Study on torque sum method for slope stability analysis

A new method for analyzing slope stability, the torque sum method(TSM), is proposed. The TSM is on the basis of the vector sum method(VSM), considering the displacement mode of the sliding body as a rigid body, and supplementing the displacement tendency of rotating around a certain point. The TSM assumes, for a definite landslide body and sliding surface, that the slide body rotates around a certain point, and by calculating the sum of the rotating torques and the anti-rotating torques of the slide body, the factor of safety when the slide body rotates around a certain point is obtained. In this work, the definition of the safety factor for TSM is given, and the formula for solving the safety factor as well as the corresponding calculation steps are derived based on the sliding surface stress of the slices method model. Two examples of ACADS are solved by TSM, and the results of circular and non-circular sliding surfaces are compared with those of other representative methods. The results show that a lower safety factor is obtained by TSM than by traditional methods, which is worthy of attention in slope stability analysis. The TSM is a supplement to the VSM which only considers the linear translational displacement mode of sliding body, and also provides a new approach for slope stability analysis, especially forever a slope with rotational displacement mode of sliding body.