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PE Civil Exam 40- Geotechnical Questions & Answers (pdf Format)
For Depth Exam (Evening Session) Set #1
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PE Civil Depth Exam (Evening Session): This practice exam contains
40-Geotechnical questions and answers each set from all Geotechnical
& Soil Foundation Engineering area.
Table Contents:
Page
1.
Subsurface Exploration and Sampling -3 Q&A
3
2.
Engineering Properties of Soils and Materials-5 Q&A
6
3.
Soil Mechanics Analysis -5 Q&A
9
4.
Earthquake Engineering -2 Q&A
14
5.
Earth Structures -4 Q&A
15
6.
Shallow Foundations -6 Q&A
19
7.
Earth Retaining Structures -6 Q&A
25
8.
Deep Foundations -4 Q&A
31
9.
Other Topics- 5 Q&A
35
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Civil Depth (Evening) Questions -Geotechnical Sample Set # 1
I.
3.
Subsurface Exploration and Sampling
PROBLEM (General rock characterization)
During a field exploration, the core barrel was advanced 180 CM during the coring. The
length of the core recovered in Fig. What was the recovery ratio and Rock quality?
a.
b.
c.
d.
3.
.80
.48
.98
.58
Good
Poor
Excellent
Fair
Solution:
R.Q.D=(30+15+18+38)/180= 0.56, Fair
Correct Solution is (d)
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II.
Engineering Properties of Soils and Materials
8.
PROBLEM (Shear strength properties)
A drained triaxial test has performed for normally consolidated clay with following data.
Chamber confining pressure, σh=108 KN/m2
Vertical deviator pressure σv=158 KN/m2
Pore water pressure, U=50 KN/m2
Find the angle of internal friction, Ф
a.
b.
c.
d.
8.
350
260
250
220
Solution:
σv=158 KN/m2
σh=108 KN/m2
Pore water Pressure, U=50 KN/m2, will be deducted at drained condition
σ1= σh+σv
σ3= σh
σ’1= σ1-U=108+158-U= 266.00-50=216.00 KN/m2
σ’3= σh-U=108.00-50=58.0 KN/m2
SinФ= (σ’1- σ’3)/2 / (σ’1+ σ’3)/2
Ф=Sin-1{(216-58)/2 / (216+58)/2}=35.210
Correct Solution is (a)
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V.
Earth Structures
18.
PROBLEM (Dam)
The concrete dam 25 m long shown in Figure is embedded 1 m into the ground surface and has a
sheet pile wall 5 m deep at its heel. The headwater is 7 m deep and the tail water is at ground
-4
surface. The permeability of the soil is k= 20 x 10 cm/sec both vertically and horizontally.
What is the Pore Water pressure at A; A is 2m above the impervious layer?
a
b
c
d
18.
15780.00 kg/m2
10960.00 kg/m2
12800.00 kg/m2
12450.00 kg/m2
Solution:
k= 20 x 10-4 cm/sec=2 x 10-5m/sec,
Dam headwater height, h=7m,
Impervious layer to Dam bottom height, H=10m
No. of flow channel, Nf =4,
No. of potential drop, Nd=13,
Impervious layer to A height, Z=2m
Pressure head per net=h/Nd=7/13= 0.54’/net
Pressure Head at A, Ph=h+H-( No. of potential drop at A x Pressure head per net)-Z
=7+10-(7.5x.54)-2= 10.96 m
Pore Water pressure at A, UA=Ph x γw =10.96m x 1000 kg/m3
=10960.00 kg/m2
Correct Solution is (b)
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VI.
Shallow Foundations
22.
PROBLEM (Bearing Capacity)
Determine the Effective Area of circular footing with eccentric load shown in Figure where,
Soil Unit Weight, γ= 118 lb/ft3, Footing Radius of circle, R=5’ & e=0.5’.
.
a
b
c
d
22.
54.50 ft2
65.50 ft2
78.50 ft2
63.50 ft2
Solution:
Where, e=0.50 and R=5’
Therefore,
Area of ADC, S= πR2/2-[e√{(R2-e2)+R2Sin-1(e/R)}]
S=3.14 x 52/2-[0.50√{(52-0.52)+52Sin-1(0.5/5)}]
S=3.14 x 52/2-[0.50√{(24.75+143.48)}=32.77 ft2
Effective Area, A’=2S=32.77 x 2= 65.54 ft2
Correct Solution is (b)
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IX.
Other Topics
40.
PROBLEM (Earthquake loads)
A building has to be design earthquake consideration having own weight 6120 kip including
the height of building, H=57 ft. Determine the base shear of the building for earthquake.
Where,
Soil Type, S=1.2
Building Type, Ct= =0.075 For R.C. Space Frame
I=1, Occupancy Normal
Z=0.2, Zone, 2B= Medium hazard
Rw=10, Moment resisting R.C. Space Frame
a
b
c
d
40.
265.00 Kip
354.00 Kip
138.00 Kip
288.00 Kip
Solution:
ΣWx=6120 kip
T=CtH3/4=1.55 sec
Dynamic response, C =1.25S/(T2/3)=1.12
Base Shear, V=(ZIC/Rw)ΣWx
Base Shear, V=(0.2 x 1.0 x 1.12 / 10 ) x 6120=136.77 Kip
Correct Solution is (c)
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