Translational failure analysis of landfill with retaining wall along the underlying liner system

摘要

The scope of this paper is to develop a new three-part wedge analysis method, introducing the effects of solid waste shear strength and retaining wall on the translational failure of landfills. A typical landfill can be divided into three parts: an active wedge lying on the back slope that tends to cause failure, a passive wedge, and a retaining wall resting on the foundation or liner system that helps to resist any movements. Using this method, the amount and direction of the interwedge force can be calculated, and the upper and lower bound solutions for the landfill stability, i.e., FS_(max) and FS_(min), can be easily determined. When an average factor of safety, FS_(ave), is used as a solution replacing the true factor of safety, FS_(lrue), the upper bound of difference between FS_(ave) and FS_(true) is not more than 5% for all considered cases in this study. The retaining wall of the landfill seriously affects the value of the factor of safety; simply ignoring the retaining wall will lead to serious underestimation of the factor of safety. The factor of safety at the interface between active and passive wedges is defined as F5_V. The values of FS_V/FS_(ave) vary between 1.95 and 2.05 and are concentrated around 2.0. The approximate solutions of FS with adequate accuracy can be obtained by assuming FS_V = 2FS.