Comparison and analysis of landslide thrust by use of finite element and limit analysis methods

The traditional limit analysis method is commonly used to calculate pile thrust, but it can not take the pile deformation into account. This method assumes that the deformation is unrestricted, the sliding force can be put into full play, and the calculated thrust is active stress. When the pile deformation is restricted and the stabilizing force can not be fully exerted, the calculated results are inaccurate. When the finite element method is used to calculate the pile thrust, it conforms to the pile-soil interaction principles and it is not the limit analysis method. The result based on the pile deformation may be active stress and the corresponding thrust distribution can also be obtained. When the pile design safety factor is small, the anti-slide strength of rock and soil is not fully exerted. The finite element method has some discrepancy with the traditional method. With the increase of discount factor, the rock and soil reaches the limit state gradually. The finite element method agrees with the traditional method. Based on the experience, the calculated thrusts by the two methods are the same under general design safety factor, indicating that the finite element method to calculate the pile thrust is feasible. Several factors for the finite element method to calculate the thrust are analyzed. A comparison between the proposed method and the traditional limit analysis method (unbalanced thrust law, Spencer method) shows that the calculated results are consistent or inconsistent under what cases.