Evaluation Of Landslide Stability And Control Measures Of Dongsheng Interchange On Jiangjin To Xishui Expressway

Taking the Dongsheng Interchange Landslide of Jiangjin to Xishui Expressway as the research object,this paper studies the cause mechanism of landslide by traditional geology,and then calculates the stability coefficient of slope safety by using the limit balance method.Finally,on the basis of the limit balance method,the slope is simulated by numerical simulation,and the mechanism of landslide formation is verified.Combining qualitative analysis with quantitative calculation,the overall stability of slope was evaluated and reasonable measures were put forward.Through the above analysis,this paper has the following main conclusions:(1)After field investigation,the length of the sliding body is about 230m,the width is about 130m,the thickness is about 3~9m,and the sliding area is about 29900m~2.The stratum is divided into:clay layer and middle weathered mudstone and sandstone.(2)Through the deep displacement monitoring combined with the deformation characteristics of the landslide and the analysis of the position of the anti-slide pile,it is concluded that the mechanism of the landslide is that under the action of rainfall,the filling of the ram from the trailing edge of the trailing edge begins to slip inside the soil.The pile is squeezed,causing the lower part of the pile to break.The angle between the main sliding direction and the arrangement direction of the pile causes the top and the top of the pile to rotate.The trailing edge of the sliding surface of the slope body is located inside the slope top fill soil,and the middle front and front edges are located at the geotechnical interface.Below the geotechnical interface,the bedrock is generally stable and does not slip.The inside of the fill soil slides and squeezes the native soil to promote the shallow sliding caused by the surface layer.(3)The limit equilibrium method is used to calculate the safety factor of landslide stability.It is concluded from the calculation results that the slope is unstable before unloading,and the slope instability is intensified under heavy rain conditions,emergency unloading is taken after landslide occurs.The self-heavy stress is reduced and the slope is in an unstable state.Using FLAC3D combined with the mechanical parameters of geotechnical layer for numerical calculation,from the calculation results of maximum and minimum principal stress,displacement,plastic zone,etc.,the slope is analyzed in natural working conditions and heavy rain conditions,and anti-slide piles are set and anti-slip is not set.The stability of the pile shows that the slope is unstable under natural conditions and heavy rain conditions,and the calculation result of the limit equilibrium method is verified.(4)According to the characteristics of the landslide and the magnitude of the sliding thrust in the study area,reasonable control measures are given for the landslide,that is,the compound treatment measures of“unloading+slope protection+intercepting and drainage engineering+grouting steel tube+anti-slide pile”are adopted.And the anti-slide pile is discussed and the structural design of the anti-slide pile is obtained.