(1991 Duncan & Wright) Slope stability during rapid drawdown

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\ £ Sl Stblty    J   h  Wh   ;  W 

INTRODTION The wters had he gea plesur of wong th Pofessor Seed on the eseh erd n ths a. He plyd n cive le in te sudies sud ies whih we gun in the ey 1980s (Wong, Duncn ad Seed 83 d contnued late unde a ntat fo the  S Ay Cps of Engnees Wgh nd Duncan 187 e gt nuence on d onbutin to  leased t akwedge rofes Seed's gt ths work ad to dedate ths pa o his memo

AID DRADON LOP BILIT PROBL hen the wate leve outsde  so dops, th sablzing nuence of the water ressue ressue n the slope slope s los If he we eve subsdes  pdy th the e ressues withn the slo do no hv tme  chnge n equibum wth the drop n exel wte evel the slo s de less sble Many filures of dm slopes n nu sopes hve cued dung d don don hese hes e ncude fo eple eple Pilos D u of of S Fncisco Fncisco  A We & Ass 7 Wle Bouldn D n  (Witeside, 176 d  num of e k sos ong  Ro ono n Pe ee d uncn, 75 Rpd ddon imss ve ve odng on slos nd is ondio  cs c s  seepss of  upsm slos of uenly te desgn ondio ams Anlysis of pd ddon s heefoe  m consdeon fr esgn of dms, nd fo desgn of he slos t wll  submeged d subject t dwdwn

 UniverslY Dinguh ofe. Vgn Poyhc In In  d S Unrty Bakb, VA  Ashley  Pidy Cnnnl Pro  C Engr. Unvrt  Txa, Ausn   A Poe o C Enn n Ny Tnonsu ng

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Dun�n W&h a W n 



at  of hgh aby can  dring pid drado but teas clay cnten ca T aalyze sably during pid radow it s ecss  di whch teal ll drain an hich will no. In doubtful c it mu b a tat dina eihr ill or ill nt cu whhver ill reslt in  low  n withn h picul o  th lowest facto of fety f th lo  s an imprabe i mprabe evet evet F  da d aOn rom a high or lvel s n nt  ee loing ca  h da it i aroat to  lo  f f y f h rapid drawn drawn con For other da da  otabl  t jtS, epi of pid down c quntly, and he to rui n  ul oti oti  conditio conditio  In h h ca i i i hih  of fty factor fo th dawdown conition a othr dsig c c   hih pbilie  cc



MTHOD OF

AAY

ili dn pid aon has e analy in o bcally fferen wa: I usin effctiv sress mhs, ad (2) usng totl ses s  hch h unind h sreh of he soil  relaed o th conolato presures in  l t adon Boh mehs at f f inig marials in he sa trnghs  aed   of efeiv sreses a  s ssum way. that  e prssurs hn hm  hrosc

  o ffctiv sress analyes s th it is latively e to vluat te q h sngth pt  ffcv s s  sh sngth pter pterss fo   rdily dtind b mans of ioopicaly coldatd ndri (C-U  t with  reur rnt Thi ty of te i wl wlll  t  o   chnc chnc la wit   e f ctiv e aly is that i i dicult to esimat wit

y   ru tha will exit withi one drang tels d dn T  ressur change urin rawdown end on th change in  ss tha ul fm th changin waer loads on th slo ad th unai r f t il within th lo o h chgs in load Whil he chane chane in   c b simae wit aablaccucy aicully a shallo de nat t ue of the slo th undain s of th sol is much haer to t. t . T chaes chae s i re presure oud  xcted to to  cosieral diffren fo teils tei ls h tend o date ui shear an os h o o Whie Whie n cipl it i ssie o esime hse r pssures us kmpo's  prss ts po 9  p s s u

f

 dug rpd ao have In st caes efe   used he sumpo  por su h r sue y shp 195 and ler us b Mo 1963 hee asumpos hav e

  

 SS

justi on e i of e f t t   cve   cs y hve n foud to ult   vu of f of fet f d tht uffer pid dwwn pid dwwn flu W e  183) f   vs of set fctor lculted using Mrgnste ui w F  1.2 f Pilito D  F : 10 fo Wter Bouldn D  of whh fl t sms liy th Bisop nd Morgenses supions for pore pressures own my b re ur  urte te for sil sil  h  not tend te nd o dil dil durng uring dw uring dwown sh th for hos th do e t dilte u, ug  sumptions my coe e wt fl of lo n mtis mti s  e not  ho  how w  rle coee  co ct d      dl dung s te te   lkel o b nl  coct    t to dlte dung ndu conve fo  he  he s of eff ef fii v    e o e Bs d Morgenst u wou  l   w  s  p esu dung u wdn gdl of w we     w ngly he gt gt d  dt dung  gh nd P (1967) suggs   resse dung wdown in wll  co  compcted sily snds snds could b et e t  ung ow nt everl invesigtors rowzin, 1961 Brhm d H H 1963; Newlin nd Rossier, 196; Desi nd han, 19 sa, 2  1977) u htcl ths to nlyz th onsad onsad low conditions following follo wing drwdown ik ik the ishop ish op and orgnstern re pressure ssutions tese meths o not consider he hvior of the ol wit gd o diltnc, nd e tu not caple of presentng all of te n fctors t conrl the re pressures during rawdown ano nd Nord (197) nd Wg nd Duncn (1987) used prurs for sng  p pss ss dg dwdwn t t t  ue ue  of dily   re pressu pressu changs changs vo vo nd No u wo-stage sility anlys  irat to hiee nsistey bwn t clcul ftor of set  e es f he  pssures nd Du us nie elent nyses to sme  ketons r pressure pmers o e sess chnge durng lcul lcule te re ressure e te  te indce indce t it i  ssile to estim estim alistic  pressures for ecv s , ut it   cubo  icult t using tot sss s s de in te followng secons rghi d Pk (196) sumz the prolems in estiming re prssurs urng drwdown in tse words "   in i n order to determin deter min the pore pressure conditions fr te t e  drwdown stte all he following factor fac torss nd o b known the lation f te undies btwen mterials with signicanly  di  d iff eren er entt prop pr oper ertitis s;; he pe perm rme ei iiiy y nd c onso on sollda da ion io n  chara  ch aract ctri risi sics cs o ch of hese materi mat erials als nd the anticipa anti cipa  mximm mximm ra ra  drwdown n dition he pore prssurs inc y e chngs in h sheing sss thmsels   n o  n ino considetion considetion   ngineng practice, fw o cn b relily deteined The gps n he vaila thse facors cn



c, Wieht d We

By  ,  e anale a ei i the folloing io p  etive  s y f  pb iat iat with tabity aals  y   av  te  o(  v by imp

t Cos o( gn 1970)  a ttage  e  ( age, hih azs s fo awn i u  p e deee dee e ves ve s of onoliatio pre aon aon e i p fa fae e The The  d ps a  to e  he g value    e s wh the  w w T   nt vae ( he d e a eteined   t  -U g eve   how  F 1 At w s, whe    enve ie ae the eeve  n n gh     envelope i  to etene engths (r the y

Either drained or   U enelope s used. whiheer ges lor strength

,

  : 

Normal stress  effect e str n bae of slie before drawdown

Normal Stess F









Srh Evelop Used in Cops of Er Mtod

T j (   di engh evel alow e i o avoi

y   h tha   negave p u, hih oul 



Rapid Dro

cause the effectve al sess us to determe te she sength is the fctive sess foe rawdw. which is wer tha the effective sess after awdow eve when it is ssud that e re pressres after dawdown  ydrosttic ydrosttic As a result the Corps Corps f Engieers metho meth o is unnecess unnecessly ly nseatve e os   nees meth avds the pblems f pblems  f estimating estimating changes n  esse d dwdwn by usng urin stregths t aayze stabty after adwn adwn By sng sn g ndrained stegths this predure pre dure accuts accuts fr the ndecy f e eal to dlate  compss dug sh While the  of the ttal sss IC-U evelo is quitively cot. it cot  jstie in detail Te cirles f se u to eel te total sess evelo mbie te efftive s ng colio wit  devi se a filure filure  d nt pret  state of sss i e  e il t y gien  r e ay that the sesses o e sli se a  relat to e ICU eveo is  sistent sistent wit te wy the eelo is lo lough e ers resutg  tese icnsistecies re ot exemey ge in os cses te se o an icosistent a illogical met  lg se s to lo pressu is undesirable undesirable As dscusse dscusse i sube ios tter tter pes fr relag shear stength t consolitio pressre ve e develpe by Lowe a araath (19)



ike the Crps  Egineers meth Lowe an araaths meth uses a two sge alysis rere. and ses uae sregs or alysis o stability urng rawdw rawdw s shw in Fig, 2, we and Karafaths meth us eves that are mre gcal than the tta stess C-U envelo for eang unin shear sengths t ndation pressures The hortal ais ais is the effetive sess sess on the failure lane urng cosoliati ( fc )  the veic axis is te shea sess o the



ailu lane at failure ( ff ) we and Karaath shwe tht the ndained seng of soils when ptted as vs 0'fc vaes with the efie pcil sess tio dung conlidatin  c



 l c "3 c The value o this ratio ca vay rm uity (fr cosolidatio under istropic stresses t K f  the vaue of 0'1/0'3 at failue As the value of K c ncreases. the ndraine ndrained d strengt increases increases Fr ay materl there is a amly o ndane ndane strength strength envelos coesnding to dfferent dfferent values of  c varying t Kf  





e maner f repeseting uai sength suggested by Lwe and Kafath, hih is shwn in Fg 2. is lgica ad accute e testing ruire o establish envepes however is diffcult diffc ult Test specin  hese strength envepes

S

Dc. Wriehl  Won

us onderble t d carful tteto cu the ree mut  wll l durg nc slwy t vod the poblt tht the .     vue  K c. th e m re t    s pu    a e       t t  wl l dn cld Fe   exenc    orn  l  , nd t    o    empl  Lw  K t    o l  



u .

  -  

+u

C  -

�   +

0 u

C O    



Effecive ess on the Fue Plne Dng Consoldn-

C;c



  Srh Elop Usd  Low ad Krfh' Meth

U    Eer Eerss t te Lwe d Krt Kr t th u the the ni sn evelopes t low tree ere he udred treth vel l ave e   enelo T th tu  ot ll       O b sb to blz  ll ndre tth n w  w     cv   e VALUATIG TT FO PD DWDOW LE

A 

e t    reptn ure ure ent p    s c d ccrte, bu eblsn the vto  Lw  & wt coldton ure ole dcult d enve



re

Rad Dawown

Bau o  dfi ivv  ng ACU ail s a num of have suggstd   esmang  rl o ACU tesS  rsus o ICU es   o n abe   his  e   o y un  I-     e a  T s cD  d,  au y  D bj    T s   pp i a snge n  li    r.

c,,y  o en, ACU sg   ul o IU      Tay (18)    (1)  Ny T   s by W,   (1983) wi t      -   eby Tay (18) rl   o te AC l   c u it �irs ph    ng  ur  f y sgs  dung   - the the met meth h sugg sugges esed ed  m o

we and Kaaiath (96) esults  nh envels f  vs of 

  t sue by   y  rsu n able

AU sngh enve

sties d by g e  983) s   is al ssibe  e AC-U ng enve  CU sn  rul rul    ntelaon ntelaon e envel envel  cosng   c l 1. n F, 2 is   ICU nvelo an  bhed  plOn      ' c  enve sndin to  c  Kf  siy he e   sss sngh envel tlis  plg val o 1 V C   ll o    ru  ( 1  1   Cf c n   n  ompu omp udd m h rsus o  IC-U axil tes ith e Envel f val of  inae ae n . ur sun Envel  K    estals y ing l t envels (   10  K   K  . is ur es t  of AC ngs mh ease   l u i lies e sy o in& in&  cut A·  Aon  s rth AC-U nels of t ty swn n  2  etlh  lin nce sig he sul o C-U tes T

EW MTHOD FOR VALUATIG STABILTY DURG PID A WDO A WDO  h un stte of   o anazn stabiliy un d dwwn it is



Duc, Wrht d Wg

 Lke he he C o ngnee ngnee h a e n Kth'   ew t us unned he ngths to aod the oml  ccces invlve n etimtn uaned  reue ur dww  Lke e a Karh' met t  e moe ue  v  ene th AC-U ngth ng th te al o K c  Fw t s  W e  (13) the AC-U trengts  emd   ilan u  sus o ICU s uned sn hJ her her  n snth hi  o v f cvi  e e  di sength    u weeve ey e sme   nde p i de fm   vv  e C Ei  .    o E  Me  eve s   wi he eecve sts dww  eteie  s.   new pred he eecve ss  w s u w i   Ue o  eve ss e dww ru I yss ys s e rs w w staes staes re he s s s he he Lwe  meh  h h thrd ae  draied sh  sd   of the l sue where the draed sen  sller tha   nh. e ew  s e t  the t ee o e t I ha   vsy  lyss  rd wdw tabl tabl  I dtio  ce   ew ew eas ea s:: I) I) t smle sm le he he ask  esm es mn n AC- S by usn e ntelation ad 2) t us   crate a le   f cn  ible ruon of uane engts t  ps d  vain o dinge

 sc eps ivole  te mt  he Dteie or eah  i te cton hethe drange ll  (1) d dwdw. T s ll ans f mn tis etenato is t e  v  he dmesoe  or  gve by he ollw ex

(1)  wc  • ccie f oldton t    ro n   lengt   p  the ccuate cc uatedd vlue v lue of T s reate reat e tha tha r equa equa  to 0  ds o excs  ssue durin wn ll   ee      e  a te mtia a lly i V o  c  lculated i dta  he t rte o ontio ri   pxe vaues or vaous s  omed ls e lted   1



pd rwdow

al 1 Apoxie Valus o  o Vous Soils Ty o Soil

socv

Co sand

> 10 2 /day

Fine snd

1 to 10  /day

Sily sand Silt

10 to Xt /day  05 to 1  /dY

Cpt clay

 005 t 5  /day

Sot clay

<  02 t2 /day

I the vale o T cacuat using quaio I is ess than 30. the undran trength should should b consiee The ollowing ses ssure t t the undraned ngth ngth used in e  e staiity staiity ays w  b ge t e de sngth  is thus conative to assu th he mtei is unin in tho cases where u e is dot whet  ot c dge w u nveos qued o the analyses or (2) Estaish the sength nveos ateas that ain dun awdown. oy the ane strength enveope is quired or mteals tha a undrined ing drawdow. th te drained ndrined nvelop nvelop (f f vs 'fc) re re quired. Th e  en  env el  op (tf f   el o f)  an d the ndrined f  s a'f f 

qu nlops or alus o K c bwen 1 and K  can   een y

sly ly..  vios  ed p vio  cuss ed p d  cuss n, as d tion,  latio ner la lin lin   ner

(3) For a lete sip sip sfe ccuate e actor o ety ar drwdown y a 3ste u: (i) Pero  ysis ysi s of sity bo drwdown usng in sengt paraters or l mes o deteine he eve no sss  c) slice Values o K c  on he ae of ach slice. nd the value o K c o each slice re deeine re  deeine n the mner sggest y Lowe and rath. aed on duing  drwdown the assumption  of no eieto of prncip sess duing drwdown These values  e sed t deemne undrained sength vaues or he y dung wdown wdown marials marials that tha t do n dn y (ii) Pero an anaysis of staility ae dwdown using undrand sengths o mates ha do not ain reey.   draind  drain d sengths seng ths or

 \V  



i mi  th  drJned sngh r any s    is lowr an th ai str nh ud in  (i. Th i n i icd ung th tt ese n the be f the lice fm te i) and oe pue f th din ii  f o y li the nd s  ng th   ta the undine ength. o the naly i usng drned ath n unin tnth  li wh th ain ln e lo

    w

(4) Ret th 3-te   e f the li u to lte th  wi the lwet act f f  Y f  lo in  aw



Th cmuttn nvlve in h me h a quite engthy, n  omput gm   pactc ecty t d al f the cmuttn e t eh f tcl lip uace u ace The nly iu i t fllwg etn wee e t th cmut pg UEXAS3 hch ncte th e mt  p aw t bilty aay



EXME nysis desrixd rviuly hv en ued 10 nlyze the a a a cu cu i th ectn ectn he ft to  th dm Pilct  Wat Bul uff lde due t api dwdw T thd   hthtic l dm   pumpd tag pject Th am  cnde t  ujt 1 l ddo a a l patg ctn f th um tg et Aordigly lib tmt  th tlty dui a   spec ally

Th mt f

mt  t makmt an t u ct  aet i hg th  mt  c p a  a lat ulel cuec

Pilito Dm Dm  hw hw n n Fg Fg 3  a homoou olld tfi mbakmnt e ct  t dm  aut ft v t upm t  upsm lo  i  2.5   t lower 58 ft t El d t 3  1 m  pt to t r (l W t t vl a l m El t El t Ot d ovmb 19 199  lid ou Dui t twO

 698 7

78



9 eoe eoe adon adon  EI 692

678



EI 698





AteE1657

Say Cy CL L: 45 P RC: 94% Ca Method - Y m 135 p eed s sfae



:

Fi   Picis m ssci



22





Rapd Dawdown

 

  t the faure t wwn rae was e ct at aut 7  r da. Te axiate n of  flure sue fnd i  expato h  hw In ig 3

 A. Wahle & Assies  P l lifi s C by e n cio Wter n   el invesigons larato tests  nases  t   re su. e infotio info tio regin  iios Dam pent in ts   bi fom e Wale a siaes   A Wl  As  T eri cpsng  us s is cls s  y ca  wi    g  n   to 0      y   4 x 1*  e iqi li is 45 t   lt lim is 23  n. e eage eld  w  y  t  of  l  siy  sng ·t' ve ve    lif Me) T bin fl envel u    f Engpu  wn n  u  of Fig. 4  e evel  in L  Kth'  the t-tae -tae pu a  in     Fig. 4.  hw i . S the fact of sfey cacuat b the s f i ue was 082 Te ctr  afet clcuated  we ad aaaths u ad the ew ure ure a th 0 Te tic cie a e  e  f a  ts as c b  i ig S Baue it us ed snths h ey e ower than uai se  w t alwas sl  f of o f sey  a   as or o r or th  ft of e c by t Le   p  e ca of itos D he   slie he te  sngs e� owe ta  unined stgth, n e fto of fety calculate usin we ad ahs t  e ew   f t  lter lin D is     emn   o a fl    ply  f hi l   f of cl s  vel; e derying k s his A sn in ,   le   ion  io n f e  e n   clayey cla yey y vel     volv in t se Overlig o f s cy  z o s s    cayey si  vel a   l of  layer t blnke  sl T   n of e pm  i s ete   pra pra e psm psm s s 2     ve Elev E lev 4  4 5 n S on on  w Elev4 cu o o  Fe  19 du an exly ri dow f  ide cu fai     e   in 5S u t    a sult of   T slie exte f  len of  f l e slo T sip   exe t 0  l   o   n  ges o  y        n of   t w eva,  y

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Fig.

  Strngh Envlop for Pllarcos Dam

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

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 eding a t Bdi Dam pre st d in hi iteside  (hieid, 1976)

pa as btand frm th

nvv  in    s  Tab 2  Sng  f e as nvv  fo  an enh v  o  o u in e Cs f ni  e (y dnition) h sam as h pates fo he  = f  nl    we and Kaa's and h new h

 

•

Strength Parameters fr Walter Budin Dam

Matera

Cayey Slty Sand

Crps  Engneers Me Draned

IC·U

c'  40 ps

c 

.'  327 Mcaceous St

 •  13 d

c  220 ps . - 5 5 g g

etaceos Cay

6 ps

c'  180 ps

' • 19d 19d

c  450 ps

•  11 d c  2 0 s   3 

Lwe and Kraat and New Mets

Ke. K to  2    3  t o  22  22 

 - 13 g

o  180 psf

o  2 ps

19d

155 

Ke. 10 to  750 ps  5 g to  480 f

•

Rapid Drawdon

7, he fact of afey cacula A hown in te Co of Eninrs'  edure wa Lwe d Kaath T facor o ety ccuat t new pu wa 1.0  w 1.0, d t v cc T cc t s   y b en n  c c cle cle f U t  w i 7.

e dam f i exampe i hown in Fig. Fi g. 8. Te emb knt a a a wide, nly cpted ilty cay c cay c T  ower i of t upm lo i a m zn with t s ngt pe  the c T upr i of  down so i a f-ainng f-ainng k  upsam lo a  of t down Befoe Cps o EnQies EnQies Ctol Cic.,  &0.93

Bere Le od Korooth Crtol Crc F 109 =

Observed Slip SUoc"

v

Beoe

Oserved Sp Suoces

Duncan, Wrighl nd Wog

 Zon

C ® G

Q

Materl

Ym(pf )

ompcted Rokf Rokf Siy Cy o

1 14

Sy Cy Rd o

1

545 Befr Drwd  E 545

Fig. 8  Hypohical Pumpd Sorage Pojt Dam Cross-Scon Stngth pamts fo te mateias  t dam  lst  Tble 3.  sct (20 ps oeso teet o te IC-U nvlp s dcatve dcatve  a hhy tnt mtal mt al he dne segt o th th   e th t un sength  te ag of sesses ow te   t to evel c,  n  ctv  ctv consodton stes o ppxt ppxt 50 ps  crn n mtly t  dpt  4 et   n  slo n 0 et    .   l n d zos a  dn  nd  hv t   h dy n tute unt h   128 nd 142  l Dy un h  usd o pon   mts       nd u u  un ht  u   on l   Tbl 3  trngh Paramrs r Hypical Pumpd Sge rjt Da Meri

Crps  Engnrs' Mhd

Lwe & Kath nd Nw hds

Dand

IC-U (R)

K· K ,

K. .0

Compced Rck;I

c' • 0

N

to • 0

NA

and Fls

"  37 de

y Cly Coe

c • 0

c

•



&

6 



•

Sl Cla Ranom

c·



0

c

•

Zn



•

6 g

• 1

'



8

- 37 g

2000 ps t • 0

t

8 Og

9 3 g

9 - 2 0 Og

2000 ps

to •

Og

220 s

t - 220 psI

0

93

•

d

9  2 0 O

• Rd Dwdown T stbility of the embnkn was anz f a dition of dawdown fm va S4S (5 fee w t rs   a) o li 380, whic s t a    a -J    T d  n pl pl waten waten o  ups t    a   m fl lay b  ll.

culat b y te Cps  e  ccula Cps of Engin  rs' ft  s  e Fig . 9, h e ft ow  i  i Fig .  ow arath's Lw e  ad Karath's  Y  calcul calculat b y Lw e  ft o fe Y  pu was 1.37 T ft wa 158. a t a cu  w  w  h s. a my b  i �  m  W� circles fo aU t m W c ritc  ritc circles F, .9 As

C ps o Eis F-1.37

Low an Korofioh r Ctco. Ccle

Befor·

FJ

Mt Ca Crcl F-156

•

Fig. 9 suls f Slit Cmputatis r he Hyhec Pump rag -

()

J)unt'an, Wri�h nd W(I1�

he ew meth  lzg l lt g pd awd e  the peious pges e ht e leed to  h st fetue o t es t he n s el t aods the ples td wth ettg poe preue n  mtea for th fe-dwdown ondon b usn undrined tength   orrt rees the stnghs of eia h d  dae urng her t  the mos accuat represettion of na ngh (vas o  f th v w the vs f ' ad  )' bu i avois th ncssi  dic ACU sent tesng b us ie terJlin of sength vau o o IU ts. B ug died egth le whee these e smar ha urad stegt the meh oids rel o stregths du o aiv e essures whi  not  not  moli f aiton aiton r dng dng c   for for eimina eimina engths due to gatie poe pessus is mo acr,  e onserai thn he redue use n he Corps of Eninee h The e eh s somewh moe onseaive ha L and rfia meh, a ovides a reliabe esime of sabliy ol awdon tha i v    ace s ssib t te n a of  . Fo h h mples desrd the ftos of safey cacuated using the  eh  15 rcen o 30 peren higher ha vaues caca usin he Cor   E h, and ro to 5 pren lowe ha a cacu    Kaa eh Ahoh he vaus of sfe faor lulat usin th  h are ol ihty aer han vaues calcua using e a Kat eh for t  xa coie coie it is iant tha he e e  aiv cau i   o ey  senghs un f ea   ha ha  L a Kaas mh ds rely o hs srnhs s, he e e eth offers the s reliability ith sc o srehs  o negav por presses s he Cops of Egeers meth i se a  accra vluion of strength nd result in vlue of sfty aco only sitl we nd aths aths meth meth Th meh meh h  liably conseai low ha we wih   undined strengths, b ds no invv cvly consai approxaions

KNLEMEN he wters wish to epre he ppetion to Hdin awn Asites  Nikk Sekei td. who prode up for th ear ph of this std a to h U S A Egees Wtews Eprimen Satio ho sppted t pha es Dk Volpe proided ifoion ifo ion regardin Piaitos m  ler phaes an Cough and Stephen Wheside provided ifoao ari al

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Rad n

7

uln D rl  o    Lul o Dke Power me a numr of epfu suggestins d prided  wte wh n opun o su e estcs of t  u rcc cdtis. e wters ateful nlge l of the vubl nbuin to  stus ta ave l to en o e  d    M   e ex  y Jorn df  gus.

EFC

isho A. W (954) ' U     Pss Ccient in actice" Gniq V., V., N.  19 .14852. .14852. rma rma S P and H, M. E. (163), "Transien velpment o t Free Suace in Hogen Hogen E D D Ghqu, Ghqu, Vol Vol 12   4 �b 1963.28-�

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zn B S (1961), "Non-S   Hogneus  Dam ater Rai Drawdown,  o  5 n.Co.on So Mec and Fou Eng P Vo. , . 51-5 s f Engn (1970) Engn  sig sig  Sbili Sbili f f   k Fi Dams" nginn Mu EM 1110-212 pnt f  y y s of Engi,   o  Chief f ngnrs pl 190.

 C. S. a Se W

. 1), Uncnne Tnsin Seepage in Sin Ba  J    Mh   Div, ASCE V.  7, No. M2 e, 1  333

Analsi o Eth Bnks er Drwn sai C S (192), Jou of t Sil ASCE Vo. 98 98 o. S    u.Div  ASCE Nve 1972, .143-16

 C

S. (19) Ddn Ddn Asi Asi of Slo by Numerca Numerca Me" Me " Ja o  .E. .E.v v S Vo.103 Vo.103 N O Jul 97  p. 767.

K.L. Dunc J M (17),   A 2 14 on  Man  K.L. Rivr, Pe, Re  he   Nar e ission

 on Snc Snc  Sys N Re h uncil Nationa cem  of Science Washingto .C. .C.

e, J III nd arafah L (19a) "Stilit  o th Dams pn Drawdown Pr. l st P Cnf on Soil ech and Found Found n .• Mexico Ciy Vo  2 p.537552 p.537552

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e e J II  Kaah L. (  9) "ff of nopic Consolit Consolitin in on

ncn Wgh and Wng



Moeste N. R (1963), taity hts fr ah Slpes Du R Draww eothque Vol 3 N2 ue 19 pp 12-11 Nay, I, a ee H  196 ( itu Ste Chaacterstcs of ot Clays" Joul of the l eh a u Div, S Vol 91 No M ach 196 p 90 kept . W 194 he Por Pressure Cefficiets  a etechiue, V 4 No.4 Dm, 954 p. 4147

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va, G d oal  (197) "Un Effecv Ss tbiity Aaysis eedigs of the  Eron Cnfrnc on Soil Mchics a Fondon Enng En ng Dlin Al Ben  o o h Gothnc Gothn c Division, Negian Istitute of Thnoo, niri of Trodhei 1989 Taylr, D W. 194, "udamtals of Soil Mic, ohn Wil d Sos, N Yo Terzaghi K ad Peck R. B. (197) oi Mechanics in Enineerg Practice So Eition oh Wley a Sons Wahler, W A a ssiates (190) stream Slop Draww a ntgatin  Remia Measures Pcios Dam, It A re  the  Fcio Waer Dpet Jue 197. Wheid S. L 9 OA Suy  he api Dradown Faie i the Walt Boin am Techcal Repr E211, Snford University Auust 197

Wog K . Dc, J M a ee, H B. 193) "Copaiso of Meths of ad Drawdwn Stabiity alsi, epor N UB/G/-5, Dmn of Ci ginen nri of Clforni, Bree mr , id ly 98 Wgh  G d Dncan, J M 197 n xnaon of Sop Stabilit omon d for Suddn Drdon ceno  GL-8-5, Gohnica araor U S  nr Wea n So cbg Mi