Three-Part Wedge Method for the Stability Calculation of Embankment Supported on Rigid Pile Foundation

Abstract

Rigid piles have been widely used to reinforce soft subgrade. However, some studies do not consider the bending failure of piles and wedge sliding surfaces, which may lead to an overestimation of stability. In this study, a stability calculation method for a multi-section linear sliding surface is first derived and then simplified to three-part wedge method based on the numerical modeling of the failure evolution process. The real safety factor is replaced by the average value of the upper and lower bound solutions of the embankment stability safety factor. Through calculations, then the average value or the approximate solution of the real value, of both the upper and lower bound solutions can be obtained. The accuracy of the approximate solution can be verified through an analysis of the relative error of the average and true values. Finally, the proposed method was verified by a three-dimensional numerical simulation method and compared with the traditional limit equilibrium method and the equivalent shear strength parameter method. The results indicate that the support contribution of rigid piles to the embankment can be effectively reflected by considering wedge sliding surfaces, and a more reasonable stability safety factor can be obtained through the proposed method.