煤巷内预设混凝土墙成巷及围岩控制技术

Pre-Setting Concrete Wall in Coal Roadway and Surrounding Rock Control Technology

为了解决矿井瓦斯排放问题和提高煤炭资源回采率,以大宁煤矿309综采工作面回风巷与瓦斯巷巷间煤柱留设问题为工程背景,提出煤巷内预设混凝土墙成巷技术,并分析其施工工艺,即在布置回风巷时,将巷道按宽面掘进,并用锚杆(索)进行永久支护,滞后掘进工作面50 m,在巷道内浇筑混凝土墙,将巷道隔离成双巷。随着工作面回采,顶板沿切顶线垮落形成沿空巷道,利用混凝土墙置换巷间煤柱实现无煤柱开采。通过理论计算对隔离墙稳定性进行分析,得出1.6 m宽度墙体满足支护安全要求,根据设计的巷道支护参数进行了数值模拟分析,最终确定巷道采用“隔离墙+锚杆+锚索+钢筋梁+锚网”联合支护方案,此项技术可为类似矿井实施巷内预设混凝土墙技术提供参考。

In order to solve the problem of mine gas emission and improve the coal resource recovery rate,the problem of leaving coal pillars between the return air lane and gas lane of 309 comprehensive mining working face of Daning Coal Mine as the engineering background,and the technology of pre-setting concrete wall in coal roadway to form a lane was proposed and its construction process was analyzed.When arranging the return air lane,the lane was excavated with a wide face and permanently supported by anchor rods(ropes),and the excavation of working face was delayed by 50 m.The concrete wall was poured in the roadway to isolate the roadway into two parts,and as the excavation of working face,the roof collapsed along the top cutting line to form a god-side entry.Using concrete walls to replace coal pillars between roadways to achieve pillarless mining.The stability of the concrete wall was analyzed through theoretical calculations,and the wall width of 1.6 m was calculated to meet the safety requirements for support.According to the designed roadway support parameters,the numerical simulation analysis was carried out,and the combined support scheme of"isolation wall+anchor bolt+anchor cable+reinforcement beam+anchor mesh"was finally determined for the roadway.This technology can provide a reference for similar mines to implement the technology of pre-setting concrete wall in the roadway.