Reactivation Mechanism Analysis And Dynamic Behavior Prediction For The Baishuihe Landslide In Three Gorges Reservoir Area

Located in Zigui county in the Three Gorges Reservoir Area,Baishuihe landslide is a large deep-seated accumulation landslide which resumes its activity many times.Based on the long-term monitoring data,the characteristics of its deformation are analyzed.Combined with the regional geological background,this thesis analyses the active mechanism by discussing the forming conditions and influencing factors of the landslide.Then the trends of the landslide stability are predicted under different reservoir water level fluctuation rates and different rainfall intensity by two-dimensional finite element software GeoStudio2007.Based on which,Three-dimensional finite difference software FLAC3D is used to predict its deformation and failure trends.Results are showed as follows:(1)The landslide stays in a creeping state all the time,and the annual displacement decreases year by year since 2008,the stage of which mainly concentrated in May to September of each year.(2)Displacement difference between different position in space:the slide body outside the revivification area stays in a steady state since 2004;while among the displacement in the revivification area,the right front area first place,back area comes second,and the middle part comes the minimum.The displacement of the slip zone is much larger than surface,the landslide slides as a whole,showing a pull-type failure characteristics.(3)Irregular gentle slope,weak slip zone and the special architectural feature are the special basic accounts for the landslide,and rainfall and water level fluctuation are dominant factors which induce the revivification.A large-scale impoundment of the reservoir for the first time has a great influence on the stability of the landslide,after which deformation and rainfall are related positively,the effect of rainfall is greater than the water level fluctuation.(4)Reservoir water level rising is in favor of the stability of the landslide,there is still some room for upward adjustment in reservoir water level fluctuation rates;while against the stability,the falling rate of 0.6m/d present is critical.The influence of water level mainly concentrates on the lower part of the slide body,along with the increase of the rate of water level falling,the displacement in the lower part and the range of deformation area increase gradually until the overall damage of the landslide.(5)Rainfalls,especially for the short-term heavy ones,are not conducive to the stability of the stability of the landslide,the critical value of which is 100mm/d.The influence of water level mainly concentrates on the back part of the slide body,along with the increase of the intensity of rainfall,the displacement and the range of deformation area increase gradually until the overall damage of the landslide.