大倾角煤层大采高工作面倾角对煤壁片帮的影响机制

Study on effect of dip angle on coal wall spalling of working face with great mining height in steeply inclined coal seam

以新疆焦煤集团2130煤矿大倾角大采高工作面为工程背景,采用现场监测、理论分析与数值计算等综合方法,分析了煤壁片帮的主控参量,建立了倾向煤壁岩梁力学模型,揭示了工作面倾角对煤壁片帮的影响机制,研究表明:工作面倾角、采高、推进速度、支架阻力、煤体内聚力及内摩擦角等是大倾角大采高工作面煤壁片帮的主控参量,受工作面倾角影响,煤壁支承压力沿倾向非对称分布,导致煤壁变形(挠度)呈现出非对称特性,在工作面中上部区域(约0.66L处)煤壁岩梁变形最大,随工作面倾角增大,煤壁处垂直应力值不断增加,工作面上部区域煤壁向采空区方向水平位移不断增大,且向倾斜上部转移,煤壁片帮概率增加,易发生片帮区域面积增大。

Comprehensive methods including field test,theoretical analysis and numerical simulation were adopted to analyze main control parameters for coal wall spalling of working face with great mining height in 2130 coal mine of Xinjiang coking coal group.The mechanical model of coal wall along tendency was established.Meanwhile,the mechanism of effect of working-face dip angle on coal wall spalling was revealed.Results show that main control parameters for coal wall spalling of working face with great mining height in steeply inclined seam include dip angle,mining height,advancing speed,support resistance,cohesion and internal friction angle of coal mass.Affected by dip angle of working face,the abutment pressure in coal wall is asymmetric along inclination,which leads to asymmetry of coal wall deformation.The largest deformation occurs at location of about 0.66 L in upper area of working face.With the increase in dip angle,vertical stress in coal wall increases gradually.The horizontal displacement of coal wall in upper area of working face continuously increases towards the goaf,and moves to inclined upper area.This could increase the coal spalling probability and potential areas.