地震边坡岩土体破坏特征探讨

Discussion of soil-rock mass failure characteristics of slope under earthquake

通过理论分析与FLAC数值模拟技术,分别探讨了地震边坡岩土体应力状态及其破坏特征。研究发现:地震荷载作用下,边坡坡顶单元易产生拉应力,发生拉破坏,其最小主应力方向与水平方向几乎一致,致使坡顶常表现为陡峻拉裂面;底部单元主应力方向发生改变,处于双向受压状态,发生剪切破坏;边坡动力失稳是因拉剪滑面贯通所致。

The stress state and failure characteristics of slope soil-rock mass under earthquake were discussed by the methods of theoretical analysis and FLAC numerical simulation techniques.It is found that the top soil-rock mass elements of slope are easy to produce tensile stress,and occur tensile failure under earthquake load,the direction of minimum principal stress is consistent with horizontal direction,which results in formation of steep fracture surface.The principal stress direction of the bottom soil-rock mass elements change,they are under the state of bi-directional compression,occur shear failure.Slope dynamic instability is due to the formation of tension-shear fracture surface.