Potential Three-Dimensional Slip Surface Searching Based On The Variation Of Displacement Of Slope And Calculation Method Of Safety Factor

In the past decade,the landslide is the main disaster accounted for about 70% of natural disasters in China.Thus,the stability analysis of slope has become an urgent issue.Finding the minimum safety factor of the potential sliding surface is the key for stability analysis of slopes.Optimization search algorithm based on analysis results of the limit equilibrium method has inherent defects such as a great amount of calculation,complex programming,and easy to fall into local minimum "trap".Searching methods based on stress have similar defects with optimization search algorithm.Searching sliding surface based on shear and equivalent plastic strain is different with the actual situation.On the other hand,stress,shear strain and equivalent plastic strain is not easy to be measure in the actual situation while the displacement in slopes is easy to measure.Through extracting the data of horizontal displacement to search potential sliding surface of slope,this thesis aims to analyze the security of slope.In this thesis,the slope stability is analyzed by using finite element strength reduction methods.Five slopes selected whose slip surface covers the arc,line and arbitrary shape,the author analyzes the error in searching slip surfaces of the slopes based on the maximum horizontal displacement increments of specified locations in the slopes,therefore,putting forward an improved method of slip surface searching method to find out the 2D slip surface of slope with the maximum of incremental changes of horizontal displacement of limited location of slope.Getting the critical slip surface of the two-dimensional slope through the critical slip surface search method of this article.Getting the safety factor of slope by the limit equilibrium method.Calculating the critical slip surface and safety factor of slope works out similarly to the critical slip surface and safety factor calculated by the method of other literature.Calculating the safety factor of slope works out similarly to finite element results.Consequently,this method is feasible.Finding out the 3D slip surface of slope with the maximum of incremental changes of horizontal displacement of limited location of slope,through four instances including uniform slope,the top of slope under load,the slope with weak layer and non-uniform slope,the conclusion share negligible distinctions against other bibliography about critical slip surface in this approach and others,thus proving the reliability of this method.That provides a feasible method for calculating the slip surface and the safety factor of the slope through horizontal displacement data monitored for practical engineering.To calculate the safety factor of the slope based on the slip surface,a new three-dimensional limit equilibrium method with more rigorous theoretical foundation and relatively simplified calculation procedures is proposed.Two classic examples of three-dimensional slopes was investigated to discuss the feasibility of this method.