超长孤岛综放工作面煤柱支承压力分布特征研究

为了确定超长孤岛综放工作面巷道煤柱的合理尺寸,采用FLAC3D软件模拟分析了不同长度孤岛综放工作面不同宽度煤柱的支承压力与变形破坏规律。初采期间,大煤柱(宽20m)倾向支承压力整体上随着至巷帮距离的增大而减小;随着工作面推进而增大。小煤柱(宽4～6m)初采期间走向支承压力峰值随工作面推进而增大,且峰值超前煤壁的距离也增大;正常推进期间,随顶板变形逐渐趋于稳定,支承压力峰值降低,但煤柱压力峰值至煤壁前方煤体支承压力影响范围内压力增高。煤柱支承压力峰值超前煤壁一定距离,且此距离随工作面长度加大而减小。加长孤岛综放工作面长度,护巷大煤柱和小煤柱的支承压力均减小,可以减小护巷煤柱宽度。

Distribution abutment pressures on laneway pillars for superwide isolated fully mechanized top coal caving face

In order to determine the rational width of laneway coal pillars for superwide isolated fully mechanized top coal caving face,the abutment pressure and deformation-failure behaviour of different width coal pillars for superwide and common wide isolated fully mechanized top coal caving faces were analyzed by use of numerical simulation software FLAC3D.At the beginning of mining,abutment pressures on the wide coal pillars(20 m in width) decreased with the increase of the distance from laneway coal slide,and increased with the increase of mining distance.The peak value of strike abutment pressures on small coal pillars(4~6 m in width) increased with the propagation of the working face mining during the initial mining,and the distance of the peak value position to the wall also increased.As for the normal mining,the peak value of abutment pressures would reduce along with the roof deformation and gradually became stable,but the abutment pressures on the coal mass between the peak pressure and the wall would increase.The peak value of abutment pressures on coal pillar had a certain distance to the wall,and the distance reduced when the working face width increased.Lengthening the width of isolated fully mechanized top coal caving face would reduce the abutment pressures for both wide and small coal pillars,and the coal pillar width could be reduced.