厚煤层沿空掘巷工作面煤柱留设研究

Research on Coal Pillar Setting of Roadway Driving Face along Goaf in Thick Coal Seam

针对厚煤层沿空掘巷工作面煤柱留设合理宽度的问题,以沙曲一矿4305工作面为工程背景,采用理论推导、数值模拟以及现场监测等方法研究分析煤柱的合理宽度、不同煤柱宽度下围岩变形特征以及现场监测煤柱应力。研究结果表明,根据极限平衡理论计算煤柱破坏塑性区宽度并结合煤柱稳定条件确定煤柱宽度至少为7.8 m.运用FLAC3D数值模拟软件,分析4305工作面与4306采空区留设5 m、8 m、15 m煤柱对应工作面巷道掘进及回采期间的变形及破坏规律可得,煤柱应力集中程度随着煤柱宽度逐渐减小而增大。确定选用8 m煤柱。现场压力监测表明,选用8 m煤柱并采用合理支护形式的条件下可以有效控制巷道围岩变形保障安全回采。

Aiming at the problem of leaving a reasonable width of coal pillars along the goaf in thick coal seams,taking the 4305 working face of Shaqu No.1 Mine as the engineering background,theoretical derivation,numerical simulation and on-site monitoring are used to study and analyze the reasonable width of coal pillars,as well as the deformation characteristics of surrounding rock under different coal pillar widths and on-site monitoring of coal pillar stress.The research results show that the width of the coal pillar failure plastic zone is calculated according to the limit equilibrium theory and combined with the pillar stability conditions to determine the width of the coal pillar is at least 7.8 m;using FLAC3D numerical simulation software to analyze the 4305 working face and the 4306 goaf,coal pillar be set from 5 m to 8 m to 15 m,the deformation and failure law of during roadway excavation and mining can be obtained:the stress concentration of coal pillar increases as the width of the coal pillar gradually decreases.On-site pressure monitoring shows that under the conditions of selecting 8 m coal pillars and adopting reasonable support forms,the deformation of the surrounding rock of the roadway can be effectively controlled to ensure safe mining.