Nonlinear Slip-Failure Surface and Associated Lateral Earth Pressure

Abstract

In optimizing the design of retaining structures and monitoring their health, it is important to determine the actual nonlinear slip-failure surface and the associated nonlinear lateral stress distribution. This paper presents a model developed for the nonlinear geometry of active and passive slip-failure surfaces in cohesionless soils and for determining their three main associated variables; that is, lateral earth pressure distribution, coefficient of lateral earth pressure, and location of the resultant lateral force. The variational limit-equilibrium method, as applied to a normally consolidated dry granular media, and the plane-strain critical-state friction angle at failure are used to develop the model. The model outputs the governing geometry of the slip-failure surface and its associated lateral stress distribution as a unique nonlinear function of the ultimate shearing resistance at failure. Mostly existing studies are complex unilateral approaches of the lateral stress or the slip-failure geometry as separated issues. In contrast, the present paper addresses a simple coupled solution at critical state that uses a disambiguated friction angle and avoids arbitrary input assumptions such as the geometry of the slip-failure surface.