动力扰动下含软弱夹层巷道围岩力学响应特性

Mechanical Response Features of Roadway Surrounding Rock with Weak Interlayer Under Dynamic Disturbance

为了研究动力扰动下有无软弱夹层对巷道围岩稳定性的影响,利用大型通用有限元软件Abaqus对冬瓜山铜矿深部出矿巷道受到采场爆破作用下围岩的力学响应进行了数值分析并提出支护优化方案。结果表明:由于软弱夹层的存在,巷道拱顶和底板竖向应力波动幅值大于无软弱夹层巷道,底板竖向应力波动幅值变化较明显,而巷道拱顶和底板水平应力波动幅值却小于无软弱夹层;巷道拱顶和两帮的变形明显大于底板,对于无软弱夹层的巷道围岩变形明显大于有软弱夹层巷道,且变形速率较大;离爆炸源越远巷道围岩的应力和变形越小,但变化不明显,并在动力扰动0.15 s左右后趋于稳定;基于对冬瓜山铜矿现场调查,发现巷道顶板冒落破坏形式,从而提出支护优化方案,使得巷道围岩变形是无支护时的1/3,有效地控制了巷道围岩变形。

To study the influence of weak interlayers on the stability of roadway surrounding rocks under dynamic disturbance, the finite element software Abaqus was used to numerically analyze the mechanical response of surrounding rocks of Dongguashan copper mine roadway under blasting, and an optimized support scheme was proposed. The results show that the vertical stress of roadway vault and bottom amplitude fluctuation of the roadway with weak interlayers are higher than those of the roadway without weak interlayers, and the bottom changed apparently, while the horizontal stress fluctuation amplitude of the roadway with weak interlayers is lower than that of the roadway with no weak interlayers. The deformation of the vault and two sides of the roadway is larger than that of the bottom, and roadway surrounding rocks without weak interlayers apparently have larger deformation than those with weak interlayers, and have larger deformation rate. The farther away from the explosion source, the smaller the stress and deformation of roadway surrounding rocks, but the change is not apparent, which tends to be stabilized after about 0.15 s under dynamic disturbance. Based on the investigation of Dongguashan copper mine, the destruction form of surrounding rocks is roof caving. Thus an optimized support scheme was proposed, with which the deformation of surrounding rocks is about 1/3 of that with no support, effectively reducing the deformation of roadway surrounding rocks.