Abstract:
To explore the damage process and mechanism of underground roadway, by using a large-scale three-imensional simulation device and a real-time test system with acoustic-optics-pressure multiple indicators, dynamic-static coupling loading is completed under constant and variable confining pressures. The crack growth, damage and failure modes as well as the evolution process of structures in the region of excavation disturbance surrounding are real-time tracked by LCD-type optical endoscopic photography in complex geological model of Yuanyang Lake mining area, Ningxia, and the rules of acoustic emission in localized damage in surrounding rock are analyzed. The results show that complex rock deformation and fracture at different loading stages and different horizons have certain similarity and gradual nature under different loading weights and excavation steps. After the acoustic emission events have undergone barren period-active period-back to schedule-quiet period, the number of events begin to reduce, the endurance period grows, and partial derivative disasters are most likely to appear, which further reveals the local deformation characteristics of the persistence in the complex surrounding rock.