Dynamic damage evolution of bank slopes with serrated structural planes considering the deteriorated rock mass and frequent reservoir-induced earthquakes

Abstract

To investigate the dynamic damage evolution characteristics of bank slopes with serrated structural planes, the shaking table model test and the numerical simulation were utilized. The main findings indicate that under continuous seismic loads, the deformation of the bank slope increased, particularly around the hydro-fluctuation belt, accompanying by the pore water pressure rising. The soil pressure increased and then decreased showed dynamic variation characteristics. As the undulation angle of the serrated structural planes increased (30°, 45°, and 60°), the failure modes were climbing, climbing-gnawing, and gnawing respectively. The first-order natural frequency was used to calculate the damage degree (Dd) of the bank slope. During microseisms and small earthquakes, it was discovered that the evolution of Dd followed the “S” shape, which was fitted by a logic function. Additionally, the quadratic function was used to fit the Dd during moderately strong earthquakes. Through the numerical simulation, the variation characteristics of safety factors (Sf) for slopes with serrated structural planes and slopes with straight structural planes were compared. Under continuous seismic loads, the Sf of slopes with straight structural planes reduce stalely, whereas the Sf for slopes with serrated structural planes was greater than the former and the reduction rate was increasing.