Civil Engineering Reference
In-Depth Information
FIGURE 9.21
Slope stability analysis for the pseudostatic condition using the SLOPE/W computer pro-
gram (Geo-Slope 1991).
the unconfined slope face, it is anticipated that the downward movement will exceed 2 in
(5 cm). In addition, there will be lateral movement of the slope, which will also most likely
exceed 2 in (5 cm).
Summary.
In summary, the Newmark (1965) method assumes no deformation of the
slope during the earthquake if the pseudostatic factor of safety is greater than 1.0. However,
as indicated by the above example, a slope composed of dry and loose sand could both set-
tle and deform laterally even if the pseudostatic factor of safety is greater than 1.0. Thus the
Newmark (1965) method should be used only for slopes that will deform as an intact mas-
sive block, and not for those cases of individual soil particle movement (such as a dry and
loose granular soil).
