Research On The Evolution Mechanism And Stability Of The Many Preiod Times Landslide

Large multi-period landslide sliding effect range will bring huge loss to human life andproperty safety. The landslide in the west of ZaDuo County occurred in three stages, showdifferent degree of crack in the three period of the middle of landslide, With creeping thelandslide occurs at the leading edge, and shows a trend of increasing, it will threaten toresident’s journey of six rural in the west of ZaDuo County and the safety of pedestrians andpassing vehicles.The paper chooses landslide located in the west of ZaDuo County as research object.Based on the analysis of geological environment background of occurrence of the landslides,and through evolution analysis of terrace about Zhaqu River, this paper studied the differentstage of landslide formation mechanism and evolution process. With the stability analysisfor each stage of landslide by qualitative and quantitative method, we get the best treatmentplan to the third landslide based on comprehensive fuzzy evaluation. The main resultsobtained are as follows:(1) Through Inversion forming process of Zhaqu River Valley terrace in the landslidearea;the first landslide occurred after the fifth terrace formed while before the fourth formed.The second landslide occurred after the first terrace formed, and the third one happened forthe new.(2) By analyzing the formation mechanism of each period times of the landslide, it wasconsidered that the evolution process of formation of the first landslide has mainlyexperienced five stages: River lateral erosion deformation of stage, Crack developmentstage, Shatter to slip surface through stage, Sliding and Curing stage. The second landslidehas mainly experienced four stages: Leading edge deformation stage, Extension to slipsurface through stage, Sliding and Curing stage. And the third one has experienced Stressconcentration and Extension deformation stages at present, while Slip surface through andSliding stage will be experienced forecasting.(3) To draw conclusions from analysis of stereographic projection of the unstableslope where the first landslide’ backwall located that it is in unstable state. Based on Limitequilibrium method to stability analysis and the Numerical simulation of the landslide of the second landslide and the third one, we obtained the result that the second landslide is in astable state under condition of weight and weight and heavy rainfall, while in basicallystable state under the circumstances of weight and seismic. On the condition of weight, theWestern slip mass of the third landslide is in a poor stability state while the Eastern is incritical stable state. Then under condition of weight and heavy rainfall, the Eastern is incritical stable state and the Western is in unstable state. In the case of weight and seismic,the third landslide is in unstable state.(4)By using fuzzy comprehensive evaluation method, the best treatment plan to thethird landslide is to join prestressed anchor cable frame, Surface drainage, Sand drain andHorizontal hole together for Underground drainage.