复采工作面煤柱塑性区特性及上覆岩层运动规律研究

Plastic Zone Features of Coal Pillars and Movement of Overlying Strata on Repeated Mining Face

在弹塑性力学极限平衡理论的基础上建立了煤柱塑性区计算模型,分析得出制约煤柱塑性区宽度的因素主要包括:煤体单轴抗压强度、开采深度、煤层厚度及硬度。通过对复采工作面的矿压观测及理论分析得到了采场上覆岩层的演化规律;得出在房柱式复采条件下回收底煤与上层煤柱时,回采巷道的超前支护距离为38 m;在煤柱下方回采时煤体应力、顶底板、两帮移近量及压力均大于采空区下方。

Based on the limit equilibrium theory of elastic-plastic mechanics, calculation model of the plastic zone of coal pillars is established to analyze and conclude that the major factors restricting the width of the plastic zone include： uniaxial compressive strength of coal mass, mining depth, coal seam thickness and hardness. The pressure observation and theoretical analysis obtain the development regularity of overlying strata. The distance of advance support is 38 meters when bottom coal and upper coal pillar are recovered in the room-pillar repeated mining. In addition, the coal stress, roof-floor and two-side convergence and stress when mining under the pillars are larger than those when mining under the goaf.