Stability analysis of rock slopes containing faults during excavation using microseismic monitoring and numerical simulation

Abstract

Assessing the stability of rocky slopes with faults presents a major engineering challenge in construction projects. The steeply inclined faults and rock joints significantly impact the left bank slope of the Jinchuan Hydropower Station in the outlet field, resulting in highly complex geological conditions that raise significant concerns regarding slope stability throughout construction and operation. Microseismic(MS) monitoring and numerical simulation are used to reveal the evolution mechanism of rock mass from fracture to deformation during slope excavation and unloading. The results show that the MS activity can well reveal the influence of slope construction disturbance on geological structure damage and structural plane activation. Specifically, the g7 fault as a critical factor influencing the failure mode of the left bank slope of the Jinchuan Hydropower Station in the outlet field. The comparison of monitoring data, numerical simulation, and in-situ failure shows that the deformation area of rock mass is consistent with the damage area defined by MS monitoring, which confirms the accuracy of MS monitoring and numerical simulation results. These research findings can serve as a basis for the later-stage construction of the dam foundation slope at the Jinchuan Hydropower Station and offer guidance for the stability assessment of similar slope engineering projects.