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^Nalion,lCataloguing^LibraryBranch^{ol eaneda} Canadian Theses Divlsiol'l Onawa,Can ada K,"-ON4

NOTICE

Blbliot hequenationaleduCliriada OlrecUo n ducat alogage ...

Oiv;slondes l h eses can ad lannes

AVIS

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~u~::~o~ft~~~~~~~~:i~:ees:: :~~~li~I~~:~~~~:~~:'

lng . Everyefforthubeenmade 10ensurethehighest qualityof ree ecoueuen possible. .

...,

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^are

~jSSin~:'contact ttie'uni';er~jly,Whl¢h

gran ledltlo"degree. .

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Some pages mayhave'ind iSl!nC!printespecially .ll

•theoriJllnal pageaweretypedwithapoortypewriter 'fib,bo nor~tIh~univen;ilysentusapoorph,Oloc op y

Previousl ycopyrigh ted'mate~jals(iournaia:rticl~!.

publishedleslS, etc .jarenotfHmed.

.~

ReplOdu ct lonin futlOf inpart ofthisfilm tsgoverr\ed by the Canadian Copy right Act,"R.S.C.1970. c. C..30 Pleaseread thaauthoriza tionform swhi chaccompa ny this,thesis.

THIS DISSERTATION HAS BEEN MICROFILMED

EXACTLYASRECEIVED

Laqualitil de cetta micro l iche dilpend grandementdela queli tilqelalhesesoumlsea umicrolllmage.Nousavona lout lailpour. assurerun equallt i!socene cre de repro-

eucucn. I ~

.S'i!manq ue d es-pag es;veuilIe zco mmuniqu ll r a\lec. .. -

. '

l"univer sjUrq u la conlilrelegrade;

La q\:al:lte'

tnm·~fesa;o'n· de C:~rj'aines pa~~s_:

^peul

lai~511rIIdeslrer,surtou t611esp.agesorilli n,alesonti11l!

da ct~l~glaPhlilesa l"alde~ 'unrubanuse o us!~' u nlve rsltll nousalaltparVenlrunepliolOcopled amauvalaequalltll·

Lesdo~uments~ul lonl^dejlJi·~bjel d;~n'_drOiid'~u,

~~r~~~~~:~derevue, ekarriens publi es,: ! c:t ne scm

P :

Lareproduc ncn.marne perllell e,de cernicrolli m eat soumisealaLoi canadiennesur le drolldauteur,SRC 1970,e.C30.vecuteeprendreconnatssa ncedesfor- mulesd:aulo ri SatiOnql1lacco~p ag nerit' ce ltethese

LA THESE AETE MICROFILMEETELLE QUE

NOUS L'AVONSREQUE

I '

s." .

. :

" . 1 ' . :;

I

i i L

" . \

-'\ ..

.St.John's

FREEFALLl""ACTPOlETRATIatTESTS

'*

SOILS

saurendranath!ChaUdhUri.B.E. (C1vl1> @

I;

The ~ts su~tttedin pa~~ al ·fU1ff1tt.

of.thetqui reJrents forthe degT'e.eof MasterofEngi ne ering .

.Facul!yof Englneerin9 Memorlal

Ur;l ~~~i ty Of'N~folllld1and

- .

" - . _ . , " - c·

~

^{• .._.' .}

~

l'leyerhO((196.1).IIt'''~s ob~~rve dth~t resll~ts.of-f~e.fillp~netr~":,"

.. y:~n ~sts~_ShM~

^a

"9~ater~.~~ration I"1!st"sta.~~; C~"r~~d ~to;the ~

^{'. ,}

.'sta.ndardJo151-stat1c,tes t s.H~VI!r•.when~~I! ~slll t.swe.ret~anSl~ted

<, lnt otcJIC)ut~tfon.o ftileangleof:shear.resistance .~e'~f(ferencew.a$·~. ·

' ..~ns~gnlflca~t:

v

!'

"

-

.ACKNOWLEDGEMENTS

TIl'"'ctsser te t tenw esccnotetedat the FaclIlty of EnQ1neer1ng.\

ABSTRACT•••;•• ••'••••.•••••• •••• ••• •

'Pa~.

.~ 7. S~nd~r~p';pc to rCompaction Tes tforI'bde ll1ng Clay•• 8 •.

EqU1pme~

^{MixingClaySamples}

.~.. . .

^{• •}

9al Grain

she

^Di"stri bJ,.ati Oll for

Sl1lca-~a

^Sand.

9b•.-Gtai n.SizeDistribution

ft

Iobdelli'¥lC1~y^•. lOa. Triaxial

Tes~.

^{Resu}ts for}si"l ica-70

Sa~'d

. .. (51Type Soil).

lOb. r;lax 1alTestResolts-for

Sl1lca-~

^Sand

J •

" ^"\ , ^---"

...-<"."

-U STOFF1GURES FIGURE

1" Assum2!dFailure Pa tternby1"eyerhOf(1961)~.

2. Dynamit:Free"'"BodY'Oia gram of aPene troflll1te~

...3. Photograph·'ShowingDifferentTypes-of ConeShape.. 4. }ircu1t

Djag~aDl

^of

St,r~l;t /nCa:ngeme~ts

{0a,Y'al, 1974):••- ,' "

. " ' "1 · · · ·

,Sa. Cetal1s of loan

Cell 'Art'ang~~t:~

ss. Phot ographS~owing~tall$.pf-!;Da~ce11

'1,"~::J::::"::o~"; ;,;';i~;iF~,;'~i; " :

6b.

Ta~~;'

^gobson

~.

4 laljs lJr{ Machin e..:.

.'# JS2Typeseru -', '

... . .

lOc. Tri axialTest 1iesQltsforSil i ca-70 sand (S3.TypeSoil) _..,,. .lOd.

~J1iaxial

^{rest gasuttsforItldejlin gClay.}

lO~ Tr.h.xi.ill,T~~t.

^Rfsults

f~r

^{Jobdel1irig.Cl ay...,'.'}

(

,. "

"

Page

15 26

27

es

29 -33 J4

"41 42 43 44

48 I

I

·-49'

I

50• .51

\52.

) .

,"

.FIGURE Page

11. ConstantRateofStrai nShearBox - WF 25000. 53 12a. Varia tionof~with e for Silica70 Sandas

Datermlned by DIrectSneer andTri axi"alTe s ts 54 12b; Variationof,.w1thIO,f or Sil i ca, 70 Sandas

Det e r mine d by DirectSheara~dTr1~xialTests 54 13. Typ;calOutplltfroma Free Fall penet ra t i on Test. 57 14a. Comparison ofPredictedan.d Experlf111:!ntalVelocity'Of

penetr~tfonfor3".56,emseta.~neyqmeter(51. 52 and"53 types ofSoil") " .". • 65 14b. Comparis6'nofPredtc ted andExperiment alVeloc ityof

Pene tra tionfor7.62ems.dt a Pe'netromete r($1, 52

and 53Types of Soil) 66

14c. 'Comparisonof Pred1ct e'dand Exper111J'!n tal Velocityof

"pene~ration

^{for'3. 56ces eta}Penetrtll'lleter(D."15°. '.~OGand 90° )

14d. Compar iso n

of ~red1cted

^andExpert mentalVllloc1tyof Penetrationfor7.62 emsdiaPene trome te r(a" 15', 30^Dand90^D) •• ••

15a. Comparisonof PIlalyticaland!leas uredlhltrowe Resistancefor 3.56 ems dia Penetrometer

67

"

(Wa ng,1971) ",. ..• '.' 69

~'. 15b. Compar is on'ofPIla1yt;caland !leas uredlnitCone seststercefor 3.56emsdl a Penet rometer

(Orrje&~roms,1970) ••. . ", 70

FIGURE

15c. Comparison of Analyt i cala.i'Id 1"eas u.redl.htt Cone Resi stancefor 1.62ensdiaPenetrometer (Or r j e&Broms ,1910 ) .

lSd. Compari sonof~a1yticaland'l'easu redl.fJitCone Resistance for 3.56emsdfePenetrometer

xiii

P'9'

71

82

8'

(Meyerhof,1961 ) '," 72

16 . Protcr teceterat tonvs .PenetrationDept h . 16 17. Plo t ofltl1t ConeReSistance, vs . /ene.tra ti ori'-~Pt~.. ,77

\8. Plot of~latlveIDen s i ty vs.·Ma.xi mufllPenetration

Dept h 78

.19a . Plo toftecet e eart on vs, Penet rat i onIepth ... . 79

19b . Plot oftecete-aetc n.vs ,Penet rat i on Depth ..•. 80

.20a. PlotoflktttCOneResista ncevs:'~enet-;'ati onDepth

for3.56 ens dfa pere tr onetr =15°, 30°&90~). 81 20b. p'iotoflkltt Cone:Res;sta nce s.Penet r ati onDept h

for7,'62 cesdiciPenllt rometer (a=15°,30°,.&90°) .

20e. Plotofqc!YOvs',ConeSemi-apexAngle (a)._..".".

21a . P1.otof ltll t ConeRes ijtancevs.Penet r ati onDepth . for 3.56ems dla Penet rometer,({jf~=0.5, 0.6&0.75) 86

. ' ^{. .}

21 b.Plotof lktl tCone~s is t~cevs.pe~pth for'7.62 ems'dillPenet rceete r-

u w .. ~.5 .

^{0.6'&0.75) 81}

.21e . P~ ~tofq/ yOvs.Roughnes s(61,)Of.~ne Mat~,r1al^fO:

3.56 cms dia Penet romete r(51,52 &53Types·ofSoil) . 88 21d. Plotpf~e/YO^vs.Ro:ughnes s,(li/, l'ofCon7Ma~;rial^for

7.6 2 cms-dlaPenet ronete r(51, 52&53Typesof Soi l ). 89

FIGURE Page ZZa. Plotoftecete eatten'is . PenetrationCepthfor

3.56cll'6dtaPen!trt)lleter 9)

22b. Plotof teeete-ettcnvs,Pl!!net ra t1ontepth.for

7.62emsdia P1lnetrollete; .. . •. . • • ..• ... 94

23a.\plot of l.l1ltCon~Resistance'is.Penetra t ion.Depth.

t ) forJ';56emsdfaPenetroseter: " 95

23b..Plot.of.lklit ConeRes1~tance'is.Penetretton.tepth

~for

J.6?

cmS"diaPene'trcmeter".•..,..•". . ',' .~ 96 24. Plot of

q i .... c~vs~ ~gle.

^ofShear Resistance'(4)'" '.... '97- 25a "-Pl oto.tlhHcOneRes istance vs.Penet r ati on cepth'for

3.56emsdl apenet romet er (WetSand"Ta rge t ).•••.• 98 25b; Plotof!.hitConeI!es"1stance'is.Pene tra tio n Dept "for

7. 62emdlarener reee te- (Wet-SandTa r get).••." . 99 .26a. Plo t of Cecel era t 10nYS.Penetrationr:epthVar yi ng

Soil Proper t ie sandPenet ro. t er db :- "~f,103 26b. Plot of rece1@ratlonvs.Penetrationlepthfor3.56 ces

diasenetroeeter(0''''15'-.30' &90'),•• • •. .:. 104 26e, Plot of'(:«el@rationvs',:--Pf!net ra ti onC2pthfor.7",62CfIlS .

dia-senet rc eeter (a"

·t~·, . ~~ i:

^{90')••'•;.•:'.:.• 105}

27a, Compar1s'onof Analyticaland~as u redU'litCaneandlKl1t ste eve

Resh~ance,

^{for 3,56}ems dia Pen et ro meter.,.', , 106.

27b, Plat ofU1itCol1eReshta nce and U11t SleeveResistance .vs:Fe.~etrlt1oh.^{Iepth.tor3.56}~^dhPenet i"Ol'ieler.".'. 107 '21e, Comparisonof~alyUcal-and~asuredUnitrenegeststence

andUnitSleeveResis tan cefor_7,62 ems db Penet ro mete r. . 108

27d.

fIGURE

Plot.oflkJitConeResista nceandLflttSleeve Resistancevs.Penet r ati cnIepth for 7.62 ems dta

Penetromet er .:'.. 109

1\1', TlIlysurf'Ik:lughness~as ur~mentsforCone(0.=15° ) • • • 124

A2,. Tal ysurf

.

-Rou

.

^-ghness1'\'!as urements^{- , -}for Cone(0.= 30°)• .•^~ 125 A3. TlI.l '/ sur f Roughness~asuremen ts-'f~r^COne.( a,'" ,.9.0')•",-:'., '126 A4. ilil!SUrf-

~~?hne;S' ."e~~,ur.emen~ :~~~_ Pla~

^__

.:.l ~' . :

81'. Typi calOutput"fortense'Sand-

.

^.Target^{...-" -} ,.,".'".

_82. Typ1calOutput forloled1 iJln'-():>n,se,Sand Tar ge:.

83."'TypicalOutputfor Loose

Sa~d Ta~~.et

84. TypicalOut put for-qayTarget •.

.<

J

consta nt . NOTATION

Pil et iparea;cross-sect 1oNalareaof penetrometer;

.

'" :',,-.'," I

!

~.F ••G.!Ige.facto~•.

<tenstent.. M.m,~ •Jlbs sof proje ctile.

"

,v

xv1.1

V(tj Velocity attimet.

'Vn Velod'tyat ti me

tn·

Weightof~rojecti l e;wei ght"ofpenetrometer.

xvU i

....

^;

CHAPTERI.

INTRODUCTION

I

1

f .' '. ,,",0''''' ;,,"', <;"c~, ^{;0... .}

^t

""" ott;, ,;.,i " ""'0' '" L

. ~!

^{.an ne}

~o·1~s . '

^till!

staill:la~d

(ASTM03«1-75T)electric cOnepere t rceet er

~asbeen~del1l1$e-d1~ the-statlc_~e:".elther':"'t't:ha5eabed rig .

<.

'cill edthe·5eacal 'i~^(O!Ruiter,1975;It,r1cf1e"rg,·1.975) or withabOre:

:",

~Oh; ll~ta~~'~t' [~n.ed ~e :· slfngray~ (~e~~son·

^e't

~1.;~

^..

19m.

Ii l.s est11l;t~dthat

a

typi6als'itefnve$t1~iat1onhicl ud1ng dr111lng'bore netes

-~~d 1n

^..

\~t·tu test1ng'·.'II~th

^a

~t~ndan:l penet~ome~r

^costs

UPw~~d'

0,"$1"

~'11 i~~" {H1tCh1~9S

^.et.al.:,J 976).':Sucha'

deta·l1e~" 1n·Y~st1gatfon.

~y.

^not'

~ ~'eces;'\J;"

^fn

, geot~ch~tcal '~urveY$'

^or

f~~ InYe~t~gat1~n' ~'f

'a'rge tracts.for

1~cai1ng

^{'pi pe}

'1-1n~:, ~'ut~5

^.etc.

T'h~: c~n~ePt ~r·

^a

'f~e ,'f~;1 ,pen~ trW.et;~

"

'~a$'

-

tnit1at~d' .

^{at Me}- ^morial,

Urih~;S

.,

itY" ..

"^{(Dayal ,"}

·1914)witb}he1nun tionof

'~'n!l:1t

^'.as_a

~too~_ !or

^..I:

qU1d: liid;.econ~lca~

~. s

. Activltjesrele ted tothedesign'andecnst wcttcnofoffshore

':si~~ctu~s h~~e

_' ^{9ai ned}_.

great:~n~~-

_.' ^{in t'he}_r··

:l~~t·,de cade.: ' " pe~~tled

_{' .}

~ . '

·~nf~o;:m.at.!()~ t~,t.~e.s:t~~t~th.'pr.o~.t~.t~~s,:,ofSet.f1.~r:SO't l;:f~ ~_s:~e.~tiaJ,.

'._{::~orsafe a~~}ec~nom_1~a1~esIgn,of'fo.un~_a ~f.o~~.~n·:~he oce~nfloo r..

·

~n~e~t1ona1 'S~1I1~~'1ng--'p~cedures ~sed

^'on'

l~'nd 'a~' ~e~~~all;:~ot

.::.·ttv'e

'1~' t~ oce'I~~' ~c~~s'e ~./~h~· p;~s~~~ ^{- 'iif'} 'i~e' ~"te~ ~llm:

^andthe

·

_hi~h deg~

^'O·f.

d1siur~ance If

fJle SilfIIlles.'

:ll~rat~ry tes~1ng'

^of

~uch

.'

5aq11~S _~re

^{there'foretobe'lSub}stan,thJt:.

by

^{\ ther.met hods. rn-stt«}

testingUlus'fo....s anintegralpartofany'

OffshO~

^5011'investigation.

. ". '?

.:".

) _2' ("

. . testi ngof marin esol1lrnoed1at ely belowthe mud line.

Afreefallpenet ron;eter is a cone tippe d rfght,circular . cylindr icalprojec~ilewhfchts allowedtofal lon,soil"target.froma preadjusted~e1ghtof freefan. It is lnstrur:'Ented"\JjfthIcadcejls for measur ing the conetip resistance andfri cti on onthe sidesleeve

d~rlng ~enetration .

^An

accel~erometer

^isalso

rro~nted

lflithi n the

.. ' ....' . . , , ' l

.J. ", ' .,.,.

penetrometer for,recording eeceteraetcn,proJ il e_J,~ptothe,run.dept,h

0;' _penetrat~~;

^,"

I~te~?t~,~_n\~~~:~~.:~e~~;e,r~tl~~~ti~ :'~ford' :rov~des ^{. "}

ve_~,Dei~.Y"~~:S.US:~f:~,~~,rv~,whi~~_c~n:_th~n:b~llSe~-':~Ob~r:::,~~

.:

~ts~

r:

Ipl.~.~~~~~~_

^'versu's

u~: ,cu~;e~ ^{c \"} ·B~>'t:~O.~~ ,~lottin.~ .-~_~e: re~.':d ;~f ~~r~~r,~,:

t10,n~s1stance,.ve~u,~·dePth~ro.file,i sobta1n~d~'Th~:data thus .. ~ obhined is usedforthefinal aniilyslsofthesot'l..st nlllgt h properties.

, . J ' ..

I~itt,alatt~Ptswfth_.~afield.penetr~ter'Jones,_{,1 97~)}showed·

that thes.tandar dpenetrometer (cress sectional,area•10.00 sq.·emS.)

I . ' . . ., .

wasst r uct urall y inadequatein thefree.fallmode. Aco"".1etE!'lY

. . .' . ""

ft .redes1,gnedversten of thefre~:fall,:penetrometert(~r.oss.Sfcti_~n"a'rea,;, 45.62sq',c.ms:)was

succes,~ fUllY te~.t~d du~.t ng.'sea· tr1a1s' 1nPl~\centia

Bay,-

off

^Newfoundland,dn'Hay,-':197S: (Chad e't':aL,1978):

.la~rat~ry' test'~'~i~h':,ihis.re~~~i~~~d·'~enet~te~,and

^an

analysis'of'the

'~~ult~;,are pr~sent~i1 n. th<s

^d'isse.rtat1on. Freefall penetrattcntes t s'Wen!condLicte~using'the shndard~,Fugro"type-,

! , " ,'I',. .I,•._ I." :

penet~meter.,and ~he,r;edesfg ned, "Memor i alUnhers1ty ~pene,tro.me,~e~._

T~(l-types~fsoilta',rgets,Wt! re

Used. .

~Q~~.,.Gawad,r~979rcondll:t~d 'a par al.h:!l',pn;j ect,1~.carr~f~g outq~as1~st.rti'c^{tests'with the}

two

\ I

. ...

.. s

I \

i

.-,~'

the penetrometer.

2," To

st~d~

^{;t ll}e penet ration

PIl~)-~~~on -1ri 'dfffereot' S~-1 '

^types'.

3.' Tocompare'

~he ~SU.ltS o~tii~e,~ fro~

^free

fall- :t~sts

^{'wi th-}

thoseforquas1-stllt1ctests .

4. To-prop'oseappro priat e;reth~d's'^of.1nt~rpreti~g.tb~'^{resuU s.}

inthe light-O'f.theor;~ scurrently ava11abl e-fn the.

ttt eret uee ,- dissertation.

.

.

.deqre e ofsatura~10n.,etc.) . ),"_{_~.e}~ase,',ofthefree_f~~l'penet ro~ter.' itsweight ts

a~addlt1onal ·1~f·~uenc1~g fattor.·· ,~~

impor tan ceof .

~h~S~ ;

^factors',

^{, are '} ~~Ud1e~":

¹ⁿ

\.h1:i::~~p~~'~~~t~l:·_fnve,stig~.ti~ri::c- , "

,

The._~as,lC

;almS"of,

t~iS'

st&dy

are ; ' . .

1;: >J:ci~t:uilY':t"he,'i_nftue~ce;'of:.th.e: ':di f.fe,r·~~ t_c~_a·ra.cte·~i s ~ f.C:~of ..

Themajor factors which influence,the penetrationr-esist anca .1n any cone

penl!t;atio~

^test

^:1\.e

^{(1)cone apex}

ang ~e'~

^(ii)cone

dhmE!ter;(ii'1)roughness

~f

^"theicone material ;'(fv) rateof'

pe~el1-a·

.rtc ni(v )'s011properties (angle'of~hearlng're s jsee nce ,cohesion~

....

Q

SMOOTHBASE ROUGH BASE

la) FOR FLAT TIPPI~E

(b I FOR WEOOE OR CONICAL TIp·PILE

fIG1.ASSUME D'fAILUREPATIERH BYHE~ERHIlF^{(i961 )}

. ,

For conestontess soils: q," vn Nq . .(6) ForColles:v~solls: qc~-o+eN, . ... ... . • (7) Conversely,i fq,"a ndfsCarlbemeasured,theul~ jmate 'bearin9 cepecttye no hencethesoilshear proper t.tescan be detemined.

2.2 . DynamicPenetra-ticnTe st .

Atypeofdynaatc penetrationtest that hasb~enpart cr- any boreholeinves t .fgat";onis. the Stand a r.dPenetrationTe st (SPT) , wh~rei\spll~.-spoons~'ertsdrivenbyrepeated blows ofa freely fa1.11ng.standardw.ei ght. I~^{the recentpast,}the useful ness of this testhasbeenquest ioned(Schmertmann.1975). "Itappearstobe the consensusthattheint erpre t ati On of.thistypeof testrequires'not 0II1ya lot ofeeer-tence ,.put 1s to be donewithceut fon. Theot he r typeofdyn~;Gpenetration test whichis discussedtntht sthesis uses apenetromete r which hasthe sameorsimila r conf i9urationto that~scribedunoer the conepen test,

2.2. 1. HighVelocity a,nd lowVelocity-Pe net ration

\ . . • J •

In co nnectionwiththestudyof projectt l epenetrat 10ninto

a .

earth(Young , 1972) atmedi a , reseercntheSandiahasbeen 901ng onLaborat~riessinceinAlbuquerque ,the early 1960 rsNewMexico.

.

Projectiles ofdif fer:-e nt shapes, inst rument edwith.an acce l ero meter have been tes ted with~e1 ocitiesofpene trett onup to 790 III/sec (2570 f t/ se .

In -suchdynamic tess,pl!net ratton15caus ed by vtrtueof theene rgyat'thet me oflmp.a~t. Up~"-~~c~onasoil'mas s

the

project il epus hes agai nsttheso11 particles,rupt uresthe so il

\

.)

1

1

structu reand ee-sto restwtlen the projecqhenergy istot all y ctlss1pate d. Depend ing0tIthe l.., a ct veloc ity with lIIllch the projectil e strike sthesoiltar'getthepenetra tionphen~ onhnbeencla s s Hled aslow'I'elo c1tyor1'119/1veloci ty. Thebas isforthisdeNteationis the typeof 5011failure. Thet~nn'lowve locit y'isusedtodescribe tne events for willensoil fai l ure pattern issimilar to'the quasi- stettc ceses (Wang.1971;HurffandCoyle,1912;Day, l ,,1974).

Wang(1971)hnsugge S,ed,that the soil Sl'lear, zone 'tsstmllar. Q'} to_statlec~sefor\IeJoc{t1esup to152m/se,c(500.fps)but hascon-

ductedstudi~sonly~,toaIMxlmurn.impactveloc.ltyof7.~wsec(25:(ps) .. HuHfand Coyl e(19'72) In'l'est1gat ed'tJrojec t11e penetration'Inve locity range of9.1Il/ser."to 91~sec(30 to 300(ps)and ciass ifledthese tes:s aslowvelocitytest s. AlthO~ra dis cuss ionoftheexactHlllit for the1011I'vel ocit y IIlI!dlanismIs outo'f,contut•.ltcanbe seenfnJII the publisll ed re:forts that velocit ie sfn theorderof 9.1-Isec {30

fps~

^are

~learl1

^alow

·~elOtity PherlOllll!~.

^{The'ft'lOCit;}

ob~aine~

forthef1ft fall conej)l!llI!t ra tlo n test.sreporte d.in tills thesisis In theorderof1. 15II/s ecan.d isclass i fied IS low veloci.tlpene t ratl on.

2.2.2. Dynami cPenetration Theory

_Tile basicas s uqltf onsforderiving tileexpress l onsf<!r proje ctfll!pe ne traHonare (Young.1972;Dayal , 1974):

.). Tlleso tlta rget1s.hOlrogeneous and isotrop1c...

,

2. Tile penetrometer is anuhpoweredpro j ectile of~si~l e configuratlonhavi ngacyli ndri cal bollYand nos.e.1

3. There isno significantangl ebetween'tilea~1sof the• penetrometerand ItsYt'loci ty

.

vecto r.

. '

....

^:.'(

..

~

^{A(4ay_l )·'ls .'.. . ..(11.)}

10

(8)

(9)'

_(10) for Vo>,V>V

c v

_*"-,

^"'e_vZ+y

All en et a1. (1957) conduct eda se-t esof penetret tontes t s onsenewithdi ff eren t nose shapes. They qrcposedthe (01101;1n 9 theory :

where n.t sthe I!!'lss of th'eprojectile,V Is theproj ec t ll e veloc ity, and a,II,yarec Oflstants ,

Dependingupon.therelat i ve magnitudeof~,.aand'r,the sol uti ons.ofequat ionOCl are:

{l)'.for~he^casewhere62<4cay

yV~ '~

+BVo^+"

X "'~

^{1nyy2 +BV}

^{" + ."}

an Impac tatavel ocitygreater thanV

c15largely1ne hs t 1.c andat a velocityless thanV

cthe projectilesimplypushes the sand elasti cally.

Schmid(l969) es sueadthe\penetrati onequationas

for" Vc^>V>0

where ' V

o15the 11lll.dCt veloci t y a,t.-ze ro penetrationand Vc 15the crf tie;.,1 velocity.

Base d on exper 1JJJ:!nta lresu'lt s," thecriticalvelocityIVc (defin edlat er) was calc ula te d tobe'96.5m/se c. Th eyconclu ded't hat

\

\

\

I

\

\

I-

I

\

\

\

\ f

I i

I i

\ b~"~"="~~:c-:====~

(12) whereX is the 1nstafltane.ouspenetrationattimetand velocity \/:

VO1.Stheveloc 1tyo"f.impact.

A=tan- I(ZYVo⁺8)( 4",r-sz (!l • tan-l (2yV+8){ 4ar-

a2)·~

.. •.• (13)

(;oj 1) fortheca s e wherea2~4",y

where

.(14)

. ,

B..

1.

In'{2yV.+8.+(62·.4"'y )}{2YV o+ a

2 . ~

{hV+B·(6.2

-4ew) )fzYVo+a

.

^{·(a+(a22.4ay) }-.·4IlY) \'}

12 Startingfrom Newton'sequatio nofectr on , Thompsonet al{ (1969) de rivedthe hllowing"relat ions hipsfor acceleration(Al.velocity(V) andpenetratfoo dept h(Z)

A-

Mtr

^{+ 9}

p , .. • .•. 1201

." ', F '··".·' ;,,' ",/.'

v_~,'.J{~.~.9)dt

.

..''^.,:

....hereF ts tile soilrestsreace ,~i,Smas~ofproje'~tfl e .Me ts mass of~

s~n ..

m.1ving with'the^. project1 1ean'd.

gi~:the accelerat~on

.due

~Q

.gr avity:.,

',';

'I/II~ '9ldtl" ,< . :IW

. -.

-. ' , " -- , ';~:;,:_~

..

Theyconductedlabo rator y experiments,w1ththeO~iectiveof

,dt!mi:Kl- st~ating the'1~fluence '~f PhySfC~ l

^soil

pa~t:mete~~mpact' ~eJ-o~fty

"

- ' ..

andtheproj ect 11e,prope rty. Tho~sonet al.-(1969)concludedthat thesoil

' ~trength 'Pi!lra~ters

^{haveast;.ring}influence OJ).

the~Pth

^.f?f

penetration.

Young (1969)p~sen.ted_t~.~~et.ratf.on.~ redi.ct.1.~· e~lItion^es".

~x :;. '530'SH(W/A)~ 10~3 ln (J~·ioX10~6.v~)

^{• • •••(23)}

fol" Vo.<' 200.ft/S~~·

.' ••.•. • •. ••(24) Vo^>WOft/ sec ·

-

for

L~~~~ i

13

wherex..ax fs'theNili lUllpenetra tl~depth,'Sisthe soilcons tant. II is ~enos eperf ormancecG-eff1~ 1ent.WIst~eweight of proj edll e and AIsthecross-sectiona l areaof theprojecti le.

.ValuesofSliewithfn awiderange(roll0.2to50. For solving.tll~aboveequati ons,Itisnecessa~toassl,lllle-thatS.is cons t!lnt fO:"'Igi venta~ge~: TIIus .~~j.pen:trl ttonI,"',a .layt.re?.

lIe,~fU~. O~, W~de,lY, dff~e~li~ .:p~pert~ e$,

' "_

~~ ci.

Y:lue.

~f -~_ '_w~,fT,

_.

~P7n:d:-O~

^__

th.et~.t~J.·~ePt~ , p:netr:ai~~·., _ :"B_aS;d,',~ ~~ ··dita1,r~d:a~~~~.s:ts:, . . . .

.of'

o~~r'

⁵⁰⁰

'f~'Tl - ~ca l~ t;s~s.

^_.YOUng

"( 1~72)'

^{'cOncludedth"at}

p;ed1'C~f~n~'

\~~~~curat~'- Wli'~t~O:.i~proxf~~lY._·±2~i.':

"'.

' -"'" :.!

',' ". ':

':" '.,." ' :

.•....,'.J, .. '" ..

;

!

". f.:,

,-;-..

:

....

..

;.

.

^~'

..

,

~.;..

14

C'f'Oss-sectiOflalarea oftilepene trometer.

", --MurffandCOyl e(1913) also conducte d peMtratlontest s by

.

. . ,

vary1'!9 soil par ameters.penetroaetercharacteristics udimpact velocity. Predic tl on e q uatlons

were

sugl}este dinwhtththesoH .re s tsteecewas ISsumedtobeII linea'rfunct i onof the

~l<idty

and

·de ~th. Goodftt'IlUreportep'botllforchyandund.'.

.

Tur ~~9'e, .~,n.d ~~et ia{(1 969~·,a~:d.,'Tlr~.na9~ .P~~~:~. '_c~n.d~cte~.

^{_, -.. .}

.e)(~:efj~n.t.~,^..,t~.~~xllm.l.ne^.~~eV1,~COUS.:ef~~C~.~.',~,~~:,~.~.~~.1.a.~,fo~.c~s.o_~^""...

pelle~ratfQI1.r~s fstllnce:,:ora,W:1 ~v~~.jetyof,pro~,s,tzes.-'.shape~,and.

·.·pe net~a't__^fcnvel oc l t'les•

.' ne t' '':'

da~'s~ow, ~Il t

the : 'cone " P!h e:tra tfbrJ

.

re~1st~n~e

^0"

f;~; __ ~ra~n;; ;~i h wa~ ~roport~o~l} '~.~·lOCfl=Y

^and

1nY~"rselYproportionaltocane diollleter . AnelponentUlequatipnwas

~~veroped

^to

d~rlbl! ··th~·

^interrelati onship; ..'

. 'Yaryf"

~he

^sat\

prope~tjes. penttrome~e

^..cha racter ist1csand 1lllJlact;ve locity•.

oi"

y

h

(1914),perfo~laboratQI')'s.tudtnforl!~ier.

,mini ngge-otetll!li calpropertiesofsoilsusing aninstr~ntedi ....ac t .,

.·: con~.~~~t~te;.a ~rnI.~h~ .~~J~ S~ed good ."g~n.twi~

^{- . .}

..'the~l'l! ti ~ a1fIOde1-·.Theiq:~veloctttesofthosetestswe rein the

: ran~e'Clf .i. ~5~~·

.g.

f·1l/·~ec

(15'to,30'"f t/S!C) " . . 2.3.~Analysls

Dur fng'·""fr!!fal"lptn; t ; ati0n.,.the

pene~~l!lE!ter ·eIPerjence~

~S1-~tan~~ · bY '~h~··so1'1 f.~·om th~. fris~nt ot'e~t;'y~~tf1' ~e toncl~s1on of'

Penetration.'

even~. T~·e

^'dynamic

fre~ bod~

dta'gr';"

~f

^'4

peneir~~er

^•

durl ~g penetrat1~n

^{15shoWn Inr'i9.'2: 'Theanalyt ic ;l:ft}lat i·onsbip of'

~i!ferent

,parmetel"'S'.(·1_{·,R. · ' .,}

:e,:',

_.

"

soil

p~~p~:;'ties'

_' ",.. . ,

J.;~~t vel~c~tY.

.' • ,

(Tp~cont 1nue·d~QE!,16)

... ..

15

DRIVING

I

FORCE :

;

;

.... ...

< 'H

... . r

SlOE'ADHE SION

FORCE "

,;

..

^':_;'

. J

W,' WEIGHT SF·THE PENETRONETER

BEAillNG,PRESSURE.

FOR!lE ' .

'I

.i

\

"

i i i

: i -

I i ",

I~t J

pene tromet ercha r acteris tics ,e tc.]gove rningthe dynamicsoil propert iesatlowvetcctty penetrat ionaredlscussed be low.

2:3.1. Mode~fSoilSlIea l"Fail u re

Asdescr ib e d earl ie r,tnt!behav iourof 5011Lmderlow veloeft.¥;penetrat ion\loul<1 besi~l1.rtc.tnequasi-stat icca se.

.

^. -

' . .

Accordingly ,thefa i l ui'emodedllri-"g ~hefree fal l,pe net ration,isassumed tobethatprcpcsed

bYMe~~rhof (l95i)

^{fordeep'cone.}

tiP;P~d

^{pi le}

,

f~und~~'jo~,' "(h~:.reason~':f~~ ad~-Ptiri~ M~yerh~fIS ~~ilLl;e ~att'ern

^{we r e}

s~mniarl~~d bYOay~"

(l9.74 )":'a.s".foll,OWS:

(i )".

H~yer~of~

^s

,t~ellry

^tak'es'1

~tQ

^'account

the

shape

a~d 'surf~ce

roughness.of thepenet romete r.

,, '

(11) Fail ure patternas' observed exp.er iment a llyfor plene-stratn' mode l1mp 8ctp!ne t rat ion test s coutcbeapproxi mat! d .to that'

I ' , . ' •

of Meyerho f 'sfailurepathm.

.(111 ) hperllJlent al resultswerefoundto bein 9:'lld,apreement wIt h. thea~alyti ~al, val ueobta 1ne~byMe.yerhOf ' s.me t hod,

>~l thOU91ldHferent.theori.esare'avlll1able·fromre·l:li~·t ", pUblications(Dllr 9un09l uandMitche ll,',1973)wtdch.a-lsota~~into'.

accciunt ,the" pe~ti"Omet~r

^,;hape,sizeark!

roughriess . ~Ye~~~f's

theory"

is"

p~ferre dby vi r tUeofUs eesecrapPlicail?nan~itsetde

acce p~ nce .

-

-

.Fromthe r-es ultsofa se-tesoflOw'vel ocitY'penet rat ion' .tests.on'

sa~'~s;:'w~ng , (19 '7 '1,),

eXpr es sed

t.h~ f~li~ 1~9,;re'1 a~10ns.h.fp

^',;or',

,theu1tima~ be~rln,g,capaCit y: \

,, ' . ;

•• •• c(!5)

wheNOu •ultimatebear1nQcapaci ty AandC,,-,const ants,dependingon son

proper ty,penetrometershape and

:$h e._ '.. r

. . . -x· depth ofJ)!net rat1on•." .

~ ActO~ 1'~

^to'the

princ~pl~ ;f

.cons e.rvat\on

o~ ~~er'iY"_'wari:9

^':.

..

1 I

I ₁

- /" ---r-

Knowingtilemaxfrrum penetrationdepth1(1!)fora certainlmpact velocity(Yo) '

'c ; c, jut"

be

~alculated. f~-eq~tf ~

^{(ZB). ;}"'5 the'

~O~~ri bU~IOn

^of

~

^{15 very}

$mal~ (~ang, 1971q_n·c~;t~,,- .to

Cp •

A

lls"-,negl rttl! d"

~f~e /J@te~m~ng! ~ nl~1I!! o~ ~~.:

^.

A~ajn

^•.

eqaat1o~

^.'..

"' ,

.<.261

'.!'

, s,

'.','. ...) '...

. - '-.

B·~ld ^(f.,i)

~.I ^{. ..} ~mass~fthepenet.l'Qliet e r.

~olu t i onof equation(Zli)was givenas:

. - . I '

. '2 · '" C1' ZA .~ 1<'

-'1

""' Cl'ZA.It.

",'i((Va_-n~}T -ll»)e M -(T)~⁺m·IT·MH-. .(2: r

where Vais the.bipllct

veTOC.'~.

^_...

.,.¥ -r. ~."

'P'I!pefletratl.OI\dep.t h.Isa1lliU1. .ra~1I1!~projectile ROp S;".

.he~ev·pe~et~te!vel ocity

' . . ' : ! 1911: d"j~:dt::~:~:n?:~:tt~ht~,i')d' . ' :..

.

-

,"

. ,

..

: . ...

" ."

-.~

18

(25) coul,dbe r-e -srft.te n as,lNeg l ectingAl.

.. Ou='ell (29)

)

_{Consideri ng}

.

_{equat ,}._{ion(6 )}._asvalidfor. _lowve'_{Iccttyperet ra}

.

_-

tton,itcan he re-er fxt en as :

y"

;am~~.-

i- i

Wh!re'

;~

.•

avera~e

contact'preisure

i ·

acceleratio n

19

(321

ofsa tura t~dc14y s. WtlltNn(l9571has fur th r shown thattM strength Is considerably increasedunderveryrapi dratesOfload111g.

';ihl tman (1960) suggestedthat the rate effectuponst rength.ightbe caused by a changein excess poreere sse-egeneratedduringtheShear process. Datareport edbyO'Nel1 l' (962) Indicated that hishypothe s i s was substanti a ll ycorrect .

Inc.onnectt ori withtee ts onbulldozerbladeS,\jismerand luth>O?7'l1att~tedtoquantifYth estrairirateeffectsandused .th'~ecuat ten ofTurnag~and.Freitag (1969 ).andsU~gested :

CIx•('

(~)

^{x I K..}

~

^{•. . • •• .•,••,(35)}

Ci1

til)s

.f1e~^CIx'";~one tnde~at penetration

. · rilte rx",1th'cone•dlamete'r. " dx . CI_\.••_.ccne_i.index of astanda~^cone

"'ith.penetrati~~rat er s and

"

](=exponent ofsfn!ar rate·fa<:lo r.

v•

"

... . .••(e9".1) "

.e- ^{, \}

'

BaseddneXPrrt1ll!nUl'results,Wi~lIi!randL~thsuggesteda .valueofO.1'forthee~ponentta lK.

', ' Frt)lfI

eq~aqon ~ i.~l,··theo'retic~l

^vetueof

~~ne're.sl$til.nce

^for

dtffe,renti~act~e'oc 1ty..and'cOne dlllme~rcal!beca !~uhtedwiththe ql.i'asi -s.ta : k~~.etr~,t1.~~'testas theref.er:nce~rvtce- veese.'

Aga inforpure'!cchest ve-sutls"

v.

"

:

.:. ;,

I , .

I t'

, I I

'1

22

I'!ey!rhof (1976)hasghen Ne valuesfor d"lff~ti"nt^{; ;11types and} relativedepthof foundat)on"'

Knowing~ ,

^cohesion(eicouldbe

cal ~·

cut etee.

In sUII'IIIIry,itmay be statedtha

.

tfree fall proJec.tt le.pere tre- tlon at lowve loc ityis influencedby variousfacto rs. ~he5e.a red1f ·. fel"t'ntfor cOheslonlus and,COhes iv e so11S". D1ffu ent~thOdsc,urrentl .(

avetiebtecanbeusl!dtoevaluat e the5011propert~esandcompa red wHh

. - : . • 1

eachother.andalsowlth·the·trhx~alanddlre~tshear'test res ult s.;;

.

^. ~. ~

\

./

I

I I '

I I

he, 1

CHAPTERIII

LABORATORY~X PE RI HE NTALPROGRAM

3.1. ~

Theexperi ment al~rogramwas desi gned with tneobjec~i veof'"

st~dyi ngthe mechanic s of

.fre€

fallpenetrationres tstance ofsofls \ andits cor re lati ontothe st atic.pe~e trat i onmechanis m. Theinflu- ence of cone

,

angie . cone'roughnessandthe 'type

o..f.~~n

^{tar get}

.

^on

statlcpenet retaonresistanceis recogniz edand reporte din l.iter at ur'e;

The~vadables"areexaminedin'the fr ee,fa ll.penetra tion tests con- ducted. The freefall penet rometer that"wds designedandsuccessf ul Iy usedatseais 7.6 2 cmsd.iameterwhil ethestandard.penetr~~ r used tn IOOststatic'.penet rationtestsis 3.56emsdf emet.er. In thfs wor k, tests weredOn~'Nlth^{bothtypes of}penetr~eters^{so tha't}appropria te compar is ons

an~correlations c~uld

be made.

. 3.2:

APparatus - Penet rOme t er

AdetatledPhys1cal·descr.1~lonofthe-twotypes of penet~-

. .

...

-,

setersused.is.given in reb'le 1. Tipsfor~thpenetr omeyrswer,e detachablefrom theshaf tand hadvariousapexangle and rl?ughne,ss.'A compl~telfsting ofthepen'etrometer tips.used inuil s~investigati onis giv entn Iable2. Shapesandsizes ofOdfffe rentcones\together with the noseasselrblpforthe 't woperer rceetersareshawfl1hFig.3.

. , .

13.

-.

24 3..2, 1. Instrumentation

The penetrometerswert!ins t rume nted\<I1 th·th~ esensor s:

accejercnetar,coneload cell and frictionsl eeve load cell . ,Theacceleromete rees mounted1n~idethepene t rometerand alignedinthe direction ofthepenet romet e r axis, The accelerometer useein th

,

t sinvestiga tio nhad thefollowin gspeclficati ons:

ENDEVCO: Model2262-25 Type: Fullbridgepie zores 1s t h e Rated range: t25 g

Useful range : 150g ' Sensitivity: 16.7 IllV/g'(atlOY

~excl ta F onl I'\axm,transverse

sensitivity: ,1.2$

St rain gages wer e usedfo~measuringconeandsleeve friction

,

,

loads . Eachloadce ll cont a insfour pa1rs of stra1jl gages arranged

r

^{in sucha rranne rthatcompensation}is made for bending st res s and only theaxialload isme asur ed. Fo urstrai ngages'were arrangedin the axialdi re ct i on andthe remai ningfourinthe circlBl1ferentlaldf rec- tton, equi dis t ant., on theperiphery ofthe tube. The c1n:uit,d1agram is shown1nFfig.4.

Con~ "and

^{frict 40nloadcells;re}calib ratedonan

'Ins~ron'

i i . .

j

i'

"

I _I

i

tes t ing mach1ne. For thecallbratl on(/f loa dcellsspeci al ji gs were designed andfabrl cated sothat onlyaxi alload was appl1ed duri ng compres s i00 of the tube. Thecells we reloaded upt~635, Kg (1400lbr:.)for coneand 2,72Kg(~OO"lbs ), fpr'f ri c Uon'S leeveat 22. 68 Kg(50lbs)increment. Thereslll;:softheca) i br at iontests.

(!extcon'tinlledpage 30)

\

25 TABLEl. DESCRIPTI ONOFTI1EPENETROMETERS

"Fugro" type Memorial

I I

penetromet er penet r dinet e r

~.56ems(1.4{n.} 7.62 ems (3.0in.)

I

\

10.00cm2 (1. 55 In.2) 45.62 an2(7.07 1n,2 i

" i

'JJj0 .60°and160⁰ 300•60°andlailD

\

3.5 6.cms-(l.4 i n.l. "7.62cm~(3 .'0in.)

150 rln2·(23.25tn.²⁾

'64~u(cm2 ( 1~ ~n;2) /

\ ~ TAB LE 2. DETAILS OF PENETROME TERTIPS

l

^rometer Penetrometer Rcaqhness of aeseseet-

ter t1pmate r1al cone seteetet apexangl ~

(61. )1 (0)

' f

I '

i ^3.56 Sta inless stee lPol1 shedal umlnlum' 0.50.6

~~:' ~g~ :~i :g~

'Sandedaluminium' 0.75 15° . 300end 900

Stai nlessst eel 0. 5 lSD,'300 and'gOo 7.62 Poltshedaluml nl um 0.6 lSD, J0 0<1iid900 SandedallJ111infulil 0.75 150,300and'~Oo

t.:·

..;

26

zr

-- -- -- -

- -

--- --- - ---'--- -- - - - -- -'---,.

I :

I

,

-

~

FIG .~~ Ci~I~' -D,l~G,~ 'O(~~.~~.-'G.,~ ,~GEMOO'·S, ( -,~.1 .i9~~' )

.FIGSa.'DETAllS,O~LOAD CElL ARRNlGEM£'lri

WATERPROOF BUS..ING O-RING

FRICTiON- STRAIN GAGE E- AIH'GAGE

28

..W TH ROD

:;,",., .~'. '0 - RING

..

\

. . ...

/ ..

.-'

1lO.T .TO'SCALE

r _' r

I

I I

I

I

29

~~plot ted an<! tileloadver s ~sstrainindicato r teadfngcurveswere

'--'"

.

obta i ned forthe10a ~cell s. The lstraingage bridgesulfibf tedexcel- lent l1n·earity. rjesecalfbratfon curves ,"ere~~e<I^{toreducethe data}

·frollpenetrceeter tests. Detailsofload cell arrangellll!nts'isshown

"i nF~.gs.Sa'andSb.'The following are the sped fica t i onsof cone and

fr1'c'tfon sleevel oad ~lls:

Gage resista nce: 120Ohms

.Gage.f~ctor(G.Fl

Z .'

1. I

1

,I f,'

.Sensl t.1Yi ty: 200kg/mV (3.56cmsdfa.penet rOlile t er) .

and 329 Kg/mV(7.62cmsdia ;penet~/neter) 3.3. Recordin g Sys t em·

.The output'signal s of th.e·ecct erceete - ,conelo·ad

Cell

and fr icti onsl e~veload cellswere recol"(ledon a hi.ghspeedchart recprder(GOUl D 2000).and alsoatape recorder(HP3968 A).'.The stgnal~wereilIlllllf ie d.byselecting suitablegainon the aqIltfler before feedfng into

th~ \reco"n:ler.

^{'The char t}

reco~·er

^isaself-

COntaineduni tho,ed.·~n250mlM~n-fralN!chassisto_acc~date three isolatedrecord tn9channels. Thfj,cha rtspeed used.1nthis investigatio n was 200 IlII/sec: Therecorded diU. onthe tapes wi ll be~se dforper1Mnen t r:ecordandfurth erreferencewhenrequi red .

. . '

3.4. Exoer1ll1entaJMeth),d

,... 'sererestarting,:a;htest...tIlefOllowfn.~Ubr'at10n.

checksweremade:

1. The actual gafnofa" amplff fer 1nc1udfngthat ofthe

·tape recorder. 2. Balancing ofthe4.q,l1 f1en.

cells.

I

L

I '

I

I '

31

.3. Thecalibrati onof theac~ le rtllleterby turnoVf!r llethod,i.e., byllr1entl~gttssensitiveuls inve-ueetdirection'and thenturnlng over180~resulting'ina change of'2g', ,4, Ba h nc~ ngthe bridge ofthecone and frl ctionsleeveload

,

.T~penetromete r was at tached toa releu ln g'rnechanismwh1clTwa~

fnturnattachedtil,anylon rope. Thus the penet rometercanbe,pulled

"uPto

~, ce;taln

^fhl!dhe1gh'tand released by

~ q~.fCk

^{rel ease;'chanls .}

l~~te~ lt~~t h.!1 ~~.

^{. .}

.

T~ he,1g~; Q.~'

^{rreefall ...}

a~

kept constantlit.3.06

Ht-~s

^for

this.Investigationand'correspondi ng,veloc1ty oftlllPlCt was7. 15wsec.

care'was

tal:.e~· ~Q ~ 'nta1n

^the

vert1~al1'ty

^of.'the

~net~ter

befol"'!

-, every'experiment. ~h ecanPleteset-up(frame,n!leas l ng mechants m, pul ltes,etc. )for free fallimpactpenetrationtests Is shownin Fig. 5a·.·.

3.5. Roughness oftheCOneMaterial

Surface~~ghnessof the,penet~terhlS's1gnificanteffect on the penetratfonreststenee(Meyerhof.1961;laraf h th, 19n).''

Ca~flll consideni1~n

^wlS

!l'.Ye~

·.h i le dete!""1n1ri9,the..:oU9hness of

.the cone....tert al. L

For

'~st~,in

sOils'r ou9hness.ts

gener~lly,expressed

^as

~

rattooftheIngleof frictionbetweentile penetreeeter-material(a) ....

, , ' ',, '11

andth~SO!lfrictionangle(.Li e.•relative roughness(6/.) . In

Ithislnn stlgat l on absoluteroughness values were a1$o dete,l'1IIlnedin

terms

of the centrelineaverage (a.A). Tayl or-HobSon 1+0.4Talys urf

.'

. 1

31

(Fig.Bb}anditrect ilinear recorder were'used to evalu atesurface roughn ess ofthree dIfferentconetips~sedin thisinves t igati on.

Tlie res u lts areshOlininAppendhA. Theroughne~~(CSA^{895;1962 )} isexpre ssed Intermsofcent relineaverage(CLA(1nmicrons.overa cut -offle ngthof 0.2541IIlI. Themeas ur edroughnes s values are presentedtnTable3a. F:om"these,resu1t~.itisseenth~tthereis

S~~.d tfference,if\.the,.Cl~ V~~~Sof~:~E!pl at es andco~es,.T~U.S.tbe

\(al ueo f 6 obte tnedfort~epfatesfro~direct sheartes,ts~ouldbe 'S'119htlY:differentf~r-th~'cones_^{actuallyusedl'n,}t~-penetration

-.

'~t~'s.:~~: " ':-'1 ~~'~';ectfO~: ~~_ct?_~_ ~~~_ t,here;;ri, ~_PP'li~'~ ·t~·',dlc'u~a.te ~he-.

f1 n~1

,v"Ilu es'of.

, rou~hri'~:~~for ~ifferent',~one'

materfa;s,.

3.6;.TargetPrepara tfon'.

Twotypes,of~D1 l't argetmat er-f al s were,'sele ctedfor thts 1n,ves tf ga tf on:

(l)Sil ica- 70sand '(il)MOd~ni ng'C1a,y

Themateria.l~"!ere readily,available and_'.' - .sa~ies'. ." could'

.

~'p'repaf'1!d

.

easi1y. sestcee,~^{these were'chosen as.re-P}resen,tat1ve'ofp~relY^non- tiirge'ts.

\

I

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"

FIGsa, PHOTOGRAPH SHOWI1lG EXPERIMENTAL FACILITY

33

zo 34

~ ~ ^"

^{~ ~}

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^{:g :E}

~

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~ ~

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.,

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~ ~ _:

^{Iil ~ ~ ~~}

a

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^{10 01' 0>:e}

~' ~ ! .9

35

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36

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37

to 1IliL1nta'na cons ta ntdensityatall de pt hsforloosesand.

COlourmarkingswereIWdeina woodenboll.(0.9l 4.ll.0.685II ll.

8.914 .,

at2Semintervalsand sandwasc~refull)'pla ce d upto therequi ; edheight. Coq:lac~i on"as~(joe'witnthe help ofanelectri- callyoper ate d vi brator: As soonas the top layerofsandreachedthe 2~mar k-ing . a furthe rquant ity ofsandwasplaced and...tbreteein. the samemanne rtJ'It l1thedes iredvoll11lewas obtained. Tnis was ecnte ...edbyco"t roll1 ngthe tfmeofvi bl-a tfon'foreachlaye r . Aft e r compactionwas'completedup to the topmos t layer, tota lweightofsand was

d·e~enn1ned.

^TIlus , knowing't he volume.tI1effna1unftwe f ght was ca-l.- culated, Ra1 n1Agtecbntquew.asusedfor cons truct i on of loose ta r gets.

.

^'

..

.

Send "as pouredin ...hthimaint aini nga consta nthei ghtofdrop frDllt

.

"

the exist ingta~etsu r f~ ce.:Assoonas.thedes ~redheightofthe sa~lew~sob t ained .thebOiwas ",,?i ghed care fullJ. Thusthe firia l unitwightwas

Cll ~ulated.

^{Thre e}diff e re ntdensit ies'ofsandurge.t·.

prepa.recI:

1. Ile1Isesand(51type) : 16.18W.^J 2. Hedl1Jllldens e.~and⁽⁵²type ): 15.05

rJt/,,J

.J. loose sand (53 type): 14.09KN/m3 Forsatu r at edsaqlle s,thesa~rprocedurewas adopte das p.rll:!v10usl,yde s cr i bed fordrysaql1es. After thetar !ltt was co'n- structed,wa terlJla~addedtn the fomof11.9htspr ay.·Thecont a iner .that he ldthe soilwasnotperfect ly wat e r tightresultinginsome:

drai nage ofwaterfr om the.s ample. Saturatedsampl estes~din.this investigationere.not fullysaturatedin thest.rietsense .

3.6.2 . ModellingClay

Before prep arat i onof thetargetmater i al ,St andard Proctor compactio ntests were done toobtaintherelat i onshi pbetween dry unitweight andwatercontentfor thistypeof soil. The results areshowninF 1g.7 .

rhesete-tetvesthoroughl y pulverized and dried. a pre-

dete~l n\!d qua~t1 ty.

^{ofwat erwasadded to'the s}

ou

andplacedin a large concrete m1xingmachi ne {f i g.8) . When themixturewashoneq- eneous then1twas taken out frtlm t rmac~ine. The volumeofa, 'cy lindr ic alcont a iner (0 . 9144 of xO.4572'}l1)~asaccurate lycalF~lated.

Thesol1 mixture was placedinsi de the containerandcompactedwft h a Modif ied AASKTO hand hanmer, The desiredbUl~densl1;ywas'ob:tained using precalculatednumberofblows per hye;' of soil,

Re present a ti vesa~leswere taken at randomand at different' depthsduringthe targetpreparatio nto calculatethe exactwater contentand bulk, densi tyof the target mat eri al. Cylindri cal steel tubeswer eused to coll e ctsampl es forcal c.ulatin gthe'uni tweight ofsoil anB alsotoper formtriaxia l shear tests. Vane sheartest s

,wer e'also conductedbefo reandaftereachsetofexce-teents

~t

^{diff -..}

erent depths.,Twd.d1fferent typesofclay samples were usedas follows:

(1) Mediumstiffcl ay(Cltype) :.()ry density ~14.51KJl/m3I

\iater content'"29.61'l (it)··Softclay (e2tyPe) •

Drydensity =13.50K~/m3 WaterCDnte nt=34. 15%

39

3.6.3 . Targe-tprolllJrties

In additiontotargetpreparati on, se veralte s tswereco'll-

)~

ducte dto det ennine thephysicalprope r t i es of soil. Thes einclu de specificgra~itY Igrain sizedistributi on,Atte rberg limi t s(clay) andmaximum andmini mum voidratio(san d).,These.test swerepe rfonned .,. immediate lyafterpre ~ rati onoftheta rget.

Classification dataforstttce-zosand are:

Meandiameter '"O~11 5 nrn~

CoooW"ficientofuniformity ..,;95 spect rt cgravltyof9rain~ E2.60

Maxi fl1.lmvoi,drert o ·0.95

Minimumvoidratio : 0.42

•The gra dati oncur ve~orthissot!is sh~wn.in Fig. 9aand is cl ass ified as medi umto ffnesandsh e.

The gr ainsIzedlstr'lbutf onofmodellingcl ayisshownin fig.~b. Ithas thefol 1owingpro~erties:

l.l :3n

'P.l "21%

Plas ti cityInde x ..l6~

spect ttcgravity ..2.80

Ac~'eteset"of propertlesof..t~etargetsare tabulat;d:ln

, "Tables4a.4b andac,

1

1 36

tr:l ax:l a.l compression

4 . :::':h:::':,,,ng'h'f,"10,-70

tests anddi r e ct shear

"" ."

tests

dete...teed

. whl1e

" "'J

fur

. .

. \ ,

li'~: <': ~" ^. ''',,~ .~ ^.. ~." .~~.\ ^... y.,L.I.':'\;~' ~

^,

r:""-~'_o;A"'-;:;:,t:'~~i~~rt:t,!;,.,,?:,,,_

^..,..

~,~ '..,

^\

^Jj

40

roodel1ing cl ay, thest rengthpr;;p~r{1~weredetemtnedusing triaxial compressiontests and vaneshear tests. Triaxia ltests wereconductedw;-thconfining press ures103'.4 KPa(15 psi),l37.9KPa (20 psi)and206. 8 KPa (30psi) . The resultsare showninFi gs. lOa, lOb.lac,10d andlOe.

A ser iesofdi rectsheartest s were conducted onsilica-70 sandto determi ne the valuesoftheangle,of shearresistance(+) andrelatIve roughnes sof differentcone mat;;;;al(6/" ). Thetest s. wereconduct ed Ina constant ratey( strain shear,bo~,WF25QOO'(Fig.

,l

"'~;' ^{11)" Thevalueofangle'sh ea'r}resista nce-(~)as obt ained fromdirect s~ea rtestsare compared withtr iaxialtest res ul tsIn~l gs .12a and 12b.

A similar met hod was adoptedtodet ennineadhesi on(ca) betwee n oodelling cl ayand steel. Theresultsare showninTable 4c.

comparison

o f

^{vaneshea"rte stresultswi t h}that cotat nec from trfaxf al testsfO~delH n!lclayis shownin Table4b. Thefinal val ue of

c~hes; on~)

^{aas takenasthe a;era geofthe twotestresults.}

3.6.4.1.Penetr OlTM! t ert~^SoilFr1ctlo~^Angle

Todetennfne thefrict ion angl ebetween thepene t rometer material andsoil .tes tswere conducted1nthe WF25000 shearbox, Theupperhalf was fill edwith

Si1iC~70

^{sand atadesiredinitial}

densit y andthe lower half,oftheshearbox 15 replaced ,by asolid plat e ofthe penetrometermaterial. The resul ts areShO~in Table 3b.Thethree differen t penetraJ t e rcone mater ials tes te d are:

'(l extcont1nue'dPage:55)

41

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1000 1600

1200 1800

1700

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FIG 8. EQUIPllftlTFOR MIXING CLAY SAHPLES

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FIG 12••VAlUATIONOFI/>WITHl!FORSILICA 70SAN aASIHE Rt-IINED .8Y DIRECTS.HEAR.AND TRIAXIAl-·TESTS

.. / .,/.,

/ / .. ..

7 ..

o ' . .

/,

·1 I .

ss

1. Stainl ess Steel

•2. PolishedAlumfniln J. SandedAluml n!~m

The valuespfdlrectshear testeere corrected for theactual cone roughness. The eorre ctto nfact O,f Swen! obta inedfromtheresults of

"Ielysur-f" tests onDothplat esand coneasshown inTabl e3a. Correct i on factor sof 1.125,1.2and1.1~6we reappl ted forst ai nlesssteel , pol is hed alum.fn1umandsandeda.1umfnll1ll,respectively. The cor- rectedvaluesofrel at iverou9hnes~ (~/.lare:

Stai lflessSteel 6/' 0.;5

Pol h hedA lumlnlum' SandedAlumi nium

6i• •

0.6 6/ . . . 0.75 Inthe next chapte r, these valueswillbeused 1nthecal- cvts ttons,

3.7.~

The met hodsof preparingthesoil.terc ets

and

thephY,sical prepertf es ofthesoils and thepe~eti-ornetersare ghenf~this chepter-. Resultsofconventionallaborator y tfsts have beenpre sent ed andthese resultswtllbe used forccepaet scnand correlati on withthe penet romet ertests.

)

~'-'.'"

i

f

CHAPTERIY

'illLYSIS OFRESULTS ANDDISCUSSION

4.1. General

Freehllpenet rationtestsas-descr ibed1nthe previous chapter wereconductedand the output frOllthepelletrometer'was recordedon"a)-channelchartrecorder.endalsoanl~ strlllllenta tio n taperecorder. Typicalraw dat a fromthechar t record er is shown in fig.13.'The recordobtai nedisavoltageoutput , fromthe .accelerometer ,theconeload celland theIsleeve

ro~d

^{ce"l, as a}

function'of realtlme.·Represent atiYe Nwdata for differenttypes ofsollIs given InAppendlx B.

(alAccelerati on/decel er a t ionrecord'

As soonas the penetrometerisreleased,itisunder a constantaccelera tton 'g' duetogravitytillitst r ike s thesoil

.c·

tal"get. Thiseoe-respcndstothe initi alhorizontal str aightlineof the decel erationrecord. Upon'l11Pact,thepenet roo'eterdecelerat es,

'. "" . ,

the IIilgn1t udl!ofwhichincreaseswiththe depthofpenetra tion , as shownintherangeab of therecord. At.b,'thed~cele~ation^isa

. . .

.,

maxlmumanafttapersoff1nthe"rangebe.

"tc, therefsanaccelerat ion,pulseatthe endof penetration eyent ."At

~;~\1l1le

^the

pene.tromete~

^haspassedthrough'll1Il xfmWll

" '

. ,

penet gat.tu n andiseltp:erfenc.ing,.averysmall.upwardmoverent . The so11res istance'woul d thusbenegat ive. SCot t andPearce(1975)

56 (Te~t~t1nUed.pa ge58)

57

., .

CDNE RESISTANCE

. . '

.

^~

,DE'CELERA-r:IDN

C2 TYPE SOIL PENETRDMETER 3. 56 em. DIA. CONE 30·

STAINL E SS STEEL

\

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"

. ... . ....

FIG

~;

^..mICAl

ooz."!'j~- ~ ~:E/~ PEHETRAT.I~.: ~~

^-,'

.-l··

».

....