Dynamic response of a physical anti-dip rock slope model revealed by shaking table tests

The anti-dip rock slopes are common geological features in Taiwan, and the failure of this type of rock slope is prone to be triggered by seismic loads. Thus, it is important to investigate its dynamic behavior for further mitigation and prevention. The response of an anti-dip slope to an earthquake was modeled in this study by conducting a series of shaking table tests to determine the stability and the failure process for an anti-dip slope under different seismic loads. A high-speed camera was used for noncontact measurement and the captured images were analyzed to identify block sliding, rotation, and toppling. The results demonstrated that (1) an anti-dip slope with a low block inclination angle ψ_p has better resistance to seismic loads; (2) for the same peak ground acceleration (PGA), the lower the frequency, the greater is the extent of block sliding and toppling failure; (3) at a constant frequency, the greater the PGA, the greater is the extent of block sliding and toppling failure; (4) when an anti-dip slope is subjected to a seismic load, the blocks with the smallest aspect ratio start to move first and the order of force transmission between blocks depends on the aspect ratio (Δx/Y_n); (5) the noncontact measurement and image analysis indicated a maximum error of only 5% for block displacement. In conclusion, this study determined the sequence of the movement of the blocks in an anti-dip rock slope model subjected to seismic loading. The results showed that the slenderest block defines the stability of the models. The models could be used as benchmarks for numerical approaches aimed at mitigation of anti-dip slope failures.