Pseudostatic seismic stability of slopes: Design Charts

Abstract

A variational limiting equilibrium approach that is an extension of Baker and Garber's analysis is presented. In this extension a pseudostatic seismic force is included to assess the stability of simple slopes. The normal stress distribution over the potential slip surface is determined mathematically so as to render the minimum factor of safety while satisfying explicitly all limiting equilibrium equations. The equation describing this distribution contains terms related to seismicity and it makes the problem statically determinate without a priori statical assumptions. A closed‐form solution is then obtained for a log spiral failure mechanism. Consequently, a parametric study of the effects of pseudostatic seismic force is conducted with ease. Furthermore, design charts for assessing the seismic stability of simple slopes are presented. For nonseismic cases these charts coincide with Taylor's chart. For the seismic cases, identical results could also be obtained by using a conventional log spiral analysis (though with much greater effort). The design charts, therefore, should be acceptable by a large group of readers.