“三软”煤层回采巷道的中空注浆锚索支护

Support research of hollow grouting anchor cable in three soft coal seam mining roadway

为解决"三软"煤层回采巷道围岩大变形灾变关键问题,以大雁矿区雁南煤矿典型"三软"煤层回采巷道为研究背景,采用FLAC3D数值模拟方法,分析中空注浆锚索支护与锚网索带支护条件下回采巷道围岩位移与应力分布规律。中空注浆锚索相比锚网索带支护,巷道顶底板最大位移量减少53.5 mm,降低了26.6%,巷道两帮最大位移量减少80 mm,降低了33.3%;最大水平应力降低0.7 MPa,最大垂直应力降低0.7 MPa。针对现场工程实际确定最佳支护方式,给出最优支护技术参数。工业试验表明:中空注浆锚索支护控制巷道变形量由原来1 129 mm减小到265 mm,经济技术效果显著。该研究可以为类似条件下"三软"巷道支护提供一种新的围岩控制方式。

This paper aims to address a large deformation disaster of the surrounding rocks occurring in ＂three soft＂ coal seam mining roadway. The study building on the typical case of ＂ three soft＂ coal seam mining roadway in Yaniaan mine belonging to Da＇yan mining area involves adopting numerical simu- lation method by FLAC3D to analyze the law behind the displacement and stress distribution of mining roadway surrounding rock under the condition of hollow grouting anchor cable support and anchor net ca- ble belt support. The comparative analysis suggests that compared with anchor net cable belt support, the hollow grouting anchor cable support provides a 53.5 mm decrease （26.6%）in maximum displacement of roof and floor of mining roadway; an 80.0 mm decrease （ 33.3% ） in the maximum displacement of two sides of mining roadway ; a 0.7 MPa decrease in the maximum horizontal stress ; and a 0.7 MPa de- creases in maximum vertical stress. It follows that the hollow grouting anchor cable support can offer both the best support method and the optimum support parameters designed for the practical engineering. The industrial field test proves that hollow grouting anchor cable support affords a remarkable economic and technology effect by decreasing the roadway surrounding rock deformation from original 1 129 mm to about 265 mm. The study may provide a new control method for surrounding rocks of ＂three soft＂ roadway support under similar conditions.