停采煤柱合理留设宽度影响因素及变化规律

The Influencing Factors and Variation Patterns of Reasonable Width of Coal Pillars for Stopping Mining

基于弹塑性理论和FLAC3D数值模拟,以实际工作面为背景,分析了采厚、埋深、煤体内摩擦角以及采宽对停采煤柱留设宽度的影响。通过分析显示,随着煤层厚度的增加,开采过程中停采煤柱内超前支承应力峰值逐渐减小,影响范围逐渐扩大,使得停采煤柱留设宽度增加。停采煤柱留设宽度随着埋深增加逐渐增大,当达到一定埋深时逐渐趋于平缓。煤体内摩擦角影响采动应力传递,停采煤柱留设宽度随着摩擦角的增大逐渐减小。同时,基于关键层理论分析了关键层破断距与采宽及停采煤柱之间的关系,采宽增加使得煤柱内部应力集中区域扩大,导致停采煤柱塑性区增大,最终使停采煤柱留设宽度增加。

Based on the elastic-plastic theory and FLAC3D numerical simulation,this paper analyzes the effects of mining thickness,burial depth,friction angle inside the coal seam,and mining width on the width of the coal pillar for stopping mining,with an actual working face as the background.Through analysis,it is shown that as the thickness of the coal seam increases,the peak stress of the advanced support inside the stopping coal pillar gradually decreases during the mining process,and the impact range gradually expands,resulting in an increase in the width of the stopping coal pillar.The width of the coal pillar for stopping mining gradually increases with the increase of burial depth,and gradually flattens when reaching a certain burial depth.The friction angle inside the coal affects the transmission of mining induced stress,and the width of the coal pillar that stops mining gradually decreases with the increase of the friction angle.At the same time,based on the theory of key layers,the relationship between the fracture distance of key layers and the mining width and the stopping coal pillar was analyzed.The increase in mining width expands the stress concentration area inside the coal pillar,leading to an increase in the plastic zone of the stopping coal pillar and ultimately increasing the width of the stopping coal pillar.