高应力软岩缓斜煤层沿空掘巷窄煤柱宽度研究

Study on Narrow Pillar Width of Driving Roadway Along Goaf in High Stress Soft Rock Gentle Slope Seam

为研究在高应力软岩条件下窄煤柱留设问题,以曙光矿2~#煤层开采为工程背景,采用理论分析与数值模拟相结合的方法,得出错层位外错式沿空掘巷窄煤柱的确定方法,即从上区段采空区侧向支承应力分布规律、护巷煤柱宽度的理论计算、煤柱垂直应力和煤柱塑性区分布4个方面综合考虑护巷煤柱的宽度。理论计算得出破裂区为3.35 m,塑性区为5.76 m,利用数值模拟得出煤柱合理留设宽度为3.37~5.13 m。通过对不同煤柱宽度下巷道围岩应力分布进行数值分析,结果表明:当煤柱宽度为4 m时,巷道围岩变形小。

To study the problem of leaving a narrow coal pillar under the conditions of high soft rock,the mining of 2#coal seam in Shuguang Mine is taken as the engineering background.Using the methods of theoretical analysis,numerical calculation,we obtained a certain method of reasonable width of narrow coal pillars along an empty roadway with external-misaligned stagger arrangement,which considers four aspects for the pillar width from distribution laws of lateral support stress in upper goaf,the theoretical calculation of coal pillar width in retaining roadway,vertical stress and plastic zone distribution of coal pillar.Theoretical calculations show that the fracture zone is 3.35 m and the plastic zone is 5.76 m and the numerical simulation shows that the reasonable retention width of the coal pillar is 3.37 to 5.13 m.The numerical analysis of the surrounding rock stress distribution of the roadway under different coal pillar widths shows that when the coal pillar width is 4 m,the surrounding rock deformation of the roadway is small.