Block element method for time-history stability analysis of a rock slope

Block element method (BEM) for dynamic analysis is developed and applied to historic stability analysis of rock slope. Combining the idea of visco-elastic boundary with the theory of BEM, the artificial boundary condition of BEM is formulated. Visco-elastic boundary has the merits of numerical stability and convenience to integrate with computational program. The inertial force of rock block is firstly computed from its acceleration obtained by dynamic analysis and then decomposed according to supposed sliding model into sliding force and force perpendicular to the supposed sliding direction, which is used for calculating resistance force. The stability factor against sliding is defined by the ratio of the resistance force to the sliding force. As the seismic process finishes, the time-history curve of stability factor against sliding of rock block can be obtained. The application of the water intake slope in a hydropower project demonstrates the capacity of this method.