Analysis of stability against upheaval for foundation pit with anisotropic soil strength

Natural soil is usually nonhomogeneity and anisotropy. However, the calculation methods of stability against upheaval which are commonly used are applicable to isotropic and homogeneous soils. Considering the failure criterion of nonhomogeneous nonlinear anisotropic rocks and the primary anisotropy of soil, assuming Prandtl failure mode, analysis of stability against upheaval is given using the model of foundation pit bearing capacity. According to capacity calculated by the slip line method and using finite difference method combined with boundary conditions, the related calculation program is compiled; then stability coefficient against upheaval is defined. The results show that the larger the anisotropy ratio of soil strength is, the smaller the safety factor is. And with the increasing of internal frictional angle and the retaining wall insertion ratio, the safety factor will be enhanced significantly.