Study On Water Level Threshold And Deformation Prediction Of Muyubao Landslide In Zigui,three Gorges Reservoir Area

Taking muyubao landslide as an example,based on the general situation of landslide engineering geology and its deformation monitoring data,this paper studies the deformation inducing factors and sliding mechanism of the landslide.The research shows that the reservoir water level is the main controlling factor of muyubao landslide.Then,based on the landslide monitoring data,the deformation rate reservoir water level curve of landslide is obtained,the reservoir water level value of landslide with sudden change of displacement rate is studied,and the reservoir water level threshold of landslide deformation aggravation is obtained quantitatively.Finally,based on the threshold of reservoir water level and its sliding mechanism,the deformation law of the landslide under the condition of water storage above the threshold water level is analyzed,and the deformation of muyubao landslide is quantitatively predicted.The main research contents of this paper include the following three points(1)Induced factors and sliding mechanism of landslide.Based on the macro deformation and monitoring data of muyubao landslide,displacement reservoir water level analysis model and displacement rainfall analysis model are established.Starting from the deformation law of landslide,the inducing factors and sliding mechanism of landslide are studied.The research shows that the main controlling factor of landslide deformation is reservoir water level.The rising of reservoir water level leads to the buoyancy of the anti sliding section immersed in water at the front edge of landslide.The weight and anti sliding force of the anti sliding section are reduced.The high water level immersion leads to the deterioration of the mechanical properties of landslide and sliding zone,and the cracks in rock mass are formed after water filling The size of the hydrostatic pressure and the mechanical properties of rock mass are directly affected by the change of fracture water content,and the superposition of many factors leads to the acceleration of deformation.(2)Reservoir water level threshold of landslide.Based on the analysis of landslide sliding mechanism,it is concluded that the reservoir water level is the main controlling factor of muyubao landslide deformation.Through the calculation and sorting of monitoring data,the correlation between the change of landslide displacement rate and reservoir water level is obtained.The threshold of reservoir water level for landslide deformation is studied.The results show that the threshold of reservoir water level for landslide deformation is 170 m.When the reservoir water level is higher than 170 m,the displacement rate of landslide increases suddenly and the deformation of landslide increases sharply.And the longer the reservoir water level > 170,the greater the displacement rate.(3)Deformation prediction of landslide.Based on the water level threshold of intensified sliding reservoir,the deformation development of muyubao landslide was studied by using exponential smoothing prediction method combined with curve fitting,and the deformation law of the landslide was predicted.The results show that,with the passage of time,the sliding acceleration of muyubao landslide will gradually decrease,the displacement rate will be nearly uniform,and finally the landslide will tend to be stable.