Abstract: A large-scale 1:200 three-dimensional dynamic model of the slope blocks combined with complex structural planes of Baihetan hydropower station was designed. By inputting seismic waves of different amplitudes, the responsive displacement time history and residual deformation distribution of the block under strong earthquake were studied. Residual deformation distribution reveals the failure mode of the slope block and the failure category and characteristics of the slope block were evaluated. The test results show that the seismic stability of engineering slope block was good under the design conditions. In the process of seismic overloads, the residual deformation occurred firstly in the trailing edge crack, and the residual deformation decreased gradually from the two triangular parts near the edge toward the inner slope. The triangular parts are the areas prone to failure first during earthquake. The seismic failure mode of the slope block is the double-slip failure along the bottom and side. Based on the residual deformation and statistical results after earthquake, the allowable design residual deformation should be less than 15 cm and the first obvious mutation. After the residual deformation of the engineering slope block exceeded 30 cm, the displacement mutation is strengthened, and the slope block may slide completely. Slope anchoring should pay attention to increase the tensile strength of trailing edge crack and the shear resistance of the bottom surface of block.

Key words: slope block, strong earthquake, destruction mode, failure category, shaking table model test