Analysis of cylindrical cavity expansion in anisotropic critical state soils under drained conditions

Abstract

This paper presents a semi-analytical solution for the drained cylindrical cavity expansion problem using the well-known anisotropic modified Cam clay model proposed by Dafalias in 1987. The prominent feature of this elastoplastic model, i.e., its capability to describe both the initial fabric anisotropy and stress-induced anisotropy of soils, makes the anisotropic elastoplastic solution derived herein for the cavity problem a more realistic one. Following the development by Chen and Abousleiman in 2013 of a novel solution scheme that establishes a link between the Eulerian and Lagrangian formulations of the condition of radial equilibrium, the plastic zone solution can eventually be obtained by solving a system of eight partial differential equations with the three stress components, three anisotropic hardening parameters, specific volume, and preconsolidation pressure being the basic unknowns. Parametric studies have been conducted to explore the influences of K0 consolidation anisotropy and overconsolidation ratio (OCR), and their pronounced impacts on the stress patterns outside the cavity as well as on the development of stress-induced anisotropy are clearly observed.