煤矿大断面托顶煤巷道围岩变形破坏机理
Surrounding Rock Deformation Failure Mechanism of Large Section Gateway with Top Coal in Coal Mine
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摘要: 为了解决煤矿大断面托顶煤巷道支护难题,借助理论分析、数值模拟等方法对王庄煤矿7105工作面运输巷围岩变形破坏机制进行研究,分析了不同巷道断面、顶煤厚度在无支护时的围岩塑性区、位移场、应力场的演化规律。结果表明,顶煤厚度对大断面托顶煤巷道的稳定性影响重大,顶板下沉量随顶煤厚度增加而变大;随着巷道断面的扩大,围岩塑性区相应增加,两帮和顶板变化较大,底板无明显变化;适当减小顶煤厚度,即增大巷道高度,可有效控制巷道顶板变形,但应对巷道两帮加强支护;若巷道宽度,即跨度增大,顶板的位移量增加,应补打锚索加强顶板支护。监测结果显示,基于此结论设计的支护方案能有效地控制围岩变形。Abstract: To solve the problem of large section gateway support with top coal in coal mine, surrounding rock deformation and failure mechanism of Wangzhuang Coal Mine 7105 working face haulage way were studied through theoretical analysis and numerical simulation, and plastic zone, displacement field, stress field distribution evolution laws with different sections, top coal thickness without support were analyzed. The result shows that the top coal thickness has great influence on the stability of the gateway, as the thickness increases, the roof subsidence will grow; with the increase of gateway section, the surrounding plastic zone expands correspondingly, and change of gateway sides and roof will rise, but the floor does not change significantly; proper reduction of top coal thickness as well as the augment of gateway height will effectively control the deformation of roof, but we have to strengthen the gateway sides support; and the width of roadway increases, the roof displacement will go up then the anchor cable has to be adopted to strengthen the roof. Field monitoring results showed that the support scheme based on this conclusion controlled surrounding rock deformation effectively.