沿空掘巷煤柱合理宽度及薄喷密闭技术研究

Study on reasonable width of coal pillar of roadway driven along goaf and thin jet sealing technology

针对综放开采煤柱护巷效果不佳、围岩变形量大、采空区侧瓦斯溢出等问题,以建新煤矿4209工作面回风巷为工程背景,根据极限平衡理论计算出煤柱的合理宽度为7.8~9.0 m,并利用FLAC3D软件探究不同煤柱宽度下的巷道围岩塑性区发育规律、应力分布特征、变形情况,综合分析得出煤柱最佳宽度为9 m。基于模拟结果及薄喷密闭原理,结合现场实际条件,设计了巷道支护及薄喷密闭方案。实践结果表明:采用9 m煤柱和薄喷密闭技术后,4209工作面回风巷整体围岩变形量较小,且瓦斯浓度明显降低,满足工作面安全高效生产的需求。

In view of the poor effect of coal pillar roadway protection in fully mechanized top coal caving mining,large deformation of surrounding rock and gas overflow at the side of goaf,taking the return air roadway of 4209 working face of Jianxin Coal Mine as the engineering background,the reasonable width of coal pillar is 7.8-9.0 m calculated according to the limit equilibrium theory.The FLAC3D software is used to explore the development law,stress distribution characteristics and deformation of the surrounding rock plastic zone of the roadway under different pillar widths,and the comprehensive analysis show that the optimal width of the coal pillar is 9 m.Based on the simulation results and thin jet sealing principle,combined with the actual conditions on site,the roadway support and thin jet sealing scheme are designed.The practical results show that after the 9 m coal pillar and thin jet sealing technology are adopted,the overall surrounding rock deformation of 4209 working face of return air roadway is small,and the gas concentration is significantly reduced,meeting the safe and efficient production requirements of the working face.