Effect of moisture content on dynamic response law and failure mode of accumulation slopes under frequent micro-seismic actions

Micro-seismic actions are frequent in the Three Gorges Reservoir area in recent years. Meanwhile, the accumulation slope is widely distributed in the reservoir area. Therefore, the stability of the accumulation slope under the frequent micro-seismic actions is noteworthy. The moisture content of accumulation body is one of the key factors affecting slope stability. The influences of the moisture content on the dynamic response and failure mode of the massive accumulation slope in Three Gorges Reservoir area are revealed by adopting the shaking table model tests. The results are as follows: under the frequent micro-seismic actions, the failure of the model slope is damaged by "ladder" sliding. The deformation evolution can be summarized as follows: generation of cracks → extension of cracks → connection of the upper cracks (sliding of the upper sliding body) → formation of the bottom slip plane (failure of the slope). During the process of accumulation sliding due to the connection of cracks, the failure of the high moisture content model is "locally integrated", while the failure of the low moisture content model is "collapsed and scattered". The acceleration response of the slope shows obvious altitude effect and skin effect, leading to the first crack in the shoulder of slope. The enhancement of moisture content promotes these effects.