MECHANICAL ANALYSIS METHOD FOR DANGEROUS SLIDING SURFACE AND FACTOR OF SAFETY

In order to analyze the stability of slope,a method based on limit equilibrium theory is proposed. Assuming that the slope is made up with elastomer only affected by gravity,the stress distribution can be obtained by analytical solution of elastic mechanics. The sliding surface is described by piecewise quadratic polynomial function. When the piecewise interval is short enough,this description method can reflect arbitrary curved shape. According to the Mohr-Coulomb criterion,the factor of safety is defined,which can be expressed as a function of polynomial coefficient. The polynomial coefficient of the most dangerous sliding surface can be obtained by using the mixed penalty function optimization method,then the factor of safety can be obtained to analyze the stability of the slope. The proposed method is different from the previous methods. It does not need to divide the landslide body into vertical slices and to assume the normal stress distribution form on the sliding surface. It directly uses the existing slope body elastic stress solution. The results of the calculation examples show that the factor of safety obtained by the method in the paper is very close to the results obtained by the simplified Bishop method and the finite element strength reduction method. They are basically between the finite element method and the simplified Bishop method.