厚层膨胀型泥岩顶板巷道沿空煤柱合理留设分析

Analysis on Reasonable Retention and Setting of Coal Pillar in Roadway of Thick Layer Expansive Mudstone Roof

针对王家岭煤矿厚层膨胀型泥岩顶板巷道沿空掘巷小煤柱尺寸确定中存在的问题,采用理论分析、数值模拟分析等方法进行研究。理论计算表明,采空区边界煤体与采空区中基本顶的断裂位置之间距离为10.47 m;数值模拟计算发现,采空区煤体垂直应力集中系数最大可达到2.0,在距侧向煤壁5.5~10.5 m范围内,垂直应力值达14.58 MPa;考虑到工作面煤层强度较低,并且顶板为厚层膨胀型泥岩,综合确定工作面留设5 m煤柱。结果不仅能够优化工作面支承应力分布,减小沿空掘巷围岩支护难度,还能提高煤炭开采量,减少资源浪费。

In view of the problems in the determination of the size of small coal pillar along the hollow excavation roadway of thick layer expansive mudstone roof roadway in wangjialing coal mine,theoretical analysis and numerical simulation analysis are adopted in this paper.The theoretical calculation shows that the distance between the boundary coal body in the goaf and the fracture location of the basic roof in the goaf is 10.47 m.Numerical simulation results show that the maximum vertical stress concentration coefficient of coal body in goaf can reach 1.94,and the vertical stress value of coal body in goaf reaches 14.58 MPa within 5.5~10.5 m from the lateral coal wall.Considering the low strength of coal seam on the working face and the thick layer of expansive mudstone on the roof,5 m coal pillar was set for the working face.The results can not only optimize the bearing stress distribution of working face,reduce the difficulty of surrounding rock support along hollow excavation roadway,but also improve the coal mining amount and reduce resource waste.