Seismic cumulative failure effects on a reservoir bank slope with a complex geological structure considering plastic deformation characteristics using shaking table tests

To investigate the seismic cumulative failure effect (SCFE) of a reservoir bank rock slope, the dynamic displacement response of the slope was analysed using shaking table tests. A plastic effect coefficient (PEC) is proposed to reflect the plastic deformation degree of the slope under the influence of earthquakes, and its applicability in analysing the SCFEs of slopes is verified by using the Arias intensity (Ia) from the perspective of energy. The effects of the wave frequency components on the SCFE and local failure mechanism of the landslide are discussed based on the frequency-domain analysis. The results shows that the PEC fully considers the plastic deformation characteristics of the slope, and its physical significance is clear; thus, it can reflect the local failure of the slope better than the peak ground displacement (PGD). The analyses of the PEC and Ia show that the seismic cumulative failure process of the slope includes the progressive failure effect stage, initiating effect stage, and accelerated sliding stage. In addition, according to the frequency-domain analysis, the high-frequency components of seismic waves have a great impact on the accumulation process of the local slope deformation, while the low-frequency components have a controlling effect on the overall instability of the slip mass. The seismic instability of rock slopes containing complex geological structures is a progressive and cumulative failure process. Obtaining a better understanding of the SCFEs of slopes can provide a scientific basis for the identification of the seismic damage status and appropriate seismic reinforcement.