Dynamic Characteristics And Stability Of Prediction For The Badong Group Marlite Debris Landslide In Three Gorges Reservoir Area

The badong group marlite debris landslide is one of common type of landslide in the three gorges reservoir area.Take the Cao Fanghe landslide,Xin Datian landslide and Long Wangbao landslide as the research object,based on the monitoring data and combined with regional geological environment and geological structure information,analysis of the deformation characteristics of the landslide.Then use GeoStudio software and Lizheng software for numerical simulation of the landslide main profile,in order to predict the stability of the landslide under different conditions;Finally choosing Cao Fanghe landslide,quasi three dimensional model is established by using finite difference software FLAC3D,for predicting of landslide deformation mode of space.The main results were as follows:(1)By analyzing the landslide monitoring data,surface monitoring displacement of Cao Fanghe and Xin Datian landslide are generally small,when more rain,the surface deformation is obvious,other times deformation law is not clear;at this stage,three landslides are in a stable condition.(2)Landslide groundwater level monitoring data and flow field simulation shows that the slope of the water table and the water level in vivo are in good agreement,indicating that the landslide has good permeability.(3)When the water level drops,the landslide stability coefficient decreases first and then gradually increased,the greater of the drawdown rate minimum stability coefficient is smaller,the more negative the stability of the landslide.(4)When the water level rises,the landslide stability coefficient rise,then fall,but the decline is limited,it has little effect on the stability of the landslide,at this stage,velocityof reservoir water level have greater upside now.(5)Both the 145 m or drawdown under the three days of continuous torrential rain effect,landslide stability coefficient will be decreased rapidly approaching landslide threshold,indicating a higher susceptibility to landslide rainfall.Short-term heavy rainfall on landslide stability have great impact,the greater the intensity of rainfall,the smaller of landslide stability coefficient,the more negative of the landslide.When rainfall increases to a certain extent,there is the possibility of landslides instability,it requires more attention to prevent this happen.(6)By quasi-three-dimensional simulation found that a large deformation is located in rear area of Cao Fanghe landslide,a small area in front of the amount of deformation and displacement of surface displacement is greater than the deep;From the plastic zone on the map,after the landslide margin of tensile stress concentration area,tensile stress concentration area is located in the rear edge of the landslide,the shear stress concentration area is located in a position slip,indicating the type of landslide might destroy creep-crack damage.(7)If the landslide was thin and had good permeability,the landslide stability greatly increase the sensitivity of rainfall,such as Long Wangbao landslide.