Slope
DEC 302 – Geotechnical Engineering
DIPLOMA IN CIVIL ENGINEERING
GEOTECHNICAL ENGINEERING
(DEC 302)
ASSIGNMENT NO. 1
NAME
ID NO
LECTURER: NOORBAYA BINTI MOHD SALLEH
DATE OF SUBMISSION:
SEPT 2012
Page 1 of 4
DEC 302 – Geotechnical Engineering
QUESTION 1 [TOTAL = 50 MARKS]
a)
Indicate THREE (3) differences of short term stability and long term stability for slope failure analysis.
[CLO1-PLO2:C1] (6 marks)
b)
Discuss briefly THREE (3) methods of changing geometry of the slope for the purpose of slope stabilization.
[CLO1-PLO2:C2] (6 marks)
c)
Explain and illustrate briefly FOUR (4) types of slope failure.
[CLO1-PLO2:C3] (8 marks)
d)
For the slope shown in Figure Q1 (d), find the factor of safety against sliding for the trial surface AC.
Figure Q1 (d)
[CLO1-PLO6:C4] (15 marks)
SEPT 2012
Page 2 of 4
DEC 302 – Geotechnical Engineering
e)
Figure Q1 (e) shows a slip circle. By using the method of slices for total stress analysis, calculate the factor of safety against slipping along failure surface AB for the following conditions:
i.
ii.
Allowing for the tension crack empty of water
Allowing for the tension crack when full of water
4m
γ = 21kN/m3 c = 10 kN/m2 ϕ = 12˚
PLO2:C3] (8 marks)
Figure Q1 (e)
[CLO1-PLO6:C4] (15 marks)
SEPT 2012
Page 3 of 4
DEC 302 – Geotechnical Engineering
QUESTION 2 [TOTAL = 50 MARKS]
a)
Discuss briefly the principle of Rankine’s active and passive state.
[CLO2-PLO2:C2] (5 marks)
b)
A retaining wall with a smooth vertical back of height 9m retains soil having an unsurcharged horizontal surface. The position of water table is 5m from the bottom. The soil properties are: c’ = 0
ϕ’ = 32˚
γsat = 20.5 kN/m3
and above WT, γ =18kN/m3
Determine the distribution of horizontal stresses on the wall and also the magnitude and position of the resultant horizontal thrust when the groundwater level is standing (without
DIPLOMA IN CIVIL ENGINEERING
GEOTECHNICAL ENGINEERING
(DEC 302)
ASSIGNMENT NO. 1
NAME
ID NO
LECTURER: NOORBAYA BINTI MOHD SALLEH
DATE OF SUBMISSION:
SEPT 2012
Page 1 of 4
DEC 302 – Geotechnical Engineering
QUESTION 1 [TOTAL = 50 MARKS]
a)
Indicate THREE (3) differences of short term stability and long term stability for slope failure analysis.
[CLO1-PLO2:C1] (6 marks)
b)
Discuss briefly THREE (3) methods of changing geometry of the slope for the purpose of slope stabilization.
[CLO1-PLO2:C2] (6 marks)
c)
Explain and illustrate briefly FOUR (4) types of slope failure.
[CLO1-PLO2:C3] (8 marks)
d)
For the slope shown in Figure Q1 (d), find the factor of safety against sliding for the trial surface AC.
Figure Q1 (d)
[CLO1-PLO6:C4] (15 marks)
SEPT 2012
Page 2 of 4
DEC 302 – Geotechnical Engineering
e)
Figure Q1 (e) shows a slip circle. By using the method of slices for total stress analysis, calculate the factor of safety against slipping along failure surface AB for the following conditions:
i.
ii.
Allowing for the tension crack empty of water
Allowing for the tension crack when full of water
4m
γ = 21kN/m3 c = 10 kN/m2 ϕ = 12˚
PLO2:C3] (8 marks)
Figure Q1 (e)
[CLO1-PLO6:C4] (15 marks)
SEPT 2012
Page 3 of 4
DEC 302 – Geotechnical Engineering
QUESTION 2 [TOTAL = 50 MARKS]
a)
Discuss briefly the principle of Rankine’s active and passive state.
[CLO2-PLO2:C2] (5 marks)
b)
A retaining wall with a smooth vertical back of height 9m retains soil having an unsurcharged horizontal surface. The position of water table is 5m from the bottom. The soil properties are: c’ = 0
ϕ’ = 32˚
γsat = 20.5 kN/m3
and above WT, γ =18kN/m3
Determine the distribution of horizontal stresses on the wall and also the magnitude and position of the resultant horizontal thrust when the groundwater level is standing (without