Sus1tna Hydroelectric Project
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PROPOSAL FOR JUNE P979 SUS1TNA HYDROELECTRIC PROJECT PROPOSAL FOR SUPPLEMENTARY SLii3MISSI ON EARTHQUAKE EP:GlfiSEER iNG JUNE I979 The contents of -this pr~posaharepr~v%'ded -far tile sot e use OF the State of Alaska, the Alaska Pob~er Authority, a~dsuch other agerats of the A3 aska Pokier Authorl-ity as may be designated to i-evieitf aarrd evsnl uate its cont2ntsI Pin~prieta~yinfi)rmdtion IS eontc;ined heref no Unauthovs"zed reprsducta'on or disclosure of the contents, in k~5alecr in part, do ,ny individual or organization other than thosc specified, wi"th~lit the express approval of an sfF!cer of Acres h~erican,is strtctly prohibited, ALASKA POWER AURW09ITY --SUSTTNA HYDROELECTRIC PROJECT TABLE OF CONTENTS SUPPLEMENTARY SUBMISSION - EARVHQU,\KE ENGINEER 1NG 1, I NTR9DUCT ICN 2, ACEES AMERICAN CAPABILITIES 3, R&M CONSULTANTS CAPABILITIES 4. 14OOBWARD-CLYDE CONSULTANTS CAPABILITIES This document is a sugpl ementary submi ssion to the Acres-R&M-Elsul iu-SES proposal ts Alaska Power AuChori.tS, Far the Sess"nna Hydroelectl-i Project- The pukepose af- the skabm-jssion is to provide add-itkona'! dem~nstratkionof the capabjl l"", of Fhhe WRMT group in earthquake engineering and design of major projects 9" n sei smical7y act";e ereas To rtre~gdhenthe e~rpertise availabl e ts the group in earthquake enqgineerl'ng, the sbpport sei~vicesof Wss&,~at-d-ClydeConsultants Inc. have beer added $a the group on a ncn- exclusive bas -!s , Section 2 of this i;ubn-r"ssisn deals w-idh the capabill"&Ses of Acres in seismic work, Section 3 wfth R&M and Section 4 with Woodward-C%y(ie Csn- sul%?nts. These thtree members of the group bring to the Sms'tna Project a stk-sng team o.F expert-lse jointly capable of' hand7 iny a1 1 kispeclts of seismic design of major engineei-ing s tr~etures, particrr'l arly in f:he A? as kan env i ronment , 2, ACRES AMERICAN--- CAPABILITIES Acms has been $nvolred with several projects 'iocated in high-risk earthquake nones. Acres experience ranges from the chs7lectl"an sf seismic dal;a, skate- mekit of the problem, de"Lermi natr'r;asl a-F earthquake effects on f6u~d;ttion materials and earth structures, 1abimratory testing &sf dynamic progiei-tf es of the materials, and earthquake stability analysis both pseudnstati c and 4ynami c for design of structures including dams, pawrhouses, spi 1 l~jaysand sd;*ucturaf but ldings, A few of the recent prajects are ~cst"Ba"nedals fol IOWS, I KPONG HYDROELECTRIC PROJECT GHANA 1976-g~nesentlyunder construeti on Acres Kpeng Hydroelectrtc Project 5s located in a high earthquake rSsk zalze, $Re pmject consi s ts broad9 y sf cens~etestructures, a't7c"Pding a powei-house, a spillwqv kunrded @n bedrock, and an earth-fin dam and dikes approximately 4 miles long founded on f10odp"taa"pt sol1 deposits, di seismicfty stu@jwas carried out by Acres which led $0 consideratiofi of an earthquake tqitk Q,25 g acceleration in design, Dynaml'c analysis usfng the response spectrum techniques was utiRxed to cal cu'fate sejsmic loads 1nduced on &Re PQIJ~B~~QUS~ and spi l4wv structu~s, The enPpgy of design earthquake was accounted for In the stabilr"ty agalysfs for the eartn structure by appl isation of a constant horizontal accelera%%on ts tlhe cr.a""%s"cals"%atjs failurta concE.Stfon, The djkes are founded an fIoodp%a3n depasa"@s(apprsximatev 192 m thick) csniiistl"ng s?'F s ,lty c"8y underlatr, by loose sands, The foundation was analyzed for its ssdscep%a"bl"lity $0 liquefaction for postulated ground motion by ealcu%a%ionof cyclle shear stress ratio and correlating it to the relative density OF unde~lyingloose sands as determined Prom standard penetration resistance in several boreholes. The bbooratsry tests carrfea o~aton the foundation materdals lncl uded "Lfaxlal load tests Lo sjmulate dynamfs: stress condi ticrns, / GREAT CANADIAN OIL SANDS SLUDGE POFiD FORT Filebllf Riasly, ALBERT4 BYNAMIC TESTS AHbf EARTHQUAKE ANAL'ISI S I The stu& included establishing the ground motions wh'ich could be i~nducedby ,,r an earthquake bn the area and cfeterminata'on af time-de~end-t~t shearing ! stresses in a sludge pond under a random excitation produced by the earth- quake, The var%"a%isnof &nama"s: shear stmsses within the sludge plond ~lth depth by the earthquake agatnst time was analyzed, T&? total height of the dike surraund-;nq the pond was 250 ft, The %a%a~*a$orytest% carried out +o determfne the &naml"c propert'a"es sf the sludge materSa9 4ncIezded cyclic axial load tests to sl"fnulate Qna117jcstress conbjtions and detcm!t~z%Ionof 1ts esceptib"i%ity $a faihure asad torsi"ana1 vjDrata^on tests to measure its defsrmats'saa nodul~asdur.ing cbnarwtc !raadim~g, %926-p~sentlyunder construction Acres Shawi nigan Limited The project involved the study cf the seismici t). of a transmission l!rie route some 530 miles long and earthquake stability analysis for the design o-f transmission lowers. The faundation condi 'i~n-and earthquake load5n~lsalong " the transms"ssion route are illghly v; ,i-c3~ 'tin9 P'R variable horia:ontaH and iferlical accelerations, Bsruca Hydreekec'trSc PwJect is IocatecP -in a high earthquake ~$58:26ne in Costa Rica, The project consists sf an tX°)O-ft hfgh rock-f-n"H ddan~ and concmte structures, incl bading powerhouse and a spi 9 %\.ray, Wo~dsfirard-Cfyde conskaltants alee involved with defining of t?~emaximum c~d"P"b2eea~thquake and establs"s919ng of er%'tica"ggrsllgndmotion rharacteristf cs, The detajled avsa'!ys$s and evaluatjon for an earthquake is being studs'ed by the csnssrs-tia;m, eompt4fsa^ngcalculation of static stress fn the embankment prlar $10 the occurpence sf an earthquake and of stresscs induced due $0 pastulated seSsm?c eve!?& by linear f.a"nr"deelements method of analysis and further ev~aluationof the stabdliity of the embankment during and at dhdo selected ttme 4r~tervals after the postulated earthquake event. The zeismic analysis carried ouL shall be reviewed by DP, He Seed and Qr, Re Peck, HOT SPRINGS, ARMNSAS / T'iiilRGS DISPOSAL DM i Acres 1 The Hot Springs Tailings Dam Project int;olved the raising of an exfsting tai lings dam to provi de adequate pan5 storage capaci ty far maximum probable floed condf tion. Since the embankment is cons"Lrual@edprjmari ly af mine tailings, an evaluation was made ef the liquefaction potential of $ha dam durl ng earthquake can4S %ions, This portion of the ~~oS.CC%consisted of determfning the design earthquake and conduct1 ng careful standard pea?etraQ"l"o tees tc ~n the ex3 sti ng embanknlent to use in a corelation with the liquefaction potential using the method by Seed and ldrfss (1971), A direct result of "cis ana%ys%'swas to provs"de :n the design provs"sl"or-t For adequate tnternal drafb~ageto provide greater- ef-Fecti ve over$ wrden stress and thus reduce 1iquefac-ti on potentfa % under the design earthquake, Stabilit*y analysis sf the dam was conducted tirs%ng pseudostati e analysis. URAVAN, COLORADO / TAILINGS DISPOSAL EMBANKMENTS Cur~.entl,~in progress Acres consis ;: cf ex.l"sⅈtgtaf lings pule tt hhrfghts rid aver 150 feet Bs uf lhmat;efy determf ne nne;i?s ef stabi IS zing the piles under earthquake loading, W preibahi l isti c apprha~i!LO ear-tir~uakemagmi tude has been conducted by ot!?e!rs ancl &ese desfgr8 vval ues \.ri"a "a ututi zed to pericmf stabllf ", v.,r?;a"fysisof the $a i I ings embankments, Saudilern A"l&ka is in one of t53e world% sos".,'active seismjc regjons, Large earthqi~akesare common. For exanpt e, the 3an-g";st recorded earth- quake s"n Nortii America, the Great &lark3 Earthqlnake of 1964 with a mag- wi tude of 8-4-8.5, was centered in the Prince Mif T iam Sound area of Southcentral Ahask?. FI.ope~*dydamage and vi sibl e ground mcvement were extensive PJer a large area of the slate. Due ts the potential occurrecce sf large nagnituee earthquakes in southern Alaska, sei smf c anal ys~smust be igc f ubed in engineeri~gstud3 2% and designs far many majcr faci7 ities, R&M Consul $ants, Inc,, k~asper- formed several detailed seismic analyses for a -1ariety of projects. Analyses have vtnr-ied in detail rrorn seismologs'cafii~terpa-edstionto preda"ct.";anof qrocdnd response for various earti~quakemagmi,tudes and structural response sipectr~ma~a7 ysis, Special foundation de2a"gns are COEIIK.?~~y r@co~:haierder!based on this design data, A representative 7 ist- ing of projects on which R&M has performed varying degrees af both static and dyt1am3ic seismic analysis includes the fo1'laws"ng: Peterson Powers (high rise office bui 7 ding) ; Anchorage, Aias!:a, I Geologic Material s and Mazavds ~nalysis,Proposed Nev~ gal +-Cat Sf$@; Nil low, Alasks, I Cockslope Design, Dewateri ng, Reanforcement, Val dez Pipet in@ -jeminal; !laldez, Alaska, Municipal Light and Tckqsr 1.1 5 KV Swi tchyat*ds ; Anchorage, Alaska, EIi Seismic Risk Analysis, Seward Marine Share Station; Seward, Alas/iz, 1 Inkol vemen %s on $hi s varied p~oject profi l e kve deliions trated R&M3s capcbi 7 l" lies to exbend s ta te-of -the-a$.@ approaches ti-rrouqh innsl~vative design so'intfcr!c For example, rat the 5eh.rdr.d !b!a~-ine Skstll-e Station a 1 probabil i ty study of seisn-ric risk far permanent slope alsg~laceancntwas I providepi, ctnd as a portion of the deqign packag~for the Milnicipalityks 14 l f 5 KV swi tchyi:rc;is, a response spec kra dl~alysis was prelia~-ed hhi s i analj/sis has been "9"ncoraporated into a set ~b"seismic design critea~iafar 1 the b!uaq.r"c; pal i ty k ffutilrd use.