Failure Mechanism of Anti-Dip Layered Soft Rock Slope under Rainfall and Excavation Conditions

Abstract

The phenomenon of toppling deformation and failure is common in slopes with anti-dip structures, especially in soft metamorphic rock slopes. This paper aims to explore the instability mechanism of anti-dip layered soft metamorphic rock landslides. Taking the slope of a mining area in the southern Qinling Mountains of China as a geological prototype, a large-scale centrifuge model test and a numerical simulation based on the combined finite and discrete element method (FDEM) were performed. The deformation and failure process, failure mode, and failure path of the slope under rainfall and excavation conditions were simulated. The results show that both the physical centrifuge model test and the new numerical model test can simulate the instability process of anti-dip layered soft metamorphic rock slopes, and the phenomena simulated by the two methods are also very close. Rainfall mainly weakens the mechanical properties of rock, while the excavation at the slope toe mainly changes the stress field distribution and provides space for slope deformation, both of which accelerate the instability of the anti-dip soft metamorphic rock slope. The failure process of an anti-dip layered soft rock slope can be described as follows: bending of the rock layer–tensile fracture along the layer–flexural toppling and cracking perpendicular to the rock layer–extension and penetration of the tensile fracture surface–sliding and instability of the slope.

Stability of Unsaturated Soil Slope Considering Stratigraphic Uncertainty

“…It has been recognized that uncertainty has a significant influence on the stability of geological structures such as slopes. However, in the stability analysis of unsaturated soil slope, the stratum was usually considered to be deterministic in the past [28][29][30][31][32][33][34][35]. Recently, increasing attention has been paid to the unsaturated slope stability analysis considering the spatial variability of soil properties [36][37][38][39][40][41][42].…”

Numerical Analysis of Interbedded Anti-Dip Rock Slopes Based on Discrete Element Modeling: A Case Study

“…A number of studies have been conducted using the numerical simulation method to throw light on the stability and failure mechanisms of anti-dip rock slopes, and many meaningful results have been obtained [7,25,26]. Various numerical modeling approaches can offer different advantages.…”