深部破碎巷道应力演化与围岩控制技术数值模拟

Numerical Simulation of Stress Evolution and Surrounding Rock Control Technology in Deep Broken Roadway

为解决某金属矿深部破碎围岩巷道支护的难题,采用FLAC^(3D)对不同支护方案下巷道围岩失稳破坏情况进行了数值模拟。分析了巷道在无支护、锚杆支护、锚喷支护和锚喷+锚索支护等不同条件下围岩的变形规律。结果表明:在不同支护条件下,巷道围岩垂直应力在距离巷道帮部约2m~5m处出现了“耳廓型”的压应力集中;巷道围岩水平应力呈现非对称“蝴蝶型”分布;锚杆、锚喷、锚喷+锚索支护对控制巷道变形有较好的效果,较无支护条件,顶底板最大位移量分别减小约50%、60%、80%;在巷道掘进过程中,巷道围岩变形量的规律为:两帮>顶板>底板。然而,对两帮和顶板采取支护后,巷道底鼓现象仍然严重,对此建议矿山对巷道底板采用混凝土硬化处理。

In order to solve the supporting problem of deep roadway with broken surrounding rocks in a metal mine,FLAC^(3D)was used to simulate the instability of surrounding rock under different supporting schemes.The deformation law of surrounding rock in roadway was analyzed under the conditions of under unsupported,bolt support,bolt shotcreting support and bolt shotcreting+anchor cable support.The results show that,under different support conditions,the vertical stress of roadway surrounding rock forms a auricle-type stress concentration area at about 2m~5maway from the roadway side.The horizontal stress of roadway surrounding rock presents an asymmetric butterfly distribution.The bolt support,bolt shotcreting support and bolt shotcreting+anchor cable support have better controlling effect on roadway deformation.And compared with nonsupport condition,the maximum displacement of roof and floor decreases by about 50%,60%and 80%respectively.In the process of roadway excavation,the law of surrounding rock deformation is ordered as two sides>roof>floor.However,the floor heave is still serious after the two sides and roof are supported.Therefore,it is suggested that the floor of the roadway should be hardened with concrete.