厚松散含水层薄基岩下厚煤层防水煤柱综放安全开采分析

Safety mining analysis of water proof coal pillars by fully-mechanized top-coal caving method in the thick coal seam under thin bedrock overlain by thick alluvium

通过对朱仙庄矿87采区厚松散层及薄覆岩的含水层、隔水层及基岩风氧化带工程岩组特性的分析,采用物理模拟、FLAC3D数值计算及现场实测的综合研究方法,对一次采全厚综放开采覆岩移动破坏规律进行了深入研究。研究结果表明,采区内松散层下部的第四含水层组富水性极弱,补给条件差,且基岩风氧化带具有较强的隔水性能,可以留设防塌煤柱开采;采用综放开采时,其覆岩最大垮采比为1.69,在-240m标高以下的防水煤柱内实现了一次采全厚放顶煤安全高效开采,取得了显著的经济效益。

Based on the analysis of engineering property of thick loose bed, water-bearing strata, water-resisting layer and bedrock weathered zone in thin overlying strata with thick alluvium in NO. 87 district of the Zhuxianzhuang Coal Mine, comprehensive research methods, including of physical simulation, FLAC3D numerical simulation and in-situ measurement, are used to examine the overlying strata movement and failure laws by fullymechanized top-coal caving （FMTC） method of full-seam mining. The results show that the fourth aquifer group is characterized by weak water and poor supply conditions. The weathered zone of basement is of strong regenerated water tightness, and it can be mined under collapse pillars. The maximum caving height ratio of overburden strata is 1. 69 with the FMTC method. Safe and efficient mining are achieved in water proof pillars with the FMTC method with a full-seam under -240m, so that significant economical benefits are obtained.