3-D Shaking Table Model Test Study on Dynamic Response of Composite Block Slope with Complex Structural Planes

Abstract

A large 3-D dynamic model test with scale 1:200 for block slope combined by complex structural planes is designed. The test model is composed of slope and damping boundaries. The model slope with a thickness of 1.5 m, a length of 2.95m, a height of 1.91 m weighs about 20t, and its volume is around 6.45 m3. The block is combined by three structural planes, with volume of 0.174m3 corresponding to prototype volume of 1.39×106m3. The dynamic characteristics and responses of model slope are studied by inputting white noises and different seismic waves. Test results show that natural frequencies of the slope model are almost not influenced by shaking before failure, but damping ratios increase after shaking. The distribution law of peak acceleration amplification factors along the slope height is basically similar under the action of different seismic waves. The amplification effect is significant around the crest of the slope and amplification factors are equal to 1.0 almost at the middle and bottom of the slope. Acceleration amplification effects of the block are not significant, but they are significant around the corners cut by structural planes. The test results can be used as a good reference for the seismic design of composite block slopes.