Study On Characteristics And Stability Of Landslide In Chenhe Village In Bashihe River Basin

Loess Plateau in the northwestern China is the main distribution area of loess in our country,while the special loess landforms are created,the loess geological disasters also happened frequently,especially the multi-cause,multi-type and multi-period of landslide disasters.These disasters brought huge economic losses and casualties.In this paper,we conduct detailed investigation on the Chenhe Village landslide in the Baxie River Basin,Dongxiang County,China.The characteristics of the landslide are analyzed comprehensively and systematically through field investigation of the landslide,and the causes,formation mechanism and evolution process of the landslide are also discussed.Moreover,stability of the landslide is evaluated,and finally we put forward the corresponding landslide treatment program.The main research results are as follows:(1)Through the field investigation,the basic characteristics of landslide are identified.The landslide plane shape is of smooth rear wall,steep front edge,crack development and clear perimeter.The distribution of cracks has the characteristics of extremely inhomogeneity,group arrangement and length correlation.Deformation and failure has specific performance of cracks in the trailing edge,irregularity and large concavity;the front edge of broken soils,large scattered elevation,dense cracks developed in both sides,relatively sparse cracks distributed in the middle and other micro-geomorphology.The landslide structure shows the variation process of loose loess,short columnar loess and medium-long columnar mudstone according to the core.(2)The rock mass quality index RQD was statistically analyzed and the type of landslide was determined.The landslide is the loess-mudstone contact surface landslide.(3)The deformation and failure characteristics of the landslide are analyzed,and the evolution process of the landslide is restored which can be divided into four stages: the creep and the crack formation stage of the slope,the crack extension and the wetting peak descending,the instantaneous descent phase of the rear part of the slope,the progression penetration of slip plane and landslide occurrence stage.(4)According to the landslide stability calculation and numerical simulation,the landslide is stable in natural state.However,it is unstable under heavy rain and continuous rainfall,earthquakeand so on;Moving the frontal part of the landslide,it becomes unstable under three different conditions including natural state,heavy rain and continuous rainfall,earthquake and so on.A reasonable and effective prevention and controlling scheme is put forward: conducting land-bearing drainage,monitoring and greening to support slope cutting and load reducing,anti-sliding retaining wall and crack tamping.