深部宽煤柱开采的煤柱安全性与地表变形特征

Coal Pillar Safety and Surface Deformation Characteristics of Deep Wide Coal Pillar Mining

煤柱安全性与地表变形特征是煤矿开采过程中亟需关注的问题,基于深部煤矿煤柱的流变特性和大变形特征,以山西省某矿煤矿宽条带煤柱开采为工程背景,采用现场实测、三维相似材料模拟试验和理论分析相结合的方法,研究了深井宽条带煤柱开采的煤柱安全和地表变形特征。结果表明,在深井条件下,煤柱塑性区宽度明显变大,煤柱垂直应力呈马鞍形分布;煤柱侧向变形主要集中在距离煤柱边缘9.5 m的区域,呈不连续、阶梯状、突变状。此外,若只开采一个条带煤柱工作面,则煤层开采造成的影响程度更弱,地表沉陷和曲率更小。若多工作面条带煤柱开采,则地表沉陷明显。

Coal pillar safety and surface deformation characteristics are issues that need urgent attention in the process of coal mining.Based on the rheological properties and large deformation characteristics of coal pillars in deep coal mines,the safety of coal pillars and surface deformation characteristics of wide strip coal pillar mining in deep wells were studied by combining on-site measurements,three-dimensional similar material simulation tests and theoretical analyses with the engineering background of wide strip coal pillar mining in a mine in Shanxi Province.The results show that under deep well conditions,the width of the plastic zone of the coal pillar becomes significantly larger,and the vertical stress of the coal pillar is distributed in a saddle shape;the lateral deformation of the coal pillar is mainly concentrated in the area 9.5 m from the edge of the coal pillar,which is discontinuous,stepped and mutated.In addition,if only one strip coal pillar working face is mined,the degree of influence caused by coal seam mining is weaker,and the surface subsidence and curvature are smaller.If multiple working faces are mined with strips of coal pillars,the surface subsidence is obvious.