悬顶采空区下煤层开采压架危险性评估及勘探技术

Risk Assessment and Exploration Technology of Comprehensive Matched Coal Seams under Hanging Hollow Area

榆林市某矿房柱式悬顶采空区综采过程中,出现了多次压架事故,为了减少压架事故发生,保障煤矿安全生产,从该矿压架机理分析入手,进行了压架危险性评价,提出应力集中区勘探技术方案,为卸压防治提前打下基础。结果表明:工作面出煤柱开采安全的煤层间距临界条件为D0≥67.46 m,该矿5-2煤和5-3煤间距远远小于临界条件,开采5-3煤过程中存在压架风险;5-2煤层房采悬顶采空区下部5-3煤长壁支架富余系数为19%,压架危险性评价为为危险;采用地震波CT法对悬顶采空区导致的应力集中区进行探测设计,设计道间距为6 m,炮间距为3 m,每次探测覆盖范围为沿工作面长度为66 m,达到工作面超前卸压范围要求,每次12道检波器合计66 m循环探测,直到工作面探测卸压完成。

In the process of fully mechanized mining in a room-pillar suspended-roof goaf of a mine in Yulin city,there have been multiple support accidents.In order to reduce the occurrence of support accidents and ensure the safety of coal mine production,starting from the analysis of the support mechanism of the mine,support was carried out.Dangerous evaluation method,proposed the exploration technology plan of the stress concentration area,lay the foundation for the pressure relief prevention and control in advance.The results show the critical condition for the safe coal seam spacing for coal pillar mining at the working face is D0≥67.46 m.The spacing between 5-2coal and 5-3coal in this mine is far smaller than the critical condition,and there is a risk of frame pressing during the mining of5-3coal;the surplus coefficient of 5-3coal longwall supports in the lower part of 5-2coal seam room mining suspended roof goaf is 19%,and the risk assessment of pressing frame is dangerous.The seismic wave CT method is used to detect and design the stress concentration area caused by the overhanging goaf.The designed track spacing is 6 m and the shot spacing is 3 m.It is required that each time the 12-channel detectors total 66 m for cyclic detection until the detection and pressure relief of the working face is completed.