寸草塔二矿下层煤过集中煤柱矿压防治技术研究

Research on prevention and control technology of ore pressure of over concentrated coal pillar in lower coal seam of Cuncaota No.2 Coal Mine

为解决浅埋煤层工作面过上覆采空区遗留集中煤柱期间容易引发强烈动载矿压灾害的问题,以寸草塔二矿31109工作面为研究背景,综合运用理论分析、数值模拟和现场试验等手段,对工作面过集中煤柱时受力、矿压显现特征进行研究。结果表明,31109工作面回采通过上覆采空区遗留集中煤柱时,煤柱失稳破坏后其顶板与工作面采空区顶板同时破断,垮落时极易引发强烈的动载矿压灾害;现场通过采取下层煤回采巷道补强支护、上覆煤柱水力压裂等措施后,31109工作面回采巷道顶底板移近量最大193 mm,两帮移近量最大150 mm,且工作面支架工作状态良好,确保了31煤工作面安全通过集中煤柱。

In order to solve the problem that the shallow buried coal seam working face is easy to cause strong dynamic ground pressure disasters when passing through the concentrated coal pillars left over by the overlying goaf,taking the No.31109 working face of Cuncaota No.2 Coal Mine as the research background,the characteristics of stress and ore pressure behavior when the working face passes through the concentrated coal pillars were studied by means of theoretical analysis,numerical simulation and field tests.The results showed that when No.31109 working face passed through the concentrated coal pillars left over by the overlying goaf,its roof and the roof of the goaf of this working face were easily broken and collapsed at the same time after the instability of the coal pillars.After taking measures such as reinforcement and supporting of lower coal seam mining roadway and hydraulic fracturing of overlying coal pillars,the maximum displacement of the roof and floor of the mining roadway of No.31109 working face was 193 mm,and the maximum displacement of the two sides was 150 mm.The working condition of the support of the working face was good,ensuring that the working face of 31 coal seam can pass through the centralized coal pillars safely.