Rigid retaining walls interacting with unsaturated soils in axial symmetry

Abstract

The slip line theory is applied to the problem of an axisymmetric retaining wall interacting with unsaturated soil. Active and passive failures of a rigid vertical wall are considered. The slip line governing equations assume the limiting equilibrium state of a Mohr-Coulomb soil. A linear variation of the contribution of suction to the effective stress with depth is assumed. A standard finite difference method is used to solve the governing equations. The finite difference procedures were validated with recently published literature on axisymmetric retaining walls retaining dry soils. It is shown that adopting the effective stress concept enables the influence of suction in unsaturated soils to be considered in a simple way. An example of analysis is presented to illustrate this. Moreover, the paper shows significant influence of the length scale and the magnitude of the circumferential stress on computed earth pressures.