两软一硬煤层巷道支护技术

Research of roadway support in two-soft and one-hard coalbed

为解决云盖山煤矿一矿21203综采工作面回风巷道两帮和底板变形大、支护困难问题,以现场实测资料为基础,结合该矿"两软一硬"煤层上覆岩层移动规律、垮落特征及超前支承压力分布规律,将巷道原锚杆+锚索+锚网的矩形断面支护形式改进为马蹄形U形钢缩性支架支护形式。基于围岩单轴压缩实验参数,进行FLAC^(3D)数值模拟。结果显示:改进后的支护形式有效改变了巷道应力特征。现场应用结果表明:马蹄形U形钢支护形式能够有效控制两帮移近量和底板臌起量,解决回风巷道变形量大的问题。该研究为矿井掘进相似巷道提供了支护设计依据。

This paper is concerned with a solution to notorious difficulties, such as a closer convergence between the two sidewalls, a greater floor deformation and a more challenging roadway support, as occurs in NO 21203 fully mechanized working face return roadway in YUN Gaishan Number one coal mine. The research builds on the data derived from field measurement and is combined with the law underlying the movement of overlying strata, caving characteristics, and the law governing the distribution of initial support pressure, as is typical of the coal seams, known as ＂two-soft and one-hard＂, in the mine. The study features a horseshoe U shaped steel bracket supporting form developed from the currently-used roadway supporting form—a supporting form of rectangular cross section comprised of anchor rod, anchor cable, and anchor net,and highlights FLAC^（3D） numerical simulation based on experiment parameters behind uniaxial compression of surrounding rocks. The results demonstrate that the improved support form may enable an effective change in the roadway stress behavior. The field application shows that the horseshoe U-shaped steel supporting form may provide a more effective control of the extent to which there occur the convergence between the two sidewalls and floor heave; and a better solution to a greater deformation occurring in return airways