Time-history Stability Analysis on Double-layer Sliding Surface Landslide Under Rainfall
To find out the stability variation process of double-layer sliding surface landslide under rainfall,take Shitoupo landslide on Weiyuan-Wudu express way as the study object.According to the field monitoring and survey data,the time-history calculation model of double-layer sliding surface landslide was established by using ABAQUS finite element software.The time-history calculation method for landslide point safety factor was used to analyze the time-history variation of parameters,e.g.,plastic zone expansion,point safety factor and displacement respectively.The initiation-deformation-instability process of double-layer sliding surface landslide under rainfall was found out.The result indicates that based on the on-site monitoring data and deformation,it can be inferred that Shitoupo landslide is a double-layer sliding surface landslide.Its displacement of the first leading edge is smaller than that of the trailing edge,and it is in through state.The first sliding surface is in through state,and the second sliding surface is in non-through state.The influence of rainfall on the first-level sliding surface of shallow landslide is greater than that of the deep second-level sliding surface.The trailing edge of first-level sliding surface starts first,and pushes to the middle and front edges.That is a thrust load caused landslide.The middle edge of the second sliding surface starts first,then driving the leading edge of trailing edge to break and resist the slip.That is a complex landslide.According to the analysis on time-history curve variation characteristics of key point safety factor,the first-level sliding surface landslide can be divided into 3 evolutionary stages of initiation-deformation-instability.The second-level sliding surface landslide can be divided into 2 evolutionary stages of deformation and instability.According to the analysis on displacement-time history curve variation characteristics,the time-history variation rule of the displacement and the point safety factor is consistent,which is consistent with the field judgment conclusion.It indicates that the point safety factor can be used as the quantitative evaluation basis for the landslide evolution stage.
road engineeringdouble-layer sliding surface landslidepoint safety factorplastic zone expansionrainfall conditionstability
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