Dynamic Response Characteristics of a Toppling Rock Slope Under Seismic Excitation using Time-frequency Joint Analysis Method: A Case Study from the Southwest of Sichuan Basin, China

Abstract

\n The two-dimensional dynamic analysis was used to study the dynamic response characteristics of a toppling rock slope based on the time-frequency joint analysis method using the FLAC (Fast Lagrangian Analysis of Continua). Two-dimensional dynamic analyses were carried out on two numerical models. The results of the numerical dynamic analyses show that the toppling slope has an topographic and geological dynamic amplification effect. There are an elevation and surface dynamic amplification effect in the toppling slope. The impacts of the structural planes in the models on their wave propagation characteristics and magnification effect were discussed. Directions of ground motion have impacts on the dynamic response of the models. Based on the frequency-domain analysis, the relationship between the frequency of waves and the dynamic response of the models was further studied. The geological structure have a great effect on the high-frequency components of waves. The analyses of marginal spectrum show that the energy mainly concentrated in the frequency band of seismic wave (7-10 Hz). Moreover, the seismic failure mechanism of the toppling rock slope was discussed. Geological structure determines the seismic failure mode of the slope. Cracks initiate in the top toppling plane, and the surface slope is damaged firstly under earthquake excitation; with the increase of seismic loading, a large-scale slip mass further forms gradually from the upper to the lower slope body.