design flood peak information for the design of the project and for assessing pre-and post-project flood conditions in the Susitna River reaches located downstream and upstream from the proposed Watana and Devi 1 Canyon dam sites. ~Ji thin this context, two types of floods were studies: the largest annual floods and the largest annual floods during ice conditions (October-May). Procedures were developed to estimate the annual instantaneous peak and the October-May instantaneous peak for selected frequencies of occurrence on ungaged rivers within the upper Susitna River basin. Procedures were also developed to estimate the error associated with estimates made by the above mentioned procedures. Typical hydrographs were developed indicating flood shape, peak, and volume for selected frequencies of occurrence. flood volume-duration frequency curves were also developed for the May-July period on the Susitna River at Gold Creek. Selected results are presented in the attached figures. • M .. -{-f-:-riM" .. . lllffll··-···-·:··· ..... -.. .. susiS/nl TABLE 3.8 PHYSIOGRAPHIC AND CLIMATIC PARAMETERS 1 Mean Main Mean Area of Mean Minimum Drainage Channel Stream Basin lakes & Area or Area or Mean Annual Precipitation Annual J~=1uary Stall on Area Slope Length Elevation Ponds Forests Glaciers Precipitation Intensity Snowfall Temperature Name location ~-'"'·> <rt./ml.) (mi.) (ft.) (%) (%)-{\) (Ln.) __ {ln.J ... (in.) (ll»f) Susitna R. at Gold Creek 6,160 10.2 189.0 3420.0 1.0 7.0 5.0 29.0 2.0 200.0 -4.0 Caribou Cr. nr. Sutton 289 13.6 30.0 4190.0 0.0 10.0 0.0 28.0 1.5 80.0 2.0 Matanuska R. at Palmer 2,070 79.7 77.0 4000.0 0.0 14.0 12.0 35.0 1.5 80.0 4.0 Susftna R. nr. Denali 950 56.6 51.0 4510.0 1.0 1.0 25.0 60.0 2.0 400.0 -6.0 Maclaren R. nr. Paxson 280 133.0 23.0 4520.0 1.0 0.0 19.0 55.0 1.5 400.0 -6.0 I Susitna R. nr. Cantwell 4,140 10.0 107.0 3560.0 2.0 5.0 7.0 32.0 1.5 200.0 -4.0 .. Chulitna R. nr. Talkeetna 2,570 23.0 87.0 3760.0 1.0 22.0 27.0 55.0 1.6 250.0 -5.0 Talkeetna R. nr. Talkeetna 2,006 35.0 90.3 3630.0 0.0 25.0 7.0 70.0 2.5 150.0 -2.0 Montana Cr. nr. Montana 164 -'114.0 25.0 1930.0 3.0 54.0 0.0 40.0 2.2 90.0 0.0 Skwentna R. nr. Skwentna 2,250 ,30.6 98.0 2810.0 5.0 34.0 16.0 43.0 2.0 140.0 -5.0 Tonslna R. at Tonsina 420 71.0 46.0 3600.0 4.0 27.0 11.0 25.0 2.0 ' 180.0 -2.0 Copper R .. nr. Chitina 20,600 14.4 178.0 3620.0 ... 3.0 22.0 17.0 37.0 2.0 120.0 -4.0 1 Values in this table are from the report entitled "Flood Characteristics of Alaska Streams 11 by lanake (1979). I I ·I· !I ,. ,. l ' II ll l i ,, ·I II . '. i :I .. i ...... 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""·--+-··I · ·-r----: g • c~ t T-:: ~.!.~= t .. :C-1 ~J. : : ·-' ' ; . :-~· ·t·-•••·t7't·--i-l-::•~:t·~t·-~ j-• • i ' ; ~ 0 ,.; 0 C\1 0 0') CX) ,... U) _; 0 0 0 0 en o· rt') 0 C\1 d -. (/) a: >--0 0 a: Lz.J 0.. z a:: ~ 1- Lz.J 0:: DIMENSIONLESS CURVE ALASKA POWER AUTHORITY FIGURE 3.3 DESIGN DIMENSIONLESS REGIONAL FREQUENCY CURVE ... ' '' .... "' ' -·------ SUSITNA. HYDROELECTRIC PRClJECT FLOOD STUDIES ANNUAL INSTANTANEOUS FLOOD PEAKS I I I I I I I I I '. I ' I I ... I I I I , I l -!~?Pl._.,..,__ -·-: • ~ _· -j--i . -; --~ Gi __: -=f ----::r.:-. ~ .. _:.....p-.-1 0 . • JC%--""1-. -·;r--: ::::±= -. -:r -o-re ·--:---:~:.-f-. .J--r-==t----r, ..--:±--:a::: @.::£!! __ · tf ~ .. ~ · · r . I . -~--r--• · -i· 1 ,---------:VJ-.-.H!:-l_,.;;i-·"':-o -y-t-1 .. _n -·-f-·F !\ :::r:::J ___ • , . --t-~~·:5?.-:r-~ ..z• ... '-··r~-·. . . · -4-~ __ __ 1 \. ::.."ClF·';;;;:.~ . ·.: " . I 1 • ·-.C::-.:C..-..0 .• <:). 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O')tti,.._ wIt)~ rei rJ -ode o o o o o ~--~~----~--~--~~----~-----J DIMENSJONLES S CURVE FI~URE 3.4 DESIGN DIMENSIONLESS REGIONAL FREQUENCY CURVE ALASKA POWER AUTHORITY SUStTNA HYDROELECTRIC PROJECT FLOOD STUDIES OCTOBER-MAY INSTANTANEOUS FLOOD PEAKS ~~ j• I • ' " J )1 I J II J ll I II II II 11 Ll ~~ Jl CJ) 0 0 0 ..J u. ...J <( ::::) z z < u.. 0 -----~----.-----,-----~-===J:::::J:::::::::::~====~~====~-----·~'-----~ ·--~~--=.....l...---!!----1~----r----1--·+·---+-----.!-.~---+ --------"! I I . ' , I • I . : I • . I . I I . . 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I ·---1-------·--==~·--4---+-:----t·---t..·:.~ .. ~ .. ·.~·.·t.•.t•.·r---:~---:.~~ ___ ,_ -----. --------.!----4----+---t---.;.;.; ... ;.;.::;.: -:::·:.::;::.~:::.::: --·-t -·----r-------. ·-_·~::j·~:-=-=-~~~l=~~~=~·====~=====i;~~~~~·:-.~~~·;!·!*·:_·=--==-=··ji.:~-=·f·=·~f:·:§:~:·:::::j·~==~·==~==:~::~ 2. 0 ~ 1 I •,•,•;•:•:•.•:•:•: ,•.·.;.;.;.;:_:-::_,• - -l---f------;--· ·--- =1 -----~-· ~.~-:-:-::--::-. . ·.·.·.·.·,·.·.·.·· l --·~----• ---il i~~~~:~:~i~~ -===· ~~~~~:~s~~ :::--: --. O"" ·.·.·.·.·.·.·.·.·. --·--·.--........ . I ·"'---1 ---l,---~---t----+-1 ..-t:). :-.~-·-·.·.·-~7· ·.·.·.·.·.·.·.·.·. . • I ' .·.·.·.·.· .. ·.· .·.·.·.·.·.·.·.·.· 6 cu .·:.-:~.:·::.:·~· -· ---i·· . -.. . .___ __ ............. --.... _ __....,. -eft)-•••••••• •• ••••••• : ·----~ __ ; ·---·-:~::;.:;:::::;:;: ::~;:~::;;::~~ . ·.· ... ·::-:::.:.:.:.:::::--. % ....... ---~ . • ! .--............... ·.· .. ·.·.·.· ... •.•. . . . . .• . . . 3 ·-· . ------·--· ---~ --___ ;__ ---··:¥:·:--:.;.:..;.. :.:-:-:-:-:.:·.-:--:~·:-::·:::-·· ::::.:-:::-::·7·~· ' ----. -. . . . . . . . . . . . ·.·.·.·.··::: .·.·.·. . . . . . . ......... · ..... _._ .. l . . .... . ·-· .. -~---l· +----. + --:::-:~::-:::::::\: :::::::::=:::::::• ·::::::.:::;::::: ::::::.::::::-::::-: •:•:•:•:-:•:•:•:•:~ 1 ~. 0 I" • F M A M J ·: s 0 N D MONTHS OF YEAR .-- SUSITNA RIVER AT GOLD CREEK PERIOD OF RECORD-1950-1980 De.; FIGURE 5.1 ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FLCCC STUCiES PERCENT OF AN~~UAL MAXIMUM FJ_QQDS ~&M CONSULTANTS, INC. MARCH 1981 ......... .,. ~~neo..o••••• .-.. ..... ._ •w•we•o.• I I I I I I I I I I l. I ! I I , I ;, 'I j ·~ 'I j ,, • I i .. ' . ~ . .. . . . , .. .. ' ' ~ f • • • • I' t • I I . i. J I • .. ''I i l ' . •;" I . ' ' I . I I I I ,. '' I I I' J . . '• • I I. t ·' I . ' I I t 1 I t -' : 1 t I ' t · 1 ' f 1 • t_J ' ~ .,.... . . ~ .1 J ~ t i J 1 f 1 I i ~ t ! IJ! I I I I I • l I I u I I I l1 I t I II i I I I I I ~ I _1 !I I I 90 so_ 61 70 60 ... ' 'j_l I I I • I ltol 1n r l I! I II[ IU ltlf II II I _1_1 i II I I• 1 II II I 1 I. IIi I i I ~ I 1tt, i; I 1 • I I • I I !II I ! I l I I I t I I I I I I l I ! 1 II I I I I IU I I l J j I 1 I I ! I i i I I i IU Ill 1 ! I J.l I I • i i 'I i I IJ I I I • I II _l i I i i I • I II I j_i I I I I _l I I _l I I l II lllj II I I II II ; l I I I I I i I I I I I I I I l I I -.=-_--.... - '' • l • f I . . . I . • I'": If t f I• • • '1 • f ' 'I I I i 1' I f f '11 t • i • , I i j , 1 i. • I : ! I Ill • l I 1 i I Ji tj_ f f I i ; I t :! It l i ; ' I i 11 I I I I I I I I I I_! i ' I i I I I lj I I f I ! A:N NUAl I I i I I I I I II I I .k'1" MIO.Y .:..: nt 1L_I•fl ; I I I I I I LJ..1"' 1./_ I Ill I I i l i I ! I r...~ llj).-~ v AUG~Ii'ij; CT.i I I I .....,..H11 ~rn II !A' I II Lll I I t ,_ . -===r::::ssrs --~. -__. .. (/) Ll.: (.) 50 + z 30 LtJ (.!) a: '. . ,, . !_!_ ' ' .. ' ' . . - f. t I I 't • t • I ' ;, .. . ' I . ' . . I • t t ,. ' . . ' .. . . . . • _j_ . . . 4 It It t I t 1 t % 1-'~'_j_+-+-++~;..o· "-...+ I • • f t _j I • 1 ; I • • I • I 1 ~ ,, . •• t--~(.) 20Ht~f"t •ttl ,,~ ... t •• , I• ' I I ,. ~ t I I :t•· •• f...+:+'+',_' t-1!-";-;-• + t : :; : I : · • .J..+-1 +-4-' ~~~~,1-4-f++I-H-:j--'~~.t!-1 +-+-i-,t-t, til li":o-1~!..ttl .+...j.-!_i!--Jj..--;..' -+'+'1 !'+I++-' -;.·--1 c I I I! I j_l! I • I J • II: I I • :ttl I t I I I I • ! 1 I I I I ' I I 1 1 -~ j l ~. ; 1 till • • 1-+J...H+-+-:-' i-' IH-!-_l-+1 +-Hr+l~l I l I J ..: I I I ,-I I I i I I I I I I i-J;....-.;1--j..,-+,+-, 1:-TJ-i--i'l~-! I I I Ill I i I i T l I i -~-1-+--~:..:-r-....;.--i I I I I I I I ' I I I I I I I !Ill I I l t1 I I I I I I I I ll • .... IU I I I I I I I I' I .I I J I IJ I I j I. I I I I I !II I I I U I I 1! i I II I I I ! 1 1 II I I Ill I II J I ill I I I WW~11~1 l+1 ~1 +1 H+1 ~~~~1 H1 ++iH1HM~1~1 H++rr, rri,-t-.t,IT,t,h, mrtt+r~lt~trjttja:lnl!tl!t~,:i~ rH :I II I I I II I II 1 1 I II 1 I I I ! II! I I I :!I I I I I 0 LiJ I I I I I I I I 2 5 10 20 50 100 200 500 EXCEEDENCE INTERVAL-YEARS SUSITNA RIVER AT GOLD CREEK PERIOD OF RECORD ·1950-1980 ANNUAL SKEW IS 0.6830 MAY .. JULY SKEW IS 1.130 AUG-OCT SKEW IS 1.134 FIGURE 5.4 ~~nl~ I ALASKA POWER AUTHORITY 0;~ 111_·,~---~~-:-:.-:--:--:::-:-::--;:-:-;.-:-::-::-:--n SUSITNA. .HVOROELECTRIC PROJECT FL.COC STUCIES SEASONAL DISCHARGE FREQUENCY CURVES I t I I ll I I ~ ' ·. ---- 90 80 ; ... ~- 70:-:- 60 I' I I • ... ' :. I. '.I. • I ~ : i •• ! • i I! .. -- =.:=:.=-:-- ry. • I • I I • I " I i 1 I / I 1 !I II: 1•,11 I I: i I ~"-4-++M--t-~'-ttTt: I I I • I ,. ' I I l I I I II v I :: I I ·-- ·t-t-. 0 ---r. ---:-==--::.;::::::..J~ I ·-e-1 · ·-==.r. Cl) 50 =--t UJ-~;._ ·~----::::::::a :EO) :::;) 2 40 ...J ox >I() ot- o "'-3C o--...J L&.. t ~ • • . . ',;" .. ; .. • '0 ./ ,. y. ~ •• .•.. -~--1 ' :• t / / 1 " •' y I 1 I I 20~~--·~. ~.---~,~.~;~.-~~·~·~:~/~~.~~~v~.~o~o;+'~ .. ~·~~~~~~-~-T'-ti--Htttl~~:.~~~~+-~·;~1,~·~~·-T·~ ~:r:=:::::p.:::;:. ::· :(::;·:I· =l=DI 1~/f.!.-' ...:.·~·1?~'/· :;..· ..:._: +·~I.:..· +'~·,-t-V7-71 -+'-:-t-t--:-: -H'it'ttttt:tt:t::t' :!:t:t 'I I . I ! I I I 0. ~ • I • ; .. ' / • :/; I l• ., . I • I I I I I I I I i I ' I -4.....:.--l+.;,.:.,._;..t-+~h~-t-....;,_~:-;-:h-f-' ~ I I I l IIi I 1 I t•··=r:=J:•:P:! =++: i_• Ljl f7~1 .!.' :..j· ~0 _,7G_:/· h:~:~·;...o t-. .:;0 ~ ';:r~Y"7. ~:-· 7-' +1 _:·+~:f-,:-tttttf.~t! rtt1 -t-t!t "j, II ; 1 1 I 1-I ! I I • • l i ; ./.' • • I ~..r~· ..;.: .:..I ·~l-1---:l....;lr-++-:----!---l ~~~ ~-1-4--;..-+--+-~++!-i-+~---~ l l I : : ! : • : I : li : : 1/, ! ; ~ : I :/ . I; ; I : ; I I • i I I I I I I I Ill I j J. I • I I i I. • j i I ! I:.,Z Ill j v. I ! :: llllll l I I I I I !4-;.:-4-4-:' '...:..'-:-'-r-:-1-rl-t-..!.._r+-Wl i I I . _:..· ~i~I_:'J_......l,!_JtV.~,~~...;.~+~·t~'../l"~':t-:-i ..:...: .;.'-4·~' !--' :H+! ·~i~'++l-+i-ll--7-1 -t-:: -71-tr:T.' i~~~"7~Ti!--T--tf...:__l ll!! i ll I II L··_l:l_~~i~'Jill!l1Li:Ulil;L;4J'Illtil~ol~?f.~,Li ~~~~~~~·~~~i:~l~l;~~~~~~~~~ ll~l-r~:~I~4~Ji~, l~·~~~~~~~~~~~rt~~~~ .. 10 2 5 I 0 20 50 100 200 500 I -i ~ J EXCEEDENCE INTERVAL-YEARS FIGURE 5.6 i I \ SUSlTNA RIVER AT GOLD CREEK PERIOD OF RECORD-21 yrs. j ~~~------------~------· LEGEND ------95 °/o CONFIDENCE ·LIM ITS VOLUME FREQUENCY CURVE ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT FLOCO STUCIES FLOOD VOLUME FREQUENCY CURVE AUG-OCT ,a II ,, II II '·. I~ tl' II ~~ , I ll. ' j ~ ' ' ' . . ' # ' . ' . . . ~, ' l -~==--~· ----~----~~-----:r---::t~::--~··r------·--~~----~1~---------t·----~-----~----~--~r---~:r----~~--~,----~-----~-----~----------- { I l 1 • I ~ 2oo tll:::::~i .. ::::~:::::;, ===-~-:::]:t:::~~2B~~:::t: ===~-=====~~1:=====t====~~=-=-::_j~ c:::::~====·~----~r----l~:::j~:::2-'~t:~~ I i t t:::::E::::::~:::::l~====~==~::j:i:~:::3E::::~,~~r~ ===---,~~~-·-===~~:--~~~~~=====:·====~ j i/ ~ I ' ' 1 II U. 1 . i 1 ! • I 0 ,_ 0 tl :::::r:'· ==+=----:~t-'..:....,;_-1~----11==:=Jt::= I ~\ I I t' I 1 I \ -I I 1 I ! 1 .~--iii--'"\-T--· !----i'-----i----1r----j c:::::~~====~----~· -----r~-1:t:::::t:: ! \ I t::::::,~====~----~~---1~~t'J::::::t:::::t·. =~,~~ ----t==~==~==~===F~-:~· ===t===±==~==~===4===--l ---1 l ' I ' i l I I '\ : I 1 I ' o t:::::~~~==·==:~====-~,' ~~~~-tf-~~.~~~l~/-t:"~,::t:::::r~~:-2 __ ~-~~~,r-~~--~~~~--~ 0 I , ·I \ I Ol ~o , \ = , "' (/) u.. (..') c;. I / ; ·., 1 i ,' ' . I ' V · ' . 1 1 • ~; l ' /.---1 ' I I :j I i I r"-·· / t::::J:::::~~==F==+!t'+-~~ti'==:L~:::j):::::t:::::L::::~-~~~--. ., J t1 ' I i t==~·~~~~~.==~·:t/C:~I~·==~---~~/C::il::t:'j:::t'~\:::t:::::t'::::: I w aot:::::t·::==:t~L~:r,~::::JF~:·/~'~'F=~/~:t~-~c::±t:'~,:::t:::::tl~:::::t::::=f::··--~ o '--: · / . "" : :./ ./ \ I '~"!'::~==--~;..:.·~ '-----+-----r-·· ---·-c: -"' / I /:_ ; I .-'-. i ._:'-'~--t-----r!,---:;_...........,__ ~ =-----~~~~-4----~~~---~~---~t.,r---~=-~-~~,,-----r-------~ / ' ~ I I / • I ~ !L u r:::==~~--~-~~--~·t-~~i~'r--~#~;:::t:::::r~~-4--.---~,~---~k,----_,~---~ 1-i 1./ , i ., ~ : I ! • · L :-; • -' . ' . ..!-----4--'_:''--jo....-...::-:.:·=..--~·~'~-:--t-----7:' ;---::j 0 b--.....;_+-I~--:~· -":;._--r-1-' ---j~;rJ-f"--_:_-~-:-•-o -.,...... I, -.... 40 r--.. ! ""' I ,.... I I ... ~---_ _;,_ ___ -! r-:::~~--=~~~~~;=~~·-~~~~;~~~.-r-::---t==~;:t::,:::t:::::r:l::=:j ' ·--~~~~-·--~T--;--r-··~·~'-~~---~----·-r~--r~--r'------~---.-~--r-='~··-~-~--~L=~~~--}~-----t--·-~:--~--~~~--~=··-~~---~---~-----r-----;-----._; • i ,,.._ ! I r-:::::~~~==~~===F:~~-~~~-~r-~.--r~~==t:::::t:::::t::::::~---~~------ o cr--:..:,·:···::::::4-[1: ::::,::::::;_:.·:.:.:.:.f, =: :~:=sE===·==E::=· =:=.~t~· ~===-:_ +-~ ----~ -_-_-:_ +~ -_ -_ -_ ._._ ~-· +_l· ~ .• ::.:::.:J::.:.:.=..:_·~·.:!_·:..:::..:.::jl5 -15 -10 -5 PEAK · 5 10 TIME-DAYS SUSITNA RIVER AT GOLD CREEK 't;0,500,10000 yr.FLOOD VOLUMES Lt:.Gt:ND Flood Volume ft 3 Peak Discharge {cfs} -----100 yr 122..~ X :o 9 104,550 FIGURE 5.9 ALASKA POWER AUTHORITY SUSITNA HVOROElECiRIC PROJECT F!..OOO STUC!ES FLOOD HYDROGRAPHS . MAY-JULY --500yr 178.2X 109 151,870 I --~~~ooy 5!0.0X!~--I-sa_,o_o_o __ ~~-=-~-;_~_c_.?_-_~-~-~-ft~-~-~-~----T-~-~-!~_~_~~;-M_A_n_c_H_1_9_s_,~.- 5-14 H ,, I I I I I 1·. . I I .. I .. ~ 1·~ .. . -· I ..:. .. ·- ~•• I I . .. I . I I l ! 0 ~-~~~---4.----~-----+-----r~.--r~,.--~!----~-----T---~----oot?_Q~====~i::::::~::;:;.~,===~=+=====J~=~~~~~~--t·~~~i_-_-_-_-_~~-----_-_-_47---~-----+~---~--~~~~---_-_-_-1~ X 1-·t-----4--+--~-+-..,._; ~~---+=\-l-!--i-1 ---.---~--1---, ----1 ----~~:-----4-~-~~~i'~·~--:~-----~f: __ ~IT,--T-ii ______ -rt-----; .. t~-----+-~--·~ ! ___ ~ f I J_ \-t--,'r---·--+----·-~---1-I m ' \ - -' ~ ~--~!~---4----~,-----+------r--rt~~\r-~,~----~.-----~----+-------~----~ (..) I t· \I ~---+----i! __ . __ I ---~~--~--~~-·-----T-----r-~~r.-~ .\: -. . I . r-i : ~( 1 \: 1 : w an : : ; . '/ 'r'~\ --+---_-~:-------+~-------!-:-----1-; ~ : • l -r+~+:s=--~ t 2-· --=i-r ___ ·L~ cr. . I I I I \ . I • _\.. -I I -~~~·-~-:X: -------:~----+---... +-1, ---+--:/ ,, , \--\-~-~~· : -!1 : =-~ '.Qt= ' . ~~~~ • •: • ,r ~ ./ ~--:~,\~ . -_-: >. + __ j-+·---r---~ Cl ~· I= i_ / : /}. '\-~· ~.. -t -----~ 1 • .,, I . j I J ~ I "\... ~ -,...... ; / ~~-'-~ . :r::z-::Q--..; ~ . I -L, ------ , __ -----,-t----t::::--=-----+:j=~•--. -j+::;=:--.. ?~L' ~~----=-.-_J__:_~l-:----~ I I : ..-1 ,.. l 1-r--,......, ! I ,.._ -_.,.,-· -t' -- . I L i ---~--~ . ---I ~ ·------~-.. ----,. -I J r------. ·-~-----------~.-..------t I ; ---l--· . I . I-------t-----T----+----! 0 I + I I. ~~--; .. . I __ I . -·• I I : ! l . -1s -to -s PEAK 5 10 15 . TIME-DAYS SUSITNA RIVER AT GOLD CREEK LEGEND -----100 yr Flood Volume ft 3 g· 53.s x ro --SOOyr 78.8 X 109 ---IO,OOOyr 140.0X JQ9 "eok Discharge ( cfs) _...;....._..-,;....;..... __ 90,140 119, 43(.) 185,000 FIGURE 5.10 '[~nnw I ALASKA PoweR AUTHORITY I nburo I i-s us IT f.l A H 'I 0 R 0 ELEcTRIc ;> R 0 J E c T ....._ __ i=i-OCO STUC!ES FLOOD HYDROGRAPHS AUG-OCT I I I ' I I . ! .1 ~ . I '! .• I .;·. ~· .. , I " -\ - I . ;, ·I· : ' . \ -- ' t: ·.(:~: I .__ .. I \..:. I ,_ . I· . '· .. ~ ........ ·, 1·'. ! ·~ . ' ... , I ~ ' ·. l Probable Maximum Flood Studies I f I J, I I ,, I I, r· I ' . .. t I· I, ,,..H,. I -- 1 \.",. 1.~ ~· T ._, ... I I Probable ~1aximum Flood Studies The original scope of Acres work as described in the Plan of Study of February 1980, comprised a review of the PMF estimates made by the Corps of Engineers in their 1975 study. The assessment determined the sensitivity of the PMF estimates to changes in critical meteorological and basin parameters. The magnitude of these changes were considerably significant and the estimates could not be used in the design of facilities without more detailed study. The meteorological data used in the COE estimates were developed by the National Weather Service (NWS) in a preliminary study which gave a general range of criteria within which it was believed values from a more comprehensive study would fall. In their conclusions to the study, the N~JS noted ... 11 Time hasn 1 t allowed checks, evaluation, and comparison of the several types of data summarized here 11 • The NWS naturally recommended further study. This is borne out by the increases to the PMF peak found in the sensitivity analysis. It was decided that a re-evaluation of the PMF is necessary to define flood discharge capacities of project facilities which presented an extension of the scope of Acres studies. The approach to the re-evaluation of the PMF is described below. The approach entailed re-assessing precipitation maximums, temperature gradients and temperature maximums based on a thorough study of the meteorological characteristics of the Susitna River Basin. Applicable storm maximization techniques were used to develop a probable maximum storm for both spring and summer seasons. Paralleling the climatological study, a further calibration of the SSARR model was undertaken to develop a reasonable watershed model based on procedures that follow generally accepted mathematical modeling techniques. The calibration started with assuming that the basin's meteorological and hydrological parameters used in the COE estimates of the PMF are the most representative. These parameters were adjusted as analysis progressed. When the set of watershed parameters that gave the most reliable estimation of spring and summer floods were determined, a verification study was conducted using this data set. Several floods that were independent of the floods used in the calibration study were used in the verification process which detennined the accuracy that can be reasonably expected from the SSARR model. Estimates of the probable maximum flood at critical locations along the Susitna River for both spring and summer were determined using climatological data developed and the most reliable set of basin parameters. Synthesized PMF inflow hydrograph at Watana is attached. ---..... -.. . -- ~ . . "' . ·-------_, __ ., ___ -~-... -------- ' -I I:. -----·-·-----·------~------- . . ~ .. . -... ... ~ -~ . ·=~~ ... --."'""""""-""-~~ .. ----:---:----~~----.. ~------,-·----~""'""'-,_,., .. -.. --..... --~-··-"'--.,.~ ... . ... . .. ... .. -. . _'" __ .,. ~---.--... _ _,_. ---·-,-~_ ... _____ ,.,_. ... ____ .,.. ___ .... -7 --... ~ ..... , .. _,.. . ,,.. .." _.., ,__ "' .. ------.... :-;' :-----·.: - ., ·---+..-. ,..,_,-.. -' ... . . ~ • + ~"" -· • ~ ..... ~ "' :! ·• .. ' . ; :! ~-~ .. . . .. .. ·--.-.. -,.~-...... -~·-· ---..---_., .. -···--·· I' ~(..t~:.2..! ~--""""' .. _, __ .,.., -···· ···-~· -~ ,..~ .. -............ ,.. ..... ~-·-----~ .. -.. .. - 1~--r.; .E?.;:.: .. ~?~.:~~~~~~=-:~::~ -·--. . .. .. : ~~;;..:..:~~~;_~:;..,-----... ,. ... ,~. . ... -~--·· _.,. "'-- r'fi i t .. :: ' -u·-,_ ·~ ; '1 " ' ' , ,--('·r ' . " ·... ~ ,' : ..., i . ..; ' ·. ~ . . [·. ' '- L. r . [' l f ~"' '" ;~-. * . ~ ,r ... ~ : " \ . " ', ~>. i'tt:.'' tK·:" . .. . • ,_ ··t;····,. t . c' ......... _ ' ... Project Flood Flows < • ,, J'r;.·_· . '· . J'~l -r:· .. ~.-\ . -~ . ·.· .. '!)"' !11, ' rr:·.' . . . : ; ..,.. r r""' ; . ,..~ } ·. . .... ~ \· {'{~-1 '. I i "'· ' rf ' ~- ·- SUSITNA HYDROELECTRIC PROJECT PROJECT FLOOD FLOltlS From the r\~gional frequency analysis and the PMF study, a set of project flood flows were determined for design of discharge facilities. These are presented in the attached tables. Assumed reservoir levels at the start of flood routing and facilities available to discharge design floods are listed. :fJsnNA HYDBbELEtrRic PROJEct ~rOJECI ELO\iS. r ·r <' ~ ~ +, TABLE 1-RIVER FLOWS CFT 3;s) > .'~ • ;{!FLOW RETURN PERIOD . . . YEARS , :",~4N ANNUAL · .. -( 1 IN 50 ~ 1 IN 100 [. 1 IN 10.~000 CDESIGN) · Pr·1F i vJATANA ANNUAL SUMMER PEAK PEAK 36_, 000 .84.POOO 92.~000 70.~000 156.~000 326.,000 DEVIL CANYON* ANNUAL SUMMER PEAK PEAK 41.~0001/ 53.,000 54,000 140.,000 320.,000 . ! t~ .~ ... -. --------------------- 1 ~ ~-~ . --·{· ' I .· i ' ! \ : \ f \~ITH ~JATANA DEVELOPMENT UPSTREA~1 • . ; ;,[. NATURAL FLOW. ···r· i . ... r ..... :tf ~ ir "'' ' . :·,.A r ![' • 1 ' . ' ' ' ····.[· ~ ' .,. • ·-r .. [ [*11 i . ' ~.ll ~:[··· .. ~ . • ' -!1'i . . > ·[·~ ' ~ ; • 1-, . ' [ 1-.. . t . ' ~ "-. .......... ....... I. • >, . I TABLE 2 -ROUTED FLOWS FOR DISCHARGE FACILITIES <FT 3/S) RETURN PERIOD YRS. 1:50 1:100 ANNUAL 1: 100 SUr·1MER 1:10.,000 PMF WATANA E8.,0CO 45.,000 L!S., 000 120.,000 270.,000 DEVIL CANYON 53.,200 50.,000 50.,000 140.,000 320.,000 FIGURES TENTATIVE BASED ON SPECIFIC GATE SIZES AND OPERATION 6 OPTIMIZATION STUDIES UNDERWAY. ~ .[· > • ".,.: ~-r \[ ' c~[ ; . r·~r ~-·[ . ~- ~·[ :~{ J ·- r·,[" I . I ~ • ;:: . ~' !l I . l-' :l . ' [. . . . ' •, . . I·~ ...... ' I.,, :I Spillway Design Criteria r-SPILLWAY DESIGN CRITERIA :[ . ~ [· [ :· [ j ;-·[ :-[ ·[ .[ ! r.l""' l r ·r r[ rl I. ....... !"[ L ... I[ .[ ~ ,( I A$ Watana Develooment 1. Spillway facility comprises: (a) Service Spillway -tunnel outlet with H.B. valves (b) Auxiliary Spillway -chute with flip bucket (c) Emergency Spillway -fuse plug and rock channel 2. Spillway -Avai'lability of Facilities Flood Return Period 3. (a) 1:100 yr (spring/summer) (b) 1:10,000 yr (c) P~1F Starting Reservoir Levels for Flood Routing 1:100 yr spring flood 2172 ft 1:100 yr summer flood 2215 ft 1:10,000 yr design flood 2215 ft P~1F 2215 ft Discharge Capacity -up to 1:100 yr flood -1:100 to 1:10,000 yr flood (project design flood) -1:10,000 yr to PMF Facilities Available -service spillway and 75% powerhouse flow -service spillway and auxiliary spillway-powerhouse not available -service, auxiliary and emergency spillways - powerhouse not available -simulated maximum level at beginning of June -normal maximum operating level -normal maximum operating level -normal maximum operating level ' ~-. :·· ~-· · Ll '.··· B. Devil Canyon Development 1. Spillway facility comprises: (a) Service Spillway -tunnel outlet with H.B. valves (b) Auxiliary Spillway -chute with stilling basin {c) Emergency Spillway -fuse plug and rock channel ~-· 1 . 2. Spillway -Availability of Facilities :·I :·I I !-I ·I i-1 ' ·I f :... ,I i I - ··I ~ •, I ' ! l-~ I [I • 1 1 ... - ,I l ' I -~ Flood Return Period (a) 1;100 yr (spring/summer) (b) 1:10,000 yr (c) Pr·1F 3. Starting Reservoir Leve1~ For Routing. All Floods pischarge Capacity -up to 1:100 yr flood -1:100 to 1:10,000 yr flood (project design flood) -1:10,000 yr to PMF Facilities Available -service spillway and 75% powerhouse flow -service and auxiliary spillways -powerhouse not available -service, auxiliary and emergency spillways - powerhouse not available 1455 ft (normal maximum operating level) '1 ' ' . ' ' lt • 1~ d . '~· }L . u: ' ' n· ib 1~ SUPPORT MATERIAL TO TASK 4 SEISMIC STUDIES I ~ tU I - I i [~ , n, ~~ ~w ~- w ! W· l ~ ' rn 1M TASK 4 -SEISMIC STUDIES 1 -Introduction Seismic studies are being performed by Woodward-Clyde Consultants (WCC) under a subcontract to Acres. The studies were broken down in two stages: 1980 Activities and 1981 Activities. The results of 1980 Activities were presented in the 11 lnterim Report on Seismic Studies for Susitna Hydroelectric Project, December 1980 11 by wee and are summarized here for ready reference. 1981 activities are partially complete and preliminary conclusions drawn to date are included here along with the total Scope of Activities and the current status. Preliminary conclusions are considered to represent reasonably conservative seismic design parameters for the project studies and are not expected to change significantly as a result of ongoing studies. 2 -Summary of 1980 Activities As a result of activities completed in 1980, it was concluded that the Talkeetna Terrain, in which the project is located, has the following boundaries: The Denali fault to the north and northeast; the Totschunda fault to the east; the Castle Mountain fault to the south; a broad zone of deformation and volcanoes to the west; and the Benioff zone at depth. The Talkeetna Terrain was judged to be acting as a coherent tectonic unit within the present stress regime with major strain releases occurring along the boundary fault systems. \~ithin the Terrain, strain release appears to be randomly occurring at depth within the crust. This strain release is possibly the result of crustal adjustments resulting from perturbation impos1ed by the Benioff zone and by stress (associated with plate motion) imposed along the Terrain margin through the Terrain. Within the site region, 13 faults and lineaments were identified as requiring additional investigation to better define their potential effect on Project design considerations. These 13 faults and lineaments (designated sigfiificant features) were selected on the basis of their seismic source potential and potential for surface rupture through either site. Four of these features are in the vicinity of the Wrtana site (see Figure 4.1) and nine are in the vicinity of the Devil Canyon site (see Figures 4.2 and 4.3). Preliminary estimates of ground motions at the sites were made for the Denali and Castle Mountain faults and the Benioff zone. Of these sources, the Benioff zone was expected to govern the levels of peak horizontal ground acceleration, response spectra, and duration of strong shaking& The ground-motion estimates were preliminary in nature and did not constitute criteria for design of project facilities. Further details of specific findings of the 1980 studies are presented in Section 6 of this summary. On the basis of these f·indinas, a detailed scope of investigations for 1981 was developed and is currently in progress. n. lt 3 -Scope of 1981 Studies The scope of 1981 activities was developed on the basis of the original Scope of Work included in the POS and results of 1980 Activities. A list of 18 objectives was formulated by wee which formed the basis of discussions with Acres, Acres External Review Panel and APA Review Panel (Figure 4.6). The final Scope of Activities as agreed upon, is summarized as follows: ~ (a) Subtask 4.08 -Preliminary Dam Stability Provide assistance in evaluation of dam stability during earthquake conditions. (b) Subtask 4.09 -Seismology Evaluate location and source(s) of moderate to large historical earthquakes within Talkeetna Terrain and north of Talkeetna Terrain to better define their source and impact on floating earthquake within the study areas. Evaluate available seismology :lata to determine stress regime within Talkeetna Terrain) refine MCE on Benioff zone and prepare long term seismologic network recommendations and operation manual. (c) Subtask 4.10-RIS Evaluate RIS using results of 1980 and 1981 studies and its effect on the project. (d) Subtask 4.11 -Seismic Geology Evaluate 13 significant features identified during 1980 Activities (see Figures 4.1, 4.2 and 4.3) by performing remote sensing, Quarternary ·Geology, field mapping techniques, and determine if a feature is "Fault 11 and if it is a fault, with recent displacements, determine MCE along potential seismic sources. (e) Subtask 4.12-Report Prepare final report to document these studies. (f) Subtask 4.13-Ground Motions Refine attenuation relationship, determine earthquake design parameters for Watana and Devil Canyon sites, and perform seismic exposure analysis. (g) Subtask 4.14-Dam Stability Provide assistance in evaluation of dam stability during earthquake. (h) Subtask 4.15-Transmission Line Seismicity Evaluate ground motions along the transmission line, assess ground stability conditions along the transmission and access road corridors. r r ··r l ,,. -r· . . r· . f" .. r .. ~ .- :[, I , .... _ .. I 4 -Status of 1981 Activities A schedule of the activities is shown on Figure 4.7. All activities are proceeding on schedule. Field geology studies were completed with the review of field data on September 2 and 3,· 1981 at the site. Completed activities are as follows: -Aerial reconnaissance was performed for all 13 features_, -Field mapping was conducted at 300 locations. -Thirteen ground magnetic surveys were conducted across the Talkeetna thrust fault, Susitna feature, and feature KDS-3 near the Devil Canyon site. -One seismic refraction survey was conducted across the Talkeetna thrust fault. -Low sun angle photography was flown (at a scale of 1 :24,000) and interpreted. -Existing color photography at a -scale of 1:24,000 was interpreted. -Approximately 2,500 ft of core in five borings which crossed the Watana River feature (KD3-7), the possible fault (KD-5-43) on the left abutment at Devil Canyon and the possible fault (DC-1) in Devil Canyon was reviewed . -Three trenches (total length 450ft), which were excavated within the zone of the Talkeetna thrust fault and the Susitna feature, were logged. The approximate location ·of these trenches is shown on Figure 4.8 • -Data for mines in the vicinity of the Talkeetna thrust fault (KC4-l), and features KDS-2 and KDS-3 in the vicinity of the Devil Canyon Dam site, \t~ere reviewed. -Quaternary geology air photo and field mapping was conducted at more than 60 locations. -Eleven samples were submitted for c14 dating. -Two samples were submitted for K-Ar datingo -Field review sessions were conducted with Bela Csejtey, George Plafker and Norm Ten Brink. -.Review of field activities and results was perfonned by wee Internal Review Group on September 2 and 3, 1981 in the fieldo 5 -Preliminary Conclusions of 1981 Studies The preliminary results presented below are subject to revision as analyses of the field studies and other data are conducted. m m m -m 'lli m III m ·~ Uj m . . Ill . . (a) There are three features of importance for seismic design of the Susitna Hydroelectric Project. These features are the Castle Mountain fault, Denali fault, and the Benioff zone. (b) Of the thirteen features selected for study in 1981, the following table sunmarizes the conclusions:. Feature Feature Name No. ~;._- WATANA SITE Talkeetna thrust fault KC4-1 Susitna feature KD3-3 Watana River Feature KD3-7 Fins feature KD4-27 DEVIL CANYON SITE KCS-5 KDS-2 KDS-3 KDS-9 KDS-12 KDS-42 KDS-43 KDS-44 KDS-45 The Feature The Feature is is a Fault an Active Fault Yes No No No No No Yes No Yes No Yes No No No No No No No No No Possible No No · No No (see item d) No (c) A feature at Devil Canyon, designated as feature number DC-1, is being evaluated to determine if it is a fault. There are insufficient data available at the present time to evaluate whether or not the feature is a fault. (d) . Feature KDS-43 on the left abutment of the Devil Canyon site may be the result of an old fault or slope instability based on geophysical and borehole data. The feature does not exhibit geomorphic features typically associated with an active fault. (e) The maximum credible earthquakes for the Denail and Castle Mountain faults were not re-evaluated as they will not govern the design. A maximum credible earthquake for the Benioff zone is estimated to be magnitude 7.5 (M 5 ) occurring 60 km from the Devil Canyon site and 50 km from the Watana site and a magnitude 8 plus (Ms) event occurring 90 km from the Devil Canyon site and 70 km from the Watana site. r ·r r -r --r r ~-r~- ··r . [~ [~ ·['7 ·"' :·[ [ ' .~ [ [ I[ ' ' [ " ' (f) (g) (h) Preliminary response spectra curves for the Watana site are represented in Figure 4.4 and for the Devil Canyon site in Figure 4.5. A floating earthquake of magnitude 6 to 6o5 (Ms) may have to be considered at 10 km from either site in seismic exposure analysis. Its impact on local faults or design response spectra is being studied. Both deterministic and probablistic approaches will be used in seismic .. . exposure ana1ys1s. 6 -Spectf.i£ Findings of 1980 Studies Denali and Castle ~1ountain Fault Systems The only fa.ult system within the site region (within 62 miles or 100 km of either Pr·oject site) which is known to have had displacement in Quaternary time (thf~ la.st two million years) is the Denali fault. This fault is appr"ximate1y 40 miles (64 km) north of the sites at its closest approach. The Ca.stle 'Yiountain faultsystem is innnediately south of the site region. This falJilt system has had displacement in Quaternary time • Susitna Fec1ture ReconnzLi ssance 1 eve 1 aeri a 1 and ground checking has produced no evidence of a fault in bedrock and no evidence of deformation in overlying surficial units for this feature. Review of aerial gravity and magnetics data shows no evidence of a major tectonic dislocation. Earthquakes correlated with the southern portion of the feature by Gedney and Shapiro (1975) occurred at depths greater than 43 miles (70 km). These focal depths suggest that the earthquakes occurred on the Benioff zone well below the crust and well below the extent of the SusitncL feature, if the lattel" is a fault. The feature may be the result of glaciatiJn of stream drainages whose alignment reflects structural control such as joints or perhaps foldingG Talkeetna Thurst The Talkeetna thrust fault is a northeast-southwest trending fault which may dip either to the northwest or the southeast. The fault may be connected with the Broxson Gulch thrust fault to the northeast which would result in a 167 mile {270 km) long fault that passes approximately 3.5 miles (5.4 km) upstream of the proposed Watana site. No evidence of displacement younger than Tertiary in age (approximately two to several tens of millions of years old) has been reported for either the Talkeetna or Broxson Gulch thrust faults. However, anomalous relationships in deposits of Tertiary . age on the north side of the Susitna river were observed during this investigation and may_be related to faulting. r ·-r ·r -r rr ~ [- ···[~ ~ r·~ . r· ··r . [' -t' : -[_ : [, ·t ' [ .[ . [ .. l Observed Seismic Events Seismicity within the Talkeetna Terrain can be clearly delineated as crustal events occurring at depths to approximately 5 to 12 miles (8 to 20 km) and as Benioff zone events which occur at greater depths. The depth of the Benioff zone increases from approximately 25 mi1es (40 km) in the southeastern part of the site region to more than 50 miles (80 km) in the northwestern part of the microearthquake study area and more than 78 miles (125 krn) in the northwestern site region. The largest reported historical earthquake within the site region is the magnitude (Ms) 6-1/4 event of 1929 which occurred approximately 25 and 31 miles (40 and 50 km) south of the Devil Canyon and Watana sites, respectively. Four earthquakes graater than magnitude (Ms) 5 have occurred during the period 1904 through August 1980. · . Earthquakes as large as magnitude (Ms) 5 to 5-1/2 may possibly occur in the site region without direct association with surface fault rupture. Such events would probably be constrained to rupture planes deeper than 6 miles (10 krn) • The largest crustal event recorded within the microearthquake study area during 3 months of monitoring was magnitude (t4L) 2.8. It occurred 6.8 miles (11 km) northeast of the Watana site at a deptn of 9.3 miles (15 km) on 2 July 1980. Two clusters of microearthquake activity were observed within the micro- earthquake network during the three-month monitoring period. These two clusters occurred in the same general vicinity east of the southern portion of the Talkeetna Thrust faulto These clusters of seismicity occurred at depths of 6 to 12 miles (10 to 20 km). One of the clusters gives a composite focal plane mechanism of N230E, dipping 50°NW, consistent with local geologic trends. The sens~ of movement is reverse (toward the southeast) with a dextral component of slip. The clusters of microearthquake activity described above appear to be related to a small subsurface rupture plane that does not extend to the surface. These clusters do not appear to be related to the Talkeetna thrust fault. Seismicity in the vicinity of the site, including the clusters described above, appears to reflect relatively small-scale crustal adjustments at depth in the crust. These adjustments may be related to stresses imposed by the Benioff zone and/or by plate motion. No association of microearthquake activity with candidate significant or significant features is appar·ent on the basis of information obtained to date • [ ~-r. ~f[ .. ,. ; tL ·frr·l· tt Reservoir Induced Seismicity The two reservoirs are considered as one reservoir hydrologically. This combined Watana-Devil Canyon reservoir would be among the deepest and largest in the world. It is concluded that the likelihood of a reservoir-induced earthquake of any size within the hydrologic regime of the proposed-reservoir is high (0.9 on a scale of 0 to 1); this is primarily because water depth has a major apparent theoretical and empirical correlation with the occurrence of reservoir-induced seismicity. Maximum Credible Earthquake Assessme~ Preliminary maximum credible earthquakes (Pr·1CEs) have been estimated for crustal faults with recent displacement in and adjacent to the site region and for the Benioff zone. The PMCE for the Denali fault is estimated to be a magnitude (Ms) 8.5 event occurring 40 miles (64 km) from the Devil Canyon site and 43 miles (70 km) from the Watana site. The PMCE for the Castle Mountain fault is estimated to be a magnitude (M 5 ) 7.4 event occurring 65 miles (105 km) from the Devil Canyon site and 71 miles (115 km) from the Watana site. The PMCE for the Benioff zone is estimated to be a magnitude (Ms) 8.5 event occurring 31 miles (50 krn) beneath the Watana site and 37 miles (60 km) beneath the Devil Canyon site. I . l I l . \ -·-.:·-t~ ~;:._:... .t• .... -- -1J 6 • I ... ' • _!J' ., . .., __..,..._.~ .· / , --/v / _..... ,.-" -/ ' ,_. ___ _ ._....:..---· ... _ -· _.. -----:--... --- C'l & .. . ----. <-----· ::-.__-. ' --· ...... .... ·-- LEGEND -------Indeterminate • A ieature --·--·-Indeterminate • B feature ....... Indeterminate • BL feature !;QTES Explanation of significant feature classification system m Sect~ on 8 2. 2 Exptanat•on of all:Jha·numeric symbols is presented m Appendix A ........... WATANA SITE SIGNIFICANT FEATURE MAP flG~P.E 4.1 - - -Indeterminate -A feature -• -• -lndetarminate · B feature .. • • • • • • • • • • • Indeterminate -BL feature -"""""=~~ NOTES 1. Explanati~n of significant feature classification system is presented in Section 8·2. 2. Explanation of alpha-numeric symbols is presented in Appendix A. 0 6 10 Miles ~~~~~~~~~~E3~---,----~:]I 0 6 10 16 K!fomelers --Indeterminate • A feature -• -Indeterminate • B feature • • • • • • ! • lndmrminate • B feature NOTES L 1. Explanation of significant feature classification system is presented in Section S.2. 2. Explanation of alpha-numeiic symbols is presented in Appendix A. DEVIL CANYON SITE SIGNIFICANT FEATURE MAP 0~~~3=~1~~~~~2 Mil~ 0 1 2 3 Kilometers FIGURE 4.3 , ~ z ~. :·:·-·~~ ~·-:;::~ ........ __.....-:--... ~--c~,..-...... ., .......... --~";!·~------··--,.~~·, -: <.:·,.·,,, _, 1 ~ ~~ ~~' ~~1 ~--"§'~ =·~-~;,-~ • -- _. '" .i '-_:!!!!' 'I. 1 [ . . ..... ...... _1_ -"-. ---': ·-.,,:.,"'lo.c ---~ ,-,: I:-'.::0.~ c.::;· ' -;.; -----~ - ... ~ ;-...J ~ ..• .. ~-.;;: --, . ' ' -_ . I I . ~ . . ' : !..--~ ..::. ~ " 9. -J •-- '1--~ a •-- - . ' -- _:· - .. ; . ;;; l. = --.-.,;;;.. . ~ i =: ~ : : I . . ~--.:. :-:<:.-- . --§ ~ it iS. ._. !I ; _g ~ ~ --~ ~ c•--"" = -.-· : . ... -~ . -. . \)- ::::::; ::;-<:: ·- ~ ·--·-·- -~ ' ~· i : -·-- .• ;;.-::=' -'L . :..::=: 1 I J I ' I ( I I (· •·. I ........ ; [ ' [ • ..• ·-.. . .. . . ~'.., .. Memorarnium . .. . lo ;~ I . .... ?ilc .C.l<ilCA H+i-ll . ~ 30 April 1981 ~ BUIXIC'S POR T.Ht: lS Ozs.n:c"riV!:S 1~ KCH~ Pl-W-1.;2 S\.ll;)t.aa'k _.-N ... c .... _• __ i_._ . 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Lift~·~ ~0&4 $~1U)i11~y DcAioff ~ h~~anuaticn .Ravia ion Ravise ~po*ur• An&lyaia N-e~vo:r"~ KD.."lal. - De.t.A ~lyt1$ Md :1\Upcn.. ~~;at.a for ~ni•uat;icn, ~.,_: Plam.~in; Pi:to4 P~· . . . . ... .. -'"' .. . . -.. } ... l.. cn,'ac:t.ivo Rea• aftCS D4ta:riptionw llt"a t...\to•c i.n Rt:fte::ab:ium ~-1'2 and· le1:.ter ~4-G-0. 2.. Ehll)t:.ask lie~. ar• tho.a in .a.e::ca n=w:ric:o.n 'lnc. ~greu::;.,u~t. No. PSi0~.1·0.4l el'M lott.cr ~55. l. lhu~90ta Ztr• azpreaa64 1c $J:lol. 4 • · lncl.u6cs 0~"-ernary 9e-a1ogy, field =ap;p!.ng, trenching, ·~: ... : r•~o<t.• r.cna.ln9, li:d.t·•uS Qeo~l'•i=•• end :aview a.n4 t.rovol.. It. cJ:Ol'l~•* c.al11;)rat1on •t.'-141~ on ~e Caatl.• ~Uin t&U1.t. Whicb ~vcr l:>.en a•let...-1. S. · 1ncl. U6o4 in w69et. for Obj ..:'ti v•a l ar~ 2 • 6. lncl~ed 1n ~49•~ for O~jectivaa ll ~ 1~. .. ·. •. .. .. . . •. .· -• • •I ·-·~ ~ . . . . ' -• ; t .. ~ ... ... . • -: X • ...... ... . ... ... -.. _ .. .. : 7 •. Thi• t.c:ri:k1. (l•••·t:lte f!:ec! fee of $6~,0<.t0) corraapoJ:;oc!• vi t.'h t.hll~ in 1at.ter · ~4-SS, :n. ia $23 , ooo l.••• 'Lhan ·. . . • •. tl.e ~u:rca:nt. (;57~,000) in 1ett.oro W""-hh4•SO. "fht: :t2l,ooo FIGURE 4.6 ·L · . . . ·· has bo•n aat. .aaic!• u,· 6cfray, iD ~r'~, tho ~'t.s i6cn- ·. . ., t.ifiec in l•t.t.er '\or~"'-"&· ••••• :~.~ ... ~>..:,.•,. Ill' .~:~· .. ,!.,• •• ''-"~i~:.·,· •' ·:r:.:• •...... ~~.~ ........ ,. ........ : •......... ,.;;., .. ,., .................... : .. ,.. "1''• ..... ,.,lo~ ... ~,. ....... .-.,./ ..... ,.,, ..... ,.,h ....... ).·· .. /, ... ~ ..... ,. ................ ,; . ..;.· . ~. __ ;.,~ .. -:-••.-_,.,.,.,_,,, '''"''••• • ,.,,.,, •••••• .. • •••• • "•'""'•• • ••• •• ,,~..,., ... •'•~•••••-••'•'••&Oo ..... u.~ .,,.., • • '• • • :~·· • • , .. !,•, u-• '•\ :,., .~. :' n .(] ~.OS PRE Ut.~lt,ARY Dt-.1: STASILITY t;.O!? SEIS:.mLOGY HJS1orical Ear1hqvakes N1nwork r.'.anual Benioff t.~aximum Ea:-:.'lquake 4.10 FH:SERVOIR l!WUCED SEISI.',ICITY ~.11 SEIS~.".IC GEOLOG'I' Remote Sensing Ouatl:!rnary Gt>ology r.·ap;:>ing Trcnchmg Field Review 4.12 • REPORT Analy!.is and Drah Report WCC Review ~ 13 GROUI-.lD MOTIOt~S ~.14 0.!\fl. STABILITY 4.15 TRANSMISSION LINE SEISMICITY ACRES REVIEW AND UJPUT ACRES SPECIALIST CONSULTANTS MEETING APA EXTERNAL REVIEW BOARD MEETING V!oodward·Ciyde Consultants@ 1981 AND 1982 SUSITNA TASK 4 SCHEDULE FOR SUBTASKS 4.08 THROUGH 4.15 .... ..,. Jl ----------~----------1982 ---.....:....-"'-- :. tt .1 ... ,. ... ! I t• •• '"1 C~1n1.r1 ~ 11. 1.:. ... ::. ... ~. \ 1 ... t t !"' r[t'rt.·r.rr J.:c~1.,.~, ~•rrk ... 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""-·. . -/'• ·--, ... ::. ... , SOU'.:OAR"' FAULTS Faults Wlth recent displacement SIG~.;IFICANT FEATURES ------lndt:terminate A feature ---• --·-Indeterminate B feature NOTES 1 . 2. Explanation of significant feature classification system is presented in Sectton 8·2 • Explanation of alpha-numeric svmbols is presented in Appendrx A. ~ -N- ~ BOU!~DARY FAULT AND SIGNIFICANT FEATURE MAP FOR THE SITE REGim~ (., 10 20 30 ~0 ......---- 0 10 20 30 40 50 t(itometer~ FIGURE 4.£ •· fP H rr 'if .. . ' tl ! I, • > SUPPORT MATERIAL TO TASK 5 GEOTECHNICAL STUDIES ;1 ') I'~ ·····L .; : -• L ·C f"'"' ·--L ·,C c c 1) 2) 3) 4) 5) 6) 7) 8) 9) SUSITNA HYDROELECTRIC PROJECT OCT 6-8 MEETING l1~FO PACKAGES GEOTECHNICAL DATA I ~~DEX WATANA DAMSITE GEOLOGY f1APS & SECTIOi~S DEVIL CA,~YOi~ GEOLOGY MAPS & SECTIONS WATA1~A DAMSITE EXPLORATIONS DEVIL CAi~YON DAMSITE EXPLORATIOt~S WATAI~A MATERIALS DEVIL CANYOi~ f1ATERIALS WATANA RELICT CHA.~~~EL WATA1~A DAMSITE -FOUt~DATI01~S, EXCAVATI01~ & ROCK ~1ECHAI"~ICS CRITERIA At~D DATA DEVIL CAt~YOI~ DAMSITE -FOUi~DATIOaiS, EXCAVATI01~ & ROCK f\1ECHANICS CRITERIA A1~D DATA 1) WATANA DAMSITE GEOLOGY .,.., L~ c 'PI ,--·L.J --r~ t . ...;l -C t 10 ,, ____ I' G l I F W-5 t E -- 0 I \ I I I I I I ~ .1>, ~ ~ ~ I i ! 6 ---:......-·----~-----~ ··----=::.4-· s.::... E C :.)1. 4 '~' _ ___..___....,;.;: ,_ .... ..,.:...--·--· ~, .. -,.. '· ,l-..... .i:,.)L. .. ---.. .. 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S~tARS' ~U'£0 WHEI!t l~"l:'I!'C: t>I~E j ·; ~ i rl !: ,, ,• ;. ,, .. :<~ ~ '' f ~,·t f' ~. t' ' 11 :[i t. .~i; A fr tl f .I ll r1 [t ~ !I u fl ~ " H R I \:,_ .-- G F E - 0 c.l B <'A ~ .. It b 1: • J lO 9 8 7 /!1 ,' LJ'I ~) 0 h ... 6 .. .. -.. '":.:~r ; .... ••« -~·"-·--. 2. DEVIL Ct.l4YCN JOINT ?~TS I 1 .~ ~ { l ~ ~·t ?, I) t ' ./ ,. I I {I L. fll ;· I.... fl I . w rn I G F E 0 cl I . B 10 =~ I t~OC ••o<.: eoo 700 i !OC J ecncw-11~ · w ----- 7 e --------·--·-: ;;;;.:=---· S"~t!! -~ Pt.-.ltf lCNt -_,..., __ .. _ .. __ .... _ .... + -~3 ____ .!_t ___ 22:._,_ __ _!,... __ __:__ ......... , i 'J I~ ~ ••• •• • " : \< •••• ' '" ...... ' .. ~.,:· .. ~· ~ : • •• • • •• ~ i 10 i G l 'i iiiOO J !Tot i F \ ' I&OC ., l . ,! • 1:.00 ' >&«. ' ' ·= E I ... ; l:OC I = l !0 ! ,J i --t: U'X\ IOOC I 0 90C I I ... c I I I B ~ -' I l I t ' I ~t t ~' ¥• ., i'' i ;, 9 e 7 ' --~----/--~=-=:-=-=--- / -~--9---"" / -/ -----_.. ...... ...... ------ SZ.~ iJqA"t'Ol G11AV'EL 0'1 r..J.t\lo.L. ilU. ---------------- ~--~. .. ·.·J 3 ·~ 1200 1100 1000 !100 1100 70Q roo i, ~; ' ~----r---·-... --_ ... , ;_~.---- 1 ! ' r :~; ~---·-·---... ~-71.-_ .. _ ... ___ ' _ . ...t ~·'"-'"'··--"' - I I I I I I ~ I I !I I I I I ;I ~I fl ~ < ''I 1;1 rt ,-----------------------------------·-------------~=============~=========-----.=--=----------.----_-_-·_-_-_-_-_-_-_-_-_-.--.. -~--~. -".-=.:·:_-_::.-_-..... ~'":"__.-.-~--~------~-.. -_-~.· '··---·---- N N .... "' ~ N (T) ~ ~ (.? z ;; 0 f ! l \ \ ... I "" J ,~E. ---:..~~ . I I t; I, I I .. _ ..... -. ,~,. ~\. E--r ' . \ . -_...- \ :::: .. \ ~ ' \ \ \ ' \ \ '· \ .... \ ' ·~ \ \ .· ,.-ri'il-._ -.... '\.-""\ -. ·,. \ . .. "- ... '· ... .~"" S. --:~., r ... -- ....__ . ._ . ... .. ~ ..... "--'-----..,._ -----··-_,.;.------' \ A ! ... ;.....~-.) ,,:: ...._ ,.- ~. r?.~-.· \ \\ ' \ ,.... -~-·~-.:.\.._.-;. _,;·p,~~;.v ... :.,:.--.::..· ~----,... --:.. ~- ~- ~· 3j WATANA DAMSITE EXPLORATIONS ~ I n- ; ...... ~.i IJ-, ' c n '· .t I ~ i .tt * ti l ' .... I If ~ ·f&L Jl i I J. I J. f!. ~ ~ -. n 0 1 rr ! n ' i > n u n l ~ • ' .. • ' ~- ~~:ATANP. STRUCTURE: 910 ' HIGH ROCKFILL DA~ INVESTIGATIONS: VSBP. 1~50-1953 RECONNAISSANCE COE 1£75 RECONNAISSANCE COE 1978 22500 LF SEISf1I C 28 BOREHOLES 30-EOO I DEEP 18 AUGER HOLES 27 TEST PITS L!7EE5 LF SE I S~1 I C 10 PIEZOMETERS 13 TEr~P. PROBES . SIGNIFICANT FEAT~RES: ACRES 1980 ACRES 1981 3 HOLES 37E-752'DEEP 21 AUGER 24800 LF 4 HOLES * ! 300-955'* 18 AUGER 21 PITS * 38200 LF 1 PIEZO 4 PIEZOS* 1 THERMISTER 2 THERMISTERS* VALLEY 300' AT BASE) fOOD' AT RirJ 3Q-6C 0 SLOPES 10-40' OVERBURDEN S-40' ~EATHERED ROCK ALLUVIL!r1 -SANDS AND GRAVELS) sor~E TALUS) POSSIBLY PARTLY FROZEN P.ELI CT CHANNEL L:PSTREAf1 OF DAr·L GLACIAL AND ALLUVIAL r:.~TERIALS UP TO 45~' IN DEPTH. r'!AJOR SHEAR zoNES <"THE FINS" J /lFINGERBUSTER 1 .. ) BORDER DAr~srTE. LOCALIZED NARROv! ZONES OF SHEARING AND INTENSE THER~1AL P:LTERATION. 3 MAJOR JOINT SETS <PROMINENT N30-EC 0 W) DAf'~SITE IN PLUTC~L BOUNDED BY VOLCANICS AND SEDI~iENTS3 *NOTE: IN PROGRESSJ NU~BER MAY INCREASE. 9/16/81 ~~ [ .. r ! r-l I [ f r ' _:. I [.- . ' { 11 1 ~ ~ w . . [l t ,_ lij \.... u \ .. ~ .. ~ . IJ . . ~-· ft 14 '........ ' Q .._ U_- (l . ' ~1ATERIALS SOURCES: CONCRETE AGGREGATE & FILTER r·1ATERIALS AVA! U\BLE 2-L~ r~11 LES D0\'!NSTREAr*1 OF SITE. ROCKFILL ,l\VAILAELE FROr1 EXCAVATIONS AND It-~MEDIATELY A]JACENT TO LEFT END OF DAM CREST. GRAVEL SHELL MATERI1\L AVAILABLE IN RIVER Y.!ITHIN E-8 f-11 LES UPSTREAf·! AND DO~!NSTR:Ar! -STILL BEING EVALUATED FOR SUITABILITY. IMPERVIOUS/SEMIPERVIOUS MATERIAL FOR CORE AVAIL~BLE 1-3 r-~ILES UPSTREAr~ oF AXIS. AREAS TO ADDRESS IN DESIGN: MAJOR SHEAR ZONES LIMIT UPSTREAM AND DOWNSTREPJ~ LAYOUT FLEXIEILITY. LEFT ABUTt-1ENT SHEAR ZONE AND P.L TERED ZONE Lift: IT STRUCTURES., vl ILL REQUIRE ADDITION/l.L GROUTING .L\ND DRAINAGE PROVISION. DEEP ALLUVIUf:~ IN CHt\NNELJ OF UNKNOvJN DYNAr-'IIC <SEISt~IC RESPONSE) PROPERTIES t-1ANDATES REf:iOVAL UNTIL PROVEN SUITABLE ft.S FOUNDATION. LOCAL SHEAR ZONE INFLUENCE UNDERGROUND STRUCTURE ORIENTATION. DEEP RELICT CHANNEL ALLUVIUri REQUIRES INVESTIGATION FOR ~~lATER TIGHTNESS AND SENSITIVITY TO HYDROSTATIC HEAD FRO~~ RESERVOIR. SPORADIC PERr1AFROST \'fiLL REQUIRE CONSIDERATION IN CONSTRUCTION. UNDERGROUND STRUCTURES: ROC[ Q~ALITY GOOD BELOW 250' IN DEPTH} PERMEABILITIES LO~ • STRUCTURES REQUIRE ORIENTATION TO AVOID LOCAL JOINTING}. SHEARS. f~ ~~ ~ ' ~ i r:.~ . . • :..~~ i i H :i . I II !i 11 'I !I 1\ II II ' IJ II il •I !, ll ll l: >i !! q ,, "' .~i q ll f! . ,! ·!l lt ,fi " H 't r, (;! \l . !: I ~ ' • j "" t M' u t ~ ,. fJt !_ .. n . '-·· ll .. . -·· n . L I ~~ l I ' ~ .. -,. I . ~1ATERIALS SOURCES: CONCRETE P:GGREGATE & FILTER r·1ATERIALS AVA! LABLE 2-L~ r~ii LES DO\l!NSTREAr·1 OF SITE , ROCKFILL AVAILABLE FROt1 EXCAVATIONS Jl.ND It~MEDifl.TELY A]JACENT TO LEFT END OF DAM CREST. GRAVEL SHELL t1ATERIAL AVAILABLE IN RIVER lt!ITHIN t.-8 f-1ILES UPSTREAf·1 AND DOv!NSTREAf!-STILL BEING EVALUATED FOR SUITABILITY. IMPERVIOUS/SEMIPERVIOUS MATERIAL FOR CORE AVAIL~BLE 1-3 r-~ILES UPSTREA~ OF AXIS . AREAS TO ADDRESS IN DESIGN: MAJOR SHEAR ZONES LIMIT UPSTREAM AND DOWNSTREPJ~ LAYOUT FLEXIEILITY. LEFT ABUTr·1ENT SHEAR ZONE AND ALTERED ZONE LH~I T STRUCTURES.. v·!I LL REQUIRE ADDITIONAL GROUTING AND DRAINAGE PROVISION. DEEP ALLUVIUr-~ IN CHANNEL) OF UNKNOvJN DYNAtiiC <SEISr~I C RESPONSE) PROPERTIES f·1ANDATES REr'iOVAL UNTIL PROVEN SUITABLE ~.S FOUNDATION. LOCAL SHEAR ZONE INFLUENCE UNDERGROUND STRUCTURE ORIENTATION. DEEP RELICT CHANNEL ALLUVIUri REQUIRES INVESTIGATION FOR \:.lATER- TIGHTNESS AND SENSITIVITY TO HYDROSTATIC HEAD FRO~~ RESERVOIR. SPORADIC PERr1AFROST \1ILL REQUIRE CONSIDERATION IN CONSTRUCTION. UNDERGROUND STRUCTURES: ROCK 0t'ALI1Y GOOD BELO~J 250' IN DEPTH) PEP-.r~EABILITIES LO~l~. STRUCTURES REQUIRE ORIENTATION TO AVOID LOC~L JOINTING). SHEARS. i---------~--------------~------------~ CD • ~ Q NOTE: APrr • I) SECTION SHOWN ON FlGURE - 2l TOPOORAPHIC c:nNTOURS AR£ APPROXIMATE L Previous Work ,.. --f 1981 Work 1981 SEISMIC LINES SCHEMATIC \l•am\ WATANA EXPLORATION HUBW , , ... '·~· .-) .. '. NOTE: I) SECTION SHOWN ON FIGURE - 2) TOPOGRAPHiC CON"lOURS ARE APPROXIMATE L Previous \~ork ,... --t 1981 Work 1981 SEISMic LINES scHEMATic Ianum\ WATANA EXPLORATION ROD~ , I. WATANA SITE . 1980 GEOTECHNICAL INVESTIGATlON I. 0 PREVIOUS WORK e 1980 PROGRAM -DIAf~OND CORE HOLES I ~---SEisr~Hc LINEs IVIATANA SITE I I ( r 1981 GEOTECHNICAL INVESTIGATION PREVIOUS WORK 1980 PROGRAM 1981 PROGRA~1 BOREHOLES -DIAMOND CORE HOLES I I ;--I 1980 1-_ • ., 1981 ~. ~l 1000 ~ • 1.." 1000 eoo 1100 1000 s· .. I I 1100 tooo-t ,tiM:! ' 0 ! --~~ :kP '!£} 'fFse!J Bll-1 BH-3 NORTtl ABUTMENT ...., .. , ...... ...... ...... BH-t ~rrou !tOd tJ/11 PREVIOUS 1981 n t"'l r tn-t ·~ .\;l ·p 'fti ·rn. ' .. ('tr'"'• ~ ; ·~· !74' . " i~ :·. •. ··r, ··;~;.:; • ,. • ..... ·. ..t-2. L~ .. ~. § • liH-21 1t<1nt1M rd DI'S SECTION A·A LOOKING U/S N 15• W · AT APPROXIMATE DAM CENTERLINE . .:...~ ~· ' ,..;:__j"' . ~~··. ~-=-:t ~· ~""'-"' ~ ·;:.·~· · . ~ ..... -r~..,-". -... t·,_. __ ltt • ..._ 'I "" } .,., > ~ ~ \ . . . Btt·B • 011..:~4 . (PROJECTED~a.AOAL tU DH:~ H · uwm oorm ... Q.A\' OOUOl '<llll.UIIOIOIItn: Btf-8 ton1MO Jed Ull SOUnt ABUTMENT ~n • ~H'-•~• . "'' ~ ~ . .,. NOTE: BOREHOLE LOCATIONS . AND PROJECTIONS ARE ·. AT APPROX'If-1ATE DO~/NSTREAf1 COFFERDAr1 SUBJECT TO SLIGHT CHANGE WHEN SURVEY DAT~1 _j s RE.C.E--1-VfD. fii\IOI'I IVOI "I VOl 'I IJ)O[ DH~ Dtt-1 .._ Ott-! "' .... ~ ::0 g-.. ...... u ...... :...::.: i..~n: CMOAfR ANODIII lltlll: SECTKJ1N a~e LOOKING fl.J/S N 4~ W lte M e 100 4Cie ~ t 1 KAlil • nn GEOLOGIC CRCJSS-SECTION WATANA BH-1 100011 Irs" Ull Btl-12 (ii] ' "• p lL" r b ' . ~ ~- ir ~" c [ "• v ~" 'll 11 I 4) DEVIL CANYON DAMSITE EXPLORATIONS n > : . L . r~ r • . r r~ t ·r. \ r. t Pf ~ . t. c ' ·"'. i r: L ["" . ,.,. t .. , ... i c \: .... fi ' ~· ~ ll'"" . ' ' ~ DEVIL CANYON STRUCTURE: E35' HIGH CONCRETE GRAVITY-ARCH DAt·1 INVESTIGATIONS: USBR 1957-1958; COE 1978 22 BOREHOLES 20-150' DEEP 19 TRENCHES AND TEST PITS 1300 LF SEISMIC LINES LAB TESTS: PETROGRAPHIC) ROCK ELASTIC PROPE~TIESJSTRENGTHS SIGNIFICANT FEATURES: ACRES-1980 3 HOLES., 501-750' 2 Al'GER HOLES GRADATIONS ACRES-1981 4 HOLES.,150-EOO' E AUGER HOLES E TEST PITS lEOO LF SEISMIC GRADATIONS * AGGREGATE TESTS * 150-900 FOOT CANYON WIDTH CEASE TO RIM)., 45-80° SLOPES 75± FEET OF ALLUVIUr1 UNDER SADDLE DA~1 AXIS VIRTUALLY ZERO ALLUVIUM ON GORGE WALLS SHEAR ZONES AND FAULTS IN BOTH ABUTr1ENTS LARGE OPEN JOINTS AND DETACHED BLOCKS ON LEFT ABUT~~ENT 3 JOINT SETS <PRO~INENT N25W) BEDDING DIPS SOUTH., 50-70° 35-SC FEET OF WEATHERED ROCK MATERIALS SOURCES: CONCRETE AGGREGATE AND FILTER MATERIALS READILY AVAILABLE WITHIN 1000' UPSTREAM OF AXIS ROCKFILL AVAILABLE FRO~ EXCAVATIONS CBEING EVALUATED FOR SUITABILITY) OP. QUP~RRY SITES v!ITHIN 2 ~1ILES OF AXIS., ON SOUTH SIDE. 9/1E/81 *NnTF.: IN PROGRESS ,. t: r·. r ·- I . .. ..,...,. r. ~l __ ,, . .... [ :ii, . -t~· [ ::t. ,-i' ' ... •' .. , .. ( _ . ., . ~~ [~7. ·~· ·~ r~ l,.- fJ . ' 1 . ..... c ~-. '; . ~ . . ·~ POTENTIAL FREEZE-THA~·/ RESISTANCE PR_OBLE~~ IN ROCK AND/OR AGGREGATE - TESTING PROGRAt·1 \•!l LL EVALUATE ~!,A.GN I TUDE OF PROBLEf-L !~PERVIOUS FOR SADDLE DA~ -NO READILY AVAILABLE SOURCE IDENTIFIED: ~!ILL REQUIRE PROCESSED ROCK OR LONGER HAUL FROr: GLL!.CIAL TILL SOURCE. AREAS TO ADDRESS IN DESIGN: LEFT ABUT~~ENT: SOl'THERLY DIPPING BEDS OVERHPJ~G.~ r!ILL REQ~IRE EXCESS EXCAVP~TION f\.ND EXTENSIVE DENTAL TREATr~~ENT. SIGNIFICANT ROCK SUPPORT r·~AY BE REQUIRED LOCALLY. THRUST DLOCK WILL REQUIRE DEEP ANCHORING. RIGHT ABUTf;1ENT: BEDDING DIPS TOV.!Jl.RDS RIVER, \'!ILL REQUIRE LOCAL SUPPORT SADDLE DJl!~: EAST-WEST TRENDING SHEAR ZONE AND BURIED CHANNELD BEDROCK UP TO 90 FEET BELO\•! LAKE LEVEL. SPOP.PD I C TO POSSIBLE J.:EEP PERf1P.FROST, UNDERGROUND STRUCTURES: ROCK I~:1PROVES \~ITH DEPTH.~ To UNIFORr·1 r,oon QUALITY BEL'Jv! 1so FEET. PERr1EAE I LI TIES LOv! AT DEPTH. £/lE/81 ,? • • BOREHOLES BH TEsT PITS SL AUGER AH DEVIL CANYON SITE PREVIOUS GEOTECHNICAL INVESTIGATIONS •• AH-G4 t ' • f. . . .. ,,-tW, '"' !:.,_ li [ l~ l PREVIOUS • BOREHOLES • TEST PITS t--f SEISMIC LINES 9/16/81 DEVIL CANYON SITE !N 1981 GEOTECHNICAL INVESTIGATIONS 1981 0 BOREHOLES ~ TEST PITS ,_.--f SEISMIC LINES ~ ·~ i -; :~ ~.... < ·1 !~ ........... tr-J . -·~ ,... .i 1!100 1400 IJOO 1100 ti 1100 Qll ... ll 2! 1000 S! ~ d woo 100 'JOO eoo SOO-·• ... ~ I(. . ;J r-r;·-1 •l .-d t""~) rr-""""'"1!: f''r"~ r-r''"'~ r·~r--'rt • t J '• \,,. ~ .~ .o: j t -~. , .i1 r .it , -• -·~ ..., NORTH .-oUT~NT BH-2 f'ROJECfi:D 100" Oil PREVIOUS WORK BH-5b . BH-1 .Onoa. no• uta LOOKING U/S N 11• E i r-·1 .. ··r·····~ .. ·;·---1 .. --'·,~;! .. "-·~·-·-a:·-···-~...,. ·-~...,..:.,.;.;.;,.a ~ t " ..... JJ t . { .,, _'j j . :J ) 'f-:-' ·--. ' .., • ~ ~'~) • DH-11 PROJECTm) Bll-3 SOUllf ABUTMENT BH-5a 100 .o t roo 100 ~ -·"L-Mil ltAll .. rut fiUUl9fCU: l IUIIUU Of' fi[CUMAT10t 0 ttiO l tOflPS OF llfOINU:JP:I, ltJI l SUII~ "eo WvtSl~JIOel BH-7 eonou :no· 011 .,;~',• OVtfiiUIIOOt or ,.,..SI.Y NfiJ IDUI.bliiS A"CIU.fft. • PtrtU.nt NOTE: SECTION AND HOLE LOCATIONS BEING REVISED SLIGHTLY DUE TO NEW DATA FROM SURVEY CONTROL NET, D '! 1981 GEOLOGIC CROSS-SEtTION OEVILCANYON • <1/1 I=' /R1 r-" ! ___..tS!l\:Co_,...,.. t(r~ I' .I .~ ... ~ ' l.~ t; ~ ·~ :] IJOO 1100 t 1100 .., ... c z 1000 I ,00 ""'·-,.,.,..u~ iiot ,~ 1 ~ ~ • ·! rr-i . ,-i rr--: ..., 100 NORTII AbUTfdEHT 700 coo SOO-·· D '! 0./1 f=' /R1 BH·2 f'nDJtCYr. 100' Dfl PREVIOUS WORK 1981 r ~p·~ l! H ; •. l,. '!.:;' r-~ ~ . i.' '1¢ ~ Btt-1 rT"~ I \ , Jl BH-5b . ao'noM no• UIS LOOKING U/S N 11• E r··~ :--·r··l I .f ,..._if] 1· t.\ ,._ BH-5a ....... r,.->0¥.,,,.~ I."' .. ·.t: .... JJ Bll-3 ···r-· .... , ..... ~· . ' ' .ji ... 1' •J.,.. ...... Dtl-1 I PAOJECJID) SOUnt ABUTMENT IC10 10 • 100 100 ~ "!t:-::J auu 111 ran MTlR9fCUs l IUII[&U Clf' ft[C:UioUII'IOH 0 1110 I toRPS Of (HGINU:ftt • .,.,, II $UII!.4Vi lt!IO llfVUT ~ f lOIII ... ·~,..,., ,.,. -.. ,._""''1 -·-~ ~ t ' ~ ~t '.,.-·. • '" .. -21 f~ L-~ , .,~• OV(IIIIUI'iOOI or ,~Sl.'~ Mit IM.IItils t.IOlltRATtl'Y fftACl\JI'lfD · BH-7 Oft·4 tonou uo• 011 NOTE: SECTION AND HOLE LOCATIONS BEING REVISED SLIGHTLY DUE TO NEW DATA FROM SURVEY CONTROL NET, GEOLOGIC CROSS-SEtTION DEVILCANYON ii] 5) WATANA DAMSITE MATERIALS v.. 0, c 0 v.. c 0 3 WATANA- POTENTIAL BORROW AREAS jJoJJ l'ii ' # '\\ D.7I}PROPOSED NEW A __ \..2.)FOR INVEST!GATIO NOTE: PPEPS B.~C.,F HC\VE PEEN DROPPED FRa~ USE, 0 .5 I ! ; SCALE IN MILES . i . l [1. l •.. _· i ...... f . ·_ ·fl I . --iL j ~ I ,, l !_II ~ ' . . ; \ ! . 1 ~ ' I .l •!! I ; •• ' ~ t ·~·'<· • ' I foe~ .. :·· ,"' ·I " \__. I I. I I. I I AREA A (QUARRY) B (QUARRY) C <GRAVELS) D <CORE tiTL) COE ACRES E <FILTER &AGG) COE ACRES \1ATANA· BORR0\~1" AREA· EXPLORATIONS (ALL INVESTIGATORS TOTAL) TEST SEISMIC AUGER PITS LINES HOLES APPRO X AREJl. . EST. VOL. NOT NECESSARY -LARGE AREA 700+ ACRES lCO+ MCY OF EXPOSED OUTCROPS. (1.13Mcv/FT OF DEPTH) COE SITE -SEISMIC LINES SHOWED EXCESSIVE DEPTH OF OVERBURDEN -ABANDONED AS POSSIBLE AREA. 1 3 0 1000-1500 200-400 MCY COE FILTER & AGGREGATE SOURCE -13 f~ILE HAUL NOT CONSIDERED AT THIS Tir~iE -AHEA E r~iORE USEFUL. 14 6 24-630 20+ MCY 2(GRAB) 6 14 650+ 73+· MCY (lMCY/FT) 6 5 0 550± NOT CALC 21 3 9 fOO± 28.5 MCY (.95MCY/FT) F <FILTER&AGG) E 0 0 130 NOT KNOWN COE AREA.~ 10 r1 I LE HAUL., UNKNO\·JN DEPTH AND AREA. NOT CONSIDERED FOR USE AT THIS TIME. H CCORE MTL)ACRES 2(GRAB) 0 RIVER ALLUVIUM IN PROGRESS 12 <SHELL GRAVELS) 9/16/81 9 350-1000 14-40 MCY (20-SO'DEEP) 0 210 UPSTREAM 19+ MCY .. ·, ' ' " . ' .. ~ ~ 1770 DOWNSTREAM145+McY (AVG 50') fl. I- I« I ':".·'~ ' ' :I· . tt, .. I·· ~ ~ " .. ., 1 .. ' I t~ .. ., •• •.- ' ·a •. '···· . 'l ' "" ~ .... . , I I . ~IATANA DAM EMBANKMENT QUANTITIES <x1o 6 CY) <DEPENDENT ON FINAL LAYOUT REFINEMENTS) TYPE OF. MATERIAL REQUIRED EST. AVAIL. SOURCE IMPERVIOUS 10~15 50-75+ AREA D AREA H FINE FILTERS COARSE FILTERS ROCKFILL GRAVEL FILL CONCRETE AGG. ROUGH TOTAL 9/16/81 s~6 1-2 - 55-60 15-40 12.5 16 40+ AREA E AREA E RIVER ALLUVI ur,1 100+ QUARRY A 47-104 WITHIN 6 MILES OF AXiSJ IN RIVER. 164+. WITHIN 11 MILES . <1 r·1CY 10+ AREA E < SAJ\iE AS FILTER SOURCE) 71-83 r1CY 2-5 Tir~ES REQUIREMENTS} BASED ON PRELIMINARY TAKEOFFS • fl fl_ 11 ' 1: .. . . i ' 1. ;~ ~ ; ,, ' : '., •• ~ ~ .. ·~ 17 ~~-- •• , .. I . I . •.· ' : ; ' ~ ... ~. I I I 'I·· I WATANA DAMSITE -AREA D GENERAL MATERIAL PROPERTIES < CORE MATERIAL SOURCE) FROM THE DATA TO DATE < MOST OF THE 1981 SA~PLES ARE BEING TESTED AT THIS TIME) IT APPEARS THAT THE MOISTURE WILL BE THE MOST CRITICAL FACTOR IN USING THIS MATERIAL. THE TESTS INDICATE A DIFFERENCE IN PROPERTIES BETWEEN THE SHALLOW OUTWASH ~1ATERIJl.L., \~JHICH IS LESS FINE GRAINED AND ~!ETTER., AND THE f~ATERIAL BELO~I ABOUT 20-30 FEET IN DEPTH.THE MOISTURE CONTENT ALSO APPEARS TO BE RELATED TO EITHER FROZEN MATERIAL OR OVERCONSOLIDATED r.1ATERIAL., OR BOTH. FURTHER DATA IS NEEDED ro coNFIRr~ IF THESE ARE TRENDS. 0-20 1 20-75' MOISTURE CONTENTS -'"' •._I ,.. 7-25% 6-12% LIQUID LIMITS-EXTREME 14-56 13-23 NORMAL 14-23 13-17 PLASTIC LIMIT -EXTREME 11-22 13-15 SIGNIFICANT NORMAL 11-22 13-15 NUMBER OF : PLASTICITY INDEX-EXTREME 0-33 2-7 SAMPLES THAT DID NOT SHOW NORMAL 2-6 2-4 ANY PLASTICITY. GRADATION CURVES SHOWING TYPICAL AND A FULL ENVELOPE OF SAMPLES TO DATE <COE AND ACRES) FOLLOW. DATA OBTAINED BY THE COE IS PRESENTED BELOW ON CORE PROPERTIES FOR DESIGN -ACRES TESTING IS IN PROGRESS. -- •< I ".' ~ ''' ' ) ~' . ~ ~ &'• : ;f RJ ~ l, . ....a 0'11 I ...... , ~ _, ==: )>tu):» C::O:;j m:::o-m:::oz ::0~, i§,~ r:::o::;: rn~V1 t-t s 0 nl -11 Ul :I: ~ 2 ~ n~u~~ ' '• " II J ~·-1-~ k '; a 0 0 c::::, J <>--.. ·. /~~-" :~>, ... · ~ .. :.<·~ __ ·_. ·.-~ ·. ::,.,.·.: ,.~ i ~,·-~ J ~ 1 .,,. •• 0 $fJS!TN~ RIVEif .. ICI~I ' . ~·-2 ::t • lOG: 1000' 1100' liioo' I --:-~~ J ~ • . ~ ~ ~·~~ ~' .--~~~~. 1~ r......-a _.-.. .-. ···~ ,pr~ j~ ~,~. '•-!. '· -~. ~ ---~ ···~ ~ ·-:-1·· -;-E· ·Tl· T'J u.S. Stnnslor4 Sltvt Opening I In klchn . U.S. Slonllor4 Steu Humlhn flrdtOIIItl .. ) z ' l'l • '5/4 1/Z 5/!1 5 4 G e .10 '" '' zo 50 4o ~o &o 10 100 140 zoo zrq_ 0 0 100 1\ I ~~ ~ ~~ I I I I I f I I I I I !1 . .. ~ ' ' ~r-:-. 1'--r..... 90 ........ ~ .... " ....... 10 . \_ ['.... 1 r--~ ~ :: ~ ~ \ I' 1'-. () ' A ..... ' ~ ~~ 80 20 ....... '){ ;-.. ... 1-~ ~ ""'· '~"-J D 2 5 -~ - A i(-0 -~ 1_....... '-...... ....... ~ ~ '~ ~ /L I D 2 B . -70 -30 .c -,...~ :".. "~.. ~~ ' ~ f £ .,. .c ~ .. O• .. ;; " ~""' R ~ ~ I ~· ·ID l· 5 ~ 3: 60 ~ 40 ... / ~ ~I'-~ ~' ~ .Q .,.. ~· 0 -· .Q .. --.. ... "'r-. ' ~ "' ~ .. u 50 ... c 50 -........ "-' -~~ 0 ·-r-.. -· 2-9 0 IL. ~ I' ~ A u r -L ~ ~~"S: ~~ -c '-l'\ ., 40 60 c u II .. AfJ .. -It) / I ~" I'~ ~ ' ~ u ., ~ ~ ... II 4. / ~ I' ' ~ ~ ~ 4. 30 L !'-. 70 ,..,.,. ' ~ ~ ~ AU-• 3 -i' ~ •• -..;; ~ ~ ~ 20 ~ 60 ~~ ~ ~ l "" ~ ...,~ 10 --~ 90 ~ ~~ ~~ I" ~ -S:. ~ :-,;;;; 0 eoo --100 50 10 5 I 0.!1 0.1 0.05 0.01 O.OO!i 0001 • Groin Siu In Millimeters I Co~[i~ GB1V~b fl~l I Co~ni I M!d~ij~:~u t : Fing I ~:ILT or CLAY I '"· SAMPLE NO. ~8~Vf:t OAY Ll PI CLASSIFICATION 8 OESC~liPTION D[~SI'f'f . TYPICAl GR8P/\llON~ -APPAKt.N 1 VAKlA 11 uri \'lllt1 utt' 1" Ali-Dl-5 SM AII-Dl-6 SM I IMIIED TO MOISTUBE CON}fNT -AND ATTERBE~G LIMITS. All-01-7 SM GRAJJAllQNS FQbbCn\! ~AIRL¥ NA,RRO~! GRADAJION. --All-02-3 SM All-02-4 SM All-02-5 SM --l\11-02-8 SM . Ml-02-9 SM DRAWN BY DL R$M BORROW AREA 0 APPROVED BY -CONSULTANTS, INC. . DATE DEC. 1980 ·-SUW~RV OF GRAIN SIZE DISTRIBUTIONS -PROJECT NO. 052504 --- I t ••• b 8 t..J I. ,. Ol . 0• I I i I l ! l . , I I . l 1 l 1 ~ • D • • ,,_. . . . " • U.t. &iAI~lO tm'l OfD.f.IJtl iJ ~IOte1 I y 0 10 JG lO I 40 fi so g 0 ,1) ~ 10 f 00 -·---.J~Q 1 o~--•--•-·•-- ! . , . . : , • I • • . . ENVELOPE :QF. ~~4D~TIONS .. ~!ATA~A AREA D .• SOLID ZONE I~. ~pE SN1PLES, OUTER LINES ARE . EXTREME RANGt OF A~RES I ~VESTI GA TI ONS.. MAJOR IJY OF SAMPLES .FOLLOW SOLID .BAND. . . I . I I • . : t fl . ~ . . I • I . . . . : ---·---0 /1 f.-/ Q.1. . . . I l. ,. . I' ' . i I I ! ! :· t I • I : I I • : .. , f .... -·-· .. # .... ·~- ~ llllf -rll!ll ~-~-·~ rfle ............ ··-.~ ....... ··ia...---•···liM··iiJiil ... --~~ • ~~~-".-. ""-~ l .,~_,, .,.,"',... '· . . ~ --·: -· . . . : ·;; . . .•· ; ~ . • 1 .• BORROW AREA D ATTERBERG LIMITS FOR MATERIAL 0-10 FEET • • Natural Water Contents #200 SIEVE 10.--- DO :l __ • .. -~,. ~·." I I I I I I I / ., ·@) I I I I I I I 40 ~ I I I • • ·Z - I .-~~ ~50. I .. I I I I ..., I I • I= en @ . j .. A. I I A •TESll PIT 20 . I I • AUGER HOLES • --10 7 4r-~- " 0 10 NP 20 30 40· eo 80 70· 80 tO 100 LIQUID ·LIMiT .. AH = Auger Hole Results -·-TP = Test Pits NP = Non Plastic Samples . 9/lE/81 . . . j ;! r I I I ' l I I 1 • . .• = I :: .. ·-- .. ~~----. . . . i .. {~ ~----:*-' , .,. · ~ ........... ._ .. ~--.. iallf .... r..-,. ~ .. ,~ .-., ~-~ ; • : I • I . .. BORROW AREA D ATTERBERG LIMITS FOR MATERIAL 10-20 FEET eo fill ...... ~ Natural Water Contents #200 SIEVE eo • .-~ @) s 4o I -I I -I I I I I :7' · I I I -~ ao I I · I I I I Y I , I I ~ u J= ~ @ zo 1 -1 1 t · 1 r 1 1 1 1 1 1 IC 7 4,_ __ 0 9/16/81 • 10 NP 20 . • . !0 40 eo 60 70 80 90 100 . LIQUID LIMIT • :I , I'" ·I~ . ·l~ lilt'! ,.. ~--;tllll r: ....... ,~...~ rfll!l ~ :~ .. ,; .. --~ .......... : •. , ......... : .....• ·'·· .. ~ •.. tliiJ t~ . ' 1 ~ t .. .. . . BORROW AREA 0 ATTERBERG LIMITS FOR MATERIAL >20 FEET Natural Water Contents #200 SIEVE. 60 ... ..- ( • ~ .~ •• ; .. J, eo ... --~· D O(J {.._ •• '" ._._u '-'I'll.-I I • "® 40 I I I I I I I ·~ z -• I I I I I I _,-I fi 30 != I . w I . ~ I @ I I I . f I I . 20 • 10 7~&:.---u .. .._ __ _ 0 , . lO NP . 2() !0 40 00 80 10 LIQU80 LIMIT 9/16/81 I . . I I 'f • . 80 10 100 .. I I I I I I I 1- . I- I ' I .. _' 1-, \.... .: I . ; ; .. . . . \...,., .. .. I ; '\._ ' !~~- '' ' ' ·- PRELIMINARY DESIGN VALUES vlATANA -AREA "D'' SAr~PLES OPTIMUM MOISTURE CONTENT <95% STD PROCTOR) OPT IMUr·1 DENSITY SPECIFIC GRAVITY <BULK SSD) PEru1EABILITY <MrN~s 1 rNcH) AT 126.E PcF 6 % (LJ'' MOLD) 7.5%(6 11 MOLD) 129-133 PCF 2.671 1.0 X 10-5 CM/SEC TRIAXIAL TEST DATA: UNSATURATED_,Ut~CONSOL, U1~DRAII~ED ANGLE OF INTERNAL FRICTIONc PHI 35 .. 5° .} 0.14 TSF -. ... . . .. ..... AND COHESION .. CO.NTR.OLLED .STRAIN (OPTIMUM WATER-::-4%) • • • . • . • ••••• 41 • -- . TEST PROCEDURE aS HOW I NG RANGE OF TEST VALUES FOR VARIOUS MOISTURE ABOVE., AT., AND BELOW OPTIMUM. .. : BACK PRESSURE f·1.ETHOD (CONSOLIDATED., UNDRAINED TEST) " 33.5° .1 Oa66 TSF (OPTIMUM WATER) 1.75°., 0.44 TSF (OPTIMUM + 4%) o· . 12.3 .1 lp07 TSF (OPTIMUM WATER) 12.8° .} 0.52 TSF (OPTIMUM MINUS 4%) CONSOLIDATION -PERCENT AT 1 TSF 0.85% 2.38 4.82 0.7E% 2.12% ;,;: . ~ •:, . A 10 TSF 32 TSF - 4:~~ (oPT-4%)(oPT.wc) L! .49 6.86 (oPT+L~%) I ,r \ I . 11 .. ' -' ... II II II. , II i' I . __ , • • ... • ·RaM Ccnsulb1t D:.. ysoRATQRY COMPACTION C0NJRQ.. REECfiT · . .: . - ,. . . . . · ~ " . . ~-. .. .. " . -.·. .. ~. . . ~ "\ . '!. ~ ... . · .• :· -tOHcne.,u;w::;mKl.._....::ii~ ..... --~~ ..................... ~-~-----------..,;,._....-~ -·-· • • .;. : ·.1" =~-· .. - . Aft:tlitect orEr9ftl~ k:ras -.ricaa d' • ••• .: ·· . . -. . -. .. . . .. ... . . . ·. A. o..:ription ofScU: tlell·~ 'fill•-GRAVEI.t.Y SII.ft ·SAHt> W Jl Mclt.-ial Marit B . . . . . . . . . =ICCticll SK · . . . 5cun:a d Mcferiol Deadlaa!:l ereiek Sa.!pl• .0. w-ao-300 (A rea D) · . . -.. . . . .· .AASHO OassifcatiCift . •. ~Water Ccl•rt §-it •t. Natural ery· O..if1-----PCF SpeeificGrO!lity_---t l.iq.id L.inlit lieD V±scoas ~1. Plastic Umit~-· . ___ •!.Plasticity tndu Hem Plastic· . . C. Tel R.utts:Malimum Dry Oensity-....::~l:::.:~S:c.;.l:..li!O;;...-·----PCF Optimu~-~ter Cont~t-~~ n v s1.m~ AD&lysia · 0 Si:e 100 95 93 89 87 a6 80 8 76 ... 58 E 26.9~ 9-.2a: 3.~ %."3cn Q/1 F;/R1 ~ > ~ ! 125 ~--~+-~-+---i--+-_.;..! > ! 1 H 0 L E 0 f r : ' ' .. . • ' ' . ' . ' ' • • • . A . . I .. ... -_r=~---{~--~-~::~.._·@!~re_ .. ~~---~···tft'l-~·~,~-··-:··-·f!!8_···----·~.-r n ....... ~ .... ._ .. ~. · . " •AH-E9 8' @ · : t1 tP-B0-18 e AH-·EB 3. 75' . ~ ,.. . . teoo·-· -~-------______./ -,,_--------A\ -- -f~- ~ \\I'> T' \' ~ _,:0 ,..~---·/ . SUlf ~. ,:;;r jd • tc01 1000' • .oos liOtf WATANA BORROW AREA E .·· PREVIOUS EXPLORATIONS 21 TEST PITS FROM 1981 NOT SHOWN 0 I TP-80-17 ·-' , . ' •' i ; ~ ·-""'" " MliG -. aiMC &tll. lllll'lUS 10\lJ • flUe II ~»~•rr ta. J-Ll:l! -f Seismic line . ··nll-·7 Auger Hole o rP--tJ Test Pit 90 20 50 10 SAMPl.E NO. ll PI Engineering 6Geologlcol Consultants ANCHORAOI£ FAIRBANKS ALASKA JUNEAU 9/lE/81 · Fin SilT or CLAY CLASSIFICATION 8 DESCRIPTION COMPOSITE GRADATION CURVES FOR BORROW ·AREA E SUSITNA HYDROELECTRIC PROJECT 0 10 "' l r. [; U.S. Standard Sin• Opentnvo II' lnchu PJ.S. Slondaut Sine Humbert Htdromehr 100 3 2 I Ill I !/4 Ill 3/8 3 4 8 8 HI 14 I& 20 30 40 eo 6010 too 1-10 200 no 't 1\11 ' II 1 11 I 1 I ...._,_ I! 1 I I t l I' t-- 90 ' "' I'<! ,... 1\ "' - ~ eo ~ -r-:-m ~ ·"' 70 .. .c 01 ·; 3: 60 » ..0 ~ "' 1: '1 p E l21 r-l SHAllOH '\!) -(0-8 FEET) \ ~ "'"' .... ., 50 .5 lL t'-. .-. ~ I'-.. c ., 40 " ~ DEEP SAMPLES IJ "' ., D.. 30 I 20 10 r GO 10 LL PI Engineering a Geological Consultants ANCHORAOE rrAIABANKS A LASKA JUNEAU 0/1 ~ /Q1 GM ""-.~-, • I' ~ .... [' . ....... ....... !"..... ~ I ~5 ~~ Grain Sire In Millimeters SAND Medium .. t!T I? E ~1 t--2 0.0!5 0.01 O.OO!S SILT or CLAY CLASSIFICATION 6 DESCRIPTION GRADATION CURVES FOR BORROW AREA E SUSITNA HYDROELECTRIC PROJECT TYPICAL GRADATION 0 10 20 . 30 -10 50 60 70 80 90 100 0.001 ... .c Ql ·; ~ » ..0 .... ., ., .... a l1 .... c IJ u "' ., D.. -,.,.. ... ---~ .. ----.--... ------· ------ Jj -~ A l.,i.{.j,_.,, !,1. -~ ••• ·:--------~~-~---------- ·-.... ·----. ---·---- 50' ABOVE I' , -------.. 1425W.S. ~~~~~~~-~~~~~-~~--~~~~ __ /._' ~'\1~----...:;..1,---:::--_ lOQO-2760 ' =-- --~ 7400 -----=-· 1400....--.:::. - - --------- '-- - - - -14370 1300 1200 INfERRED f•1ATERIALS 1000-2760 FPS 7400 FPS 14370 FPS SECTION LOOKING WEST IN BORRO\>.' AREA E CUT AT TSUSENA CREEK ON SEISMIC LINE SW-10 J"=200' HORIZONTAL & VERTICAL SANDS, GRAVELS AS PER TEST PIT RESULTS POSSIBLE SATURATED GRAVELS (APPROXIHATE WATER TABLE) TAKEN TO BE TILL UNTIL PROVEN OTHERWISE. BEDROCI: {DIORITE AND/OR LAVA FLOWS) WATANA -RIVER ALLUVIUM ------_,)- ;/ .i '.. '----- , ......... AREA E 7400 14370 -------- 1600 1500 1400 1300 r 1200 ~ :I . ·I :I. .I ;I I. ·I, 1• lt ' ' f ~ ; l ll 11 ! .I .I WATANA DAMSITE UPSTREAM RIVER ALLUVIUM QUANTITY -DISTANCE CHART MAXIMur1 HAUL D I.STANCE TO AXIS <MILES). 3 2 1 INFgE.REJr1Y SB SM I C LINES P ESERVES LOW CONFIDENCE 5 10 15 20 25 RESERVES -r1CY IN RIVER AND FLOODPLAINS RIVER ALLUVIU~~ CONSISTING OF GRAVEL & SANDS NOTE: FOR A SKETCH OF THE AREA UNDER CONSIDERATimL SEE ~~~.fAT ANA RIVER ALLUV IUW' 11xl7 FIGURE . ENTIRE A REA INVESTIGATED IS IN THE SKETCH. I . I I 1: I I I I I I I I I I· I I I I 1f 1- l " '· i 1500 . ... / .... 8000 ----~"" SL81-2 7000 - .,.,_ -----. -----' 5000 ' .--~----, .;,. • I 'TERRACE· . ·j. l '1 WATANA -RIVER ALLUVIUM --/ / __ .., .. --- .. ,. /:\ I .... INFERRED MATERIALS 5000 FPS 7000 8000 RIVER ALLUVIUM, SANDY GRAVEL AS OBSERVED IN GRAVEL BARS. SATURATED, COMPACTED GRAVELS OR TILL GRAVEL OR TILL. BOTH ZONES TAKEN AS TILL UNTIL PROVEN OTHERWISE. .' .. .; . .' i· ' I I HATANA DP~SITE MCY DOWNSTREAM RIVER ALLUVIUM QUANTITIES BI!RJ£. ' -1 ~· I 140 I I -. _ .. ,, I I I -. l' 120- I I ..... ~ -~~ ,. 1001 -· };::~< ,, '' I 80 I I I 1-' . I !'\ 60 . ' I !I 40 l ~ I II 20 -1 I ' ·I l J ll '-,·· . 1 . I I l *I 0 l .i I 2 4 E 8 10 12 i . l I r~XIMUM HAUL DISTANCE TO DAM AXIS ; NOTE: FOR A SKETCH OF AREA APPEARANCE., SEE 11 V!ATANA RIVER ALLUVIUM" I BORROW AREA E PLATE.ALLUVIUM BORROW AREA STARTS AT ISLAND SHOWN AND CONTINUES APPROXH1ATELY 8 t1ILES DOWNSTREArt 1l 9/16/81 ,.... ._;_~-~~~r;-"""J!jr-~~-vr~-z''''",.~~-; ~-'~~~-~v--· .... ~ ·rr -:;:~~-"~~-~<;~~-\,-~t'~~J!Y":-~, ~-•. n -~~! .. -~ ·~ ~' tva' ll1iiil1 ... ' ~ .. --n&l&l -. ····-··---81-8 -0--~ I .......,.,.. ____ L ' .J 15000 10000 S55E- 81-9 r•soo L ~~ 3000 ICE SURFACE 3500 .,... --- -----.._a--a-----------a---e---------a------------o-- 8600 1200 -7 ...G ..... -~ ~ ~-,, ·~~~ ', ~/ .......... 0-----e--... : // 14000 --............ ..,...,.,., ...__ _______ --o-,, 1300 1eooo VELOCITIES IN FEET PER SECOND~ SECTIONS LOOKING UPSTREAM TYPICAL SEISrHC LINES -Dm:NSTREAM ALLUVIUt-1 9/16/81 ..riff",•"' ·(:' ....... -, .t -,·•; _,.,. ~ ~ ,··. ~-~ lf'tllll. .• ~ ~·.....,. ,. ~ ;!Jill .,. .. •NJa ..• 'filii -- 81-7 1450 l~Q---l~ __ j_ j r 1 i' i ___ Gl_Q __ j a_ . (ll---~ . ~'"", :__......,.,.-"" -...-a-___ __. '·a ..... _ 1300 ::t plh ·. 9/16/81 ··:.- D '!ll--19000 ltiOOil 1160 Uorlronlal Scala: 1 Inch • 300 feel Vertical Scale: 1 Inch • 160 feel 1000 81-6 1500 COMPRESSIONAL WAVE VELOCiliES IN .FT/SEC 1450 . Anunnd 6000 I -1-"' / Anumed 16000 l-1400 Uorltonlal Scale: 1 Inch • 100 leet Vertical Scale: I Inch • 50 11!91 . 1350 SECTIONS LQOKING UPSTREAM TYPICAL SEISfHC LINE -DO~!NSTREAr·1 ALLUV1Uf·1 '. ,, '" i!· I( =:Y:f'rfrl ·' ";-... ,- . :; _ _J;•-" "' ,y F;·\ ~t,..f •.:.;:!. __._ '::.. -.-~ .. -- 0 !!' ;:; Cf· ..• ;;..;,---:..:..~..:..: ___ . -·-~-··--·~·--······ .. -·· w.-•·•~' '-"-;.,..j-, .. 1--,_:.~•~"'•'-< >~<"c-.--.-."0>•" ..... "-·,.-.,-.; ,, ~ ~ ~ . . .r..t.o.ilt ~ I~ .--~ If-.· ~-,\(--~-·~ .. ~-.... ~ li'illliiJ 1illil .. ~ --: ~---·~ (-·~~: . . Hrtttllltllr ·U.S. Slaftllu• Slue OpenlnQI lA Inch II U.S. Slen•ar• t•n• H~mhn :S " t I ttl 'I • !1-4 rn '{a :s 4 t I 14 " 0 0 .. 1!0 1101 roo ••o zoo no_ 100 ~ ~ I II ·I I' I I I I I I . . -- 10 " ~ ~ f ! ... ·' t'... ""~"-• .. l 1--· . ~ r'll r-.. ~ . 10 ""· .. -...: .... ~ . -. ,.[J;~ ~ k--w· .. ~: s 70 -... --l--. .. I . -~ ~ ~ li ' 00 ;~ ;,; ' ~ ~ .!' ~ i . ~ 2~ 6 ~ 10 . -II... ' ~ Pre}iminary limit of Gradation }; ......_ ~ '!'oo!J~ • -~ ;..... ~0 . ~ ........... k7'... IL .. .. N ~ . ~-- ti u 40 .. -I~ ~ ~ ~· a. ' ~~ • 30 . ' . .... ~ -f- .. ~ . -·· ·""''ii -I'( ,, ao . -. -.. ~ ~---~-~ . .II... ' ~ 1-. """' ~ 10 _.... . . '""'t-. . o,oo .. . · _so .. : 10 ·~ I ot 0.1 0.05 0.01 0.005 .. ' Groin Sin in Mllllmelon I . . ·gfi,~E!. . I ~gor~g· I -SAND ' .I lo SILT or CLAY : . CUg[u _ ~-Fin! Mg~ly!Ji I. Fino SAMPLE NO. · Ll PI W-80·256-10.9 21.7 9.2 . W-B0-257 ---.-- _17. 11 12.3 2.5 ------ -......,....._,._ -- R ¢ ~1 CONSULTANTS, INC. L < ',.~ . . '""·· .. -:·:· _,, ~·:,'"' 1\ ., __ ··--- BORROW AREA II BUMMI\J\Y OF GRAIN SIZE DISTRIBUTION r-. ~ - 0 ' 10 .. 20 30 -.c 00 i ·; ·. I ~ ItO ,.. .a .. . ., :! ~0 0 0 u c 60 • _u ... .. a. 70 eo ~ 90 -~~ 100 0.001 I DRAWN B'r' DL APPROVEDB'r' DATE DEC. 198 (!- ""·~- r;_-; ,-•; ~I I I '0 4:lo . . ' ~ .......... • .. t- . . ~. . .. ~ • ·(4. ... .. I I r ,. R 8 M Consultant Inc. ' t I~ f ' ' I ... LABORATORY COMPACTION CONTROL REPORT Job Nome and locohon Susitna , .. Slksnc l.Jam ~u-r 1 Architect or Engin-~ Acres :~erican 't.."le:. ContraCtor · ' : ·. .. • -----~_,.~,;,. __ __;_ ____ ..:......:. __ .....;__J A. Description of Soil: POOrlv Graded .. Till'~· srLTj" GRAVEL ·aw SA'NT)wtTRJ>.cr ern 1 Material Mark . C --------------~ ·GC-se . Source of Material .Borrow Area· .:e · Samole No. W-BD-256 .. Natural Water cOnte..nt 10 .• 9 · 0 /., Natural Ory:·Dens~y _ _..;_._:. __ Liquid Urnit 21.. 7 %Plastic Umit · • % Plost.icfty lndex_._:._..._'----1 a Test Procedure Used.. T-Jao Method "D" .;. M C. Tes: Results:Maximum ~Density 1.39·. 0 PCF ·optimum Water Content ~ . -~ I \ ·I I I • '"' .I Sieve Analysis I I' I \ .t I I ~ I I .. I ' ~ize \ Passinq I .. ~ I I I I i I ' I •I· I . -r • I I I I I \ I I I I I . . . ' t:: 100 95 88 84 81 78 71 64 53 140 I 1 I I I I 1 I . I I I I I \I ·I \ I \ .. I I J j ' I I j I \ I I I i l I I ! U. t , . 2" 8" 4 40 00 .02mm - 10 ~. .005 .002 l I J~ I ' 11' I a \tl :; 0 1.1.. 38.2 ~ 24.3 ~ 13.6 v !1. 6 f5 c. ui CD ...J I >-1-u; z w c >-cr. c J' "---i) ll ~ 9/16/81 '0 I I I I I I I l I I 155 I I I I I I 1../ I IT I I I 1 I I 130 : I I I I I I I I I I I I j I I 1 I I I I : T -:1 '\. -I l. 'I I IT I '\! I I I I T7 '"' ~tC~_· I T T ,-, I 1\. 'n I T v ..... I ·, A I \. ; I I 71 I '\I I I I I I I I 1\: f'S: I I I I 1\, ""' I I I I I ~ Yr; I I c: I I I QJ I I I . I I I I ~ I I I I c: \i I I I 0 I ~ I r..J 1\ I T I I I I s.. l\ I I I I QJ ' I I I ~ I I "' I I I I : I :0:: I I I I I ... l \ I I ! I I ttl I \ I -1 s.. I I I .S· : \I I I "' . I ' I I I J z 1\ I I . . \ I I ! 1 I I \ I 1 I I • I L I I I I I I I I \ I 5 10 15 WATER CONTENT ~ PERCENT OF CRY WEI\OHT ,~: !f .;:, I I I IJ, ,, ' ~. , I t !.'; ·) ,~t ..• I \ .!'.'a -l, ' ' . l , I l ., \' ~· ' ' i~ l ·,1 I 'it- ' ~,. ~ ·~ ,, .I ., ., .il V,! {1. ,, 1 . ., . . .. AREA G -ALLUVIAL FAN USBR COE ACRES QUARRY CORE MATERIAL FOR SADDLE DAM DEVIL CANYON DAMSITE BORROW AREAS EXPLORATIONS TEST PITS 13 RES AMP LED 2 TRENCHES 0 SEISMIC LINES 0 2 0 0 EXPOSED BEDROCK AUGER HOLES 0 0 4 0 ACRES 4 0 4 APPROX EST AREAS VOL 38 ACRES NOT CALC 38 6 MCY 38 TESTED * 34 ADDL INFERRZD BEING MAPPED BY GEOLOGISTS AT THIS TIME I BEING EXPLORED AT THIS TIME. * NOTE: SEE VOLUME -ELEVATION TABLE AND GRAPH FOLLOWING, ,... ,., r ,,...., ' •. ~->' ··~;: .. .) n . I < ,i', "~' . ,i' ·i . '~: '. .o I ' . t I I ' {I ' ' p I \;. ' I "" t· ~ p ' ,, "-! I • Jl ~ {' ' ' DEVIL CANYON DAM SITE CONCRETE AGGREGATE AND FILTER MATERIALS <x 106 ~1CY) DIVERSION POOL ELEV. QUANTITY S~1PLED 920 FEET 2.8 935 2.0 950 1.4 980 0.5 1000 0.0 QUANTITY INFERRED (INCLUDES SAMPLED) 5.o· 4.0 2.9 1.5 0.5 TOTAL CONCRETE AND FILTER REQUIREMENTS ESTIMATED FOR SITE: 9/16/81 CONCRETE FILTERS 1.9LJ MCY 0.08 MCY 2, 02 r1CY ,: .<;: \J ~· \. 4-... -..._, !.r- .. --~ -~ {~,i ';: . \· " r;; .;::-s -~·.,.· ,,., l0 L< 0-, •• ·c~ '· c ;' ,{\' ·~-. .., ' ., ··.- 1\: ' ' . il. ' {I ' I 1;: ·~ :t l 11 I t ·1 ~~ ~- ~ 11 ·!I {t ? ' - DEVIL CANYON -DAMSITE AGGREGATE QUANTITIES QUANTITY -ELEVATION CHART DIVERSION HEADWATER ELEVATION <FEET) NOTE: ELEVATION OF DIVERSION 100 980 9EO ooo--· -( 920 . . . POOL MAY BE SET PARTLY BY ECONOMICS OF BORROW EXPLOITATION COSTS, <EXISTING) 1 2 3 4 5 6 RESERVES -MCY OF CONCRETE AGGREGATE AND EARTH DAr1 FILTER ~1ATERIAL TOTAL REQUIR81ENTS -ESTIMATED CONCRETE 1.94 MCY FILTERS 0.08 MCY 2.02 MCY SOURCES: SAMPLED RESERVES ARE IN CHEECHAKO CREEK ALLUVIAL FAN INFERRED RESERVES ARE IN ADJACENT TERRACES) FAN DEPOSITS. 9/16/81 ·''• ··· ... , ,,; ,.,-~ • ,I,. ., i I I m o:f l • '~ il . ···l :·~~~ il i: ;:~t c'l· ' ' ~ ' j ftl ~~ '{ ~11 ( ;B i l· ·~~ ' ~.D :J 'i l! •n ill jt i , I l ; i ! l J t l i . l ~- .. ~~ ·-~ ------" " . I} / -~ .,. ...... ~,-__ ..p._,_- , _____ --_...._.--I'· ~ ·-' ' -11. ~ ' §"' ·-·- ARGI · 1:. - A ® ~IORITE __.--· -------_,.--~ ~ . , -·--. .-':""_ ... , ;t• i ~ ~ .; - .f 1 ·~ ......... -----·"' ··--· --~ ,- ~ -· ~f ·""· L*T£ QUARRY SITE '}.~~-\~\)c.; ·• T\.'V.l~~\)\J\"-.. /.1. ./.), A. -------r ,.. __, ~1-:--:o~\t\Lfc~I ~-_-. --. -;. " ... ---. q ~ .....__r {; ____ ... -~· ~~ ' ' .. ..-.--....... _ - a~ '~I·' -"" .'" _,.,.· ..... ~ .~( " .. --... ··--- •/ *. -- Ct·i.-/f\ rJ, ""'---~ .. r \ l . ~ ~ ·~ . ~~ ~ \' \ l '.. ~,-if :-:: .. ~ '\.,. \ \ \, tr\A~N\D~M "'lfi t/11 .· : \: \ . ~ _,.,.--; .' ;· . l '\. _,.,.---~ / 7 / ' ! \ / /-/ /!;): :I ~ ,\\ \\ . I )L-~~~ .: \ -/ . ' . -~-' / ..__. .. I Jl/,.• '··'--' , ., ll, TERRACE • , J(' . . ~ ' • A.---.___ ~~--. · 1\ · "=:----_ • ·, ________ Jic'r· 1~~~~ ~-------.., ____ 1---·· ---' ~~·--... ~ 'I . . -~ ~-. --. ..._____ IJ:.• ' • ' __. ~ ~ ' 1' --··.. .. ~ '-...._ ''-...__ '-.. __ __...~ . J1 · . '\ \ // _/__...~LLUVIAL FAN . -..._ -~~· Ji\. . - ·. ---A ...-c--'~~ '· / • ' 4 '---'-.... -~~~~. ~ 'b-:---. "11.--......,._----~-.. "'--/ . / 1/f ~ ~. (! ·: . 1 _. 11\ A 'r-... .. 1ft \1,l-A A ./· ARE 1 A G • _ 11;, '11 ~r rw , ·" A \ '<' :--.. .,f' 'If" ~ -lij ---,J{ 1• ALLUVIAL FAN FH, '\'1 '!-------~ : ~ ~· \,~ /A ~ It y-~ . . , :~-~ . . ' 11, ' i J, l IN ' ' :. 2., .-I _#_..-----"t\"' . ' . -~ > \.;...----. i.. . ~---------------pr~-. \ '-.. , · ' AREAS J. · " CA"YO'i BhRO' t(\ . ,....--->-FLOW ------------· DEVIL ·' ' TERRACE J l I I I ll I I g· m ft ft 0 ~ D II I I I ~j L' I WATANA DAMSITE RELICT CHANNEL CUTOFF SCHEME DETAILS OF GENERAL SLURRY v!ALL & GROUT CURTAIN CUTOFF PROPOSED IF FURTHER INVESTIGATIONS C IN DESIGN STAGE) SHml THE NEED. TOTAL LENGTH OF CUTOFF 14275 lF ALL NUMBERS SUBJECT TO SLURRY TRENCH LENGTH 14275 LF REFINEMENT PENDING FINAL GROUT CURTAIN LENGTH EOOO LF INTERPRETATION OF MAPPING IN SADDLE DAM LENGTH 2300 LF PROGRESS) AND . . . (MAX 23'J AVERAGE 20' HIGH) RECEIPT OF 1981 SEISMIC LINE SHORE RIPRAP PROTECTION 2800 LF REPORT. RELICT CHANNEL SPECIFICS <ASSU~~NG 2215 NORr·'IAL OPERATING POOL 2235' r~:.'\}\ suRCHARGE ELEVATION.) q11 li/Rl MAXI~UM OBSERVED DEF1n 454 FEET FROM SURFACE 450 FEET FROM POOL ELEV. DEPTH UNDER SADDLE DAr1 SHORTEST PATH FROH POOL TO OUTLET <TSUSENA CREEK) ESTIMATED FLO\~ DISTANCE ESTIMATED ~!IDTH <POOL ELEV) HEAD LOSS -MAX OPER POOL -MAX FLOOD POOL 0-245' POSSIBLE 145 AVERAGE BASED ON INTERPOLATION. 6200 LF 7700 LF AT DEEPEST POINT 14275 LF 590 FEET 610 FEET 0)' ,,. f\ t~ . ·~ ,---r,-1, .··,-;>" l• ,,. I I I I I ;::;; I I I I ~ DATA POINTS • DRIU. HOLE 6 SEISMIC UNE STATION -DEPTH TO BEDROCK CONTOUR APPROXIMta'E -BURIED CHANNEL THALWEG e@ MAJOR BEDROCK OUTCROPS ~" INFERRED LOCATION OF '~··· SHEAR ZONE Cl5Z::l:? l' ·-KNOWN LOCATION OF SHEAR ZONE -.PROBABLE ._ RELICT CHANNEL ENTRANCES WATANA ---SPECIAL FEATURES ..... ..-·-- @ tJ ••••;;MM!a;az. ::a . ; ; !fiPN&ttt JJJ¥, :CIUli dB L JWI$ •• • ,, •iliii'W '""l'T!i'< . -' '' .? IJIIPI'4'"""~ . ~L~·· t-"$!=. ' -,, .. •: '\! I 'I 'Jt~ ··,'· .. .. i:l-· ,, (iiJ fj . ~ < < ~ < II I I I I ·I I ~ ~ II n tl il II ll II II II r-N69°W tl81-t 2000 2215 -__ '\7.1::.--__ _ MAX OPER PDCL 2215 FT WATANA -RELICT CHANNEL PROFILE SADDLE DAM ~ \ ~< ! DR~l9 I SW.:.3 D~l-A I SL 0-2 ~-- S69°E ~ N45°W Sli-1 1625' 1470:: DR-18 --- 1500 BEDROCK DR-20 SUSITNA RIVER 1000 SECTION A - A "THE FINS" to TSUSENA CREEK EXISTING EDGE OF RIVER TO TSUSENA CREEK= 9300' OPERATING POOL = 6200' DIRECT LINE, SHO~iEST DISTANCE ON UPSTREAM FLANK OF DAtJ, SITE PLUTON !--+ N32°W S32°E <I>'" f SL 8·1-3 t 2215- 2000 1500 1000~- MAX OPER POOL 2215 FT -~ 1\~..0± / - - : SUSITNA RIVER EXISTING EDGE OF RIVER TO TSUSENA CREEK = 12,000' OPERATING POOL TO TSUSENA CREEK = 7, 700' N75°W f I I SL81-16 SW-3 DM-A ---('450;' I ---- -v t CUTOFF LOCAT~ . DR-22 SECTION B - B SECTl ON ON APPROXlf1ATE THALWEG, LOCATION ABOUT 4000' UPSTREAt~ OF UPSTREAt•l COFFERDA!•l 1"=1 000' LOOKING DOV:NSTREA!~ . RELICT CHA~NEL PROFILES TSUSENA CREEK S75°E + I ~ I SL80-2 SL80-l ----- BEDROCK N45°W ------- TSUSENA CRE:EK <c" n if u- (.- l; i tn ln II) .,.1 r. I 1:1 n a l;l n ! ~1 ~ ! ll j -1 I l ~ I 1 •· ' . i f i . - RESERVOIR _,_"-- WATER ----------·------------ SOUTH / ..-~DAM SITE HANNEL ---· _LOOKING ,--c---=:::: _ =-~ / WATANA RELICT C ~--. .....--~ .. / __.-L-----~ ~ .... , ~f;;eoRciK ~TODAY .-· 1 /HA RESERVOIR _ SADDLE DAM ==------1 -... rr-;· ; ~.· ~ --~ 4'~ 'ff.~/ -4;( f.~ -----1i ,.1 '· / '--.........~'I' l '/ ,·- ~ •I .' r \ -"· .. ,, "-;'' . ,. '~·· / - -·-~ .. ~ ..... -----~--------- ~ ~~- -1 ,. . J .•.•.. ..,. j·. [ l,// ~ ~ I .; I r .... , .... ~ --" " -,~ ',' j '.~ I· I· I· I I I· l I !I I }J I \I I I tl I I I - 8) WATA~~ DAMSITE FOUNDATIONS, EXCAVATION & ROCK MECHANCIS GENERAL FEASIBILITY LEVEL DESIGN CRITERIA . ~--:r 1,; <.~· () ~~ \) I I·_ I· J I I I I I 1J I I ' J ·I I I D. EXCAVATION SUSITNA HYDROELECTRIC PROJECT WATANA DAM MAIN DAM OVERBURDEN -AVERAGE 20 FEET DEPTH OVER ALL FOUNDATION AREA. \~EATHERED ROCK UNDER CORE AND FILTERS -40' DEPTH. WEATHERED ROCK UNDER SHELLS -10' DEPTH. MAXIMUM SLOPES -1H:2V BELOW 1800' ELEVATION 1H:1V ABOVE 1800' ELEVATION CONSOLIDATION GROUTING 10' X 10' GRID OF HOLES 30' DEEP OVER AREA OF CORE AND FILTERS. I 9/16/81 ·.• •:_, l .. c· 1 f·· 1·. ·~ I · (~) 1.·.· ·(; I ~--- 1· I· I I ' ' I· I ' SUSITNA HYDROELECTRIC PROJECT WATANA DAr·1 CURTAIN. GROUTING DOUBLE ROW CURTAIN-VERTICAL •. 350' MAXIMUM DEPTH <AT MAXIMUM HEAD). 50' MINIMUM DEPTH IN ABUTMENTS. HOLE SPACING PRIMARY 40' I SECONDARY TERTIARY QUATERNARY SPLIT SPACING TO GIVE FINAL SPACING 5', GALLERIES FULL LENGTH OF DAMJ APPRCXIMATE SIZE 10' X 10'. DRAINAGE 50' DEEPER THAN GROUT CURTAIN. HOLE SPACING 10' I DRILLED FROM GROUT GALLERIES. ' FULL LENGTH OF DArt EXTENDING 600' INTO LEFT ABUTr·1ENT, a l I I 1l lf ' ~ CONNECTING TO INTAKE AND SPILLWAY STRUCTURES RIGHT ABUTMENT. HOLES INCLINED DOHNSTREM1 15° FRm1 VERTICAL 9/1E/81 ... ~, ~·· ,.jt 'Z ,, "' ,-,. ~\· f,l ' ./ <j- "';" . ~ •' f.l i ( W ti.3J..!.~ NMOC( AJNI)I001) • " 'tl311iJ :J 3"!1Cor111V~Q. qNit 91f/.ll!o}li) ...... -· ·- /' rl v !.Jl31.J 3 ~HI tJ 1Hrt:l 11\1l.JJ10 ~ D W~Q (INbJ-L~M f:JN.!UOS' ~ \ I vtv o"& \ ' l.Y91i.,. \ ; 70.£-tiW~ .... ... ..._ I I I I I WATANA ROD SU 1 1~1.;P., I I Borehole OH-1 OH-t. OH-5 DH-6 OH-7 DH-8 DH-9 OH-10 OH-11 OH-12 OH-21 DH-23 DH-24 OH-28 BH-2 BH-6 BK-8 IJepth Ground Surface El. 14!19 1462 1462 1716 1716 1910 1913 2033 2034 1951 1480 1952 2061 1971 1835 1605 1976 Average Top Of Rock El. 1415 1384 1402 1713 1708 1894 1909 2020 2018 1942 1407 1947 2054 1958 1826 1598 1964 Borehole Dip 59% 45% 45% 60% 45% \ertical I II ·i I l ,I Deoth ROD 0'-50' Drilled (ft) 51.4 45.2 47.9 48.9 49.1 54.5 67.0 48.6 70.3 51.6 59.7 70.5 50.9 29.5 61.2 58.5 59.2 924.0 ROD length ( ft) 14.25 29.9 22.1 24.3' 23.6 32.3 39.6 10.2 49.6 30.8 50. 9' 31. B 35.5 10.6 33.!1' 29.3' 25.7 494.3 ROD% 28% 66% 46% 50% t18% 59% 59% 21% 71% 60% 85% 45% 70% 36% 55% 50~ 43% 52% 50'-150' II 27.6 69.2 97.2 64.6 79.3 139.5 100.5 144.1 99.9 110.0 41.7 82.1 62.4 119.8 118.4 116.2 1472.5 12.55 57.3 49.2 38.9 52.8 86.4 68.5 111.6 53.3 93.5 20.5 57.4 6.3 28.1 75.5 86.8 898.95 45% 83% 51% 60% 67% 62% 68% 77% 53% 85% 49% 70% 10% 2't"' 64% 7!1% 61% .... 150'-2!>0' II 72.1 3i1.8 65.0 105.1 121.7 124.t. 115.8 114.5 753.il 31.8 31.1 55.3 80.5 101.4 67.2 99.1' 94.4' 560.9 44~· 89% 85% 77% 83% 54% 86% 82% 7il% I 250'-350' II 33.9 118.3 85.6 115.3 114.6 i167.7 28.8 96.8 64.5' 93.6' 91.1 374.9 85% 82% 75% 81% 79% 80% I 350'-450' II 109.5 114.4 11i1.3 338.2 91.0 93.6 95.8 280.5 83% 82% 84% 83% 115.2 117. B z:n.o -450'-550' II 81.3' 95.3 176.65 ~1"' 1M~o 1~g~8 550'-650' II 4~8 74.7 89.3 164.0 79% 88% 83% I I Hole II 79.0 45.2 117.1 146.1 113.7 133.8 278.6 183.9 279,4 290.5 519.2 112.2 133.0 91.9 391.0 732.4 738.6 4485.6 Average 26.8 29.9 79.4 73.6 62.5 85.1 157.8 109.8 216. 5' 193.4 433.7 52.3 92.9 '16,9 193.4 547. 3' 578.6 2950.2 34% 66% 68% SO% 55% 64% 57% 60% 78% 67% 84% 47% 70~ 18% 49% 75% 78% 67% I . I I ~ I "*..,._..~,_ ~ ''· ~~;lllllf)e.~ .~ . ~,4. ~- 9} DEVIL CANYON DAMSITE FOUNDATIONS, EXCAVATION & ROCK MECHANICS GENERAL FEASIBILITY LEVEL DESIGN CRITERIA ' ~ '! .;·: .• ··"' '- ,, ':' ~~: •"!: ,, .. EXCAVATION SUS.ITNA HYDROELECTRIC PROJECT DEVIL CANYON DAM MAIN DAM OVERBURDEN -RIVER BED 80' MA>C 20' MIN. -CANYON WALLS 15-20' MAX., 1-2' MIN. -ABOVE EL 1300' 5'-35' AVERAGE 20' WEATHERED ROCK -VARIES FROM 10' DEPTH TO 80' OR MORE ~iHERE JOINTING IS OPEN ADDITIONAL EXCAVATION HILL BE .REQUIRED TO SHAPE CANYON WALLS CONSOLIDATION GROUTING 10' X 10' GRID OF HOLES 30' TO 70' DEEP OVER FOUNDATION AREA ClOC' UPSTREM1 AND DOWNSTREAM) AND UNDER THRUST BLOCKS. 9/16/81 !I+.¥;; -r'"'*l _..'l""", l¢l,F ,. .. """'"'".!I I¥ .C I 4 441 i1 •Nt!Q Q 4W, ~P4,<W. A4 0 '. §I # ;....- ,, li ·;- <:;f''~ o· \,J. ,, ~·I'_' . ·~f ·/ j I I I I I I I I -,I I I I I l -~-- 1 I I 11 'J "' I~ I SUSITNA HYDROELECTRIC PROJECT DEVIL CANYON DAM CURTAIN GROUTING MAIN DAM <CONT'D) DOUBLE ROW CURTAIN VERTICAL 300' MAXIMUM DEPTH <AT MAXIMUM HEAD) 50' MINIMUM DEPTH IN ABUTMENTS HOLE SPACING PRIMARY 40' SECONDARY "TERTIARY · QUATERNARY SPLIT SPACING TO GIVE FINAL SPACING 5' GALLERIES FULL LENGTH OF DN~J APPROXI~~TE SIZE 10' x 10' EXTENDING UNDER THRUST BLOCKS. DRAINAGE 50' DEEPER THAN GROUT CURTAIN HOLE SPACING 10' DRILLED FROM GROUT GALLERIES HOLES INCLINED DOWNSTREAM 15° ADDITIONAL DRAINAGE HOLES DRILLED FROM SURFACE MAY BE REQUIRED FOR SLOPE STABILITY OF CANYON WALLS BOTH UPSTREAr~ AND Dm~INSTREAr1 OF DAM L~ I 9/16/81 ""'', . , ,c it 14 ¥ -g f " PU I r 1@1( q • )1111 j f ,,: ;p ; 4f"W ::t,. '!;#¥ 4¥ 44 J4 + ; """" ¥ \1' <, '· (· 0' I, II <- ,' I I SUSITNA HYDROELECTRIC PROJECT . "'· DEVIL CANYON DA~ I -/ll'll> >r, I SURFACE STRUCTURES Iff I lliTAKE _Arm_ SPILLWAY EXCAVATION -OVERBURDEN ~. lf.' ' 'i' -20 1 APPROXIMATELY I -WEATHERED ROCK -20 1 APPROXIMATELY I CONSOLIDATED GROUTING -10 1 x 10 1 GRID OF HOLES 30 1 DEEP t,, it..-, . l I CURTAIN GROUTING -CONTINUATION OF DAM CURTAIN FROM GALLERY <SPILLWAY ONLY) UNDER STRUCTURE -so I ~1IH Ir1UM DEPTH I -SPLIT SPACING AS MAIN DAM I ' ..... 1 ·; ~c I DRAINAGE -FROM GALLERIES IN BASE OF SPILLWAY <SPILLWAY ONLY) STRUCTURE I I TUNNEL PORTALS <TUNNEL SPAN = D) r COVER TO TOP SOUND ROCK 1.5D t ~ I SPACING CENTER TO CENTER 2 I 5 D I ~I HERE TUNNEL Is STRUCTURALLy ; REINFORCED SPACING MAY BE REDUCED TO 2~0 D I ALL TUNNEL LININGS CONTACT GROUTED I DRAINAGE PROVIDED IN LININGS OF DIVERSION TUNNELS L I I L . ~ -t' (\ ./ .: fl It .. 0 ·, ~ .. ' ,. '. D I ·~ I 9/16/81 • ":·.·~~i:.· ~. ·. .. •.... ~ L_ .. I I ; ...... I I: I I I I I I .. I I I I I I i .- [1 I SUSITNA HYDROELECTRIC PROJECT DEVIL CANYON DAM UNDERGROUND STRUCTURES -GROUTING PENSTOCKS -RADIAL CURTAIN GROUTING MAY BE REQUIRED IN PLANE OF DAM GROUT CURTAIN DRAINAGE -GALLERY IN AREA BETHEEf~ TRANSFOR~1ER GALLERY J PENSTOCKS AND POWERHOUSE 9/16/81 'b ... ;,'.1 'i .. ·;._ ,.~, r "" ·". ".": (1. r~.: . ,, . " \ · .. · :: 'l' '' ' '"'·t . ':~ ,' ·r <· 0 r :~ ... -.~-' ...-~-~--,"" -"'~-~, ...... ~----...~~..,.,......._ ___ :,.....:.. ____ . ---·-· . iili' ------l.. ·--.. -... --· .... --~--·-- _, I I t5oo I /lfoo \ I 13oo 12.oo' /IJ>O ' /DOD I CJoo' Br»' 7oo1 LIM liE«. SPILLWfl'"/ \ \. \ GROliTIP.I~ ~Alb biZAtA.IA~E 0.4LLI&4Y Access ' ' ..... ..... ('-OOKJA.'C ..... ' Sus 1TN A HY b~D Eu:c.l/l.tc:. Plo:rt:c.T DEVIL CA-W YDIJ bAM {;.£ouTIIIJ C 1Tit R..fw' E.hEu"i' ..... ..... ~ ORJC-1~AL G~OLIAJb .JUlFtttE ' ..... ' '4 \ r ' ll-.S~une.b EJ!.. C4¥ A-TIOA.J LOJc, I , \ ' .. " \ \ V t ST;(E:A-f'-1 ) \. \. \ '\ \ \. GA-LLEI\ 'I I ft) b ~~ I I ' "' I I I I I TO &IJU.iUY IIJ 1 ....... b~""t / ' ' ..... _ - ------.· / , 3oo' / I ,.- / / "' _, I / I I J I I I I El I It.'S ,_I ..,.,.,~UJT ~ I I "' ... ... " ~ I I I I I I I I I I I I I I I I I I I ; I I ~ /EY-TetJT Of! I GtlouT C.ulll11tJ I I I S 1!1'7 14 I <J 9 I ·.r.;>... (~ t_~ : I I \,;" DEVIL CANYON RQD SUMMARY I tiOrehoJ.e BH-1 ~~~ 6.~~4 BH-:,a ~~>b ~"~ ~ro~ Ground Surface El. 1415 1)53 980 I Top of Rock El. 1404 1212 1346 ----Depth Borhole Dio 67° 60° 60" 45° 45° so• 320 Averaoe Vertical --~ :?---;-· '~~ Depth RQD I 0'-50' Drilled (ft S2.7 60.2 58.2 72.5 71.8 (i7 .9 94.3 477.6 RQD Length-34.7 47.6 50.6 46.35 45.55 39.6 77.2 341.6 RQ~ (ft 66~ 79:"; 8711; 64~ 63:'; sa:; 8z:; 72l; '· I 50'-150' " 107 .o 113.4 113.8 138.7 128.5 134.8 188.70 924.9 69.8 82.15 111.0 110.2 105.5 85.25 139.0 702.9 65:"; 72l; 98:00 79:'0 8z:; 63:; 74:'; 76':. ~.- I 150'-250' n 108.8 116.4 117.9 143.2 141.2 100.2 727.7 94.2 104.4 105.4 117.9 121.9 45.4 589.2 87~ 90:; 89:; 8zr:. 86':. 45% 81% I I I ,I ! 250'-350 1 n 111.1 115.1 114.3 142.2 143.4 626.1 95.6 100.4 103.2 125.55 117.95 542.7 86~ 87':. 90:; as:; 8z:; 87% 350'-450' n 109.8 117.2 84.5 101.3 412.8 98.7 109.6 80.65 84.8 373.75 90:; 94% 95~ 84~· 91% 450' -550' " 107.7 116.2 223.9 103.1 98.25 201.35 96':. 85':. 90% 550'-650' " 113.8 15.0 128.8 95.1 14.0 109.5 84% 96% 85~ 650'-750' " 34.5 34.5 29.3 29.3 85% 85~ I . I I l t I ' I Jq I Hole n 745.4 653.5 488.7 597.9 200.3 487.3 383.2 3556.3 Average 620.5 556.8 450.85 484.8 151.05 364.7 261.6 2890.3 83':. 85~ 92lll 81l\l 75lll 75lll 68% 81% ---. I j .! I \.1. 0 -:r . I J .j I -~'-: I (J I Lle " +t i ;w *'" •+P'W4P?f0 #¢ Q$ .i!( . J2 WJ _i •. I ' . . . . i~, • 1" " ; -. . . . I l~~~~~-· . ......:~.-:..:.~-"-"~1-'" · --· .. ~~ec·;,,L~~ ~.. ' • !t .· .. ·;' ;· .·· .. ··.·C;,J:>r: ;t: ;'(:·::'~1\! ' n r·· I" r { ' 1 i .• SUPPORT MATERIAL TO TASK 6 DESIGN DEVELOPMENT \ li 'i: • . .. ! ·J l .. .. .j " i WATANA LAYOUT STUDIES t' i i· . I l I ! ' 1 1 ! . I ,;. ., lt'";r- ft r:· I (1 ; I l '. . ! t ::1 I ~ ' . .- ::J ·~· ~ " .. l] ··- '·t·· . . . ~·~ . rl . u __ . Ll··· L--- •• ; l L·~· .. 1 !I '-- •••• ····~' I r· ~l \ I u \J ~ l \\. v I t 1 -INTRODUCTION As discussed in the DSR. the recommended Watana deve1opment {P1ates 12 and 13) consisted of the following: -Dam: • Crest: • Height: • Volume: • Slopes: • Cofferdams: -Spi 11way: • Capacity: • Type: • Location: Earth and roc;k fi 11 2,225 feet 880 feet 63 million cu. yds. 2.75:1V upstream 2H:1V downstream Integral Three-gated agee section 235,000 cfs (PMF) Chute and flip bucket Right bank ~ Power P 1 ant: Studies have continued to deve1op an optimized genera1 arrangement for the Watana site. 800 MW (ultimate), left bank _" ___ ... I ' t l e a ... ~ I I r~ I I I w~ t-"" I :::>l! 0 9 ~I (.) Z< o- \ §i w (f) I \ ' I ;· 8 si 2 0 .. 0 .. .. .. ~ I ' ~ ~ ~ i I \ \ 0 I (.) . I ' 0 t. 0 ' ~. ~ fS~ 0~ ~\ i=3 ~' O"' 5~ " \ w• 9~ (f) ' ~ i \ ~ s uar ... ~ s ~~ .. .. .. .. .. -· g ., ... i~ a. < ~ ~ ~ ' ~· ~ ~ \ ' ' I \ l I ;i I ' l C' I I N ! i\ I ~ I 0'1 I i I <( \ I I ~ . I <( t\ i ~ <c z< ~ .. Q- i \ .... ~ ~~ ~~ \ ... i I .J; ... ... ~ ~. ~ ~ 8 ~ R • Sl s ~ .. g H .. .. .. 0 ~ ~ .. !! ~ ~ !:. ~ ~ 8 0 ~ 0 lit l! ~ .. g ~ '! ~ B .. .. - -r--[--rau t·i .. aiJ I ·-. . rail - .. • . 1 u/a 2.5a1 a-l!lat aide curved d/a 2~1 upettoa u/s 2.25a1 dQht and left aldea d/a 2a1 curved upehe811 . 2 u/a 2.25a1 r l~t and left sldeq d/s 2a1 curved upab:e011 2A u/a 2.25&1 d!#tt an.t left aldoa d/a 2a1 28 u/a 2.2Sa1 a-1ght and loft aldaa d/s 2a1 CUi"Vod upatro011 2C u/a 2.25&1 a-ldlt and loft eldea d/o 2a1 oorved upatro8111 3) u/a 2.5a1 r Jf#lt and loft atdaa d/o 2a1 curved upatre~~~a ' 4 u/a 2.5a1 left bank skewed d/s 2a1 upatro&ll r-;-:-·""'"1 ;, .. .. -.. -.... ~ ! .. f-- r' . flip bucket rl~t bank csocado, ulnglo left bank coolrol structure c&flcado, dusi loft bank control structures dotillo etlU1ng loft bank baa in double atll ling baaln · fUp bucket cascade fUp bucket left bank loft banfc lef~ bank lof~ b~ ... ..,--1 .. inclined ..-unod chamel 4<~,~-J E!lf flip bucket ---., 1!11' left bank Jlght bank .. L __ .____ ____ --------------- ei1 "'-~-. .,. -< •• ··-·-l -I f!lll " ... ~ 1 . . ' j I!W· =-· 88 tocat!f!! I ' 1 mdorground loft be1'* st~rface right bBfltc surface right b&flk aurfateQ right b&nk aurfece rlght bank mwrground l'ldl~ bank undergrotMld loft bank &Jlde l'QfDII.Ind laft bank lfl l ! ~- 1 I I] , I \ ' ~ l r1 ; I . ' ~ ' : l. ; , 'I 1 r ~ { ~ . ;-.... : rl· J·. L rl !._ fl {.._ ..... I . J ,. ~_:,;. rl I . \...... ~·· . r ~ ..... _ ~ ! 2 .. .. ( • i l ;··· tUJ . ·L.. ... ... . ' l i_;,.,;. r·l t ........ il ' ' ......... ... \ ~ ... g ! 0 ( \ l 0 2 .. ... ~-· ""--;~_· ·U ...... ' ~. ' i ~ ' ~ ~·' . I f .r_. r·~-, I ~ : : j ' . l ' fl .,, ,.,.1 I • I . ; ' . ' ·-~1! ' !· , . . . - f"l !' .. ' . r __ ~ •. ' : . . .... rt . J ·~ I f1 t, •• f·l l - 1 •••• i ' ·I· . ' ; 't 8 ! ( ... ~ ; rm· ·. ·. ! j . . . .. . fl • > , rl ~ : . ' I . : t r_.~. i ' ' · .. ' . , ·~I ' ' .~ L . r .. ',fl. ,., ! . ' ' ·-.. rl ;~·-· .... ' ..•. ' ' l· ·. rl I .. .__ . rJ ' l ' i' \.- ' . r:l·· ' } , . ,_ · rl ~ .. . ·· rl .. • L. rl" • t ~-. \..._ . i I . -~·-. . . ' .·; : .. . ' . ~. ' l i ' ' :.:. ·~I ' ' ' . ' '; 'i. ' . . ·, l!.' ·. ' ' ' C •.. ' l' ~ "·. ' :1 t~- ' rJ·. ' ' [_I : ~··' ; ' c . rl I ' ~~ ,' "*:.. Fl ~~ :. '1.·· ', ' : i . 5 .;..,_,;,.,! ' '1: \ ~ ' ,, ' . ~ 1 ® I ( . ·-- :""• .. !ti fl iE ; •.. ' . : ~ !I rl '·· t . ' :~ ~-···· : ' ,.i i:l L. r-1 . . ' Lo...:. r.l' ; •··· ~• ~-. i r, ~ ... ;, ~; _,. l ' .. ,-, ~ • ! . 1 .•. . ' i ,;_ ~1 1:. --· . . . ~'-1 . f"l ... , .. rl·· t ., 1-' '~~ - :I ·-- !·1 . ! ··-·! '~ . '''j :I ·~ -I! '· , ' : -~. [I '·~ -~ '~ :. ''1 t l ,.I ! . ~ ", I ; . ~~t • 'I . •· 'll : r 1. '·" I .. ~ .: .. ;a ~~ ~a l· ~· '. tl l..-... il ··IJ : ,' :I ., ~c<.O ;I i ~~ I ;I 8 ; c I ( 1 I t ·. \ \ ; ; ~ ! \ 0 ~ .. ... .. ~ ;~ § : ;;; 2 ui 1&1 !« w ~ 2 Q. Je~ z~ 1:1~-~~ "<i. a: <tw ~l!t:l i<C< ) ···m i :J : . ~ ; 1 . 1 i. ! . . . ;, rfJ I . ·L-_ .. ~-~.:J t~ L" , .. , I·-'1 t l .. " L: 3 -COMPARISONS OF FOUR PREFERRED LAYOUTS The four layouts described in Section 2 were developed in greater detail {see Plates 7.1 and 7. 3 to 7. 7), taking into account any new data that had become available and based on expanded and updated design criteria. Capital cost estimates of the layouts were prepared and the schemes were evaluated to determine the two arrangements that were the most favorable., -Design Criteria The principal project parameters and design criteria on which the layouts were based are shown in Table 3.1. Parts of this criteria wilil be superseded as more information becomes available. Where assumptions Wf~re made, they were based on the best information available at that time. -Evaluation Criteria The review of layouts was carried out and assessments of the different schemes made on the basis of the following evaluation criteria: {a) (b) (c) (d) (e) (f) Technical feasibility of the scheme; Overall cost of the scheme; Ease of construction of the project. This will pa.rtly the cost of the scheme and be eva 1 uated under (b);, Impact on construction schedule; Environmental considerations; and Operating characteristics. -Selected Schemes The selected schemes for further development are: be reflected in (a) Right bank diversion, mid-level release acting a!S a first-stage service spillway, right bank chute and flip b~cket as a backup spillway, rock channel.as an emergency spillway, and a right bank underground powerhouse; {b) Right bank diversion, left bank rock cascade ser·vice spillway, right bank rock channel emergency spillway, and a right bank underground powerhouse. These schemes are shown on Plates 8.1 through 8.4. -Cost Comparisons Table 1 summarizes cost comparisons for the four se'lected developments. TABLE ~.1 DESIGN CRITERIA River Flows Average flow (over 30 years of record): Probable maximum flood (routed): Maximum inflow with return period of 1:10,000 years: Maximum flood with return period of 1:500 years: Maximum flood with return period of 1:50 years: Reservoir normal maximum operating level: Reservoir minimum operating level: Area of reservoir at maximum operating level: Reservoir .live storage: Reservoir full storage: Dam Type: Crest elevation at center: Height: Cutoff and foundation t~eatment: Upstream slope: Downstream slope: Crest width: flm Diversion f"•lf! ~~t ..... Lll ["~ L~ I r J i l I . .... I . . . 1. ' ' r . ~--~ . r.··'~i~ ! 'f ! I i ' ' ' > Cofferdam types: Discharge capacity: Cutoff and foundation: Upstream cofferdam crest elevation: Downstream cofferdam crest elevation: Maximum ·pool level during construction: Water passages Outlet structures: Final closure of diversion tunnels: Releases during impounding: Spillway Des i gn. fl oods : 7,860 cfs 235,000 cfs 155,000 cfs 116,000 cfs 87,000 cfs 2,200 ft MSL 2,050 ft MSL 40,000 a~res 4.6 x 10 acre ft 10.0 x 106 acre ft Rockfi 11 2,225 ft MSL 890 ft above foundation Core founded on rock grout curtain and down- stream drains 1V:2.75H 1V:2.0H 80 ft Rockfi 11 1:50 yrs. routed flow Slurry trench to bedrock 1,560 ft MSL 1,500 ft MSL 1,555 ft MSL Concrete lined Low level structure with high head slide gates to operate under low heads Mass concrete plugs in line with dam grout curtain 2,000 cfs min. via bypass to outlet structure Passes pmf, preserving integrity of dam Passes routed 1:10,000-· year flood with no · damage to structures ~· ' • .. . ' . TABLE 3.1 (Continued) Spillway (continued) Main spillway -Capacity: -Control structure: Emergency spillway -Capacity: -Type: Power Intake Type: Number of intakes: Draw-off requirements: Drawdown: Penstocks Type: Number of penstocks: f -~ Powerhouse L . r·m·!o'.' l ; ' '· L I r ; : j, L .. (•!) " l ' ') \..;... ~-~ 'I' ' :•,• . ' t ,! I , I " r . ..... I t ( ;_ Type: Transformer area: Control room and administration: Access -Vehicle: -Personnel: Power Plant Type of turbines: Number and rating: Rated net head: Design flow: Normal maximum gross head: Type of generator: Rated output: Power factor: Frequency: Transformers: Routed 1:10,000-year flood with 5 ft surcharge Gated agee crests Pmf minus 1:10,000-yr flood Fuse plug Massive concrete structure embedded in rock 4 Multi-level corresponding to temperature strata 150 feet Concrete-lined tunnels with downstream steel 1 i ners 4 Underground Separate gallery Surface Rock tunnel Elevator from surface Francis 4 x 200 MW 690ft 5,300 cfs per unit 745 ft Vertical synchronous 222 MVA 0.9 60 HZ 222 MVA-13.8-345 kV, 3-phase ~· . ' . r, f· 1. -!! ' ... ''"it···· . ~' :::.. ~ -~ {. J . I L. .. rt 1..-- -~m \ r ; , r •. L.; r£ L-'· ~ Pf:· C' rz· 1 ~A I ,. j L, t· --j . I • I '-- I' \ l! I '-- • •••• TABLE 3.1 (Continued) Tailrace Water passages: Elevation of water passages: ·Surge: Average tailwater elevation: Main Access: Transmission: 2 concrete-lined tunnels Below minimum tailwater Separate surge chambers 1,475 ft MSL Assumed from the north side Assumed from the north side. .. r·-··--· r-·--, ~~ ···----~~-r:-.'<> r-·--1 '-:.::.:1..... •·· ..-...., ~! ~~·-~~ r ....... L!~ ~~ r·· ....,_ 1 ~t·· ·•. ~-.. -, .----·· ~ ·; IL!I C.!!!i . ~ I ~ ... •-.-.1 "{t:-, r.~ .. ~-~ .._ -~~. "~ ~ \~ ~ 'w--·~~~ ~ • . . • ' '~/" . "Jl Unit Description Unit Price --·-. - Diversion/Cofferdams [~cavate Rock Portal cy 15 [>:.cavate Tunnels cy 55 Concrete liner at Portals cy 260 Concrete liner Tunnel cy 250 Concrete Inlet Porta 1 Hcadwa ll cy 260 Concrete Inlet Portal Pier CJ( 295 Concrete Outlet Headwall Clf 260 . Concrete Plugs C)l 500 Upstream Cofferdam C)' 4.20 Downstream Cofferd~n C)' 7.35 Dewatering LS J,675,000 Cutoff LS 6,825,000 Reinforcing Steel Ton 2,100 Rockbo Its T unne 1 s Ton 3,500 Rockbolts Portals Ton 3,500 Rock Surface Treatment sy 15.80 Support Steel Ton 3,675 Gates, Etc. LS 4,600,000 SU8101Al OIV[flSION/ COff[ROAMS TABl£ 1 -WATANA COMPARATIVE COST ESTIMATE -NON-COMMON ITEMS JUI.Y 1981 (JANUARY 1982 OOlU\RS) Scheme :lA 5cheme JA1 Quantitv $000 Quantity $000 290,000 $ 4,J50 290,000 $ 4,350 435,000 2J,925 536,00fJ 29~480 4,200 1,092 4,200 1,092 67,6110 16,900 83,600 20,900 17,200 4,472 17,200 4,472 600 177 600 177 7,500 1,950 7,500 1,950 20,000 10,000 20,000 10,000 3,140p000 13,188 3,140,000 13,189 125,fJOO 919 125,000 919 3·,675 3,675 6,825 6,825 1,226 2,575 1,306 2,911 475 1,663 575 2,013 125 438 125 438· 2,700 43 2,700 43 1,250 4,594 1,525 5,604 4,600 4,600 $101,386 $112.637 ! ~~ ., 4 •• \ ~ ~:-::~~~ -~ ... ' ~ "" -- ·--.... 1 ·~ -·--~\ -~ ~~:-~.;-.·:~:if~ I ·i~ Page 1 of 5 Scheme 'AZ SCheme 4A ' Quantity $000 Quantity $000 290,rmo $ 4,J50 290,000 $ 4, 350 435,000 2'5,925 450,000 24,750 4,200 1,092 4,200 1,092 67,600 16,900 69,900 17,475 17,200 4,472 17,200 4,472 600 177 600 177 7,500 1,950 7,500 1,950 20,000 10,000 20,000 10,000 3,140,000 13,188 3,140,000 13,188 125,000 919 125,000 919 3,675 3,675 6,825 6,825 1,226 2,575 1,249 2,623 475 1,663 500 1,750 125 430 125 438 2,700 43 2,700 43 1,250 4,594 1,300 40 777 4,60Q. 4,600 $101,306 $103 1 104 ....... ~ ,~ _ _.,_ ~· ...... ...... ~ .-.... fi::~·· . ~ F~:.:· ~\~ -·-~ ~~-4{~ WATANA ·~·· ...... ~-~ COMPA~ATIV£ COST ESTIMATE -NON-COMt-10N lll:HS (Cont 'd) -LJnlt . il!~·a. ·~ I lii:;'"•"•-""l Scheme 4!A Description Unit Price Quantity $000 Service S~iiJwa~ (,..cavate Rock cy 17 1,567,200 26,642 r.,..cavate Overburden cy 6.30 1,301,000 8,196 Concrete tla lls formed Ono face cy 260 32,600 8,476 Concreto Walla foraood Doth faces cy 280 19,100 5,348 Concrete Slab Approach cy 190 . 2,900 551 Concrete Slab No forms cy 170 79,600 13,532 Conct·ete Slab formed One face cy 190 2,100 399 Concrete Slab formed Both faces cy 200 15,500 3,100 Concrete Gate/Chute formed One Side cy 295 2=500 738 Conc1·ete Gate/Chute formed Both Sides cy 315 . 5,100 1,607 Concrete Structm·e No fot·ms cy 210 2,1011 441 . Concrete Structut·e formod cy 250 11,400 2,850 Concrete 81•idge cy 600 2,150 1,290 Concrete lmu~r Piers Bridge cy 295 NA NA Concrete lower Bridge Deck cy 500 NA NA Reinforcing Steel Ton 2,100 5,896 12,382 Rockbo)ts Ton 3,500 1,000 3,500 . iitflflliil ~ ~·---. ·~~ Scheme ~Al :~ Quantity $000 3,114,000 52,9)8 969,000 6,105 59 0 000 15,340 75,300 21,084 . 2, 600 494 284,500 40,365 . a, 100 1,539 NA NA 2p200 649 4,700 1,481 3,400 714 10,100 2,525 2,000 1,200 NA NA NA NA 15,7J5 :n,o4J 106 651 ~~ . ~~ ~.· ~ ... "!. ~·.c::tl ~. r;~.;_-:~ . :~1 ~ . . "" Page 2 of 5 Scheme JA4! Scheme -lfA Quantity $000 Quantity $000 1,456,0110 24,752 10,074,000 171,250 1,224,000 7,711 2,150,000 13,545 30,700 7,982 950 247 / 19,500 5,460 19,700 5,516 2,600 494 3,900 741 70,400 11,968 13,000 2,210 9,100 1,729 20,000 J,aoo 13,800 2,760 NA NA 2,200 649 3,100 914 4,700 1,481 11,200 3,528 J,400 714 11,300 2,373 10,100 2,525 17,400 4,350 2,000 1,200 J,OflO 1,800 NA NA 9,700 2,861 NA NA 3,900 1,950 6,081 12,770 5,577 11,712 920 ),220 8,460 29,610 _,... r--··; r-·~··· ( ·-~ r~ r-~ 1 r--·""'j )"~--~ ~ .._ • ....,.\ .... 1, ... ~: ............... ~~~~~·~~~ .... .oJ ... -, ~ :----·.., mAil WATANA COMPARAT J\'E COST ESTIMATE -NON-COMMON IU:MS (Cont 'd) lfnl.t !lcllcme ZA Description Unit Price Quantity $000 Cates LS 4,500 Dental Concrete LS 4,800 Grouting lS 2,100 Winterization LS 7,000 Alluvium Removal Above Water level cy 7 760,000 5,320 Alluvium Removal Below Water level cy 17 860,000 14,620 Additional Haul Roads Mile 40,000 2 80 Surface Treatment Vertical sy 15.80 17,000 274 Surface Treatment Horizontal sy 10.50 30,400 403 SUBTOTAL SERVICE SPILLWAY 128,149 [mergcnct SJ!i!lwa~ [)l.cavate Rock cy 17 NA [)l.cavate Overburden cy 6.50 NA Place fuse Plug cy 6 NA SUBTOTAL EM£RGf.NCY SPILLWAY ---~----- ~-·-·, " ~_:l ~ &heme ,,A 1 _.,! ~ Quantity $000 2,900 4,800 2,100 11,000 NA NA NA 50,000 791 56,100 589 208,308 1,383,000 23,511 3,551,000 23,082 54,200 325 46,918 ····-· .1 .... . "' . " .. I ·~ 1st~ •H-i.O.,' .~ ... ·-1 ~ ~ ...... ..., ..... , ... ,_ e ........ ,.-"'\ ..... ~ Page J of 5 Scheme 'AZ Scheme ltA Quantity $000 Quanti tv $000 2,900 4,000 4,800 NA 2,100 500 6,500 6,000 760,000 5,'20 NA 860,000 14,620 NA 2 80 NA . . 19,100 302 . 9,000 142 33,100 348 11,500 121 122,385 267,178 1,383,000 23,511 NA 3,551,000 23,082 NA 54,200 325 NA 46,918 -··. r-·-.-· r-·-·""'• r·---. ...,..,....-, ~-............. r--~-, ......... ~ ..... , ---··-; r-· -i t .. i . l • ' ~ . t ' . • ........ ·~~I ..... 1 ; ...... • ~ , ~ 1 ....... ·~~--• (~ .~ ~~~~~t~.~~~~ . .. '., ~.~~ ~~...._ ., -"(. .. -· "' • 1 ~ ~ ~.~ ., ·M ~ -· - ,...--·' ! ~ . . ...• , M --......... "' ~ ~:---1 ~· .,.., J r -···-·--; t.t!l WATANA COMPARATIVE COST ESTIMATE-NON-COMMON ITEMS (Cont'd) Page 4 of 5 lklit Scheme 2A Scheme '1\1 Scheme 'A:Z Scheme lfl\ Description Unit Price Quanti~ $000 Quantity $000 Quantity $000 Quantity $000 TaU race T unne 1 [>c.cavate Tumcla cy 50 97,200 4,860 97~200 4,860 97,200 4,860 59,000 2,950 Concrete line Tunnels cy 2'75 14,850 4,'104 14,850 4,084 . 14,050 4,004 9,000 2,475 Reinforcing Steel Ton 2~ HJO 150 J15 150 J15 150 315 90 189 Rockbolts Ton J,500 480 1,680 480 1,680 480 1,680 J15 1,1112 Support. Steel Ton 3,675 590 2,168 590 2,168 590 2,168 J60 -~,J2J SUBTOTAL TAILRACE TUNNf:L 13,107 1J,107 n, 101 0,039 Credit for Use of Rock in Dam C)' 8 1,466,001) <111728' J,900,000 <J1120Q_. 2,344,000 <181752: 9,044,000 (721352> . TOIAL NON~COMMON ITEMS 230,914 349,770 265_,044 305,969 -"' --r-, ·-r ~~i r"' ··~-r---·-.., r~-~:; . r-· ~.... -··---r··-~ .. , - 1 .... ' Blliiilliill; ..... I . I. ~· I .... J.....:. ,,)._.. ~ , . ·~ ·~ ~ M ~ ~· ~ ·~ ·~ ESTIMATE S~~HARY -WATANA COMPARATIVE COST [STIMAlE-JULY 1981 ($000,000 JANUARY 1982 DOLLARS) -·~-. . .., e Description Scheme :.!A Scheme JA1 NON-COMMON llt:MS 231 CotflON ITEMS 1,643 SWTOTAL 1,874 Camp & Suppm·t Costs (16~) :mo SUBTOTAL 2,174 Contingency 20~ 435 SUBTOTAL 2,609 [ngr/Admin 12.5~ 326 _ .... _ TOTAL 2,935 .. -. """'" ..... ~ .,.~ .. -. ., ,..--·1 '!!'~ ,_ ~-' ,__ ,· ..... !)cheme 'Al. 350 265 1,643 1,643 1,992 1,908 319 305 2,312 2,213 462 442 . 2, 774 2,655 347 332 3,121 2,907 ~ -~ ~ ~ ·~ Page 5 of 5 Scf\eme li~ 306 1,64' 1,949 311 2,260 452 2,712 339 31051 ~l -·r~· . " ~ ' :.-f . . -~: .. l • I . > -··ll· I. } ' ~ t \:!!!-'" l l ~--.. r . i ~ t l : .~l·tt, • '1, \ : .; '! I ~·: ; .\\\ ··-1' '. . I . I' .'. . ... . . ; i " '·- \ t _, . 1\ ' ' ' I I . \. . .:--. r' ~rl· !. ~ . ,__ ,-J~. , f J :1 ..... ., I r I . . \~· .. I • • c J ! I r ... 0 u • .I ' . i ~ .·-t, ' 4 ""*" t ., t i e § r~ 1-0 --r·~ 1 ~ .( tO ~ i ~~ .. ~;.·[; ; j • r ! ·-_,.. LIJ • sl 0 25 6 ...J ~~ ~ t5i a.. ~ ~ \ ...... 1'.· . 'lit ·~ j : .. I. ! . j. l '. i ' . . ·t-: ; \t . • ' ~ - Ll · c·l ,__ '.·1.: ' ~ j ,. ·..._ \ li \ 8 s s i .( .. . .. .. .. \ i ~i \ ~ s \ . I !I .. > 3 ,\ ru ~~ ! il I I 2 co i g I : ' ! ~; ! I I co i ! ~ i 5~ i I .,. --lt/ -~ I l ;I ~~ : I I: . I ~ \ ! ~I I I .. \ i c , . I I c 0 ~. i ~~ /I I.: 0 . 'I I I t. * I -; ~· ) I ~\ 1-., Sl 8 8 ~· Sl §' i /'! ,/ . .. .. .. en .. .. .. al " \ , i v.:l ~~ LIJ .. i »~ ..J ;; ;~ I "~ 1.1.. g I / .· 0 a: /I ,• I a.. ~ ..... ~ ~ § .i-~ .. /. . -.::r'!-/ . • 00 ~ .. or .. .. ~ , I a l: / /· ,' 3 -a.. b!i en .. f\ 1 ./I· ..... =~!! b :-{ /·,~ Si!" \ "• a's II ;1~/ /, ~~~ \ ~s~ g I l§ ,' 1 ~ ~ :!t i§ //~/,A ~¥ .,.., 1\ r '/ I 1,//-,. . l Lfr· .// ; ~ . < I. ·; -\ < l . I .. /1 g ' . zc l I /I.// g· I<\ \ .... ~ I I ... i \ ~~ . It· I . I ~1§ I ! \ / '/if a§ 0 -\ i ·~ ~:~ I .h ~ /: ,___, . ~ ' -~·· . s, I I ......, ~ ;ta. ' I ~ j" oft \ I ·~1 A I I I I I I I I I I I I I I I I , ! i ~ s s 0 H s i ~ § i ~ ~ ~ ~ ~ 0 8 Sl § ~ a .. "' .. 0 ! :: ~ '! '! ~ • ... .. .. • I"' 0 II. w Q u • < v-.... .. _ ·I I ""<H~ '\ f'" "' .... -"" ~-, .. ~"-'""'"' .,.,. ....... ., ~ r=·-· ·-., -.. •.; -',!>.· ~-·-~-( .. 10 c e l I r-··, r·-~. r-.--; ~-............. ~; .. ' '~ .. ~ .... ~ \ ....... ' ,_,.. • ; . •• ..... ..... • ~ ,fJ "~ '"' tJ. ¥' GENERAL ARRANGEMENT ;r,,,s--- ~~~~eo~ ICAUIA ~ ' ' 1 - 0 -.c>.U! f>, ! 0 ecA&.r. a ·-·~; ...\·-·--->: .,. . .., .. ....,. : '. l ~ . . ' . . :-l ... .... ~ ,.. ~ "' :: ·'-"' ....... , ..... 1 -~ " .. . . • 1 ·--·-·-~n. \\ ::::..~:.....: ~-···-·--··· hAICJaiP.IWC .< ~.... \:;;;;v;;;cu.-;----· ·---· -· ...•. a:o o400ru.T 5iii !10 100 I'U.T 5ii SECTION A-A ICAlUI , ll .. CQITfg!~ ~e SPIU..'Ifl.llt' oeatc~ I'UIOO ____ ns.ooo lMf.RGf.NC'i -U.-MAXIMUM FUlO!J ---nG.ODC>C.F.al CIC!M:~ -.c.6l. 1-tAXI ...... OPUIATIOIG ~-UC0 1 ~Ill WO<I-Le-veL wrm !l<l~ --a2.0a 1 WATANA SCHEME !AI PLAN e SECTION D c ,.., ,..,._ ": .... ·f- '1 . " ' .. : ) • Ill u • ~-, , ~ .. j I ' ' " J j ~, ' ·: .~:·;) H if . -, I -- I ' .. --· ,._ Ill ~ ------·-r-~; :~ \ . .. .. . <: ~ t ;~ r(~ " ---: " :l : ·-· 91 ~ ,. u . • ' ' ' I r""· ~ ' ,. i ·t . " ~ . I. ' . ... • l.tJ .. .. :=l ;f ~ ~ i a: a. ~ ~ \ tl· ..! 0. C/') CD c.D 'I z 0 ' ... i= J· ' l " ! 0 l.tJ \.. .. · C/') ~· • l ' I ~-- ··t } " : . -· ' .......... .• r. • r < I ' . < ; .,. -·· ... I a , __ I ""'-~ ~ l \I . §!i i= i 0 . a: ~ • i i . ! ~-; rl.4 § g 8 § ~ 8 ~ I ~ 8 g 8 ~ g .. ; ; .. !! :t ~ :t . ' L. " ... Ill t Q u • c , .• , v-. -... _ .. . . .I l :r ., . . ·.~ if rl ... , ' .• . , ·t· ·t •••• . -~ . :-~J·· 1. . . ·.: il: ·c ~·I ··- .~,:' i \,;.* fl .·1 "'"'"'' ,.g, ·-· .I· - ·o , ... ._. ...... J "-' ... .. "'·'••'<'"': ~f·"~ "-,. ·-·*"···, ,,, .. .., .. h1 •. """""" '\ ••. '"1 .. ,._ ... '• . . ., ' ' ' 1 ·-.--' '"t ...... ~·-·:-1 ' l . " •. 1 . • ... _r 1 '_.· 1 • !-· · ·. · --• ~ .. I~ .... • -··Ifill·-···· ,,--•.•. 1- 0 ., E D c II -t· ~ ' I 1400 uoo 1100 1100 1000 ._, 1100 noo -11100 ·~ 10 • 7 ~ONT~~ SfAUCTU~ ~· IHI.Aitla&D 1>11'"1'-) ~~ . . -··--;;~~~~~~ 5 ± ~ ,, ____ ... 1:-'"--=--: -:---~~-:.-~---~···--· .. --------------------~~~ ;.._:. .. :-~. ·-i:=:=,~-.:__:__~ ___ .:~. ~-~~;~x ~:;· ~-::. ---.-._= ... a ... ,,. ..... ·- --·--... --........ _ ~ ••• ...;;::. .. --!._ .. ·-· ·--·"C:"7:'<: -.--·-7 '·---·-------~------------ .· . '""··· .. -~-•• •·· ..... !..-.u. .•. -*·-·----------·· ! .............. ,-.: ==1 >J( ~- &------·--------' ·---·· ----·"·-._ .............. -·-. L ••• ~~:---' ~ ~_______L_______j______j_______t__t __ _j_t ___ _L______j~j _ _j~ __ l_ ___ l _____ j __ l .J J J I J l I J I I I • l t l I I 1 I ·t I_ l f __ l _l __ t & ,., II ID 2111 llO K 40 a 110 e.w.wsa llf P'U.t SPILLWAY PROFH.E eu...ll lA --~~----------~--- l~ ------------ :noo 1-------· r...T.~.) 1 ------- a&.o'ZIC•' 21110 -·liiiOO :I ''""""""--I!L.'ZIIO' ---=..IN-=-: ID..'II201 I I .. A .. B SPilLWAY CONTROL STRUCTURE (lHL&RGao) SECTION B-B &eM.&• a SCAt.l. I e, cua IIO.:ST:I~ -·------: r:.:7':!_------C-4t :~--..... _ 1110 I I ·-·--·--ll--1 I c..., ..,_ tiO'W • I&..,M WMCIL M)lllffiP CO.llB SECTION A-A SECTION C-C fEU llc.t.L& • ., SCAULte> 5eAU. & 0 bO 100 FliT ~ • fl' 0 c • I· ••• ~-. ~·· ;-, . . ~.t :1 :·-·, :I .·1· ···t· ' ~·· ' ~ r•-1 :' ,._ t . '--- ~·:1 ~I ' ~I ,__ I .·g 1-· • ·h -~ i I = .J i ~ If!-~ ~ . ~ ~ ~ -. li:l 0 ,. El -· o• c 11100 rroo ·I lt.OO 1700 1400 I 'iA ~ ' I ............... -· •"t ...... 1 .. '...,_ . ~ • + ~· ~-·;; .. .. • ~ 'U ~ I. IIIII .. -r·· -~-.... ... • ----.. .. .... QIOO 1100 1100 eooo 1901) 1800 noo UiOQ 1500 l•oo taoo uoo ZIOO 2000 1900 1800 noo IGoOO 1!100 ••oo 10 • . -· ""==--• , at.oFE 1 t-~-h.:;:'{&_~_f-_'oo.._tt_4_o_' ---!ll-·-lME--0-------------=.<:-----' I. ~~-. . ----:; -_;;sC-d--·. -~ ~-----------===---------·--------------~------~~----~~~~~~~~--------~-----~'"i~~-~~ ~ ~~.:_~ -----~?-~ ORt!Oll>N.. GROUND ~II. -......:::.:.:· -~"-./ '~ ~'~- Mllf!OQ( aJIIF'AU ""'':"' ~-7,:'7 ll!lcCJ.VImOI>I FDA OOM "-"', '\ ~ '~ --::?'7 -Woli!IU4 ""'~--.4::::;;' "'-~~--u~:;.~ .. ;,;;;;;--.............. , ___ ... _.,..,.- ~ MAIN DAM fftOFILE -• ... t-517 . ·--· I .... u·--· U.ttlt ~~'·l-~-,r~=f=srt:L-::lt:=40,-:,,-------------·-----·- r-------·----------------------~~~~-H ,1\~---~"~~-------------------------./"' 'l f\ \' ""' r-------------,.;:'r_,.~~-----.· r/J \ \~ ~ RIP PI>#'~ tTJ]LI• \ \1 ......___., ~ AOCI( ,_,~FlU. // \ \ AOCII, Am~ PlU. " ~ ~ I:I».RW. Fl\,.'fiA --ll _\ _l--~HI'll . .'JaR " ....e::. ....... ....... ~ Fl»r.Fll.:Tli\-~/IIAP£RYIW. I \ ~FJNf.Pli..TIR " ./ ~-- .L.L ' .} ' 1 AtRYI MAIN DAM SECTION AT MAXIMUM HEIGHT • aCCI'nllDIM ·~V'mOtCH UPSTREAM COFFERDAM SECTION I "' WATANA VALVE Tl'PE-SPI!..lWAY ALTERNATIVE MAl~ nt.M ANO DJVERSIOH j - til , IE .. ... D c II . . . f • .. • 1 . -~· ., --·-·- Ul7l:l . ' -.. J~ ··--.. .-.. ~·"""'"-"" ~ .. _, ,... . -~ . ~ _ .... : ..... 7 0 llM\.~§tiij''"lliiP?l ..... -I H--flti)D 1100 - fOOO F 1100 ·-------·~-•·11··-·-·-· llf.M I&' 4 COJ«:, LINeP feli5TOCI<. IJOO ·-·-··-------- f"' ~ou _..., 't :"" 7 ...... '1 ~-.. . ..... " ., . ---- • .. , ............. __ .-,__ -----·--- ... ~-·····" -···---------- . '1 .. ,. ·-----------· ·-···· l -.. I - • ., , !GOO c· .. . ..... ~.H-··--··--~~-----·-. ~--. u 'jiiUtG~~:~~~~~R ------------· \ ~ 1 11: E r \.\. I. lBO' .. I • n LJ ..et.~· -----....__ • IIICO -··-·~ .. ---· .. ·• D c: • ~A ~ ' I 1400 2400 uoo 1J:10 ZIOD 1JXP f·WIIEfl. NDIIHTEO OAT~· !S'Vh4&'11 ~~UII.!--· ll!lllf PlAINS POWER FACILITIES -P~ILE 1100 1---·-------· .. -· SPILLWAY -PROFfCE I frt~ trloo ---z--.co---· ... OQ ~·00 ·-···· --~--· . ··~ -t """'" .~ ..,_, __ ........ ··-· ~--· ~---· ------··--------· .-co IGiOO ··oo IGoiOO ·~-=:-------.. ----' ~- --==:--~·-- ... D --------.---·---- c: ·----- • Ill! CO ~017 '2t~ lt>OO B-1 AlASKA POWEI·A~;;,.~-I A ' -- . -· ·-f~?-'}."'=_---~*" .. !:_··.--:~~'-,._ ,..;_-.-.·, .. -.-:"'.: .. --_• ... -_·.~ .-.. ·.·._._._ ... -__ ..... -.'_.·.·_._ '-'-·, _, .... ·.·-._· ... ~-··-__ ·· .. ·----_._.-_ .. -·---~-··, .··-·_·__;._-_··-._ .. · .:·_~l,,._ .... ,'"---""'"'---"-' ""~ .:""~~ -·~~~~.,. ._.. ~-,.-~~-__,_..,...;.:_~·-··~........,._. """""'""'"'""'"---~-~-".:;_ ___ _.!, ______ ,,_n·---~--~~.:..~.-~-·~· .:_,..:;.t::;_~ _ __.,•_,£:.:._;;~-:._~~:J:,:.~ .. ::: ... <~~-'·-/·.t~:..~..,,~._'!,.~-;._--'-~~U'.O::;;._;,~--• .-":!:_.,.: •""""":'·-· •-~:_. f1 r1 fJ :·1 l l • { 1 ;J WATANA DAM DESIGN t:u::::::a ! l !' 1 r.- ;1 r.·:·l ' rl I • WATANA DAM DESIGN f 1 i I l 1 ~~.-~ Ill ~·- ; ··~ ·1. . . . i? '.: J .. i .. • . ·. ' ' CONTENTS 1 -GENERAL 2 -TYPICAL CROSS SECTIONS 2.1 -GENERAL :I 2.2 -CREST DETAIL . ~--~.; ' .t f · ·u. 3 -INSTRUMENTATION 1(·, ... " ~ '• : • l ·----· _.,. fl .· [J: · r1 \ . ;.-.. L[ ! ·i [. \-. ,~f . L~. rl ll - t ~ ;·., ... ' i ~- 'J j i .... , ; ·;_ ,· ! ' i ' L~ cr . r::r1 ·+ I \-: \JL._"l · r.T~ L:-·''~ ' · vt !.:.- WATANA OAa., 1 -GENERAL THE WATANA DAM WILL CONSIST OF A CENTRAL VERTICAL IMPERVIOUS CORE PROTECTED BY FINE AND COARSE FILTERS ON THE UPSTREAM AND DOWNSTREAM SLOPES. THE OUTER SHELLS OF THE DAM WILL CONSIST OF RIVER ALLUVIU~ GRAVELS AND ROCKFILL. MATERIAL. THE DESIGN SHOULD PROVIDE A STABLE EMBANKMENT UNDER ALL LOADING CONDITIONS. DYNAMIC AND STATIC STABILITY ANALYSIS ARE IN PROGRESS. ,., ~-~ .Lt : ,'f !. .. ~· ~ ·: . I'•· < •' t ;;. cr :U ' r~r . t.~ .~ ' ' ti. ' .. · r·· L. \,.... f ' ) .• ~-'<~ 2 -TYPICAL CROSS SECTION 2.1-GENERAL THE TYPICAL CROSS SECTION OF THE DAM AT THE MAXIMUM HEIGHT IS SHOWN ON FIGURE NO. 1. THE SLOPES AND THICKNESS OF THE VARIOUS ZONES ARE BASED ON A REVIEW OF PREVIOUS DESIGNS AND THE PROPERTIES OF THE CONSTRUCTION MATERIALS. MINIMUM CORE-FOUNDATION CONTACT WILL BE 100 FEET REQUIRING FLARING OF THE CROSS SECTION AT EACH END OF THE EMBANKMENT. THE UPSTREAM AND DOWNSTREAM FILTERS ARE SIZED TO PROVIDE PROTECTION AGAINST POSSIBLE LEAKAGE THROUGH TRANSVERSE CRACKS IN THE CORE THAT COULD OCCUR DUE TO SETILEMENT OR RESULTING FROM DISPLACEMENT DURING A SEISMIC EVENT. THE WIDE FILTER ZONES PROVIDE SUFFICIENT MATERIAL FOR HEALING OF ANY CRACKS IN THE CORE AND THE INCREASED SIZE OF THE DOWNSTREAM COARSE FILTER WILL ENSURE ITS CAPABILITY TO HANDLE ANY ABNORMAL LEAKAGE FLOWS. THE SHELLS. OF THE DAM WILL CONSIST OF ZONES OF ROCKFILL AND RIVER ALLUVIUM GRAVELS. SLOPE PROTECTION ON THE UPSTREAM SLOPE WILL CONSIST OF A 10 FOOT ZONE OF OVERSIZED MATERIAL UP TO 6 FEET IN DIAMETER. 2.2 -CREST DETAIL THE PROPOSED CREST DETAIL IS SHOWN ON FIGURE NO. 2. THE SLOPES AND THICKNESS OF THE VARIOUS ZONES ARE CONTROLLED BY THE 35 FOOT WIDE CREST. '.l ,I I W ·g.,. ··1·1::-__ ._· .. · .... ·.·•· ... · ..•. ~ •. ···" ~----"-" ~ il I il I t il ttl II i\ jl\ i' i i I I· fl fl i a- tW ...., ..._ ::0: fC) -It--< ,... ... _, ... ___["" """"' "'" [t.2215 ___.._ --- \_ROCI: AND GRAHULAR rill ' I i J I COARSE rJLTER Ia FIll£ fILTH. l I• ~· . H 35ft. 'I ~1 El. 2240 tmCI: MID GR/.'1\Jl"R fill \ CO~RSE rlLlER fliiE rJL1ER IHrERYIOUS ~AI~ DAM SECTION AT MAXIMUM l ~ I il \ -~~NORMAL OPERATING LEVEL EL. 2215 i I I. I I I I. I ill· l ' 'l I ~17.5ft.~ EL. 2240 EL. 2215 ~2.75~3 ,___ ___ COARSE FILTER ___ __, SCALE 1:20 CREST DETAIL [· ·- f~ ll l 1.: .. I' I , I 1 .. m.· I •• ·~ i i 1 1};:; i ;· I J . ·;I I 3 -INSTRUMENTATION. INSTRUMENTATION WILL BE INSTALLED WITHIN ALL PARTS OF THE DAM TO PROVIDE MONITORING DURING CONSTRUCTION AS WELL AS DURING OPERATIONS. INSTRUMENTS FOR MEASURING INTERNAL VERTICAL AND HORIZONTAL DISPLACEMENTS, STRESSES AND STRAINS, AND TOTAL AND FLUID PRESSURES AS WELL AS SURFACE MONUMENTS AND MARKERS WILL BE INSTALLED. THE QUANTITY AND LOCATION WILL BE DECIDED DURING FINAL DESIGN. TYPICAL INSTRUMENTATION IS AS FOLLOWS: A) PIEZOMETERS TO MEASURE THE STATIC PRESSURE OF THE FLUID IN THE PORE SPACES OF THE SOIL AND ROCKFILL. B) DEVICES FOR MEASURING I~7ERNAL VERTICAL MOVEMENT. 1) CROSS-ARM SETTLEMENT DEVICES AS DEVELOPED BY THE USBR. 2) VARIOUS VERSIONS OF TAUT-WIRE DEVICES HAVE BEEN DEVELOPED TO MEASURE INTERNAL SETTLEMENTS. 3) HYDRAULIC SETTLEMENT DEVICES OF VARIOUS KINDS. C) INTERNAL HORIZONTAL.. MOVEMENT DEVICES 1) TAUT-WIRE ARRANGEMENTS. 2) CROSS-ARM DEVICES. 3) INCLINOMETERS. 4) STRAIN METERS. I { . • ' . I \ I I 11 '· I .. : I .I I I I I ·I I l i· ~ t I : ·~~ ·i ·' '· I D) OTHER MEASURING DEVICES 1) STRESS METERS. 2) SURFACE MONUMENTS AND ALIGNMENT MARKERS. 3) SEISMOGRAPHIC RECORDERS AND SEISMOSCOPES. II f' I· . I ' 1~ .. ' r . •• \ I. i.: . ,. 1: '·· E. ~ '· ll;· .· :. 1· . . . I .. I I I I . :.~ I t I ~ ·. STATIC AND DYNAMIC STABILITY ANALYSES FOR THE WATANA DAM I· I I . 1: I . II i t· 1: I ll .~ .~ I I I I I: t; ,. t t TABLE OF CONTENTS 1 -INTRODUCTION 2 -METHODOLOGY 3 -STATIC ANALYSES 3.1 -General 3&2 -Soil Properties 3.3 -Loading Conditions and Factors of Safety 3.4 -SAP IV Analyses 4 -DYNAMIC ANALYSES 4.1 -General 4.2 -Soil Properties 4.3 -Design Earthquake 4.4 -Dynamic Analyses NOTE: Only Figure 1 Dam Cross Section, Figure 3 Static Stability Analysis, Normal Operating Case and Figure 12 Design Earthquake Time History are included with this submittal. II" " . 11, 1 ' r I t " •• \ I ·,,._ I <' " ' ' ' m:· " ' ._, I~ ""~" I . . . ... __ • 11. I I . . " . I IY IJ: II: .• ' [. ' . 1: .. 1 -INTRODUCTION Static and dynamic stability analyses are being performed to establish the upstream and downstream slopes of the Watana dam. Static and slope stability analyses indicates stable slopes under all conditions for a 2~25 horizontal tu i.O vertical upstream slope and a 2.0 horizontal to 1.0 vertical downstream slope. Typical cross section and details are shown in Figure No. 1 . The static analyses have been done using the STABL computer program developed to handle general slope stability problems by adaptation of the Modified Bishop method and a linear elastic finite element progr~ (SAPIV) to determine the initial stresses in the dam during normal operating conditions. The results and conclusions are presented in the Static Analyses Section. The dynamic analyses have been done using the QUAD 4 finite element program which incorporates strain dependent shea~ modulus and damping parameters. The design earthquake for the dynamic analyses was developed by Woodward- Clyde Consultants for a Benioff zone event. The results available at this time are presented in the Dynamic Analyses Section . I I I < . ' ' ll I ' I. ~ ·~ \ I I l.' ' .~ 15 I II I! ~ - 11· li: ll I I I . I I 2 -METHODOLOGY An assessment of the static ana seismic response of the Watana dam for the ' static and postulated seismic loading involves the following: Static Analyses -STABL program to determine general slope stability. -SAPIV (linear elastic finite element program) to determine the initial stresses in the dam prior to seismic event. Dynamic Analysis -QUAD 4 program to determine the dynamic shear stresses due to the postulated earthquake. ~ GADFLEA program to determine the pore water pressure generation and dissipation. The data available on-site specific materials are limited, and therefore, the static and dynamic properties were assigned using the material characteri sti.cs. and published i nforma ti on. .· ..--; I f I· \ 1:.· '. ... ~~ . " IJ ,. I \ I l . I I. I. I ll I I I . I I 3 -STATIC ANALYSES .. 3.1 -General The slope stability analyses were done using the STABL computer program for the general solution of slope stabil1ty problems by a two-dimensional limiting equilibrium method. The calculation of the factor of safety against instability of a slope is performed by an adaptation of the Modified Bishop method of slices.which allows the analysis of trial failure surfaces other than those of circular shape. 3.2 -Soil Properties The following soil properties were used in the analyses: Core Material Fi 1 ter Materia 1 Rockfill Material Y Wet ( 1 b/ft3 ) 146 146 129 Y Sat (lb/ft3 ) ·~ 147 30 150 35 140 40 c ( 1 b/ft2 ) 500 0 0 3e3 -Loading· Conditions and Factors of Safety The following conditions were analyzed: Condition Construction Normal Operating Rapid Drawdown Normal Operating With Maximum Pool Minimum Factor of Safety 1.3 1. 5 1.0 1 o3 Calculated Factor of Safety · U/S Slope 0/S SJope 2 .. 9-2.2 2.0 1.8-2.0 2.0-2.1 The calculated factors of safety as shown in the above table and on Figures No. 2 through 5 indicate no general slope stability problems. [ f . f . I r· I ' ( [ I I (. I. I I I ... I t I . I .. I 3.4 w SAP IV Analysis The static analyses using the linear elastic finite element program (SAPIV) were done to determine the initial stresses in the dam during normal operating conditions. Young•s Modulus was determined from the following relationship: where: E -·:= Young • s Modu 1 us Pa ~= Atmospheric Pressure a 3 = Confining Pressure Kjn = Constants The initial values of the parameters K and n and the Poisson's Ratio (v) for the various dam materials used in the program are as follows: -K v n --- Core Material 300 0.333 0.2 Filter Material 2000 0.299 0.2 Rockfill Material 2000 0.263 0.3 A parametric study utilizing a reasonable range for the K values will be performed at a later date. The resulting initial stresses are used to determine material properties for QUAD 4 and for assessment of dynamic undrained strength. The following plots were developed from the linear elastic finite element program. (SAPIV): I I f . ( .. ~ (. i r· I r- ' ., I. ( ( I I I t I I I FigoreNo. 6 7 8 9 10 11 Subject Finite Element Mesh Two-Oime~siona1 Confining Pressure Three-Dimensional Confining !Pressure Vertical Effective Stress Shear Stress Maximum Shear Stress r r r· r~~- ~. f---=. ' ' ["";' ' ~· .. r~ i . [~ .. ("' .: .. [ r·· ['. 1"7' 1 ... l··r -~ f. ' ~~ [ I: l· 4.4 -Dynamic Analyses. Two one-dimensional models were analyzed to determine the sensitivity to the number of elements. One model consisted of 20 elements of equal size while the other model consisted of 8 elements. Both were the same height as the full dam model. Convergence was reached in three iterations. A comparison of the results indicate that the full dam model as proposed would provide satisfactory results. The two-dimensional finite element model of the dam Figure No. 6 was. ·-···analyzed and the following plots were developed: figure No. 13 14 15 16 17 18 19 20 21 22 Subject Maximum Dynamic Shear Stresses Maximum Dynamic Shear Stresses Divided by the Vertical Effective Stress Vertical Slice Acceleration at Center of Dam Stress History for Elements 20 and 30 Stress History for Elements 33 and 35 Stress History for Elements 54 and 57 Stesss History for Elements 59 and 78 Stress History for Elements 81 and 83 Stress History for Elements 94 and 96 Stress History for Element 105 A copy of the computer output showing the accelerations, material properties~ and maximum stresses from the three iterations is included in Appendix A. No laboratory data is available for the e..yclic shear strength of rockfi11. The procadure adopted by Sidigh ct .. al. (1978) will be followed, i.e~ cycl·ic strength values for sand at the same relative density as the rockfill will be increased by 70%. Strength will be defined as 5% strain in 25 cycles. A comparison of the results from the dynamic analyses and the calculated available shear strength of the rockfill material is in progress at this time. r r r r- r: r·~ f~' r-· r lr '[ m·; JL. .tr .. It. . , .. 1 .. 1 .. 1. t 4 -DYNAMIC ANALYSES 4 ;1 -Genera 1 The dynamic analyses were done using the QUAD-4 computer programo Complete details of the program including theoretical basis, data preparation, and output are given in the manua 1 ( Idri ss, Lysmer, ~Jang, and Seed, 1973). The dynamic analysis model is shown on Figure No~ 6. 4.2 -.. soil Properties The initial values of shear modu'lus and damping ratio used in the analyses were derived from typical values available in the literature and are as follows: Core ~1a teri a 1 Filter Material Rock ~1ateri a 1 G/Su 2500 100 180 Da-nping/Shear T.ype·curve · ~ ·clay ·::.. .. Sand Sand A parametric study utilizing a reasonable range of K2 values will be performed at a later date. 4.3 -Design Earthquake The required earthquake time history was developed by Woodward-Clyde Consultants and is shown on Figure No. 12. The significant features of this earthquake time history are as follows: a) Magnitude 8.5 Richter. b) Location 40 kilometers below site (Benioff Zone) • c) Maximum acceleration of .436g. d) Duration of strong motion -45 sec. e) Significant number of cycles -25. ;.:, j ', r· ~~- r r~·. I; [ (...'· I'· l~ 1': l: ,~ _· ~--= -~· [. .. I 1:-·,: , ' The penneability of the rockfi11 material is estimated to be greater tha- 100 em/sec indicating that possibly -;he rate of pore pressure dissipation will be equal to or greater than the pore pressure generation. A para-- metric study will be done using th~ GADFCEA program to establish the required rockfill properties for equal generation and dissipation. I I I I. I 1..-- I ' I ••• ·-- •• ~ ~ ~ N .. •• -I • -;: ;: ~ i .. ,. ' ' I .. ' . I ... I. I ! I ... --' ·-'' I ! I I I I I I I .....I i !! § § ·~ I ~ I ~ ! ... .. .. .. I c.t.Ju> ICiUwirn· I I ell ....: «") . c z ..... !5 I , ~ Col:' -~ u If c = = ..... . . . ~ > N N N ... "" ..... C!J ..... c z "" -wi 5 ..... u 1:1. :!: Q = ~ = "" c CD "" I ! 1 ..... < = y Q = :z: = ...J -~ I I I I ) I . I I I I I I I I I I I ', I I ~ .. 0 z lM ~ =· •• ! -IJ. t; "" c "' IJ. = CICI = 5 . . . > --N = ... "" ~ IJ. < 1.1) ~ I Q "" Q u -< ~ IJ. = = ·-= < = u "' I I I 1."' < = u = = .... -< I.a.. ••• •.• J ·;·. ·- I u •• I I r.n ,..,. .... I Q N . .... "" .... 8 , .. I g.. 11~ 1"""1·' I r·· I .. I l ... I --·- ,., C) L..J<> :z {.) (..)() <t. ·-: (.) w' UJ c( (!10 L' .. ~ .. : .. !---' ... ·-r~~~~--~~~-r--~--~--r-~~-. JQ,QO JL.OO 42.00 ~a.oo 54.00 TIME fSf:CJ ;-·-:--·--·-.. - I I 1 ~4.00 90.00 96.00 DESIGN EARTHQUAKE Iii TIME HISTORY IJI[f FIGURE HO. 12 II(·· I I I I I ; I I . I I .I I I I I I I I . I I REFERENCES 1. Idriss, I.M., Lysmer, J., Hwang, R., and Seed, H. Bolton (1973) 11 QUAD-4, A Computer Program for Evaluating the Seismic Response of Soil Structures by Variable Damping Finite Elements,11 Earthquake Engineering Research Center, Report No. EERCi3-16, University of California, Berkeley, August. 2. Sadigh, K., Idrisss I.M., and Youngs, R.R. (1978) 11 Drainage Effects on -· Seismic Stability of Rockfill Dams, .. Proceedings ASCE Geo. Engino . Div., Specialty Conference on Earthquake Engin. and Soil Dynamics, Vol. III, June 19-21, Pasedena, California • ','~ ~ :m ~ I~ ~ ; .: :-.. • ·· --··-· · -· · ·· :c"~;::. .. :::~:e~:":t,.""::'j(l~:l DEVIL CANYON LAYOUT STUDIES 1' 1 if \., ':'; ·~ 'r 1 -INTRODUCTION The layout for the Devil Canyon Project presented in the DSR (Plates 10 and 11) were·the basis of further refinement and optimization studies. Principal features of the DSR layout are as follows: -Dam: • Crest Elevation: • Height: -Diversion: -Main Spillway: o Type: • Capacity: • Location: -Auxiliary Spillway: • Type: • Capacity: • Location: -Emergency Spillway: • Type: • Capacity: • Location: -Power Plant: • Location: • Capacity: Thin arch concret.e with earthfill saddle darn (left abutment) 1,460 feet 650 feet Twin concrete-lined tunnels, 26 feet diameter Three-gated ogee section, chute and tlip 90,000 cfs Right abutment Three-gated orifice, 15 feet x 15 feet 40,000 cfs In arch dam Fuse plug 100,000 cfs maximum Left bank Underground, right bank 400 MW, 4 units ~ ~ ~-~ ~·· ~· .· ~ ·~ ~ @ . ~l ------. -~~\----'---• .~ M 'v / '\, ' J .. J ·9-26 ~ ~ ~ -~~ ·~ ..,.,,c>&.,.ao '~ ........ !) -•• GENEQAL ARQANGEM£NT ~ ~ ---:···· . -~ PLATE 10 ~ ~ DIVIL CANYON ICI!II:MI I PLIIII ANO lt:C110M ~ r r ·r r r r r r r [ r ·L r. [ ~" .. [ f [ I I ' I I I I I l I l :z Q g If) :z s 0 ~ 0 ~ 1 l 1 ... ! = f1 ~ H b ~~ !§ ~· . u ~ l :i ~!% / ~~ il l: >· / ~~. / en Ill E -1 ~ ~ ~ :I (l( F£ :z 0 i= 1,) • w 1/) ...... C\1 I 01 .., ~ ~ 8 § ~ 8 i !:! ... r ' ,. I r r r r r r r ~ . r· r.,. ~ r ~. [. ' f t. ' t t [ 2 -ALTERNATIVE LAYOUTS CONSIDERED . ,. The DSR layout formed the basis of the continuation of Devil Canyon layout studies from which three basic components were developed for comparison (Plates 7.1 through 7.4). These layouts were based on the criteria listed in Table 2.1. Cost comparisons are listed in Table 1. r r r r- r [ r.· """·"' r r !' .: ~ ... , r .. ". [ .. i ~. . l-. i • ~· . TABLE 2.1 -PROJECT PARAMETERS AND DESIGN CRITERIA River Flows Average flow (over 30 years of record): Probable maximum flood: Maximum flood with return period of 1:10,000 years: Maximum flood with return period of 1:50 years: Reservoir normal maximum operating level: Reservoir minimum operating level: Area of reservoir at maximum operating level:· Reservoir live storage: Reservoir full storage: Dam Type: Crest e 1 evat ion: Height: Cutooff and foundation treatment: Diversion Discharge capacity: Cofferdam types: Cut-off and foundation: Upstream cofferdam crest elevation: Downstream cofferdam crest elevation: Maximum pool level during construction: Water passages: Outlet structures: Final closure: Releases during impounding: Spillway Design floods: 8,960 cfs 270,000 cfs 135,000 cfs (after routing through Watana) 42,000 cfs (after routing through Watana) 1,455 feet MSL 1,400 feet MSL 21,000 ac~es 0.75 x 106 acre feet 1.1 x 106 acre feet Concrete arch 1,455 feet MSL 635 feet above foundation Founded on rock. Grout curtain and downstream drains 42,000 cfs Rockfi 11 Founded on alluvium with slurry trench to rock 960 feet MSL 900 feet MSL 955 feet MSL Concrete lined Low level structure with slide closure gate Mass concrete plugs in 1 i ne with dam grout curtain 2,000 cfs minimum Passes P.M.F., preserving integrity of dam Passes routed 1:10,000 year flood with no damage to structures r ~ TABLE 2.1 (Continued) r r· r r· r ., r- r . r·· r· .. ~ [ E.~~ r.: t·. r Power Intake Type: Number of intakes: Penstocks Type: Number of penstocks: Powerhouse Type: Transformer area: Control room and administration: Access: Massive concrete structure embedded in rock 4 Concrete-lined rock tunnels with downstream steel liner 4 Underground Separate gallery Separate gallery Rock tunnel ,..~ ~~ f . I v-·· . ~· ~1 ~- ~ ·~~ I --. Description Unit Diversion/Ccfferdams E~cavote Rock Portal cy [)(cavate Overburden Portal cy [~cavate Tunnels cy Concrete liner at Portals cy Concrete liner Tt.mnel cy Concrete Inlet Portal Headwall C}' Concrete lnl~t Portal PiP.r cy r.oncrete Outlet Headwall cy Concrete Plugs cy Upstream Cofferdam cy Reinforcing Steel Ton Rockbolts Tunnels Ton Rocl<bo.l ts Porta Is Ton Rock Surface Treatment sy Support Steel Ton ~ -~ ' 'r---"; -~ -~ .-~ ·~ I TABLE 1 -DEVIL CANYON COMPARATIVE COST ESTIMATE -NON-COMMON ITEMS JUlY 19e1 (JANUARY 1902 DOllARS) Unit ~heme 1 5cherne Price Quantity $000 Quontit1_ 15 114,500 $ 1,718 114,500 5.50 146,000 00) 146,000 . 55 107,550 5,915 107,550 260 3,250 045 3,250 250 19,500 4,075 19,500 260 5,200 1,J52 5,200 295 5()() 140 500 260 9, no 2,530 9, no 500 5,600 2,000 5,600 7.50 92,000 690 92,000 2,100 550 1,155 550 3,500 1J5 473 1J5 3,500 350 1,225 350 15.00 1,600 25 ~,600 3,675 JOO 1,397 JOO $000 $ 1, 718 OOJ 5,915 845 4,875 1,352 140 z,s:m 2,800 690 1,155 I 47, I 1,225 I I 125 1, J97 Gates, Etc. lS 3,100,000 )1100 J, 100 SUBTOTAl DIVERSION/ COffERDAMS $ J2 051 ---·-----~----~----~ '---.. -$ J2.051 ··~ ~ -~ ~ ·~ \ Page 1 of 4 $000 114,500 $ 1,718 146,000 803 1Jfl,050 7,153 3,250 045 24,000 6,000 5,200 1,J52 500 148 9, 730 2,530 5,600 2,000 92,000 690 600 1,260 165 578 J50 ·1,225 1,600 25 460 1,691 ---l!.1110 i 'Jla.91R ..,... ---- ~-~~-~~ .,,< • ~-·.· ~-~ ~~ r-"1 ~ ·~ -~ ~ .,__, ··~-~ ~ ........., ··~ ~ OCVIL CANYON Page 2 of 4 COMPARATIVE COST ESHMAT£ -NON-COHt-tON ITI:MS (Cont 'd) -\ill[ Scheme 1 Scheme 2 Schmne J · Descrietion Unit Price Quanti tv · $000 Quantity $000 Quantitv $000 Service Sf!Ulwa~ Excavate Rock C)' 11 625,000 $10,625 559,000 $ 9,503 1,176,000 $19,992 Concrete Walls Formed One face cy 260 20,200 5,252 :n, 5oo o, 710 57,700 15,002 Concrete Walls formed Both races cy 280 6,100 1,708 0,900 2,492 26,700 7,476 Concrete Slab t No forms cy 170 29,100 4,947 30,500 5,105 44,800 7,616 Concrete Slab formed Ono Side cy 190 16;000 3,192 22,600 4,294 16,800 J, 192 Concrete Slab formed Two Sides cy 200 NA NA 17,400 },480 Concrete Piers cy 295 6,700 1,977 6,700 1,977 6,700 1,977 . I .. Concrete Road Deck C)' 170 NA NA 6,700 1,139 Reinforcing Steel ton 2,100 2,664 5,595 3,274 6,075 5,418 11,307 Rockbolts ton 3,5ll0 500 1,750 500 2,0JO 750 2,625 Cates lS 2 0 900,000 2,900 2,900 2,900 Dental Concrete u~ z,ooo,ooo 2,000 2,000 2,000 Grouting LS 1,000,000 1,000 1,000 1,000 Winterization lS 1,800 2,30f) 4,000 Au"i liary Cofferdam cy 7 36,000 252 36,000 252 36,000 252 Alluvium Removal cy 12 23,000 276 z:s,ooo 276 54,000 648 Plunge Pool Excavation cy 7 398,000 2,786 398,000 2,786 NA Additional •laul Roads mile 40,00() 1 40 1 40 NA J>t,water ing lS 300 JOO NA . Surface Treatment Vertical sy 15.80 10,250 162 11,300 17~' 18,900 299 ~Jrface Treatment Horizontal sy 10.50 18,400 19J 21,300 Z24 23,100 242 --.... --~- SUBTOTAl SERVICE SPillWAY $ 46,755 $ 53,32) $ 85,227 ~· Ji r---t~ --~~ ~ .. . . ").. ' . . ". . . ~·-~ ~1 ~ ,..,._., .~ ,,..._.,. .~ OCVIL CANYON COMPARATIVf. COST ESTIMATE -NON-4:0Mt.fJN ITO'S (Cont 'd) tklit Scheme 1 Dsscription Unit Price Quantity $000 Service S~iJ Jwa~ El\cavate Rock C)' 17 625,000 $10,625 Concrete Walls Formed One Face cy 260 20,200 5,252 Concrete Wal Is Formed Both races cy 200 6,100 1, 708 Concrete S.l ab No Forms cy 170 29,100 4,947 Concrete Slab Formed Ono Side cy 190 16,800 3,192 Concrete Slab Formed Two Sides cy 200 NA Concrete Piers cy 295 6,700 1,977 Concrete Road Deck C)' 170 NA Reinforcing Steel ton 2,100 2,664 5,595 Rockbolta ton 3p500 500 1,750 Gates LS 2,900,000 2,900 Dental Concrete LS 2,ono,ooo 2,001) Grouting LS 1,ono,ooo 1,000 Winterization LS 1,800 Aul\iliary Cofferdam cy 7 36,000 252 AJiuvium Removal cy 12 I 2J,OOO 276 Plunge Pool Excavation cy 7 398,000 2,786 Additional Haul Roads mile 40,000 1 40 pewatering LS JOO Surface Treatment I I Vertical sy 1 15.80 10,250 162 ~Jrface Treatment Horizontal BY 10.50 18,400 193 SUBTOTAL SERVICE SPILLWAY $ 46,755 ----........ g ·~ Page 2 of 4 Scheme Z Scheme J · Quantity $000 Quantity $00~ 559,000 $ 9,503 1,176,000 $19,992 JJ,500 8,710 57,700 15,002 . 0,900 2,492 26,700 7,476 30,500 5,185 44,800 7,616 22,600 4,294 16,800 3,192 NA 17,400 3,480 6,700 1,977 6,700 1,977 NA 6,7UO 1,139 3,274 6p875 5,418 11,387 580 2,030 750 2,625 2 9 900 2,900 2,000 2,000 1,000 1,000 2,300 lJ,fJOO 36,000 252 36,000 252 23,000 276 54,000 648 398,000 2, 706 NA 1 40 NA 300 NA 11,300 179 19,900 299 21,JOO 224 23,100 242 $ 5J,J23 $ 85.227 }!~'~. :"\'~-··~ .. :~. ··-. ~~ ·~ -~ -:~ ··'~ ~ .. -~ ..··~ ··'~ -~ l~ ' '11 _., • • ,'i .: ' ~ ; ~-); .. ' ' ~ -~ . . ' " ' ·~ ~ ll:VIl CANYON Page J of 4 COMPARATIVE COST ESTIMATE -NON-Cmt~ON ITEMS (Cont'd) 'Uillf Scheme 1 Scheme 2 Scheme J Oeser iption Unit Price Quantity $000 Quantity $000 Quantitv $000 f.mergenc~ Selllwa~ f."'cavate Rock C)' 17 1,468,000 $24,956 1,460~000 $ 24,956 1,468,000 $24,956 Place fuse Plug cy 6 43,000 258 43,000 258 43,000 258 SUBTOTAL EMf.RGENCY SPillWAY 25,214 25,214 25,214 Saddle Dam L>~cavate Overburden cy 6.30 240,000 1,512 251,0110 1,581 240,000 1,512 Earth rut cy 12.50 700,000 8,750 496,000 6,200 700,000 8,750 Core cy 10.50 285,000 2,99J 347 ,ooo 3,64fl 285,300 2,993 Transition C)' 16.00 76,000 1,216 91,000 18 456 76,000. 1,216 Rip Rap cy 12.50 34,00(} 425 23,500 294 34,000 425 -·I Sluny Trench sy 615 6,800 4,182 7,4()0 4,551 6,800 4p182 .. '( Rock Surface Treatment sy 15.80 54,300 850 52,300 826 54,3011 858 SUBTOTAL SADDLE DAM 19,936 18,552 19,936 TOTAL NON-COMMON ITEMS --- 123,956 129;139 165.295 -~ - ---~---------------~--~-- (~ i~· ~ .... 't.:r-· .. ' ' -~~ ~-~~ ~· -~ • .. 11. ESTIMATE SUMMARY -DEVIL CANYON COMPARATIVE COST [STIMATE -JULY 1981 ($000,000 JANUARY 1982 DOllARS) Ocacrlpt1on NON-COMMON ITEMS COMt.fON 11015 SUBTOTAl Camp & Support Coats (16%) SUBTOTAl Contingency 20~ SUBTOTAL [ngr/Admin 12.5~ TOTAL .~th· , ~enema 1 124 758 '002 141 1,02J 204 -- 1,227 153 1,380 ·'1!11~ ~ ·~ ~~ <~ ~ ........ -~ ... ·.~ ~ •:l . ::~ ~ • 11 :~ .,.· . . ~ ::;:., ~· . . • --r· Page 4 of 4 Scheme l ~cheme .t 129 165 758 750 887 92) . 142 148 1,029 1,071 206 214 1,235 1,285 154 161 1.389 1,446 u • . ·e.· ; a u • < v-. -·- ~- '. ,_:;, :~I 0 ,. I[ D c • f' ·~ • ~-. .·~ ": ·~; ··. COhCAa'l& CROWt-1 SECTION ----J .,_,,~ IOIX) '100 ... -·- e<oL..----·- ~· ~~ • .-Pr-•~· 1411' __ u-,. ..... . ~ •;]" -'"! •'t" ,.c••"4} "'""'-~"11 II ""'t -·-......... .. ~ -~ .. .... ~~="""= .... 1-------- .... ~-----------------· . .,... .,.._ ~ .... " "'!l. • .. I' ,. .. ';"" .... ""-.~ 111,,145 •••• "'""'~ ""' ,s -~ • '.., ',, AVIIII!-II'f II'U---D a~ e / .. "'"~' ' ----.;: , ' ... ,,......-.--MDIIOCX ~ • IJNTQ...... //./ '\..'-.. . ', .......... -{-.L .. . lifO ,, ·~, IOUWO Dto•OCOI -FAU·~ar-1 // ', I ---~--------··· ····--" ·. '\..._..-. . . . ,/ ·~ ~----------------------------- ~~, .... ·1 l I • • \. J/_ .. \.. I I . --· .. ~ '->_•, •• ,/ --• ·if-~-___d~~ ~-LS . ~ .. ___ ;, ~ ""' ,...,_,...., w .,. .... · ... ---·· ·--•.• -x:·;: •... T-.... -•. I I -----. -------... DAM PROF~ {.LOOI(flG IJP51QW,.) - .... .... ·--··-·-······----·----,---..... ~~ ........ IWL ----=~-··--!~~- '·-.......'fi"t.!r.';to~ t a._ ... __ • ~...... . ~ '• ' -14\liJAAL Slmi'AQI. •• , ~ (oiiGUT ruo.) --~ . "·' 1!00 '\'--. \ ' Ill UIIIMA•i'l\lk \ '' i5lULUtiiiiG • , . . .§ECTIOI-t T~RU SPILLWA.'I \...... '-', rt.a..!loo' ~--·:=t=r '! -.. . iili:~ . 1 ~ill"' ae"LI. o l!!!!!!!'!'!l"'[.i=;;;;;;;;:;~ (lbOIIT IWC) ;;o:~, ri>.W..TWL IlL. a'!IO' - ....__&Llt!VUMI Oli;!'~llOOW'7~ MObiL. 1\-....nOH 01' l44t' _, oot -· ...,._ .. -eout LIMo. Ill' out',~ ,. ..lUI VOl• t.tvr.l. -~ON. • ....... ... "• .. I ·-· lll.A!ICA MWII AUIHOIIIY • I I --SECTION lHRU POWER. FACILITIES J .. f' 'i D c • [ r r r ~r ("· r I I ( (: I~ ).:t.J ( ·;~ .. I.· ( I{ I I~ (. ---- c u • .I I i i I l I • • 0 0 !! (. .. " .... g . .. ,, ,, '• '• '• ,, ,, ,, lu IJI II! ,, t:1 •I bl i • 0 ~ 0 ~ 8 3 0 ~ !! :! ::!: a ! 0 0 ~ ! ~ l! • • 0 g I 8 2 UJ l.iJ . z I, S @ I en ! I .,..------..-----------------------------------,....:=~,.~--+-f"'ifi't1 ,.,. __________ ...., _______________ ,, ______________ :?~;...-.~...::;-.~.,.(--f~- • Cl u • v... ·-·- [- ( ('- ( I ,. •• I I. (. ~ ... ·~ I. ,._ r: I I~' ·~ I 3 ~ COMPARISON OF LAYOUTS As the arch dam, saddie dam, power facilities and diversion vary only in a minor degree between the alternatives, a comparison of schemes rests solely with a comparison of the spillway facilities. As can be seen from a comparison of costs in Table 1, the flip-bucket spillways are substantially cheaper to construct than the stilling-basin type of Scheme 3. The left side spillway of Scheme 2 runs at a sharp angle to the river eject the discharge jet from high on the canyon face towards the opposite side of the canyon. Over a long period of operation, scour of the heavily jointed rock could be a considerable problem causing undermining of the canyon sides and their consequent instability together with the possibility of a build-up of material downs~ream with a corresponding elevation of the tailrace. Construction of a spillway on the steep left side of the river could be more difficult than on the right si1e because of the presence of deep fissures and 1 arge unstab 1 e blocks of rock ~:1 ose to the top of the canyon. The right side flip-bucket spi'i'lway takes advantage of a downstream bend in the river to eject discharges parallel to the course of the river. This will reduce the effects of erosion, but it :ould still be a serious problem. The safest spillway would be th1! stilling-basin type of Scheme 3 which would greatly reduce any erosion prob'lems 'within the canyon. Cavitation could be a problem under the high flow velocities experienced at the base of the chute but· this would be alleviated by aeration of the flows. r· r r I I I •• I I ••• ,. I I ~~- 1 ,. I· ' I' . I 1'. I 4 -SELECTED LAYOUT The chute and flip-bucket spillways of Schemes 1 and 2 pose large erosion problems which will entail considerable maintenance costs and reduced efficiency in operation of the project at a future date. The anticipated maximum scour will also be unacceptable environmentally. The additional cost of a stilling basin over the right side flip-bucket spillway is $62 million including contingencies, engineering, and administration. This appears a relatively small cost for the additional security of this type of spillway~ and Scheme 3 was therefore selected as the most favorable layout for additional study. ~-Further development of the Scheme 3 layout has resulted in the currently preferred arrangement shown in Plates 9.1 and 9~2. - •• • -•• •• f I. (: I I •• I •• I I. I I: I. • 0 u • ------.r--____ . -. / -----~ c u • --·---. I u • c ..... . ... .. I I 0 i I I I Iii r J .. I ! ! .. . 1! I j! l i -!!_ l ! I • I ~ @ § I -l ~ ~ ~ I I i • ! I l ' I 1 I I i ~ I I ~ _§ a I I I ' I I I 01 I ~ ~ ~ § g -~ I I I I .I I i I 8 § I ~ l.'l I· u II c: .... I v-... _ I· DEVIL CANYON ARCH DAM DESIGN :1, ~ ! .-t' 1 ·-l l• "l l' l '1, / . . • "1. :I .I ··: ,~ ~~ I l lt I I I ABSTRP.t.:T FR0~1 DEVIL CANYON ARCH 0~1 DESIGN REPORT I I I I I ' . I: ~. I· 1:. I 4 -DESIGN CRITERIA 4.1 -Material Properties a) Concrete Frost Resistance Concrete Strength (365 day) Unit Weight Static Modulus of Elasticity (sustained) Dynamic Modulus of Elasticity {instantaneous) Poissons Ratio Tensile Strength: Static (for estimating cracking only) 5% of strength Dynamic Flexural 15% of strength Thermal Properties: Conductivity Specific Heat Coefficient of Thermal Expansion Diffusivity I[_ b) Foundation Rock ' I . ,.. I I. ~. ·: 'I '· I ~~ It ( I Deformation Modulus (sustained) Poissons Ratio 4.2 -Temperatures (°F) Air Temperature: Mean Annual High Mean Monthly Low Mean Monthly Highest Mean Monthly Maximum Lowest Mean Monthly Minimum ,c- 5,000 psi 150 1b/ft3 3 x 106 psi 5 x 106 psi 0.2 250 psi 750 psi 1.52 BTU/ft/hr/°F 0 .. 22 BTU/lb/°F -6 5.6 X 10 ft/ft/°F 0.046 ft2/hr 2 x 106 psi 0.2 28.9 55.0 4.4 63.8 -3.6 I I ~- 1· 11 I I J ll-. I ( f, I . -... ' .. ~-,: ,_ . I·· 1.· Highest Maximum Lowest Minimum Lowest Difference Between Any Mean Monthly Maximum and the Corresponding Mean Monthly Minimum RESERVOIR WATER TEMPERATURE Depth Below M .o N T H Surface (ft) 4 5 6 7 8 9 10 11 0 -50 32 32 46 57_ 53_ 45 39 32 70 to Reser- voir Bottom 39 39 39 39 39 39 39 39 12 32 39 91.0 -48.0 -14.5 1 _g 39 The effect of solar radiation has been at this stage neglected. Grouting temperature of vertical construction joints: 39°F 4.3 -Earthquake 2 3 _g ~ 39 39 For maximum credible earthquake conditions two versions of the mean response spectra for the Penioff zone, developed by Woodward Clyde Consultants have been used .. Peak Ground Acceleration 0.5 g 0.4 9 4.4 -Hydraulic Data Reservoir Water Levels: Normal Maximum *Normal Minimum 1:10,000 Yr Flood Level Probable Maximum Flood Damping Factor 5% 10% 1,455 ft 1,430 ft 1,460 ft 1,465 ft I I I ' ' 1 •. 11 1-.. -:.,.. I ~~ I. .. [· J~' If' fl:.. J . . ... t. f·- -. . Effe:ct of tai1water, silt deposits, ice load, and uplift loads (internal pres- sure within the dam) have been neglected. *This was a~sumed as 1,295 ft for stress calculations. However, minimum operat- ing 1eve1 has now been maintained at 1,430 ft from standpoint of firm energy considerations. Hence, this condition will be far less extreme. 4.5 -Loading Combinations£ a) Q2ual Loading Combination -Combination of basic loads that can simultaneously occur during time design life of the dam (self-weight, te!mperature and hydrostatic load condition.) b) ~1usual Loading Combination -Combination of loads that are possible, but which are unlikely to occur during the design life of the dam (probable maximum flood conditions.) c) gxtreme Loading Combination -Are related to earthquakes. The loading combinations cases are given in Table 4.1. 4.6 -Factors of Safety: a) Usual Loading Case UL-1, UL-2 -Compressive stresses-F.o.s. > 4 -Tension stresses -not allowable.* b) Usual Loading Case UL-3, UL-4, and Unusual Case -Compressive stresses -F.o.s. > 3 -Tension stresses not to exceed 250 psi. -Tensile stresses above 250 psi are to be redistributed to other resistance mechanisms by local joint openings. *These factors of safety correspond to the trial load method and are in line with the previous practice. They do not necessarily apply to other methods of analysis. I I • '. I t I I . - JJ' l I J I. IJ. I I: il I. I. , ....... J l ~- 1 I c) Extreme Loading Case EL-l, EL-2 -Compressive stresses -F. 0. S. > 1. -Tension stresses exceeding the tens·; 1 e strength of 750 psi are to be redistributed to other resistance mechanisms. In case of horizontal tensile stresses across the arches the dam should be considered as a set of unrestrained cantilevers 50 percent of full height, because of opening vertical construction joints. ioJii llfl!'l"' ... * . " --' ~ ~ ~1 QJ!~!I!. " ~ ~ 1Jlll' :~ ~~ ;~ ~ ... ----~·~ ...... ~ :"'"~· ····-,~ ... ~~ +~ ~ ~ .··~ ',_ TABlf: 4.1 I L:oml)1nat1on L:lass u 5 U A l Unusual t_)\ I rcme lo!!d Combination 1 _!:omb_!na~1on N~Jmj1er lll·-1. Ul-2 Ul-J ~-~ YNl..-J Jl..~l II..-~ 5 0 [A 0 l 0 A 0 )( X X X X X X . T A B T A I Ail' and Reservoir rcbruat·y ~ s c I Water T emperatm·es April X c l - 0 Rmmrvoir Water 1_f_455 I X X X X . A l,Lib) X 0 levels l,Z~~ X l s ~ X }\ 0 A 0 0 v N A H 0.5 G c I Ma)\imum Credible 5~ Damp. X A r. 5 E t larthquake 0.4G . s 0 10 Oampe X A 0 5 I I .~ . J· ·-. I. • ·-' I I_ ~~ It I. I a I. \1_ ~ ~ : 5 -METHOD OF ANALYSIS 5.1 -General The Arch Dam Stress Analysis System (ADSAS) program which is a computerized version of the trial load method, is used for static and earthquake dynamic analysis. In the analysis the arch dam is assumed to be a continuous structure. The dead load is applied in the cantilever direction (construction joints grouted at full height of sections). The computer program SAP IV is used for the unrestrained crown cantilever analy- sis in cases where the dam is subjected to strong earthquake motions, causing opening of the upper part of vertical construction joints. 5.2 -Method of Definition of Loads a) Temperature Load The two-dimensional heat transfer program (heatflow) is used for determination of temperature distribution in the dam body. The USBR Engineering Monography N34 is used for computation of the amplitude of the sinusoidal cycles, (Annual, 15-Day and Daily). The temperature loads input into ADSAS are presented in Appendix A. b) Hydrodynamic Load The hydrodynamic pressure due to horizontal earthquake on the dam upstream face C'added mass") is defined by using Westergaards Formula and is reduced to 60%, due to the effect of narrowness of the gorge, inclination of the dam face and water compressibility (see Appendix C.) I . ' I I I I ., • . •• ~ J I ··- 1' I I I ' 11 ! I ! 11 I ~. Jl 'I \ . 'I J, L., 6 -ARCH DAM GEOMETRY The arch dam abutments are founded on the sound bedrock of the canyon. The sound unweathered rock is determined as generally 40 feet below the bedrock surface and the foundation is trimmed so as not to cause an abrupt change in the dam profile and hence a concentration of stresses. At the bottom of the valley, the dam sits on a massive concrete plug which can adjust to any disconformities of the bedrock at the valley floor without changing the geometry of the dam • i mate ly e 1 evat ion 1350 feet on the structed to take the thrust of the Sound bedrock does not continue above approx- left bank and a massive thrust block is con- upper 100 feet of arches. A similar block is founded deep in the rock on the right side in order to preserve the symmetry of the dam profile. The dam geometry is shown on Plate 6.2. It is a double curvature structure with the cupola shape of the crown cantilever defined by vertical curves of approxi- mately 1352 feet and 869 foot radius. The horizontal arches are prescribed by varying radii moving along two pairs of center lines. The shorter radii of the intrados face cause a broadening of the arches at the abutment reducing the con- tact stresses. The dam reference plane is approximately cent~al to the bottom of the valley and the two center configuration assign longer radii to the arches on the wider side of the valley thus providing comparable contact areas on both sides of the arches at the concrete/rock interface.. The 1 onger radi. i wi 11 a 1 so allow the thrust from the arches to be directed more into the abutment rather than parallel to the river. The net eff~ct of this two center layout will be to improve the symmetry of the stresses right across the dam. . The crown cantilever is 635 feet high. It is 20 feet thick at the crest and 90 feet thick at the base. The bottom mass concrete plug is 50 feet high. The slenderness coefficient of the arch is equal to 90/635 = 0,142 and the radii of the dam axis at crest level are 710 feet and 780 feet for the left and right angles of the dam, respectively. The centrai angles vary between 51.5 DEG at El. 1300 and 25 DEG at the base for the left side of the arch dam and 58 DEG to 30 DEG for the right side. The ratio of crest length to height for the dam is 1260:635 = 1.98:1 (thrust blocks not included). I I .~ I <\' I I ·, < I . I ••• '1 I . ' ae-,,. I ' . • ' 1: I I I . •• ·JJ: I j . ' I •• The left bank thrust block is 105 feet high and 170 feet long at the base. The right bank thrust block has a maximum height of 100 feet and a length of 155 . feet and is adjacent to the spillway contro 1 structure, which wi 11 behave as a continuation of the thrust block, transferring the thrust directly into the rock. r r- r~ . r· t r t . r· r· r I' ( [ [ ( [•' [ (. ir;· J ~ ; ~1 "' :0. *" ;( •\ ·: ~~ . I ' ~.~.; ~1 J 7 -STATIC LOAD CONDITIONS 7.1 -Dead Load - In all analyses, the vertical construction joints within the dam are assumed to be ungrouted and hence the weight of the dam is considered as confined within the cantilevers, with no distribution through the arches, and directed verti- cally downwards into the foundation • 7.2 -Hydrostatic Hydrostatic loadings induced by the reservoir at specified levels were consid- ered in all load combinations. The effect of tailwater and uplift pressures will have little effect on the overall stresses and are not considered at this time. 7.3 -Temperature (a) Solar Radiation The dam orientation, running north-south, and the narrow valley will cause solar radiation to have only minor effects on concrste temperatures and hence stresses from radiation will be neglected at this time. (b) Air Temperatures Because of absence of temperature records, temperatures at the Devil Canyon site have been interpolated from records taken at two stations: Surrmit (El. 2405 feet) and Talkeetna (El. 345 feet). The stations are equidistant from Watana and their average altitude is similar to river level at Watana. The temperatures from the two stations were averaged to obtain the following temperatures at the dam site: - ·r f·· f r·- r·- r··. r-. ,. [ f" r· ( r·. [« ,. I" ' I. I (c) .AMBIENT AIR TEMPERATURE {°F) Mean Annual • • . . • • • • • • • • • . . • • . . . • • • • • • • • • • • • • • • • • • • • • . • 28.9 High Mean Monthly • • . • • • • • • • • • • . • . • . • • . . • . • • • . . • . • • • • . • 55.0 Low Mean Monthly ······••a····························· 4 .. 4 Highest Mean Monthly Maximum···············~·········· 63.8 Lowest Mean Monthly Minimum ••••.••••••••••••••••••••.. -3.6 Highest Maximum .••••.•••..•••.••.•.••.•.•.•..•••.•..•. 91.0 Lowest Minimum •••••••.••••••..•.••.•.••...••••..••••.. -48.0 Lowest Difference between any Mean Monthly Maximum and the Corresponding Mean Monthly Minimum .•.•.•••••••••.••••••.••••••.••••..••• 14.5 Three sinusoidal temperature cycles-annual, 15-day and daily are developed based on USBR ENG MONOGRAPH No. 34. The temperatures obtained are as follows: EXTREME CONDITIONS USUAL CONDITIONS Above Below Above Below Mean (DEGF) Mean (DEGF) Mean (DEGF) Mean (DEGF) Annual 26.1 24.5 26.1 24.5 15-day 28.8 42.15 15.15 22 .. 95 Daily 7.25 7.25 7.25 7.25 Reservoir Water Tem2eratur~ Average monthly reservoir temperatures are given below. Temperatures throughout the top 50 feet are as shown and below 50 feet they vary lineraly to 39°F at a depth of 70 feet. I ~ ' .. I I . I· I \ r I I (• f~. I I .:. ·. ·~ ( li ~~ I r I . I I (d) (e) Month April May June July August September October November December January February March Grouting Temperature 32 32 46 57 53 45 39 32 32 32 32 32 Below 70 ft From Surface (°F) 39 39 On account of the cold climate and the possibility of freezing, grouting temperature was selected at 39°F, as low as considered practicable, in order to reduce tension in the dam induced by shrinkage at lower tempera- tures. Temperature Distribution The temperature distribution in the dam body was determined using the two dimensional heat transfer program "HEATFLOW" obtained from the u.s. Department of the Interior (formerly USBR) and was input as a uniform tem- perature combined with a linear distribution as described in Appendix A. - I I 7.4 -Load. Combinations I Static analyses were performed for the following normal loading combinations: • I I ' I I· ' I f j I I,. I' I I. II I I I I UL-1 Hydrostatic and dead loads at normal reservoir level 1445 feet UL-2 -Hydrostatic and dead loads at maximum drawdown reservoir level 1295 feet UL-3 -The same as UL-1 p 1 us temperature (February) UL-4-The same as UL-2 plus temperature (April) UL-1 and UL-2 Conditions The cantilever and arch stresses along the face of the dam are shown in Figures 87-1 to 87-4 in Appendix B. In both the arch and cantilever directions, the entire structure is in compression and below the allowable stress of 1250 psi, except for a few isolated areas where small tensile stresses occur. Maximum (compression) and minimum (tension) stress for conditions Ul-1 an UL-2 are shown in Tab 1 e 7 .1. The arch and cantilever stresses for loading combinations UL-3 and UL-4 are shown in Figures 7.5 to 7.12. The maximum and minimum stresses along the rock/concrete interface and in the dam above the foundation are given in Table 7.2. 7.5 -Conclusion (1) Under hydrostatic loading~ minor isolated tensile stresses occur up to a maximum of 97 psi. (2) In both cases with temperature loadings UL-3 and UL-4, the compressive stresses are below the allowable limit. - i ,I I I I I I I I I I I I I I I I ' I !'"'• I I ·I I (3) In UL-3 case, tensile stresses are acting in isolated areas. The tensile stresses is possible to eliminate by refining the shape of the arch. (4) In UL-4 case, the crest of the dam is in the arch direction subjected to almost axial tension. Tensile stresses up to 200 psi are found at the whole height of the crown downstream face. Prevention of these tensile stresses is possible orily by application of special measures such as: -Low closure temperatures at the upper part of the arch which may be obtained by using closure slots between a~jacent blocks filled up with concrete in spring time when the blocks are at mi~imum temperature. Thermal insulation of the downstream face. -Prestressing the upper part of the dam by means of flat jacks. I I 11 I I I r· I I ll •• I II II I I I I I Arch ~1ax Min Cantilever Max Min Principal t·1ax ~,in TABLE 7.1 EXTREME ~1AGN !TUDES OF STRESS£5 ~~~~~~~~~~.~- ;..;.AT;.....o.;..;RO;;.;;C-.;:KI;...;:C;.;:;,;ON_C;.;;.;R;;;.;ET;..;;;;E..-I;;.;.;N~TE;;.;.;R;;..;:F A-=-CE Loading Combination (stresses in psi) UL-1 792 (D. El 1100) 23 ( U. El 1 000) 722 (D. E1 820) -27 (D El 1370) -indicates tension ! D indicates downstream face · U indicates upstream face UL-2 432 (U El 900) 3 (U El 1000) 760 (U El 900) -97 (0 El 1200) MAXIMUM STRESSES IN DAM ABOVE FOUNDATION Arch Max ~1in Cantilever . Max Min UL-1 958 (U El 1100} 182 ( D El 1 000) 575 (D E1 1000) 0 (D El 1370) - UL-2 548 (U El 1 000) -36 (D E1 1370) 542 (U E1 1000) -44 (U E1 1295) I I I· • I I I I -='J' I . I. I I I ll I I I I 11 Arch Max Min Canti 1 ever _ . Max Min Arch f-1a.x Min Cantilever Max Min TABtE 7.2 - EXTREME MAGNITUDES OF STRESS ALONG ROCK/CONCRETE INTERFACE Loading Combination UL-3 (point) 747 (U El 900) -182 (U El 1455) 689 (D El 820) -393 {D El 1370) EXTREME MAGNITUDES OF STRESSES IN DAM ABOVE FOUNDATION Loading Combination UL-3 (point) 1180 (U E1 1200) -134 (D E1 1000) ~ U El 1455l 515 (U E1 900) -75 (D E1 1370) UL-4 (point) 381 (D 1100) -157 (D 900) 804 (U El 900) -281 {D E1 1455) UL-4 (point) 717 ( U E1 1 1 00) -268 (U E1 1455) 608 ( U El 1 000) -62 (U E1 1295) I I 'I •• I I 1- ~~ 11 . ' ~. I -. IJ I I I 8 -DYNAMIC ANALYSES Preliminary assumptions for purposes of analysis are as follows: The assumed response spectra input to ADSAS is from Figure 3-4 of the Woodward Clyde Draft Report "Preliminary Earthquake Ground Motion Studies for the Proposed Susitna Hydroelectric Project". The mean response spectra for the Benioff zone is scaled up to 0.5g peak from 0.37g. The damping ratio is five percent. The response spectrum is shown in Figure 8.1. The response spectrum analysis was initially attempted for 1 to 20 modeso A larger displacerrient mode was encountered on mode 19. The high displacement induced unreasonable stresses in the dam and therefore made the results useless. The problem was re-analyzed usi n·g 14 modes of vibration. The response spectrum analysis assumed an instantaneous concrete modulus of 5,000,000 psi. The results of positive and negative earthquake are presented in the following tables. The load combinations are hydrostatic and grvity ~ earthquake and hydrostatic+ gravity+ uniform and linear temperature~ earthquake: Table 8.1 -Response Sectrum Analysis -Arch Stresses Table 8.2 -Crown Cantilever Stresses The resultant tensile stresses of 2580 psi and 729 psi in the arch and canti- levers, respectively, are greatly in access of the allowable tensile stress of 500 psi. The results of a dynamic analysis of Devil Canyon Arch Dam based on a 0.4g peak ground acceleration, 10% damping, the Woodward Clyde Consultants response spectrum (see Figures 8.2) and using the ADSAS program are shown on Figures B.l5 and B.l6. For comparison, the results of dynamic analyses for a peak ground acceleration 0.5g and 5% damping are presented on Figures B.13 and B.14 -' I I I I , .. I I ll II I I IJ I I , ~- 1 I I I The change of earthquake parameters to 0.4g and 10% damping has reduced the compressive, tensile and shear stresses at all points on the dam faces ·by a fac·tor of 1.58 con~oared to the 0.5g acceleration and 5% damping case. The case of upstream ground movement (hydrostatic, gravity and earthquake loads), the maximum cantilever tensile stress at the upstream face dropped from 729 psi to 427 psi (at elevation 1285 feet on the crown cantilever). The maxi- mum compressive arch stresses at the upstream face (crown El. 1370) dropped from 3657 psi to 2551 psi. Stresses on the downstream face are much lower than on the upstream. Downstream ground movement (hydrostatic and gravity minus·earthquake load) shows extr·emely high tensile stresses across the arches (see Table 8.3). The stresses computed are not realistic. As discovered by field observations and model tests on other projects, earthquake induced ground movement in the downstream direc- tion causes the radial construction joints at the upper part of an arch dam to open. The tension induced in the upper part of these arches is relaxed and the dam evolves into a set of independent, unrestrained cantilevers, deflecting freely in the upstream direction. In m·der to accord more closely with the actual behavior of the Devil Canyon Arch Dam, when subjected to strong earthquake motions, dynamic analyses on the unrestrained crown cantilever were performed using the computer program SAPIV. Model test on other arch dams with simulated radial construction joints, per- formed by 11 lSMES" have shown that opening of the joints take place over the top 1/3 to l/2 (depending on the narrowness at the gorge) of the dam, while the lower part remained intack. The analyses are based on: (1) The Woodward Clyde Consultants response spectrum curves for the Benioff zone with peak ground accelerations of 0.5g and 0.4g and damping rates of · 5% and 10%. I I ifi ·~ I I ll I ·-· 1 ·j .... ;' I I I I I The change of earthquake parameters to 0.4g and 10% damping has reduced the compressive, tensile and shear stresses at all points on the dam faces ·by a factor of 1.58 compared to the O.Sg acceleration and 5% damping case. The case of upstream ground movement (hydrostatic, gravity and earthquake loads), the maximum cantilever tensile stress at the upstream face dropped from 729 psi to 427 psi (at elevation 1285 feet on the crown cantilever). The maxi- mum compressive arch stresses at the upstream face (crown El. 1370) dropped from 3657 psi to 2551 psi. Stresses on the downstream face are much lower than on the upstream. Downstream ground movement (hydrostatic and gravity minus·earthquake load) shows extremely high tensile stresses across the arches (see Table 8.3). The stresses computed are not realistico As discovered by field observations and model tests on other projects, earthquake induced ground movement in the downstream direc- tion causes the radial construction joints at the upper part of an arch dam to open. The tension induced in the upper part of these arches is relaxed and the dam evolves into a set of independent, unrestrained cantilevers, deflecting freely in the upstream direction. In order to accord more closely with the actual behavior of the Devil Canyon Arch Dam, when subjected to strong earthquake motions, dynamic analyses on the unrestrained crown cantilever were performed using the computer program SAPIV. Model test on other arch daws with simulated radial construction joints, per- formed by 11 ISMES 11 have shown that opening of the joints take place over the top 1/3 to 1/2 (depending on the narrowness at the gorge) of the dam, while the lower part remained intack. The analyses are based on: {1) The Woodward Clyde Consultants response spectrum curves for the B~nioff zone with peak ground accelerations of O.Sg and 0.4g and damping rates of · 5% and 10%. - I I I l I I l I 11 I I .,~ I ~ '¢~· 11 - I I- I I (2) The hydrodynamic stress distribution as proposed by Westerguard approach and reduced to 60% due to the effect of narrowness of the gorge, inclina- tion of the dam upstre~~ face and water compressibil)ty (see Appendix C). (3} Full reservoir water level 1445 feet computer program for dynamic analysis has been used. The following combinations of earthquake parameters have been examined: Peak Ground Acceleration 11 G11 0.5 0.4 Damping Ratio (Percent) 5 10 5 10 The results of the cantilever dynamic analysis are as follows: Added Mass (Percent) 100 60 100 60 100 60 100 60 (1} The natural period of vibration urn is 0.62 sec, 0.15 sec and 0.09 sec. (Various magnitudes of acceleration and added mass have little effect). For comparison, a full height cantilever, which is slender, has been computed. The periods were found 2.42 sec, 0.49 sec and 0.20 sec. The stresses in the upper part of the arch in this case were smaller than in the short cantilever. - I I ,. '& I l I. I I I I I ~~ II I I (2) The stresses due to hydrostatic. and gravity and dynamic loads are presented separately and in combinations. In Tables 8.4 and 8.5 and in Figure 4, maximum tensile stresses of 880 psi at the downstream face were obtained in the case of O.Sg, 5% damping and full Westergaard•s added mass at 170 feet below crest level. Compressive stresses at the upstream face at that level are 1100 psi. The maximum tensile stres~ case of O.Sgt 10% damping and 60% of Westergaard's added mass are equal \o 451 psi. The change of damping ·from 5% to 10% decreases the maximum tensile stresses approximately 1.6 times .. The application of 60% added mass instead of full "Westergaard's provides a reduction of the maximum tensile stresses of about 25%. In all combinations of dyanmic loads considered, the tensile stresses at the base of cantilever have changed to compressive {except of case O.Sg, 5% damping and full added mass, where tension is reduced to 55 psi) {Figure 8.4). In the case of 0.4g, ground acceleration, the maximum tensile stresses at the downstream face of cantilever dropped to 509 psi 120 feet below the crest with 5% damping and full added mass, and to 272 psi with 10% damping and 60% added mass. The effects of the change in damping and added mass ar~ approximately the same as in the case of O.Sg acceleration. I I I I " i) Arch at Elv. 1455' (• I STATION FACE I E 1000 I . ~ I E I 1143 I E I 1259 I I E 1393 I I E 1526 I I " E 1638 t -~"' I E 1711 11 I E I I : 1714 I I (. I ...... I TABLE S.it RESPONSE SPECTRUM ANALYSIS HYDRO + HYDRO + HYDRO + I HYDRO + GRV GRAVITY GRAVITY + EO GRAVITY-EO + TEMP + EO 467 3404 -2470 3294 313 1943 -1630 1784 516 3229 -2197 3122 307 2304 -1690 2146 484 2948 -1980 2843 366 2749 -2017 2611 406 2¢98 -1686 2383 438 3019 -2143 2896 324 2033 -1385 1877 417 2566 -1732 2376 303 1591 -985 1356 342 2232 -1548 1962 274 2513 -1965 2105 576 2409 -1257 2465 267 2574 -2040 2125 607 2478 -1267 2596 I HYDRO + GRV. + TE~1P -EO -2580 ·.,... -1476 .. 2304 -1848 -2085 -2155 >;·' -1801 -2266 -1541 -1922 -1220 -1818 -2373 -1201 -2409 -1146 I I I .I I I ( ~ £.. .. ·I I I I I t .... -.,...-" ,, -~- t ... , I'; I • -~ I . I IJ" .. TABLE 8.1 RESPONSE SPECTRUM ANALYSIS ii) Arch at Elev. 1370' I FACE I H.YDRO + HYDRO + I HYDRO + STATION GRAVITY GRV + EQ GRV -EQ E 642 3657 -237.3 1000 I 255 949 -439 E 707 3222 -1808 1143 ' I 258 1597 -1081 E 593 2461 -1275 1259 I 396 2247 -1455 E 416 1634 -802 1393 ~a I 518 2558 -1522 ': E 295 1188 -598 1526 I 498 2383 -1387 E 206 1071 -659 1638 I 413 1979 -1153 E 110 1220 -1000 1711 I 374 1449 -701 - I HYDRO + GRV I HYDRO + GRV + TEMP + EQ +"TEMP -EO 4119 -1911 I 697 -691 3677 -1353 1355 -1323 2884 -852 2021 -1681 2006 -430 2323 -1757 1511 -275 2111 -1659 1297 -433 1733 -1399 1266 -954 1345 -805 I I I I I I I I I I I I I I i . I I I I aEV. FACE u 1455 0 u 1370 D u 1285 D u 1200 0 u 1100 0 u 1000 0 u 900 D u 820 0 TABLE 8.2 RESPONSE SPECTRUM ANALYSIS CR0~1N CANT! LEVER HYDRO + HYDRO:'.+ HYDRO + GRAVITY GRAVITY + EQ GRAVITY-EO 0 0 0 0 0 0 109 -581 799 56 653 -561 98 -729 925 222 1021 -577 71 -629 771 402 1111 -307 102 -435 639 544 1110 -22 223 -142 638 575 1026 124 383 -19 785 539 988 90 305 -402 1012 722 1541 -97 HYDRO + GRV HYDRO + GRV + TEMP + EO + TEMP -EO 0 0 0 0 -564 816 658 -576 -655 999 950 -648 -508 892 988 -430 -282 792 948 -184 -31 799 851 -51 113 917 842 -56 -373 1041 1508 -130 ~ ~--~ ~-~-~·~: ~ ~ ~ ~ ~.~.~ ~ ~-~ ~ TABLE 8.3 .. u a.., 1 nn\la.. na..unu 1 ua.. nn\111 \ t 1 I_ EARTHQUAKE E.LEVA1ION)UF FACE Of DAM CROWN ABUTMEfU AIRCH FT. 0 143 394 638 714 0.5G u -2470 -2197 -1686 -985 -2040 1455 D -1630 -1690 -2143 -1548 -1267 5% Damp. u -2373 -1808 -803 -659 -1000 1370 D -439 -1081 -1522 -1153 -701 u -1392 -1203 -919 -512 -1149 0.4G 1455 . D -720 -957 -1196 -855 -757 u -1267 -887 -3~)5 -341 -592 10% Damp. 1370 D _ _ _o.JHS_ _ _ ___ -~ _ ______-: 5tl9~ ~-_-1li_ -578 -306 ---------~---------------------~-~-----------~ ------~~- ': . w:--:= Node 2 J 4 5 6 1 8 ~. ..,. ' ~., ~i ~i .Jillll. _., --· ,..,. .. <.., • -p ,... . .,... 5t resses uue to Static loads (Hydrostatic & Grav ·tv) (psi) Elevation Upstream Uownstrean (ft) face · face 1428 -5 29 1375 -72 148 1322 -265 405 1269 -530 750 1216 -930 1230 1163 -1495 1885 1110 -2295 2785 Table 8.4 DEVIL CANYON ARCH DAM RESULTS Of SINGLE CANTILEVER DYNAMIC ANALYSIS fOR 0.5 G PEAK GROUND ACCELERATION Stresses We to terthqual<e loads Resultant Stresses (Concrete Inertia & Added Haas at Downstream face (psi) of Water -WeEter Goard) -100~ Ac ded Mass 6U:'G Adc ed Haas 10U:'C A( ded Mass 60~ Added! Mass 5~ Damp 10% Damp 5~ Damp 10~ Damp 5~ Damp 10~ Damp 5~ DamP 10~ Damp· + lBO + 144 +177 + 141 -151 -114 -148 -112 + 760 + 604 + 685 + 546 -612 -456 -537 -398 "+1210 + 960 +1075 + 856 -805 -555* -670 -451* +16)0 +1300 +1450 "+1150 -880* -550 -700* -400 +2060 "+16)5 +1823 +1440 -OJO -405 -593 -210 +2620 "+2001 "+2300 +1825 -735 -196 -415 60 +2840 +2255 +2490 +1570 -55 530 205 315 -- Notes: 1. Resultant stresses are computed for dynamic loads applied upstream I 2. "*" indicates maximum tensile stresses; "011 indicates corresponding compressive stresses at the opposite side of the same level. 3. (-) indlcatas tension. ~ ··fiM .. .. ... Resultant Stresses at Upstream face (psi) · 1UUJ; Ac 'dad Mass 60~ A( ided Mass 5~ DamP 10% DamP 5~ Damp 10% Damp 175 139 172 1J6 608 5J2 613 474 945 695° 810 591° 1100° 770 920° 620 1135 '105 89) 510 1125 536 805 :uo 545 -70 195 -325 -· ~ ~-1\111 . .. : . ,_,., ' ... 1 Stresses uue to Static loads ... ... -... ,...... --- Table 8.5 DEVIL CANYON ARCH DAM RESULTS or SINGLE CANTILEVER DYNAMIC ANALYSIS FOR 0.4 G PEAK GROUND ACCELERATION :>tresses Due to t.arthqual<e loads Hesultant Stresses (Concrete Inertia & Added t-1ass at Downstream Face (osi) - (Hydrostatic & of Water -Wester Gaard) Gravitv) (psi) 1uu:. Ac ded t~ass 6U:O Am ed Mass -1UU~ Ac ded Mass 6U~ Addeo tfass . ; Elevation Upstream Downstreao Node (ft) race race 5~ Damp 10% Demo 5% Demo 10% Damp 2 1425 -5 29 + 143 + 114 + 140 + 112 3 1375 -72 148 + 571 + 459 + 520 + 420 4 1322 -265 405 + 914 + 727 + 026 + 656 5 1269 -530 750 +123) + 977 +1110 + 805 6 1216 -930 1230 +1547 +1230 '+1394 +1105 7 1163 -1495 1885 +1971 +1560 +1750 +1390 0 1110 -2295 2795 +2130 "+1692 '+1097 +'1504 Notes: 1. Resultant stresses are computed for dynamic loads applied upstream 2. "*" indicates maximum tensile stresses; 11011 indicates corresponding compressive stresses at the opposite side of the same level. J. (-) indicates tension • ---~ 5~ Damp 10% Demo 5% Damo 10~ Damp -114 -85 -111 -8J -429 -311 -380 -272*. -509* -322* -421* -251 -483 -227 -360 -135 -317 0 -164 125 -86 325 135 495 655 1093 aao 1301 --~ -- Hesultant Stresses at Upstream race {osi) 100~ A( ided Mass 6U:. A( lded Moss 5~ Damp 10~ Demo 5% Damo 10~ Damp 138 109 135 107 505 J82 li56 340° 649° 462° 561° 391 703 447 580 J55 617 300 464 175 476 65 255 -105 -165 -603 -398 -791 .. •• -.. --· ......... -: ... --... ·--:----.. I I .. 1.2 .. . •• . Damping Ratio =r 0.05! 1.0 + + ' . o; 0.8 t-. •J \ ~Benioff ~one . - (/)"' .. c 0 ·p ~ cu . Qj 0.6 u u ~ ~ l 0.4l . I / "'' \~Denali Fault . . . . . ap • 0.~7g -• + . ..;' -1- o• • 1 · 1 1 1 I 0.01 0.03 0.1 . . ·~ 0.3 1 3 10 ~:-. .. Period (seconds) MEAN RESPONSE SPECTRA AT THE DEVIL'S CANYON SITE FOR MAXIMUM EARTHQUAKES ON KNOWN ACTIVE FAUlTS Figure 8.1 ··. :.::" ':. ---.... -·· -·· ... -· -... .., .. --.. ·--... - .. .. ,-... Ol ........ rO en " c::: 0 .,.. ......, rO ~ a; r- QJ u u o::( r- fd S-...., u QJ 0. V) 1.2,------------------r l 1.0 0.8 0.6 0.4 0.2 a = 0.379 p a = 0.21g p DAMPING RATIO= 0.10 .{ BENIOFF ZONE ~ DENALI FAULT Period (seconds) 0~------~~--------~------------------~--------~--------~ 0.01 0,03 0.1 Prepared by Acres, 6/4/81 from data provided by M. Powers, WCC 0. 3 .. 1 . .. 3 10 MEAN RESPONSE.SPECTRA.AT THE DEVIL.CANYON.SITE FOR MAXIMUM EARTHQUAKES ON KNOWN ACTIVE .FAULTS Figure 8.2 -----··· l _ .......... . -: -·--·--·----·-·- :t " .. .• ~· ., r I OISIHTEGR.A..TEO PAR: OF' ARCH DAM J+A :t 'k • ![~ H.YOROSTATIC.: ~ ' ('I -• ~ -'Do~ ...... ul . :t':r~> ....... __ _ /?1-------~---------~- :ltL !i '\ miL 3 1 4o l+A f.l'(DR05TATIC ADDED MASS -151 -G-1'2 -80S -880 -eao -7D5 545 t;;;;;;;;J .. 65 A.SSUMI!.O Sci-QE.MI!. OF ANAL"{SIS ·as(·&?») (~4-8) !>8'2. f::::-.J-~11 (-'2.l2) -&2.'2 (-'251) (!>~) 44-1 W -221 (-l~s~ (l"lf>) !loo '===-/o ( 1'25) (·105) tP5 ,._ :J ~'2. 6 ( 4~1!1) ~ lnoh>»m 1 eog~ Q361) <:>.5 G f 6% DAMPING O .... G f 10" DAMPING 100~ AOOEO MASS 100% ~DE.O MASS (f !SO"-IN e>AACK.E.Ts) CANTILE.VE.I< 5TRE.55E.S (PSI) 5E..CTION A-A " n __ ,..... DIRECTION OF G~Ut.ID MOVEMIE.NT NOTE.: 9 (MINUS) IND:CATeS TENSIU:. STRESS CD (PLUS) lt-JDICA.TE.S COMPR.ES~IVI!. .STf2.ES5. bE.VIL CANYON ARCI4 DAM EARTI-IG>UAK.E DYNAMIC ANAL-'YSIS FIGURE o.a Iii -;:-~ .~ .- ,. ---~"' -<~" ..,_, J-'; _ ...... ,.....,_:.,_~~ ~ ~ !;._ _::, __ j_5~l._· __ ~_ -~--.t' ,, ... ,.,., .. -· .. ~.-....:...._:___.__:_~·- 'i f ·; "";:U;"~~~&~~~~~ .. , ·'··..;;;;.~.:: -· -··-· ·~· 'c~=•c~~•• ""~"' c·• J~ ''" ·•-~ • ~~c .• •·" " " .... ~~~-··="==~· """·--•·••• '"'"• : •. -··~•··• "">•; ,.,,.,],, I I fl fl fl I fl Ill- ~ 'I ' L ~ .I I •• . . ~1EETING AGENDA ., ~~~~~~~~~~~~~~.-·-------~~-~-~-~-~----:•=-·--··-~~;--. f~ ~~--:7:"--r .. r cumrmamw ' ' ~---~-. ·' ;:a:::;:u;::m;rmc I I :I . .. . I I 'I ,_1 •• :I :I :I ··I ~ ··~- . ;··I !I 1--'-- ;·I t_.- ~·· .. "_. •• I ·I I ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT EXTERNAL REVIEW BOARD MEETING #3 OCTOBER 6-8, 1981, BUFFALO, NoY . AGENDA OCTOBER 6. Moderator: D. Wozniak 0830 Introductory remarks -E. Yould 0845 Meeting objectives and study status -J. Lawrence 0915 Report on hydrologic field program -J. Hayden 1015 Coffee 1030 Report on seismic studies -J. Lovegreen 1130 Discussion · 1200 Lunch (brought in) 1300 Report on geotechnical field program -J. Gill 1400 Geotechnical interpretation: Watana -S. Thompson (Geology, construction materials, bedrock conditions, underground structures, relict channel) 1500 Coffee 1515 Discussion 1545 Geotechnical interpretation: Devil Canyon -S. Thompson (Geology, construction materials, bedrock conditions, underground structures)-· 1645 Discussion 1715 Adjourn 1830 Dinner -courtesy of Acres (M&T Plaza Suite) OCTOBER 7. Moderator: J. Gi11 0830 Introductory remarks -J. Lawrence 0845 Report on hydraul i.e studies -J. Hayden {power/energy estimates, flood estimates, reservoir level optimization, sedimentation studies) 1000 Coffee 1015 Discussion ~~ ---... [ :] ;-I .r1 f~l ' .. I ' l .. : ~ fl :··· ... !I cl . L.. fl L" rl { Lr~ r·l il \ i .__ rl '-'" . :I :I 1045 Watana Dam Design -D. W. Lamb/Ao S. Burgess 1200 Lunch {brought in) · 1300 Watana Spillway Studies J. Hayden 1345 Watana Layout Studies -J. Lawrence 1430 Discussion 1500 Coffee 1515 Watana/Devil Canyon Low Leve1 Outlets -R. Ibbotson 1545 Watana/Devil Canyon Power Developments -J. Hayden 1615 Discussion 1715 Adjourn OCTOBER 8. Moderator: D. Wozniak · 0830 Introductory remarks -J. Lawrence 0845 Devil Canyon Dam Design -R. Ibbotson 0930 Discussion 1000 Coffee 1015 Devil Canyon Spillway Studies -J. Hayden 1100 Devil Canyon Layout Studies -J. Lawrence h200 Lunch (as required) 1300 Discussion 1400 Adjourn (Panel to prepare report) 1630 Closing Statements: E. Yould/panel. page 2