[PDF] - - C,<, o, oJrb e-- 6.L/k, 1 FE Review-Geotech t. A11 PDF Document

SLIDE 1

Question 1: A 9.61-cni3 sainple of soil vteighs 19 g. After being dried in an oven1 its \veight :i.s 17.5 g. If

0, = 2.67~ find:

/VL =- 1\j :'.:"

(j_ ()/Ct /c.cJ

.'. t,J: 0. DIC,~

,JI

\~

3

\j =:

°i . b l t

=

0 , b I ( I D :i /\,\

a) Starting unit weight~ Ym

s

=
17. s:",.<.)

::- o, o I "? ;-· l'-S .

'. lJ5 = o. I 7 7-. ,j

_

O.c,1q ~9

·-=·,._..,--.~-- .·

9, 6 /

D rl!j lA ,..>

h)

D1y unit ,veight. ya

l-J5

i\)\.~··==-

~i T_, - V

c) Water content ..

tc

LJ :::- __

(IO"--"')::=

LJ>

lt)t.,J =- lJ-

d) 'Void ratio. e

lZ- E"M.tJ'-1 1

~

;;;-R-,., /f

,j.._

e)

Porosity. n

f")

Degree of &aturatiorE S

, 0

/ ~-··-»1..J ( \

0 ,( 7L ;_s- C,<,

, oJrb
~

e--

6.L/k,

e., ~- o. l) b

FE Review-Geotech 1

SLIDE 2

t. A11 1111di:--tJ1rfa'<l• Sfll11J)fo of ch.w has. g• \yet 111.ass of

lt)O. kg, ·'1 .dry.n)t'i$SOftla kg1 .. and

.• ,l.tot,H. volurneof

tl04Hl ni. Th€ :sQlids have a specific grnvity of 2.65. Tht:' ynidratio iB•most..uearly (A) tl.31

(B) 0.40

(C1 0,61 (D} LO

w

FE Review-Geotech 2

SLIDE 3

2. A. sa

tur<tte.d sa11tple. of undisturbed clay hflS a wet ma.~ i5r3l8 kg and a dry lhf:\Ss of 204 kg. The total

Yolume of the san1ple is 0,19.3 m3• Most nearly, what is

the specific gravity of the soil sdlids? ·

(A) 2.4 (B} 2Ji (C) 2.7

(D) 2.9

\/\l -

FE Review-Geotech 3

SLIDE 4

3. A soil's grain-size distribution curve is as shown. The

effective grain size is 0.19 rnm, and D60 'is OA9 mm.

100

""'\

80

I '

..

'

.,

:

1,

'

~

20

''

\

a...__

10 1

OJ

O.Q1

grain size (mm)

The coefficient of gtadation is rllost nearly (A) 0,17 (B) 0.44

(C) 1.6 .(:- (D) 3.0

0,001

I, 1

FE Review-Geotech 4

SLIDE 5

4. A soil has the following characteristics.

percentage fines, F 69% liquid limit 72 Ftl..0 ;.A viJ I r.:::1f!F'e:::;,, CL-ll.55 1,:::::-1cA Tio~ Utfl'l.-.-1

a:

plastic limit 48

Using the Unified Soil Classification System, what is the classification of the soil? (A) GW (B) ML (C) MH (D) CH

Far classifie2'J111111, ctfi·!le---::,raaried :wrls

and m,;.g-sine,:1 tract1arc ·Cif .:,:,a:;:~iae<I

Eqaatiar, of ·~.'-iil'le

x 41J

Hc.~,rJ~ Et Pi =-4 to LL =

25. 5,,

!tier. Pl:="· ?3 [ll-'20J

w a

z

~ 30

[5, '

r;::Z'/

(I)

2()

:s

(L

10

EqillWan of "U"-une VMica: at LL= , 6 ID P!( =

7,

men P:\=M (LL-!l}

~-+,,--1--__,,..__--+----+--+---!--

71-~~

;IJ"':t:r.+ 'J"'J.,,. ""., fr'if'lrr"':..,..,..__ "v",r

4

~~-~-~-~-~-~--'--+--'---~~-~
rn 16 20

::io 40 so 60 10

a:o

so rno

·110

~

7~

~

sample of soil has the following characteristics.

6 a%

{ '~

7

'F7A,Jc

LL

~

72- >

~

s,cr-~

P:t- PLDI>

.

,

M H

% passing no. 40 screen 95 \-"I =-LL -'PL ::, 3 I - I l5 % passing no. 200 screen 57 liquid limit 37

F =-

~

plastic limit 18

What is the AASHTO group index number?

s-oi<.

(A) 5

~,:r:· = ( F --.;; s )[

O, :2.,, + 0, oc::,~(LL-'-l o)j--\- o. o \ (_

(B) 6

1s-)[PI-IOJ

(C) 7 (D) 8

2. z.( (),/ $,r

GENERAL CLASSIFICATION GRANULAR MATERIALS ( 35% OR LESS PASSING oms SIEVE)

A-1 A-2 GROUP CLASSIFICATION A-3

A-1-a A-1-b

A-2-4 A-2-5 A-2-6 A-2-7

SIEVE ANALYSIS, PERCENT PASSING: 2.00 mm (No. 10)

s 50

0.425 mm (No. 40) -

s 30 s 50

~

51

0.075 mm (No 200)-

s 15

s 25

s rn s 35

s: 35 s: 35

S:35

CHARACTERISTICS OF FRACTION PASSING

OA25 SIEVE (No. 40): LIQUID LIMIT

s 40

2 41

s 40

2 41

PLASTICITY INDEX* 6 max NP

s 10

s: 10

~

11

~

11

USUAL TYPES OF CONSTITUENT MATERIALS STONE FRAGM'TS, FlNE

SIL TY OR CLAYEY GRAVH AND SAND

GRAVEL. SAND

SAND

GENERAL RATINGASASUBGRADE

EXCELLENT TO GOOD

SILT-GlAY 11/IATERIALS

I MORE THAN 35% PASSING 0Jl75 SIEVE l A-7-5

A-4 A-5

A--6

A-7-6

~36

~36

2! 36

~36

s 40

2 41

s 40

~

41

s 10 s 10

~

11

~

11

Sill'!' SOILS

CLAYEY SOILS FAIR TO POOR

FE Review-Geotech 5

SLIDE 6

9. The ~P(>\~ifk gTaYity of the soil solids in a given

.~lmJ)it

0 is :3.11. The pon,sity of the soil is 27%. Wliat is

n1ust rwatly the (•ffcctive unit weight of the soil sarnple? ,A 1 96 lh(:ft:3 : Bl 1.1 O

lbf/

ft:'

,Cr 1:)n 1bf/ft3

,.D mo lbf;fta

I +t:_.

I+~

U\ = 27

I I

( -;g ' I I + ('.):~ ? )

,~ z

.

'-I I + o, :?, ?

10. The total unit weight of a given sojl is 120 1bf/ft3 •

Th1;:' ~1U has a porosity of 0.26 and is 100% saturated. Ti11;, dry unit w:ight of the soil is most neaty GS lbf/ft 3

t ~

I ~ Y:r

!B) 8-0 lbf/ft3

.111.-,

, t

tC) 100 lhf

/ft 3

V\

:::: o, 2. b

(D) 120 Jbf/ft3

\J IJ = \)l,J

\j

FE Review-Geotech 6

SLIDE 7

11. A l L field sample contains .soil with an initial

wf·ig;:ht of 30 N. The soil is dried completely in ari ove11

at 100:c. The weight of the soil after drying is 22 N. The m;i;.xitnu.tn volume of the dry soil sample is 1.5 L,

,HJd th<: minimum volurne is 0.60 L. The relative density

f the soil j:,, rnost hearly

I'>

~-1:, iJ\IJ\.
6,;;.MA;-

~P"II"-

(A) ;J7'){ (B) &t/;{; {C) fj2(J1, (D) 75¼

w

.:- >CY~

\J = I L.

::;

~:

C;;'.

( l(' I ~

( f,\ I VI.)

12. An undisturlx~d 10 crn wide x 10 cm Jong x 5 crn

high sample of d::Jy has a dry weight ofa2 kg. The dried soil sample is co1npw:t<J<l into a n,inhnnm w1hune, a rectangular prism 8.5 .crn wi<fo >< 5) cm high x 3,5 crn

high. What is most nearly U1(i telt.1.tive compi1,ction of the

soil sample?

'\., ~\-

'l l ,J,

('.)_ b \_

(A) 33% (B) 45% (C) 49% (D) 54%

:,.

= S"eiO t:_M

~2 k..s

~_,_,_._.·--- - --

:;t

~DOC~

!~:...~,'.:

p

... C

i I,;) o)

t

'f>' /J\J.. y

C), 0 b'---)

I

/ll\Af)

,

FE Review-Geotech 7

SLIDE 8

\1 if'lA Boil sample has the particle size distribution

::;)1own.

100

/

i-- ,--

90

I/

80

I

0> 70 C

V

·-

,,....,.. en

t-'v

co

/i.--

~I-'-

;:- 50

/

C

~

40

...

J

(I)

n. 30

V

20

j

I

4'\

L----"

'

1

\,IS"

10 0.1

0,

2.-1 particle diameter (mm}

What is most nearly the coefficient of tmiformity of the soil? (A) 0.4

(B) 0,8 (C) 3

(D) 6

D~o

FE Review-Geotech 8

SLIDE 9

14. A soil has ·it void ratio of OAL The unit weight of

the solids is 33 kN/m3. ·what is most nearly the saturated unit weight of the soil? (A) 26 kN/m3 (B) 29 kN / m3

(C) 33 kN/m3

(D) 37kN/m3

i~~, I~

( G~ t- e-) 6~

\+e_

1 s. The water content of a saturated soil sample is

26%, and the void ratiois 0.57. The unit weight of the solids is most nearly ( A) 4.5 kN/m3 (B} 9.8 kN/m3 (C) 22 kN/m3 (D) 28 kN/m3

1':,

:::--

l,...JJ,

\Is

cJ<-,J

e_ = C.0

"' ~~,;=,~ -

\111

v

I ,J L-,1

W

--A---•-

/

+--

O,L/1 b

\j

,f

) ~

"1v

:::::c ----

\j

'.,,

--

~

e--

e_

Yw

{..,) e-

I ----

::::

~J tJ

·W

( e,1, ~7)[ q, <i5f ~) ;::- 2.- I, C C>. ~ 6 FE Review-Geotech 9

SLIDE 10

16. An undisturbed soilsample with a volunie of0.30 ft3

is weighed in a. 0.2 lbf pan. The combitied weight of the

soil stunple and the pan is 40.5 lbf. The soil is then

completely dried in an oven at 100,;,G, After drying1

the combined weight of the soil and the pan is 35.2 lbf.

Tho unit weight of the soil solkls is 194 lbf/ft3• \\That" is

rnost nearly the volume of the air-in the original soil

sample'?

s:: ,l,..A-'\" '--c

(A) 0.010 ft'1

\} :.- D, 3

~:::,

(B) 0.035 ft3

L.,_j .

~· CJ , '1.-.. l

6 ( p .~ ,.j J

ir

(0) 0.10 ft3

{JJ +

W\?

=: L\ 0. S°'- \

\:J (D) 0.21 ft3

W = y b. ~

)b - 0,

'L~.· lh <e; t1 o,

W1.v + -jr

J},.

>. ':,,

l ;a,

)et'

\ i

w,,.,

~ .r-

\1 J -

~

_\

(,, l, ti

~!J ~ 0,00 ~

d'*? \)

I

b - v'-'r = 3 s I

la lb \Ci'-\~

\}

1' ~

lJ.:, - _ ~-I~ =- o. 1 t

I~ l( f;,

,..'\-

//11/ A OJO n?. ~ltnrnt:ni Sl_)i! s:nnplc is \\'(>ightcl in R

:14 kg

~;111. 1

'h(' ('(

)lH bu I('(~ \\"('lght ot tl1<' soil n,nd t

be

J)1'H 18 4t1() kg.

Th<' :st)il s;nnple JB corn.plctdy dth'd in a11 nn•n. Afl(\r

dr>·ing. i he crnn!>ilH':I wdght of th(' soH !-,nJnpfo nnd the

p,rn i~ ~18S k~. \\ hnt 1~

1llo~l tWnrly th(' \\nit weight of tlw

s.;~turnt('d ~nil i-a mpl<';

p) :27 kX,'1n:1

lUp = "3> t(

l....:J (T3l 31 kX 'in'J l

C) .n k:\' m:, k .

J

1

D) ,Jl · ·\ 1n··

q I h .-: '3-S-I t Ld\J

w,;J =-

b s:-- le:,

0 =- 0,\ ~3

F = !{

e,,_ :::-l0

&,,. ::-- t~( I

1~ h:..~

=LI, OB (<-~

1

0)5= -~

\}

~

(,)

\ IJ I

+ /, f:: r7

,,·•r•s·-,-,> ,,- ,..,_~,o~e~-,c;~~ ' C

y<;-i,~

y

V.

Y-

>

.("',.

D ,;'--

tt ~-.

l,)

ll' G2J Lrl

=-res ---;~-i

1

,1 o.

k~-~-

~

{'A 'J.

FE Review-Geotech 10

SLIDE 11

18. T1w n'sult:- of a sieve analysis are sho,v11.

i•}

l ~

I

so'.

I

l

SJ..1'

"',

g'70'

·;;

..... ..,:

...

...., ..... !

; 50;

~

40 1

"

'

~

i

.c.. .......... ,

201 .~1

v!

l

0.01

l

I

V

I V

I

11

0.1

I

'"

1 . O,L) O,Jr' rn particle diameter 1mm)

10

\Jost nearly. ,vhat is the coefficient .of curvature of the soil sample? fAJ 0.3

(BJ Q.7

IC) 2 {D) :1

0.bo~

c;,,7

FE Review-Geotech 11

SLIDE 12

D

For a fiow net shown in the following figure, determine head loss at points A, B, and C. The structure is approximately 100 feet long. Determine the flow rate in ft3/min through the permeable layer. Assume hydraulic conductivity, k = 1.64x

10-4 ft/min.

20ft.

FE Review-Geotech 12

SLIDE 13

Fl

,J

~ ,H---c,' ct+A....J<:;~ I

,J -JO (

'D ~,·1

t,

{

r::::,.,)

A-Ff5 \(_.-LA'( c\L...

eJ F

.SA .J l> Fl L- L

t.S

PLA-LGD

1'-lORJ\J.-L.(

Co,-...}<;:.OL( t::,>A""fS-t"'::,

c LA'j

L~)""c\t.._ c~-'-, C.L.A.Y)

?'0 ILi,

L1 Q\)l D L\MIT (LL)= l.\ c;:- CL---::: C'), 00°1 ( L \_-\,0)

P5

14? -

CL ~

C). 0 C) 9 ( \..\ S- I V) ::::::- 0 . 3 I '::> ~('.) \LMJ..-Lj

Cot-:l S: 6\...., p.r..

,c::D

CLA-y

?

LA:- c_c:-

<;p,.,._\ ~

:p-, L l- C) c--J >'-.l\2.-.~ Ac_C, \J'E''L"\\C.A\_ S""\\L~'.:::,..>r.rJc..,~.:A$ GP ai-~~~f),.::

ffoLJ /VltlC..rf

(..,UILL- T-HE \}Dt,:> 12ATID. (c·) '.~

· i>Or,-..J-r-

(> . pc::-G~AS~,,

I

C1.JG ,..,.-o

rt/€

~,?:G:,;,,.!::.

1.AJc.-l2-eA:-S> e.-.?

~

?_De,~

~' = '?'L:>0

I ) 1

a;-~ CY;'+ c:r,- = Z-- ~Ou ----

~-e--J

, I 7 /

FE Review-Geotech 13

SLIDE 14

( s ss-rtMA-, so -r1-14, 1 ;-1-E -rorAL-- S:EcTTLe.M'<=-i"JT""( Sc..),~

,z_/1

co.,,'F, "-•-~ cYF CD('..J S::Du p/C,l oJ (_ ~) \ S 0, OS ~

Tl'M. b \L c Q U \ \L€[::;>

Fo1L-

.s;-o t:

Co.,j,~DL l DA-Tl o ~PV

rlf+::;;.,

ro

,-A L-

c:;,.-:G-r,-L

-e- MC;-'--,- TD oc_e_ J t2..

I f;. ?

S

:::-- L 11

c_

so

b

FE Review-Geotech 14

SLIDE 15

i

t -

Ll-1--

I "--

<;u t:>~

....\ ~~}'.\,-J ~

(;.e

~

\>A,tf '13LC::C...1~0

FE Review-Geotech 15

SLIDE 16

A

Lt::>AC OF 2.oo )i

\,S

?L.A-C..C:::-1:> 0~ A -g,1~(\ 3,0-

\~t:v('.

F'

,.J

t::::>

s ~-cA_~ ~->> .µ:;r:-· FP..1 L tJz_;;: •

C) IV C ,.J '.

A=- --s,11. '(31";:: °t 1v\ .,_ F

;:=-

'°2-DD \b

I'

H-

~I{)

__;Tr7

i?v ii .· I l

/ _, /1 ./ I .

/

I/

i ;I:; I /

I,

r

(

FE Review-Geotech 16

SLIDE 17

' . i

\

-r,,..,,,---

0---+-----.._____\

\:? = l~ 6

H

c> _ r LI -,-- I

2 o

(_-,

(j t ! -

\

)

(•

!

7

S.p,.,tJ I>

0~1'2.__0fc..';:;-

(p ::;c 3 J- ~

CA.Lc___'-'LA1E

rH-c

ch./tz

..

:T~J'2.,J,.,._j C;, (V'lo0G.0T [)0-t? TD T7+-c

A-c__,,Jt:=

S:-Ae..-TH

f~£?...5 ucz.2:·"

FE Review-Geotech 17

SLIDE 18

_1. A soi1ha~anan:gleofinternalfricticinof25°. What is

nh"~~ .

rn',~;·ly

tlit~ JfonkiiW acti,·e earth pressure

Cf>t'th\'lt'U

t ;

t.\1 o.:n

1rn 0.-11

·.

C) 0.52

\D) 0.58

Cf> :::- z. s_;-¾

r-A ~- rA 0·7-.c· c,

f:'j --- o ,

</ 6 ,;:, 2.' A soil has an

angle of internal friction of 25°. \Vb.at is

mc,st nearly the Rankine passive earth · PNSsure

cocfficien t? (A} 0.59

(B) 1.() CC) 2.5 (D) 4.1

3. A retaining :s.vall supports soil with a vertical height

rjf 2 111. The soil ha-s an angle of internal friction of 32°

and a specific (unit) wejght of 25kN/ni3. l\fost heady,

v;,·hat is the active lateral soil resultant?

(A) 5.0 kN/m

!BJ 15 kN/m

(C) 46 kN/m W} 92 kN/m

/c~

I

FE Review-Geotech 18

SLIDE 19

176~,~~t--1~ UL-1! MAT~

Ot--:P..'2-~lAJ~

LA.i(.Ac.C.. 1\/

f-0 ft--

ro

0,1A.J c...,

GJvZ~.'

D!--==- s t~

y

l ~ \ -i s- [0l'3

c_ ::: \

1- D~ 1,L

1-

~o(L--- C)r <;.../:..."F"e:--i-7 -==- -:::?: ~=o

~J--=- ~,

I '-j

tJ\-:;: \

f'--J 't:::: b

_ ( \ '-- "

00 _[!,_

( c;:, I 'I) -r ( n J;.- £;) (

3 J,,)(

"

}t

?If;/

D

FE Review-Geotech 19

SLIDE 20

\

er

= cs--- -

LA.

'\/ l \

UL-=

0...__j • d

D

\ ' )

~) (q_

I I I.._-,

A

/

FE Review-Geotech 20

SLIDE 21

2 ft

8 ft

Surcharge= 1000 lb/ft2 Sand

'Ysat=llO lb/ft3

~

::: r .

H =- ,

i o ll c

11 ( , = t1 l) o 1!~

~

~)

~

Normally consolidated clay

t

.r+

Ysat=llO lb/ft3

\"l, ~;: t,,J~,l~

f?

;:-;, V IL~@._ L-

t-\ ::- 6 l'

,; {~ ( z ~

+ ll h)

U-- =-

~

·-

u

.:=-

:J '7Y ,L\ lk-.

Sand

Calculate initial effective stress at center of clay layer clay layer before application of load Effective stress at center of clay layer after application of load:

/b

L. z_.

:;;:-',c,

FE Review-Geotech 21

SLIDE 22

6) An excavation is made in uniform soil. The available

shearing resistance along an assumed slip surface is 1350 kN/m. The mobilized shear force along the slip surface is 46.5 kN /m. The slip surface makes an angle of 45

° with respect to the horizontal What is most nearly

the factor of safety against slope instability? (A) 1.5 (B) 2.1 (C) 2.9

(D) 4.l

/FF' -
r::; =-

<7\ :::- l\

rs.

1--:::- :;-o

k,JJ

t''-

'-I &S:-

k.,;-.J

IA--

_,'.))

s

I~
r::·~J:.)

G~) A retaining wall extends 3 m from the top of bedrock

to the ground surface. The soil is cohesionless and has the properties shown.

/ retaining wall

f

ground surface

H=3m

4> = 35°

p = 1834 kg/m3

Using Rankine theory, the total active earth pressure per unit width of retaining wall is most ne11rly (A) 15 kN/m (B) 22 kN/m (C) 44 kN/m (D) 82 kN/m

0. t.

t(

FE Review-Geotech 22

SLIDE 23

1 4, An excavated slope in uniforrn soil is shown

.. The

SfJ1,cifk weight is 14 kN

/rn\ the cohesion is 15 kPa,

j

If ..

··11".0 aw the angle ofinterna nct10n IS . 0 · What is most m;f1rly t}w avaihthle 1,heasing resisti:mce along the assmrw,l foJh1re plauc? (A) 550 kN/rn (BJ 600 kN / rn

(C) 680 kN/in (D) 940 kN/tn

L,d1

,,_ :~ i

[

(11:,)(__ LO)+-±

(1),3)(1u) -1Jg7,"3)( lo~

:: 1),:,,./

' 5~ 'A uniform soil slope has a pla.nar slip surface le.rtgth

f 100 m. The soil's cohesion is 5 kPa, and the angle of

internal friction is 40°. The angle that the assurned failure pla11e 1nakes with respect 'to the horizontal is 25'°. The weight, of the soil mound above the assumed failure plane is 2000 kN/m. What is most neatly the rnobilized shear force a.long the assumed fail me plane? (A) 500 kN / rn (B) 850 kN/rn (C) 1500 kN/tn

(D) 2000 kN/m

X1 -:~. = 11."3""-

rA~'!.o

)l. L ,,,.. L ~

Y--1 = 'J I'

5- LJ -

\ f ''), ::, 2.. 0 ii'--

FE Review-Geotech 23

SLIDE 24

Find the factor of safety for the-- instable slope.

C=500 psf
Y = 120 pd
c1-- = 15 degrees
~

,cc 30 degrees

theda = 26.6 degrees

c._O

Y,_:::: --· :::- 3'l. 6

I

Th~~

I

-77'----------- --·

··- + --

I

\-\ =

Lb

I

y ____

., ________ ,

_____ ,_,._,,. ----,

...... ,, ... =

l!0-1 -t

l, -

, b

?

('.l C CJ(. OSI\

cJ-=

2-0

·

!;.\ 63

L-~ :::77. L

~

/.lt)D S, ./1 \

I l. L/

)

'C:' w s;. /•I\

·
~.

,M,oD

6

6 Se,,

S. -

~

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FE Review-Geotech 24

SLIDE 25

A 25" high slo~

i:s dm,igm.,-d ,m pmi uf

a highway prqjcct

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type foilnre occu:rs~ oolculnte the f aclor of safoty_

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FE Review-Geotech 25