掘进巷道过采空区围岩应力演化规律数值模拟

Numerical simulation of evolution law behind surrounding rock stress along driving roadway in goaf

针对掘进巷道过采空区围岩变形大、控制困难等问题,以新建煤矿掘进巷道过采空区为例,采用数值模拟方法,研究掘进巷道过采空区围岩应力演化规律。结果表明:揭露采空区前,围岩应力增高区影响范围达45 m,应力集中系数2.0。进入原岩应力等值区,范围12 m,而后进入应力降低区,范围15 m;揭露采空区期间,巷道进入应力降低区,范围40 m;揭露采空区后,历经应力降低区,范围10 m,然后进入原岩应力等值区,范围5 m,再进入应力增高区,范围10~20 m,应力集中系数2.0。据此,提出掘进巷道过采空区围岩控制分为揭露采空区前、中及后三个阶段。该研究为掘进巷道过采空区围岩控制提供理论依据,对同类条件下巷道围岩控制具有重要借鉴意义。

This paper is an attempt to overcome a larger deformation occurring in surrounding rocks and consequent greater control difficulty—due to driving roadways through goaf. The solution involves using computer numerical simulation method to identify the evolution law behind surrounding rock stress occurring when driving roadway passes through goaf,as is shown in Xinjian coal mine. The results demonstrate that goaf exposure is preceded by three zones: stress-increasing zone with a range of 45 m and stress concentration factor of 2. 0,original rock stress equal value zone with a range of 12 m,and stress decreasing zone with a range of 15 m; goaf exposure is accompanied by stress decreasing zone with a range of 40 m during goaf exposure; and goaf exposure is followed by three zones: stress decreasing zone with a range of 10 m,original rock stress equal value zone with a range of 5 m and stress increasing zone with a range of 10 ~ 20 m,and stress concentration factor of 2. 0. It follows that surrounding rock control technology of driving roadway through goaf falls into three stages: before goaf exposure,during goaf exposure,and after goaf exposure. The research may provide a theoretical basis for surrounding rock control of driving roadway passing through goaf and has an important reference significance for surrounding rock control of roadway in the same condition.