A Stability Analysis Method for Arbitrary Slip Block Based on Finite Element Method

Abstract

The stability of slip blocks on arch dam abutment under earthquake is of great importance for the safety of the dam. In order to analyze static and dynamic stability of arch dam blocks, a hybrid method incorporating the advantage of finite element method and rigid body limit equilibrium method is proposed. A scheme is presented by which any arbitrary slip block defined can be obtained from topography of the studied region, and then the 3D slip block is meshed. Based on stress field of static and dynamic FEM calculation, the stress field of all blocks is obtained by interpolating stress on block mesh. By integrating stress on block faces and using the idea of limit equilibrium method, the safety factor of slip block is computed and dynamic stability of arch dam block is evaluated. The proposed method can provide instant stability of slip block during the whole seismic action, which cannot be obtained with traditional limit equilibrium method. Taking Shapai arch dam as an example, the dynamic stability of Shapai arch dam abutment under Wenchuan 5.12 earthquake is analyzed. The method gives a new way for analytical technique of dam abutment stability evaluation.