Pseudodynamic Analysis of Three-Dimensional Fissured Slopes Reinforced with Piles

Abstract

Cracks broadly exist within slopes due to desiccation, weathering, or wetting–drying cycles in Nature. The presence of cracks inevitably reduces slope stability. However, such fissured slopes have received little attention, especially when subject to earthquake action, which is considered one of the most significant inducements of slope instability. In practice, antislide piles have proven useful measures to stabilize slopes, while the performance of antislide piles in fissured slopes subjected to seismic action is inexplicit. To this end, this study aims to develop an effective method to assess the seismic stability of three-dimensional (3D) fissured slopes reinforced with piles. The modified pseudodynamic approach is introduced to properly present the dynamic characteristic of seismic waves in real cases. Based on the kinematic approach of limit analysis, a 3D failure mechanism integrating cracks and antislide piles is developed to describe the slope failure. Open cracks (cracks existing before slope failure) and formation cracks (cracks forming as part of the failure mechanism) are both considered. The effect of seismic action is expressed by incorporating the work rates of seismic force. Thanks to the principle of work–energy balance, solutions of safety factors can be obtained by the application of an optimization scheme. The proposed method is verified through a detailed comparison with previous investigations. This paper ends with a description of a parametric study to reveal the effects of cracks, pseudodynamic seismic action, and the design of antislide piles on slope stability.