Numerical analyses on progressive failure of slope due to heavy rain with 2D and 3D FEM

In the paper, based on a modified elastoplastic model with Matsuoka-Nakai failure criterion, two-dimensional (2D) and three-dimensional (3D) soil-water coupled finite element analyses are conducted to investigate a large-scale failure in a soft-rock slope due to heavy rain. Since the failure of the slope was a typical three-dimensional event, it is necessary to estimate the accuracy of 2D analysis that can be easily and commonly used in geotechnical engineering. The characteristics of slope failure, such as the development of shear strain, the deformation of ground, the propagation of shear band and the progressive failure are discussed in detail with 2D and 3D analyses. The differences between 2D and 3D analyses are carefully investigated. It is found that both 2D and 3D soil-water coupled analyses based on the modified elastoplastic model can simulate the progressive failure of a slope.