Drained cylindrical cavity expansion analysis in anisotropic soils considering 3D strength

Anisotropic behaviour and three-dimensional (3D) strength are two significant properties of soils. This paper incorporates the spatially mobilised plane (SMP) criterion into the anisotropic critical state model and a semi-analytical solution for drained cylindrical cavity expansion problem is derived based on the modified model. The problem is formulated by transforming equilibrium equation, constitutive equations and strain displacement relation into a set of seven first-order ordinary differential equations concerning three transformed stresses, anisotropic parameters and specific volume. The present solution is expected to provide more rational predictions than other solutions as both the 3D strength and rotational hardening are considered in the proposed solution. Case analyses regarding distributions of seven basic variables, the effective stress and anisotropic parameter path around the cavity are conducted and compared with other solutions. The results show that neglect of 3D strength and rotation hardening would result in unreasonable predictions for geotechnical problems.