,IPROCEEDINGS OFTHEINTERNATIONALSYMPOSIUM ON OEOTECHNICAL
ASPECI'SOF UNDERGROUNDCONSTRUCTION IN SOfT OROUND -
ISTOKYO'99TOKYO/JAPAN/19-211ULY 1999Geotechnical
AspectsofUnderground Constructionin Soft
GroundEditedbyO.KusakabeDeptll'tmen/ ofCivil Engineering, Toi,yo
Institute ojTechnolop JapanK.FujitaDepartment ojCiv Engineering.
Science University ojTokyo,Chba, JapanY.MiyazakiObayashi
Corporation. Tokyo. JapanOFFPRINTA. A. BALKEMA 1ROTTERDAM
1BROOKFIELD12000. .The Rotterdam sheet pile wan field test Test
setupD.A.KortGeotechnicaJ Laboratory, DelftUniversity ofTechnology,
NetherlandsA.F:vanTolRotterdam PublicWorks anti Geotchnical
Laboratory &Delft University ofTechnology, NetherlandsA . J o n
k e rCentre forCMlEngineering Research anti
Codes,NetherlandsABSTRACT: The recent devc10pmcnt of Eurocodes
inthe design prac;ticefot steel sheet pUing bas led te
theinitiative for a full scale field test on two steel sheet pi1e
waUs in soft soU. The mam goal.of tbis field test1$to e~ the ~
o(t,wo & cm, sincIe strutted steel sheet pi1e w a D $ wim a
Iengtb of 19 mdIaad a width of 8 metres. InonewaUapla$tic biaF wl
be developed te obtain a tedislnbution of beadinB~ts;the ether waU
is composed of double U-piIes te examine the ~ of "obquc
beDding".Pof tbis field test aquestion fortypeA ~ was distributed
te 50 ~ engineers woddwide.Tbis Paper describes tbesetuPof tbc
field test. Tbis test may contnllte te a better understaPding of
bothplastic design andsheet pi1e design wim double U-sedionsand
ma)' themore lead te a safer ad moreeconomie design of steel sheet
pi1e waUs.1 INTRODUCTIONThe introduction of Eurocodes in tbc design
practiccfor steel sheet piling ma)'.Jead to a .graua1replacementof
natoua.1 building codes by ODeEuropean Stal1dard.ENV 1993-$(CEN
1997) trellt$,together wim ENV 1997-1 (eEN 1994), tbc designof
steel sheetpiling. ENV1993-5 offersthepossibility teintroduce
plastic lnges in the designofsteelsheetpilewaUs andgives guidance
bymeaos of a stepwiseprocedure.If tbc excavation in front of a
sheet pile wall iscontinuescribes he !ayoutof tbe test site, tbe
soUdata, tbe~ details, tbe test sequenceand a possible__ wbeD
dw'blI tbetest tbe plastic ~. isdeveloped. PiaaIlytbe,... motivates
tbe questioofor predictions, wbieb bas been distributedto morethan
S O specialists in sheet pUe wall design.2 LAYOUT OF TUE TEST
SITEFipre 3 shows tbe Iayout of tbe sheet pile walls.TM four Walls
are instaUedia. all $lmost squareform. wbich sldes of about 12
metre. The top of tbesheetpilesis atNAP +1;() m (NAPis Dutch~ltvel)
ancltbegreeafield.is at NAP .(UDl.tbe flOrth. and tbe south walls
are test w$lls. In onferto minlmise tbe comer effects on tbetest
walls, fourbentonite screens have beea instal1ed andfourspecial
intetface piles have been developed wbiebare ent over a length of
16 metre.2. J Hordt waIlTM north wall consists of 10 double pHes
ArbedAZ13.Of tbem.6 foon tbe test wall, 2 tbeinterf'acingpiles
AZ13S (see below) and 2 tbe cornerpHes. TM intmonneCting interlocks
of tbe doublepiles have been weJded over tbe fulI length but fottbe
driving interlocks ae lpecW measures bave
beenI9~oooooooooooooooooo\ tol lellilW hoh '1GO 1500-taken. Tbc
sheet pdes have .been vlbrated toNAP -18 m. On test piles At. Mand
ASinclinometer tUbeshave heen .l~ Test pile A3 isequipped witb 12
earth press!ieeelis. 4 on theexcavated side and 8 on
tberetijnh\gside, and testpile A4 witb 40 vibratins wire (VVI)
strain gauges.2.2 South waUTbe test sectkln is formed by 7 double
U-pilesLarssen 607K fromHoesch,Hl to H7. Tbcinterlocks ofthe
doublepiles ha'vebeen .tded butfor tbe drivins interlocks no
spec:ialmeasl1reShavebeen talcen. Tbc lOOGt the sbeetpiles bas
beeninstailedatNAP-18mette. On~tpiIesH2, H4 andH6inclinometer
tubeshave~welded. Test pileH3 isequppedwitb 12earth~ eeUS,4 on
theexcavatedside and 8 onthe ~g side and testpileHSwitb 40vibrating
w~~ gaup.Tbcsoutb wall is compJetedby 2~ piIes AZl3Sand two~ piles
H8 andH9.2.3 &st (l1'lI/ westwallsTbe east andthe west walls
are~ formed by 20single pilesLX32 o o m Britisf:l$eel. These
piIeshave been .ostalled to NAP-20metre in order tominimise
disturt>anceoftbe paijiVe zones of botbtest walls. tbc
pilesBS6,B$i4.tJS26 and BS34 areequipped witb inclinometer
tubes.2.4 Special interfacepile$ AZJ3SAs the corners of tbc
building pit would have astrong infiuence on the test walls. 4
special interfacepileshave been deve1oped.seeFagure 4. Tbese
pUes.consistingofAZ13 sectionsareculover alength of16 mette. In
order to prevent w~rleabge into thebuilding pitthe gap bas been co~
witb a 2 mmtbielt VLDPE foU. For a betterdl'ivability of thesepiles
2 mette attbcpiletoe and lmetreat tbc top oftbepile are
J:rnaitedintact andforthe proteetion oftbc foU tbc speial piles
are. plll(l~ in abentonitecolumn wbichteaehes tONAP -USm.
Afterdrivingtbe pile is alse cut at tbc top.t5Bentordte
sereensBehindeach test wall twe bentonite screens havebeen
installed. Tbcbentonite screens.ar
eomposed()fbentonite-soilcolW1ln$lifSOO-7QOwhichare mixed-in-place
witb a hOliowauger rig. The toe ofthecolumns varies from NAP
-13Senclose to the testwaUte NAP -3.5 en at13 metres bebind the
testwal1s. Inside tbc building pitthe bentonite screens~l 'I~Figure
4: Special interfacepilesI I I1II1Ihave been left outbecause of
possible seepageduring excavation.2.6 Struts and walingsTbc plan of
the struts md walings is given in FigureS. Tbc centre line of tbe
frame work is at NAP+0.75 m. Tbc stmtsfor the test walls north and
southare desi~ in a war thatboth testwallsactindependendy andare
not infiunCed by tbe othersheet piles. Tbc differencebetweenthe
strut freesis led to thestiffHE600B struts between theeastand the
west wal1s. Thestruts and tbe walings areconstrueted as hinged
connections wim sufficientrotarioncapacitybetweenthe sheet pile
wal1saad theTable 1: Struetural data of tbc sheet
piles$ecQllAZt3L601KIx cm4Jm Wxcm ~1m137244t970070030130032205 3
9ITable 2: Summary of soil parametersTrialtial tests (1=2"')
SIiffness pIIl'lIInClm V_testsTop level Soil Type r (kNlm3)
c'(kNIm~ (0) B so (MPa) Ic (kNJm3) f,. (peat value)(m-.NAP)
(t.NImi0.5 sand18 0 30.02.07000I~clay, silty 16.6 6.3 29.43.52000
67.6sfiabtly sandY5.75 put 10.09.318.9 2.7800 65.79.00 put very
clayey 10.6 11.820.1 3.2 2000 64.310.50 elI)',humous 13.9 7.0 20.0
5.2 37.612.50 clay, sllghlly 16.2 7.4 27.1 6.2 1400 32.8sandY16.10
clay, highly 12.3 5.0 25.0 10.3 1200 30.7silty17.00 clay, sIlghlIy
16.2 7.427.1 6.2 1000,sandYio 17.50 .sand,siIty, 9.837.9 10.0
1oomedium coarse18.50 saad,coarse 20 0 38.0 10.0 1oo~ ~ Tbc strut
frame aclude8 6 pressureeens: 4 eeUs to measm:e tbc Iateral
stNtforce of tbcIiortblUId soutb testwaUs and two to measure
tbcaxiaiforce in tbc waling of tbcdoubie U testwaIL~ ?3 MATERAL
~ARAMETERS3.1 StiUitural dataTbc most relevant stmeturai data of
tbc sheetpile ispresented in Tabie 1. SiaceOM of tbcaims for
thisfield tst is to investigate a waU witb a plastic binge,it is
important for tbc design tbat tbc failure chanceof tbc north waD is
as high as possible, wbicb is ofcourse in contrast witb common
designs. Tbereforetbe AZ13 test pi1es have an unusuallow yield
stressof about f,=280 N/mm2, wbich results forelastic-plastic
stmeturai models in M,,=426 kNmlm'.For tbestmts and walings tbc
stiffuess and tbe ultimatestressmay he consi.dered as sulflcient
high.3.2 SOUdataTbc soil data isobtained froman extensive
soilinvestigatiOl1 programme cOl1sisting of common-usedin situ
tests, such as CPT's, vaae tests, andpressurerneter tests and
laboratory tests,such asoedorneter tests,triaxialcompressiOl1 and
extensiOl1tests(CUR 1998).In Figure 6 a representative CPTis
presentedasweU as tbe initialwater pressures. Tbe soil consistsof a
16.5 rnette nonnally consolidated soft clay-peat-clay
stratiflCation. Underneatb, tbe normallyCooo"'-'- !MP'Iw_.(1OIlPIl
q M g f t ~ M ~Friclloa_Figure 6: CP'fand piezometric
headsconsolidated Pleistocene saad layeris found,wbichisconnected
to tberiver Maas 2km fartber. Tbcinitialwater pressures in tbe
different soillayers isdetermined witb 9 piezorneters and 3 open
standpipes,A summaty of the mostrelevant soitdata ispresented in
Table 2.540TESTSEQUBNCEefoce tbc start of tbc test,me ~leld level
was, a leve! of NAP -1;6 m. In ordClrtomake tbc testte accessible
for tbe CPT and bpl'erias,craaes andtber constJ:'tl(m eqtltpment,
tbc site was filledI'St with OAmetre dry sand aDd. ~ ffiled llpto
Iletresand in total. The test is ~ in 4 ~.tagel!terconstrUCtioo
oftbc sheet .pile walIs,tbcmtOtlite screeas andtbc .stmtframe, a
dry(Cilvationisexecutedto NAP 4m; bath soit andllter are removedto
tbis JevekTbeexcavatiool~t is simated as much aspossible bebind
meIStwaU.'age 2l1ewater' in me excavatiOtlis ~toNAP -l.SDlld tbc
excavatiOtl is subsequeatty h1creased.to avel ofNAP-7 111. During
tbc~vtWOQ .wateJ'vel is kept at NAP -1.S111.age 3)wering the water
level to NAPS. Dl in S steps.te lntennediate steps are NAP
2.~m..NAP -3-' m,I\P 4.0m,NAP 4.5 Dl andNAP~S.O Dl. AfterdJeird
Stepto NAP 4an evaluationstep is iDtroduced.on:IetCO
assessmecritical f~lOad of me north111.'Jge4aintainingtbc fmal
water' level of stage 3 for ariod of 6 months.!ring allstage5
measurementsarec.ried out fromch me action effects can be derved,
such asera} and transverse walt displcements, strotI'Cs.bendins
moments and earth pressures,Ammary of tile activities with
acumulative timelJe is given in TabJe 3.EXECUTION OF THETESTIe of
tbc difficulties of tbc .desip. is thattbc testtbc wan with a
plastic hinge isadestructive testd tbcrefure not tree from
danpr.Moreover. the'lering of tbc water level isa lOad
COtltro1leddng procedure, whereas tbc pl$Sc mnge bas aTable 3: Test
sequcnceIlO. aetivity time
U SQda u te NAP1.25m 0l.2 saadsill te NAP -0.65m 1252
slleet.piIodriYlti 2963.1 dry .cw:avatioate NAP 4.0 m 3313.2 mi
WiCJl water te NAP -I.S m 335 excaYllOlluaderWII te NAP -7.0 m
3405.1 ~ ~ te NAP -2.5til 3425.2 I~ water level te NAP -3.5m 3455.3
~ w.. ~ te NAP 4.0 m 3465.4 evllhraoDoftest da ta5.5~w ~ te NAP 4.5
m 3555.6 lowermJwater level te NAP -5.0m 3596lo1l tmnpcrf~...-
lIme&erlIlnIlRotaIioII of top sbeeI piIe wd (ra d]1o
+---+--+---1i. 11.2J .3J t 1.,-6-11. ..FJgllFe7: Rotationoftbc
sheet pile around tbcstrut due totbc lowering of tbc water
leve!softening behaviour due totbc oombinatioo ofyieldingand Iocal
buckling (Van Toland Kort.991). Consequendy,if tbc Iowering of the
waterlevel in front of tbc sheet pile walt iscontinued
aftel'yielding in dJe ultimate libre occurs (sec Fipre I>,Dot
only theplastic mnge is developed, but also tbcresistance of this
plastic hingedecreases, which maycause asudden and unpredictable
deve10pmentof thesecondpiastic binp.In order la COtltrolthe
execution of the test, thewater level is lowered withaspeed of 10
cm perbour. The formation of the plastic moge will beobserved
inreal time wima tittmeter,wmchmeasuresthe tilt of !he sheetpile
cWseto the st.I:Uts,and a piezometer \\'bieb measures tbc water
levelinside thebuilding pit: a sudden tilt ofthe sheet piein
compari$Otl wit1l the water head inside thebuildinspit indicates
tbc formation of tbc plastichinge. sec Fipre 7.5416 PREDICl'ION
QUESTIONThe interest ofpredietions in geotecbnka1engineering is
elttensive1y discussed by Lambe(1973).Von Wolffersdorff (1997)
Otganized (also incooperation wim tbc CUR)a fI.lU~scalefield test
andinclU
