Three dimensional nonlinear seismic stability analysis of abutment jointed rock mass of high arch dam

The aseismatic stability of abutment jointed rock mass is the key problem of high arch dam.With the application of the rigid body limit equilibrium method(RBLEM),the stresses in high arch dam are not considered when the seismic stability of abutment jointed rock mass is evaluated, so the safety coefficient calculated by RBLEM does not assure the safety of dam. According to the mechanical principle of intensity repertory the method of dynamic deformation safety coefficient of abutment rock mass is employed in order to take into consideration the safety of arch dam itself. In this paper, two different approaches,i.e.,dynamic deformation safety coefficient method and dynamic intensity safety coefficient method, are used to study the seismic stability of abutment of Xiaowan arch dam with the maximum height H=292 m. And the foundation rock of the abutment is considered as continuous medium with characteristics of nonlinear large deformation and cracking. The numerical results of Xiaowan high arch dam indicate the rationality and the feasibility of the proposed method.