“上柱-下垮”复合残采区中部残煤开采可行性评价

针对白家庄煤矿"上柱-下垮"复合残采区中部残煤的安全开采问题,采用实验手段研究了多重采动影响下中部残煤采场岩层的垮落特征、应力分布规律及塑性区分布范围,结合弹塑性力学理论分析了上下煤层开采造成的损伤破坏范围,对中部残煤开采可行性进行了研究。研究表明:(1)上下煤层的采动影响并未破坏中部残煤的宏观连续性,且在中部残煤开采过程中,上覆岩层结构相对稳定;(2)采场岩层的支承压力与塑性区的分布范围基本一致,二者皆可以评价上下煤层开采后层间岩层的损伤破坏范围,其损伤范围包含整个上位层间岩层和下位层间岩层的局部范围;(3)中部残煤主要受上部煤层开采影响,处于上部煤层开采损伤破坏范围之内,因此在中部7号残煤开采过程中,其采场顶板稳定性较差,应采取合理有效的顶板控制措施保证安全生产。

Safety mining evaluation of middle abandoned coal seam in “upper pillar lower longwall” composite mining areas

Based on the safety mining of residual coal in the middle with “upper pillar lower longwall” composite residual areas in Baijiazhuang coal mine,the strata collapsing characteristic and the distribution of vertical stress around residual coal seam under the multiple influence of mining are studied with similarity and numerical simulation.At the same time,based on the previous studies,combined with the theory of elastic plastic mechanics,the calculations model is established for the damage zone of rock strata between coal seams caused by mining upper lower coal seams in composite residual areas,the above researches are integrated and provide the feasibility determination of middle residual coal seam.Research results show that:① Similar simulation experiment shows that the influence of mining upper lower coal seams does not damage the macro continuity of middle residual coal seam,and in the process of mining middle residual coal seam,the overlying strata structure is relatively stable;② Numerical simulation experiment shows that the distribution range of abutment pressure and plastic zone are matched on the whole,which can evaluate the damage zone of rock strata between coal seams after mining upper lower coal seams,the damage scope is across the upper interburden,while partial lower interburden is damaged;③ Through the theoretical analysis,the face of middle residual coal seam is mainly affected by mining upper coal seam,in the upper coal seam mining damage range,the stability of overlying strata is poorer in mining residual coal seam No.7,the stability of overlying strata should be paid more attention and the reasonable support measures should be taken timely to ensure a safe mining.