Civil Engineering Reference
In-Depth Information
Fig. 13.25
Effect of depth limitation on Taylor's curves (for
β
<
53° and
φ
′
≠
0, use Fig.
13.24
).
Note: c
′
/
γ
H
=
0.181 at D
=
∞
for all
β
values.
Example 13.6:
Taylor's charts (i)
An embankment has a slope of 1 vertical to 2 horizontal. The properties of the slope
are: c
′
=
5 kPa,
φ
′
=
20°,
γ
=
18 kN/m
3
and H
=
11 m.
Using Taylor's charts, determine the F value for the slope.
Solution:
From the charts it is seen that a slope with
φ
′
=
20° and a slope angle,
β
of 26.6° has
a stability number of 0.017. This means that, if the factor of safety for shearing resistance
was unity, c
m
, the cohesion which must be mobilised would be found from the
expression:
c
m
=
0 017
.
i e
. .
c
= × ×
18 11 0 017
.
=
3 37
.
kPa
m
γ
H
5
3 37
⇒
Factor of safety with respect to cohesion
,
=
=
1 48
.
.
