Seismic response analysis of jointed rock slope under pulse-like ground motions

Abstract

Because of the directional effect, energy concentration and hanging wall effect of pulse-like ground motions, it is easy to cause rock fall, collapse, and landslide of jointed rock slope. To reveal the deformation law and failure model of jointed rock slope under pulse-like ground motions, a discrete element numerical model of jointed rock slope in the northern Yunnan province was established to study the acceleration, dynamic displacement, and slope failure modes of jointed rock slope under bi-directional pulse-like ground motions. The results show that the period of the pulse signal extracted from the RSN147 seismic wave is 2.03s, and the energy ratio is 70.3%. Under the action of RSN147, the time of peak acceleration and peak displacement of the slope are consistent with the peak pulse velocity, and the predominant frequency is also the same. The low-frequency component of ground motion causes the global displacement of the slope. The peak dynamic displacement of the slope is about 5~6cm, but the maximum residual displacement is only 11.3% of the peak dynamic displacement, so the slope is stable. The strength reduction method was used to analyze the overall stability of the slope. The slope displacement first appears at the slope toe. With the continuous development of deformation, the slope is in a critical state, and the strong weathering rock mass slides along the fractures. The research results can provide support for the construction of jointed rock slopes in strong weathered areas.