煤层隐伏露头附近工作面开采水害安全性研究

Research on the Safety of Water Hazard During Working Faces Mining Near Coal Seam Hidden Outcrops

张集煤矿浅部煤层隐伏露头区域工作面开采受到上覆松散含水层的威胁,1306工作面原设计采用分层开采,工作面产量和效率难以提高,通过FLAC^(3D)数值模拟、类似地质条件矿井综放或大采高综采的覆岩破坏规律进行分析,选取较大的垮采比和裂采比预计“两带”高度,并与综放开采“两带”高度经验公式预计进行对比,采用“最小安全厚度”法选取保护层厚度,确定了防砂安全煤岩柱的高度以及开采厚度。结果表明,1306工作面开采区域最小基岩厚度大于全厚综放开采所需最小防砂煤岩柱厚度,工作面可采用全厚综放开采至设计停采线结束,有利于矿井实现高产高效安全开采。

The working face mining in the shallow coal seam hidden outcrop area of Zhangji Coal Mine is threatened by the overlying loose aquifer.The original design of the 1306 working face used layered mining,which makes it difficult to improve the production and efficiency of the working face.Through FLAC^(3D) numerical simulation and analysis of the overlying rock failure law of fully mechanized caving or large mining height fully mechanized mining under similar geological conditions,a relatively large collapse mining ratio and crack mining ratio are selected to predict the height of the"two zones",and compared with the empirical formula for predicting the height of the"two zones"in fully mechanized caving mining,the"minimum safe thickness"method is used to select the thickness of the protective layer,and the height and mining thickness of the sand control safety coal rock pillar are determined.The results show that the minimum bedrock thickness in the mining area of the 1306 working face is greater than the minimum sand control coal rock pillar thickness required for full thickness fully mechanized caving mining.The working face can adopt full thickness fully mechanized caving mining until the end of the design stop mining line,which is conducive to achieving high-yield,efficient,and safe mining in the mine.