近距离下煤层工作面顶板破坏规律及控制技术研究

Roof Failure Law and Control Technology of Mining Face on Close Coal Seam

为解决下煤层工作面回采过程中顶板难以控制问题,以襄垣七一煤矿近距离下煤层回采工作面为工程背景,建立煤岩力学模型,分析了中间岩层破坏损伤规律及影响其损伤悬臂梁结构力学稳定性的因素,并划分不同危险区。结果表明:不同超前支承应力条件对中间岩层的损伤不同;下煤层工作面顶板临界厚度受中间岩层强度、岩层上方采空区荷载以及下煤层回采工作面端面距的影响;根据下煤层工作面顶板临界厚度及其他影响因素,可将5101工作面顶板划分为一般危险区、危险区和重大危险区。根据研究结果针对性选择顶板控制措施。

Taking the mining face of close lower coal seams in Xiangyuan Qiyi Coal Mine as the engineering background,in order to solve the difficult roof control during the mining process,a coal-rock mechanical model is established.The article theoretically analyzes the damage law of the middle rock strata and the factors affecting the mechanical stability of damaged cantilever beam.Different danger areas are divided.The results show that the damage of the middle rock strata is different under the different conditions of advanced bearing stress.The critical thickness of the roof is affected by the strength of the middle rock strata,the load of the goaf above the rock,and the tip-to-face distance of the mining face of the lower coal seam.Based on the critical thickness and other factors,the roof of the 5101 working face can be divided into three ranks:general danger,danger,and major danger area.And specific roof control measures for the different danger areas are proposed.