Investigation of effect of rock content on dynamic response and failure characteristics of soil–rock mixture slope using large-scale shaking table test

Abstract

Slopes with soil–rock mixtures (SRMs) are widely found in southwest China. Because of the strong tectonic geological activity in the region, seismic geological disasters occur frequently. A series of large-scale shaking table tests were performed on model slopes with different rock contents to investigate the effect of the rock content on the dynamic response and failure characteristics of SRM slopes. The test results showed that the acceleration amplification factors in the horizontal direction (AAF-X) of the SRM slopes under sine-wave excitations of varying input frequencies differed significantly because of the differences in the dynamic properties of geological structures. The AAF-X values for the SRM slopes with different rock contents under El Centro wave excitations with varying amplitudes also differed, and the magnitude of the acceleration amplification effect is related to the degree of damage deformation of the slopes. The AAF-X and peak ground displacement (PGD) of the model slopes under seismic excitations were used to analyze the damage evolution of the SRM slopes with different rock contents. For the SRM slopes with rock contents of 20 % and 40 %, the damage deformation process can be divided into three stages: an elastic stage (<0.4 g), a plastic stage (0.4–0.6 g), and a failure stage (>0.6 g). In contrast, the damage deformation process of the model slope with a rock content of 60 % can only be divided into two stages: an elastic stage (<0.6 g) and a plastic stage (0.6–0.8 g). These findings have considerable significance for the stability evaluation of SRM slopes for disaster prevention and mitigation during earthquakes.