Dynamic response of down-dip multi-weak-layer rock slope under earthquake

The long-term mining of the Fushun West Open-pit Mine has resulted in the exposure of underground rock layers, forming numerous down-dip and weak-layer rock slopes. In view of only few studies on the down-dip and multi-weak layer rock slopes under earthquakes, selected the down-dip multi-weak layer rock slope at E1000 in the south bank of the Fushun West Open-pit Mine, the paper analyzed the influence of multiple-weak layers on the dynamic response of the slope under earthquake action. The finite difference software is used to model the slope numerically and analyze the dynamic response of different weak layers of the slope under the real seismic action. Then by comparing the cases of double weak layers, single weak layer and no weak layer, found that different weak layers have different dynamic response and the degree of influence on the slope is also different. The weak layer located at the lower part of the slope has no elevation amplification effect but plays a dominant role in the slope. The weak layer collinear with the slope surface has the surface amplification effect and the elevation amplification effect but hasn’t obvious impact on the slope. Bidirectional ground motions has not affected the weak layers and slope magnification effect of the numerous down-dip and weak-layer slopes. The acceleration and velocity in the Z (vertical) direction increase significantly. The velocity distribution of the slope under the action of bidirectional ground motion has obvious difference, but the displacement distribution does not change significantly.The dynamic response law of numerous down-dip and weak-layer slopes under the action of earthquakes is related to the location and mechanism of the weak layers.The influence of weak layers on the slope should be fully considered in the protection and treatment of slopes.