Civil Engineering Reference
In-Depth Information
Fig. 13.32
Exercise 13.2.
unit weight of 19.3 kN/m
3
. The fill has c
′
=
7.2 kPa and
φ
′
=
30°, whilst the clay soil
has c
u
=
32.5 kPa.
Analyse the slip circle shown (ignore tension cracks).
Answer
F
=
1.2
Exercise 13.3
The surface of a granular soil mass is inclined at 25° to the horizontal. The soil is
saturated throughout with a water content of 15.8%, particle specific gravity of 2.65
and an effective angle of shearing resistance of 38°.
At a depth of 1.83 m water is seeping through the soil parallel to the surface.
Determine the factor of safety against slipping on a plane parallel to the surface
of the soil at a vertical depth of 3.05 m below the surface.
Answer
1.37
What would be the factor of safety for the same plane if the level of the seeping
water lifted up to the surface of the soil?
Answer
0.91
Exercise 13.4
Using Taylor's curves, determine the factor of safety for the following slopes (assume
D
=
1.0):
H
=
30 5
.
m
,
β
= °
40
,
c
′ =
10 8
.
kPa
,
φ
′ = ° =
25
,
γ
14 4
.
kN m
/
3
Answer
Approximately 0.95
3
H
=
15 25
.
m
,
β
= °
20
,
c
=
24 0
.
kPa
,
γ
=
19 3
.
kN m
/
u
Answer
0.8
′
=
′
= ° =
H
=
22 8
.
m
,
β
= °
30
,
c
9 6
.
kPa
,
φ
25
,
γ
16 1
.
kN m
/
3
Answer
1.2
