深部高应力下不同巷道掘进速率对围岩稳定性的影响

研究了不同加卸荷速率条件下岩石破坏特性及其蠕变性质, 结果表明, 加卸荷速率越大, 岩体的强度越大, 蠕变越小。同时以金川二矿区巷道掘进工作面的工程地质情况及生产技术条件为背景, 研究了掘进速度对巷道围岩稳定性的影响。研究结果表明: 掘进扰动在工作面前方和巷道周围尤其在四个角点位置引起围岩破坏, 随着掘进速率的增加, 破坏区体积减小; 岩体开挖卸载导致掘进工作面前方及两帮形成耳状应力集中区, 随着推进速度的加快, 掘进工作面前方应力区向工作面移动, 围岩应力及应力区面积均减小; 掘进扰动引起围岩的位移变形, 最大位移发生在巷道顶底部, 随着掘进速率的增加, 围岩的位移减小。现场生产时适当加快工作面掘进速率, 有利于保持巷道的稳定及改善巷道维护状态。

Study on Stability of Surrounding Rock under Different Tunneling Rate in High Stress

The rock failure characteristics and creeping properties under different loading and unloading rate were studied. Results show as the rate of loading and unloading increases, the intensity of rock  increases and the creep decreases. Taking the engineering geology situation and the mining engineering factor of driving working face in Jinchuan deposit II as the background, the effect of tunneling rate on the stability of surrounding rock was investigated. Results show that tunneling disturbance  causes the failure of surrounding rock in the front of working face, especially in the four corners of the surrounding rock-mass. As the excavation rate increases, the failure area is reduced. A stress concentration due to the excavation unloading occurred in front of the tunneling working face and in the two sides of the tunnel. With the advancing speed increasing, the stress area moves toward the working face, and the stress and stress area of surrounding rock are all reduced. The displacement and deformation of surrounding rock caused from tunneling disturbance maximally occurs on the top and bottom of the tunnel roadway, which will decrease with the increasing of the tunneling speed. Practice on site showed that properly speeding up the tunneling could be of great advantage to the stability and maintenance of roadway.