Noncircular Slip Surface Analysis of the Stability of Slopes

An Application of Dynamic Programming to the Janbu Method

Abstract

Although slope stability analyses are based mainly on a circular slip surface theory, there are not a few cases in which noncircular slip surfaces should be assumed to occur. In fact, many of the landslides in Japan have occurred with noncircular slip surfaces. Even in such cases circular slip surface analyses are made because of the great difficulties involved in locating critical noncircular slip surfaces.
This paper is concerned with a numerical algorithm to identify the critical noncircular slip surface with the minimum factor of safety based on the simplified Janbu method. The algorithm combines the Janbu method with dynamic programming on the basis of Baker's successful procedure. The computer program developed have indicated through several example problems that the present method is of great practical use.