Development of shear strength reduction method for slope stability analysis under rainfall conditions and its application

Rainfall is a major cause for slope failures. At present, rainfall-induced slope failure analysis using shear strength reduction method is a complex and time consuming work. Meanwhile, the complexity of rainfall boundary makes such analysis more complex. As a result, the application of shear strength reduction method for slope stability analysis under rainfall conditions is limited. In order to perform such analysis more efficient, Geostudio software was adopted to obtain the pore water pressure within the slope which was then converted to equivalent node forces and passed into ABAQUS software for slope stability analysis. Combined with 'Field variable based strength reduction FEM', a secondary development on ABAQUS software was conducted, and a computing platform for slope stability analysis under rainfall conditions using shear strength reduction FEM was developed. This computing platform overcome the limitation of ABAQUS in simulating rainfall boundary by using Geostudio software, and promotes computational efficiency based on the field variable provided by ABAQUS software. To investigate the feasibility of the computing platform, a comparing study was performed. It was found that the results from the computing platform are in good agreement with that from the traditional limit equivalent method. This indicates the reliability of the computing platform. The study on the mechanism of rainfall-induced slope failure was then performed using the proposed computing platform.