Study On The Displacement Vector Field Of Debris Landslide And Its Stability

Combined with the national natural science foundation and the investigation ofQingshan landslide area, the characteristic of the debris landslide and the engineeringgeologic features of Qingshan landslide have been summarized; the evolution ofdisplacement vector field of landslide using the theory of elastic-plastic has beendiscussed, and the orthogonal-strain-ratio has been presented. The generalized model ofdebris landslide and Qingshan landslide has been established using the simulationsoftware FLAC herein to simulate the relationship between the orthogo nal-strain-ratioand the stability of Qingshan landslide. Here are the conclusions:1. It shows that the strain increment increased significantly when the slope enteringthe stage of yield along every direction by using the theory of elastic-plastic, whichmeans the strain increment will increase significantly when slope enter the stage ofplastic deformation from the stage of elastic deformation. With the evolution oflandslide, the acceleration of strain increment became a monotone increasing function,which means strain is the trend of mutation, after slope enter the stage of yield.2. The concept of orthogonal-strain-ratio has been used to discuss the types oflandslide which are suitable for evaluating the stability. The evolution oforthogonal-strain-ratio has been discussed. It has been found that theorthogonal-strain-ratio is a constant which means the direction of stress had not changewhen landslide in the elastic deformation stage.3. Combined with the impact of slope shape to the stability of landslide, thegeneralized model of shallow debris landslide. It shows that the more the angle, themore the absolute value of strain, the more changes of direction when the landslidecame into the plastic deformation; the less the ratio of length and depth, the less theabsolute value of strain and the change of direction.4. The generalized model of Qingshan landslide has been established using thesimulation software FLAC herein to simulate the relationship between the displacementvector field and the stability of Qingshan landslide. The relationship between X-strain,Y-strain, the orthogonal-strain-ratio and the stability of landslide of the monitoringstations of Qingshan landslide. The absolute value of strain of the surface o f the slope ismore than it inside the slope, and the inside of the slope is earlier than the surface of theslope to enter the stage of plastic deformation.