上下柱式开采对中部残煤采场岩层应力分布时空演化的影响

针对上下柱式多重采动影响下中部残煤的安全开采,根据白家庄煤矿复合刀柱式残采区中部7号残煤的赋存状况,采用相似模拟和数值模拟相结合的方法,研究了上下柱式开采对中部残煤采场岩层应力分布时空演化的影响,揭示了复合刀柱开采后中部残煤的应力分布特征。研究结果表明:1下部煤层柱式开采时,刀柱煤柱/柱采区域采场煤岩层会逐渐演化为应力增高区/应力降低区,二者在水平方向上交替显现;上部煤层柱式开采时,采场煤岩层的应力集中程度/卸压程度会进一步增强。2多重柱式采动影响下,采场煤岩层的应力分布呈现"原始平衡—初始波态平衡—新波态平衡"的演化特征,不仅揭示了支承压力在刀柱煤柱采场煤岩层中的时空叠加效应,而且证实了柱采区域采场煤岩层的复合卸压效应。3复合刀柱开采后,中部残煤的应力分布表现出明显的波态特征。

Influence of upper-bottom pillar mining on temporal and spatial evolution of stress in rock strata around middle residual coal seam

In order to ensure the safe mining of middle residual coal seam with top-bottom pillar gobs，the influence of upper-bottom pillar mining on the temporal and spatial evolution of vertical stress around middle residual coal seam was studied with the similarity and numerical simulation based on the occurrence conditions of NO.7 middle residual coal seam in Baijiazhuang coal mine，China.Research results show that:① The strata above coal pillars and pillar-mining zones are evolved to stress concentration and reduction zone respectively after bottom-pillar mining，while the degree will be enhanced after upper-pillar mining.② The vertical stress evolution of “initial balance-initial wave balance-new wave balance” not only reflects the temporal and spatial superposition effect of abutment pressure caused by the multiple pillar mining of upper-bottom coal seams，but also is closely related with combined pressure relief effect.③ The vertical stress distribution of residual coal seam also presents wave characteristics after multiple-pillar mining.