Stability Analysis and Failure Forecasting of Deep-Buried Underground Caverns Based on Microseismic Monitoring

摘要

The stability of underground caverns subjected to unloading disturbance is very important for engineering practice during construction stages. The rocks in the Xinzhuangzi Coalmine in Huainan are becoming increasingly unstable with the advancement of the excavation face. To evaluate the stability and failure mechanism of the surrounding rock mass, a microseismic (MS) monitoring system was employed to round-the-clock monitor the microseismic activities in the mining area. This MS-monitoring system was used to obtain the relationship between the MS activities and the excavation schedule. The potential risk zone of the surrounding rock mass was determined according to the temporospatial distribution law of the MS events. To reveal the instability mechanism of the potential risk zone, the seismic source parameters of the MS clusters were analyzed. The results show that the deformation and failure mechanisms of the potential risk zone were non-shear associated with the stress-induced fracturing. Moreover, the wall caved close to the free faces. The temporospatial evolution law of the MS events and analysis of the seismic source parameters could be used to reveal the instability mechanism of the surrounding rock mass, which is a promising method for determining the damage and failure zones due to the excavation-induced unloading.