INTRODUCTION
Soil is one of the most important engineering materials. Determination of soil conditions is the most
important first phase of work for every type of civil engineering facility. The geotechnical properties of a
soil such as its grain-size dis
19/10/2010
ENB 371 : Geotechnical Engineering 2
Week 13 Practice Questions
1
Q1
A sandstone rock mass which is very favourable for tunnel, fractured by 2 joint
sets plus random fractures, average RQD is 70%, average joint spacing is 0.11 m,
joint surfaces
Q1)
B x L=8mx18m
Df=3m
B =8m
Cu = 120kN / m 2
Assume no water table effect
= 18kN / m3
u = 0
Mayerhof Bearing Capacity Equation
qu = c' N c Fcs Fcd Fci + qN q Fqs Fqd Fqi + 0.5BN Fs Fd Fi
u = 0
From Table, Nc =5.14 and Nq =1, N =0
Q1) Contd.
Q1) Contd.
q
1
Q1
Q1
Df = 0.7 m
w
= 40
C = 0
Q
FS = 3.0
sat
= 9.8 kN/m3
= 20 kN/m3
= 17 kN/m3
Q=500+300=800 kN/m
Water table may rise to foundation level
d=0
Df = 0.7 m
B
d
B?
According to Terzaghis Bearing Capacity Theory for strip footing
qu = C Nc + qNq + 0.5 BN
1
Q1
(i)
Tv =
cvt
H
What is the definition of H in this equation?
H is the length of the average longest drainage path during consolidation (length of
the drainage path)
(a)In the case of double (two-way) drainage : H =Hc/2 (Where Hc average height of
the
20/08/2010
ENB 371 : Geotechnical Engineering 2
Week 5 Practice Questions
1
Q1
1.300
1.250
Void Ratio
1.200
1.150
Horizontal line at A
A
Point with minimum radius
(maximum curvature = 1/R)
1.100
Bisector
1.050
Tangent at A
1.000
10
100
c = 100 kPa
1000
Lo
10/08/2010
ENB 371 : Geotechnical Engineering 2
Week 4 Practice Questions
1
Q1
Se =
(
q0 Be I G I F I E
1 s2
E0
)
B = L = 3m
Be =
4 BL
=
4 3 3
= 3.38 m
2
1
10/08/2010
Influence factor for the variation of Es with depth, IG
E
H
20
16,000
=
= 5.92, 0 =
= 11
10/08/2010
ENB 371 : Geotechnical Engineering 2
Week 3 Practice Questions
1
Q1
Without the pressure from the tank (When the tank is empty)
20m
Ground
5m
=
.
/
5m
=
.
/
=
.
=.
=
+
=
=
.
.
D
A
At 10 m depth (at A & D)
=
.
/
/
.
.
=
.
/
2
1
10/08/2010
Q1 Con
Q1
(i)
76 mm
Bulk soil mass = 175 g =0.175 kg
Dry soil mass = 143 g = 0.143 kg
Specific gravity of soil, Gs = 2.71
D2
V=
h
4
38 mm
38 76
V =
4 1000 100
2
V = 8.62 10 5 m 3
Bulk density( b ) =
Bulk unit weight
Bulk mass
0.175
=
= 2030kg / m3
Total v
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 13 PRACTICE QUESTIONS Rock mechanics
Q1. A sandstone rock mass which is very favourable for slope, fractured by 2 joint sets
plus random fractures, average RQD is 70%, average
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 12 PRACTICE QUESTIONS Pile foundations 2
Q1. As shown in the Figure Q1, a pile was driven into the ground where the sand fill was
placed recently. The water table coincides wi
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 11 PRACTICE QUESTIONS Pile foundations 2
Q1. A 15 m long concrete pile with a cross section of 0.45 m x 0.45 m fully embedded in
3
0
sand. For the sand, given: unit weight, =
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 10 PRACTICE QUESTIONS Review of Wk 1- 8
A 2 x 3 m foundation shown in the following figure has to support the column load of 1200
kN. Using the given information check whether
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 9 PRACTICE QUESTIONS Shallow Foundation - 3
Q1. Determine the net ultimate bearing capacity of mat foundations with the following
characteristics:
2
3
cu = 120 kN/m , u = 0, B
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 8 PRACTICE QUESTIONS Shallow Foundation - 2
Q1. An eccentrically loaded foundation is shown in the following figure. Use FS of 4
and determine the maximum net allowable load t
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 7 PRACTICE QUESTIONS Shallow Foundation
Q1.
Q2.
A strip footing is to be designed to support a dead load of 500 kN/m and an
imposed load of 300 kN/m at a depth of 0.7 m in san
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 6 PRACTICE QUESTIONS Time-dependent Consolidation
Q1.
Answer the following questions.
(i)
Tv = cvt / H 2 , What is the definition of H in this equation?
(ii)
Give typical unit
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 5 PRACTICE QUESTIONS Consolidation settlement
Q1.
Using the e vs log graph shown in Figure 1, determine the pre-consolidation
pressure (c), the compression index (Cc) and the
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 4 PRACTICE QUESTIONS Elastic settlement of soil
Q1.
A square foundation measuring 3x3 m, supported by a layer of sand is shown in
Figure 1. Calculate the elastic settlement of
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 3 PRACTICE QUESTIONS Subsurface stress increment
Q1.
A steel storage tank 20 m in diameter will be used to hold a liquid petroleum
product. When filled, the tank causes a bear
Queensland University of Technology
QUT
ENB371: Geotechnical Engineering 2
WEEK 2 PRACTICE QUESTIONS Review of ENB272
Q1.
A site investigation revealed a uniform deposit of clay. A sample of the clay 76 mm
high and 38 mm diameter taken from above the wate
Rock Slope Stability
ENB371: Geotechnical Engineering 2
Chaminda Gallage
Stability of Rock Slopes
Important for road and rail cuttings, dam
abutments, mines etc.
Failure of slopes cause damage and death.
Almost all failures occur on discontinuities
Deg
Introduction to Rock Mechanics
ENB371: Geotechnical Engineering 2
Chaminda Gallage
Outline of the lecture
Introduction
Rock formation and rock types
Rock Classification Engineering Classification
more focused on applications
Shear strength of discont