Stability evaluation of rock slope based on discrete fracture network and discrete element model: a case study for the right bank of Yigong Zangbu Bridge

Distribution characteristics and strength of 3D discrete fractures have a decisive effect on the rock slope stability. How to use the fractures obtained on site to establish a 3D fractured rock slope for stability analysis is a difficult problem in the field of rock mass engineering. This study selected the rock slope on the right bank of Yigong Zangbu Bridge for a detailed field investigation. Exposed joints and fractures were measured and counted. Occurrence, size, and position distribution models of the fractures were used to obtain the parameters of the spatial distribution using probability and statistic theory. Then, a complex 3D discrete fracture network (DFN) was established and simplified. After that, a 3D rock slope model was built and the DFN was used to cut the slope model. Finally, the strength reduction method was used to analyze the slope stability. The results reveal that the overall slope stability is good (safety factor is 2.0), but the local block deformations are large and are mainly concentrated in the lower part of the slope. Due to the existence of structural planes dipping outside the slope on the right bank, local unstable blocks are easily formed. In this study, the whole process from field fracture acquisition to the DFN generation is applied to the 3D fracture rock slope stability analysis, which is of great importance for complex rock mass engineering assessment and disaster prevention.