Dynamic response and failure process of anti-dip rock slope under strong earthquake

Anti-dip rock slopes have a wide development and distribution in the Sanjiang rivers, and their deformation and damage phenomena are particularly prominent among all slope problems in the region. Earthquake is an important dynamic factor to induce landslides, which often leads to large-scale landslide disasters. In this paper, a model test of a reduced scale similar material shaking table was designed and completed using the historical landslide dam at Zongrong on the left bank of the Jinsha River as an example. By loading different types of seismic waves as well as different frequencies and amplitudes, the dynamic response and deformation damage mechanisms of anti-dip rock slopes and the influence of structural surfaces are investigated. The test results show that there is an elevation amplification effect and skin effect on anti-dip slopes under strong seismic action, the larger the amplitude, the more obvious it is. The rate of increase of the slope acceleration amplification factor is influenced more by frequency than by amplitude. The maximum values of the acceleration amplification factor occur at 0.2g to 0.3g for different amplitude values. The presence of structural surfaces changes the dynamic response characteristics of the slope, and there is a clear difference in the amplification effect of their thickness on seismic waves, as thicker sections are suppressed and thinner sections are amplified. Amplitude 0.3g~0.4g is the critical dynamic condition for slope cracking and 0.7~0.8g is the critical dynamic condition for slope destabilisation damage. The slope damage process can be broadly divided into three stages: (1) The formation of top-of-slope tension cracks and toe-of-slope shear cracks; (2) The expansion of cracks and shallow block shear damage sliding-block toppling; (3) The formation of the main slip surface of the shallow slope and slope damage. © 2023 Chinese Vibration Engineering Society. All rights reserved.