Time-history analysis of seismic sliding stability for RCC gravity dam of LudiLa Hydropower Station, Jinshajiang River

The dynamic finite element time-history analysis method is employed to compute the seismic response of Ludila RCC gravity dam at Jinsha River subjected to design earthquake loading (0.36g). The dam-water-foundation interaction and the foundation radiation damping effect of the seismic energy dissipating towards infinite domain are considered in the FEM model. The time histories of inertial force of the dam are calculated by using the D'Alembert's principle of particles system. Then, the time histories of the sliding safety factor of the dam along dam-base sliding interface can be obtained by combining the inertial force and other static loads. The complex earthquake numerical simulation results are validated by comparing the inertial forces of the dam calculated by the time-history analysis method and the spectrum method. Because the minimum value of safety factor satisfies the requirements of the seismic design code of hydraulic structures, it can be concluded that the overall seismic stability of Ludila Dam is good, and the reinforcement to improve the anti-sliding stability is not needed. The proposed method should be of interest and useful to professionals involved in the seismic design of large gravity dams.