煤层群条件下高抽巷合理层位布置的数值模拟研究

Numerical Simulation Research on Reasonable Layer Layout of High Drainage Roadway under Coal Seam Group

高抽巷抽采邻近层卸压瓦斯技术是煤层群瓦斯治理的重要手段,具有抽采时间长、辐射半径大、抽采效果好等优点。为了确定高抽巷的合理布置层位,利用FLAC^(3D)数值模拟软件建立模型,研究了煤层群条件下煤层回采后上覆岩层的应力、位移及损伤破坏特征。研究结果表明,从应力分布特征考虑,高抽巷应布置在上覆岩层应力梯形台的“腰线”位置;从位移分布规律考虑,高抽巷宜布设于近距离上覆岩层的穿层裂隙发育区;从塑性区分布考虑,高抽巷应布设于应力集中区内侧的拉伸破坏区域。

The pressure-relief gas drainage technology of adjacent layers in high-drainage roadways is an important method for gas management in coal seams.It has the advantages of long extraction time,large radiation radius,and good extraction effect.In order to determine the reasonable layout of the high-drainage roadway,the FLAC3D numerical simulation software was used to establish a model to study the stress,displacement,damage and failure characteristics of the overlying strata for coal seam mining under the condition of group seams.The research results show that:considering the characteristics of stress distribution,the high-drainage roadway should be arranged at the"waist line"position of the stress trapezoidal platform of the overlying strata;considering the displacement distribution law,the high-draining roadway should be laid in the cross-stratification cracks of the overlying strata at a close distance;considering the distribution of the plastic zone,the high-drainage roadway should be arranged in the tensile failure zone inside the stress concentration zone.