GEOTECHNICAL ENGINEERING MODULE SITUATION 1: A uniform soil deposit !s ! dr" unit #ei$t of 1%&' (N)m * !nd ! s!tur!ted unit #ei$t of 1+&, (N)m*& Te $round #!ter t!-le is !t ! dist!n.e of / m -elo# te $round surf!.e& 0oint A is !t dept of ' m -elo# te $round surf!.e& 1&
Compute Compute te effe.ti effe.tie e s stres tress s ! !t t A A& & !& %1&2, (0! -& /3&/% (0!
.& %/&,+
d& /,&*4
,&
If te #!ter t!-le t!-le $oes up -" *&% m find te effe.tie stress !t !t A& !& //&*/ (0! -& /1&2, .& /+&/' d& /3&1,
*&
In .omp!riso .omp!rison n to 1 !nd ,5 #!t #ill #ill !ppen !ppen to te effe.tie effe.tie stresse stresses s !t A if te $round $round #!ter surf!.e #ill rise up te $round surf!.e6 !& In.re!se -& Rem!in .& De.re!se d& C!nnot -e determined
SITUATION ,: A soil s!mple #!s determined in te l!-or!tor" to !e ! li7uid limit of /18 !nd ! pl!sti. limit of ,1&18& If te #!ter .ontent is *285 /&
%&
'&
Deter Determin mine e te pl!sti pl!sti.it .it" " inde9& inde9& !& ,1&1 -& 14&4
.& 4&4
d& 11&1
Deter Determin mine e te li7u li7uidi idit" t" inde9 inde9& & !& 2&%2+ -& 2&'23
.& 2&*4/
d& 2&//+
!t is te te .!r! .!r!.ter .teristi isti. . of soil6 soil6 !& ;rittle -& Li7uid
.& Dense
d& 0l!sti.
SITUATION *: A .onsolid!ted dr!ined tri
3&
4&
Dei!tor Stress = ,%3 (0!
Compute Compute te te fri.t fri.tion ion !n$le !n$le of te soil& soil& !& *,&%%> -& ,1&2+>
.& ,3&34>
d& *%&1%>
Compute Compute te norm!l norm!l stres stress s !t f!ilure& f!ilure& !& ,2/&'3 (0! -& ,1,&%4
.& ,+3&3+
d& ,%%&1%
Compute Compute te se!r se!r stress stress !t f!ilu f!ilure& re& !& 1*+&1% (0! -& 11,&4%
.& 123&%*
d& 111&*1
SITUATION /: Refer to te fi$ure& Gien 71 = *22 (N)m5 7, = ,'2 (N)m5 91 = / m5 9, = * m !nd ? = * m&
12& @ind te erti.!l erti.!l stress in.re!se in.re!se !t point A due to first line lo!d& lo!d& !& 1&+% (0! -& 1&'1 .& 1&%* d& 1&// 11& @ind te erti.!l erti.!l stress in.re!se in.re!se !t point A due to te se.ond lin line e lo!d& !& 1*&+4 (0! -& 1/&// .& 1'&+3 d& 1,&*1 1,& @ind te tot!l tot!l erti.!l stress stress !t point point A& !& 1%&%/ (0! -& 13&*4
.& 1%&*,
d& 1*&+%
SITUATION %: A .ert!in soil deposit !s ! li7uid limit of /+8 !nd ! pl!sti. limit of ,/8& 1*& Compute Compute te .oeffi.ien .oeffi.ient t of e!rt e!rt pressure pressure !t rest of tis soil deposit& deposit& Hint: o = 2&,,*lo$0I !& 2&%2+ -& 2&//+ .& 2&,*4 d& 2&*14
2&14 B
1/& Compute te tot!l stress stress !t rest l!ter!l e!rt pressure pressure ! dept of % m& in ! dense s!nd deposit #ere tis soil #!s o-t!ined& Unit #ei$t of s!nd is 13&/ (N)m *&
!& /%&** (0!
-& /'&'/
.& /3&**
d& %2&21
1%& Compute te tot!l stress !t rest l!ter!l e!rt pressure !t ! dept of % m in te s!me s!nd deposit -ut ! #!ter t!-le is lo.!ted !t ! $round surf!.e& S!tur!ted unit #ei$t of s!nd is ,2&% (N)m*& !& 3/&*1 (0! -& 32&'/ .& +'&1% d& +,&,1 SITUATION ': Spe.ifi.!tions on ! o- re7uired ! fill usin$ -orro#ed soil to -e .omp!.ted !t 4%8 of its st!nd!rd 0ro.tor m!9imum dr" densit"& Tests indi.!te t!t te m!9imum is 14&% (N)m * #it 1,8 moisture& Te -orro# m!teri!l !s ! oid r!tio of 2&'2 !nd ! solid spe.ifi. $r!it" of ,&'%& 1'& Compute te dr" unit #ei$t of te .omp!.ted soil& !& 1+&,1' (N)m* -& 13&%,% .& 1%&1*,
d& 14&+'1
1+& Compute te #et unit #ei$t of te .omp!.ted soil& !& ,1&, (N)m* -& ,2&+ .& 14&'
d& 13&%
13& @ind te re7uired minimum olume of -orro# soil re7uired to fill one .u-i. meter& !& 1&*3 m* -& 1&'% .& 1&1/ d& 1&,4 SITUATION +: Te l!-or!tor" !pp!r!tus so#n in te fi$ure m!int!ins ! .onst!nt e!d in -ot te upper !nd lo#er reseroirs& Te soil s!mple is ! silt" s!nd #it "dr!uli. .ondu.tiit" of = % 9 12F<* .m)s !nd ! moisture .ontent of 13&%8& Te spe.ifi. $r!it" of te soil is ,&+2&
14& Compute te oid r!tio& !& 2&/2 -& 2&%2
.& 2&'%
d& 2&42
,2& Compute te seep!$e elo.it"& !& 2&211 .m)s -& 2&22+
.& 2&2,'
d& 2&2*/
,1& Compute te dis.!r$e& !& 2&*%* m*)s -& 2&,1%
.& 2&,/+
d& 2&,3+
SITUATION 3: Ans#er te follo#in$ terms in Geote.ni.!l En$ineerin$& ,,& Ro.(s .!n -e .l!ssified in tree -!si. .!te$ories ECE0T: !& !tmosperi. -& sediment!r" .& met!morpi.
d& i$neous
,*& It is ! line !lon$ #i. ! #!ter p!rti.le #ill tr!el from upstre!m to te do#nstre!m side in te perme!-le soil medium& !& Stress line -& e7uipotenti!l .& imperious line d& flo# line SITUATION 4: Results from li7uid !nd pl!sti. limit tests .ondu.ted on ! soil !re $ien in te t!-le&
,/& Assumin$ te pl!sti. limit is !t 1*&/8 5 determine te pl!sti.it" inde9 of te soil& !& 1*&+ -& 1%&' .& 1'&' d& 13&* ,%& Determine te li7uid limit of te soil s!mple& !& *, -& ,4 .& ,%
d& 14
,'& Determine te li7uidit" inde9 if te #!ter .ontent is *,8& !& 1&%/ -& 1&'' .& 1&14
d& 1&2%
SITUATION 12: A .onfined !7uifer underlies !n un.onfined !7uifer !s so#n in te fi$ure&
,+& Compute te e7ui!lent ori?ont!l .oeffi.ient of perme!-ilit"& !& */&1+ m)d!" -& *'&,% .& *3&14
d& /2&21
,3& Compute te "dr!uli. $r!dient& !& 2&22+% -& 2&2232
d& 2&22+%
.& 2&2122
,4& Compute te flo# r!te in .u m per d!" per meter& !& 1*&+' -& 11&'% .& 12&3*
d& 1,&41
SITUATION 11: A s!tur!ted .l!" l!"er !s ! ti.(ness of 3 m #it ! #!ter .ontent of %28 !nd ! spe.ifi. $r!it" of ,&+3& *2& Compute te s!tur!ted unit #ei$t of te .l!"& !& 1+&1, (N)m* -& 1%&'4 .& 13&*+
d& ,2&/%
*1& Determine te tot!l stress !t te -ottom& !& 1%+&// (0! -& 1*'&4'
.& 1/1&,+
d& 1/+&3/
*,& @ind te effe.tie stress !t te -ottom& !& '/&14 (0! -& %3&/3
.& *4&1,
d& /'&+4
SITUATION 1,: A dense silt l!"er !s te follo#in$ properties: oid r!tio e = 2&/2 Effe.tie di!meter d 12 = 12 mi.rometers C!pill!r" .onst!nt C = 2&,2 s7 .m @ree $round #!ter leel is 3&2 m -elo# te $round surf!.e& **& @ind te ei$t of te .!pill!r" rise in te soil& !& / m -& + .& %
d& 3
*/& @ind te erti.!l effe.tie stress in (0! !t % m dept& Assume s!t = ,'&% (N)m* !nd t!t te soil !-oe te .!pill!r" !.tion rise !nd $round surf!.e is p!rti!ll" s!tur!ted !t %28& !& 1*/ (0! -& 1%2 .& 1', d& 1++ *%& @ind te erti.!l effe.tie stress .!pill!r" rise in */& !& ,++&%% -& ,'1&13
!t 12 dept& Assume unit #ei$t of .& ,*4&/'
s!tur!ted soil !nd
d& ,2%&,4
SITUATION 1*: Ans#er te follo#in$ terms for te $eote.ni.!l en$ineerin$ instruments& *'& Tis test is des.ri-ed !s follo#s: JTe #!ter suppl" !t te inlet is !dusted in su. ! #!" t!t te differen.e of e!d -et#een te inlet !nd te outlet rem!ins .onst!nt durin$ te test period&K !& @!llin$ e!d -& !ne Se!r .& Const!nt He!d d& 0umpin$ He!d
*+& It is ! dei.e -" #i. ! '2> .one t!t is used to !llo# independent determin!tion of te .one resist!n.e !nd fri.tion!l resist!n.e of te soil !-oe te $round& !& S!nd .one -& 0"n.nometer .& 0enetrometer d& Ru--er -!lloon *3& Tese !re pused or drien into te soil t!t .!n -e used in perme!-ilit" tests& !& 0orous pro-es -& 0erme!meter .& 0ump #ell d& He!d pump SITUATION 1/: A s!mple of s!nd !-oe te #!ter t!-le #!s found to !e ! n!tur!l moisture .ontent of 1%8 !nd ! unit #ei$t of 1,2 p.f& L!-or!tor" tests on ! dried s!mple indi.!ted !lues of emin = 2&%2 !nd em!9 = 2&3% for te densest !nd loosest st!tes respe.tiel"& *4& @ind te oid r!tio& !& 2&%3+
-& 2&'24
.& 2&'/%
d& 2&+33
/2& @ind te de$ree of s!tur!tion& !& '+&+ -& +2&/
.& ++&'
d& 31&%
/1& @ind te densit" inde9& !& 2&%2 -& 1&22
.& 2&'2
d& 2&+%
SITUATION 1%: @or ! norm!ll" .onsolid!ted .l!"5 it !s !n !n$le of fri.tion of ,%>& In ! dr!ined tri< !9i!l test5 te spe.imen f!iled !t ! dei!tor stress of 132 (0!& /,& Compute te .!m-er .onfinin$ pressure& !& 1+'&%/ (0! -& 13'&1+
.& 1//&''
d& 1,,&4'
/*& Compute te m!9& stress of f!ilure& !& ,4'&4' (0! -& *2,&4'
.& *1,&/+
d& *13&*4
//& Compute te se!r stress !t f!ilure& !& 33&+4 (0! -& 3%&,4
.& 31&%+
d& 32&1'
SITUATION 1': A .ut is ! m!de in ! stiff5 s!tur!ted .l!" t!t is underl!in -" ! l!"er of s!nd& Te s!tur!ted unit #ei$t of .l!" is 14 (N)m * !nd t!t of s!nd is 13 (N)m *
/%& !t sould -e te ei$t of te #!ter JK in te .ut so t!t te st!-ilit" of te s!tur!ted .l!" is not lost6 !& 1&+% m -& 1&,' .& 1&13 d& 1&24 /'& !t #ould -e te tot!l stress !t A& !& *+&** (0! -& */&*3
.& *%&%4
d& *,&+/
/+& !t is te effe.tie stress !t ;6 !& 11&+1 (0! -& 1%&//
.& 1*&,4
d& 1'&*3
SITUATION 1+: A li7uid limit test .ondu.ted on ! soil s!mple in te .up dei.e5 $!e te follo#in$ results:
T#o determin!tions for te pl!sti. limit $!e #!ter .ontents of ,2&*8 !nd ,2&38& /3& Determine te li7uidit" inde9 if te n!tur!l #!ter .ontent is ,+&/8& !& 2&+' -& 2&%+ .& 2&*4 d& 2&%2 /4& Determine te oid r!tio if te sp $r is ,&+2& !& 1&2* -& 1&1+ .& 1&,1
d& 1&*1
%2& !t is te .!r!.teristi. of soil6 !& ;rittle -& Dense
d& 0l!sti.
.& Li7uid