Civil Engineering Reference
In-Depth Information
Static Case.
The first slope stability analysis was used to calculate the factor of safety of
the slope for the static case (i.e., no earthquake forces). Particular details of the analysis are
as follows:
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Critical slip surface:
For this analysis, the computer program was requested to perform
a trial-and-error search for the critical slip surface (i.e., the slip surface having the low-
est factor of safety). Note in Fig. 9.11 that a grid of points has been produced above the
slope. Each one of these points represents the center of rotation of a circular arc slip sur-
face passing through the base of the slope. The computer program has actually performed
about 1300 slope stability analyses, using the Spencer method of slices. In Fig. 9.11, the
dot with the number 1.590 indicates the center of rotation of the circular arc slip surface
with the lowest factor of safety (i.e., lowest factor of safety
1.59).
FIGURE 9.11
Slope stability analysis for the static condition using the SLOPE/W computer program
(Geo-Slope 1991).
