榆神府矿区遗留房式煤柱稳定性研究

Stability of Remaining Room-type Coal Pillars in the Yuyang-ShenmuFugu Mining Area

榆神府矿区大量房式煤柱遗留井下,存在煤柱尺寸偏小引发局部矿震现象。基于上河煤矿房柱式开采具体工程实际,采用理论分析、相似材料模拟实验和FLAC^(3D)计算机数值模拟分析了遗留房式煤柱稳定性状况,结果表明,遗留房式煤柱承受的上覆岩层载荷理论计算数值远小于其单轴极限抗压强度,不会出现压裂破坏;相似材料模拟实验显示遗留房式煤柱未发生宏观破坏和垮落现象,上覆地表下沉量微小;计算机数值模拟得出房式煤柱两帮虽出现微观上剪切破坏,但中部存在较大范围弹性核,不会出现整体塑性破断;因此,上河煤矿当前遗留房式煤柱整体保持稳定状态。如果煤柱与煤房尺寸反向设计开采,房式煤柱将发生明显的塑性破坏和变形,发生失稳并引发矿震现象。研究方法为榆林地区类似生产煤矿探求遗留房式煤柱的稳定性问题具有一定的借鉴意义。

A large number of room-type coal pillars are left underground in the Yuyang-Shenmu-Fugu mining area,which may cause local mine tremors due to the relatively small size of the pillars.Based on the specific engineering practice of room-and-pillar mining at Shanghe Coal Mine,theoretical analysis,similar material simulation experiments,and FLAC^(3D)computer numerical simulation were used to analyze the stability of the remaining room-type coal pillars.The results show that the theoretical calculation value of the overburden load borne by the remaining room-type coal pillars is much smaller than its uniaxial compressive strength,and there will be no crushing failure;similar material simulation experiments indicate that the remaining room-type coal pillars did not experience macroscopic damage or collapse,and the subsidence of the overlying surface was minimal;computer numerical simulation concludes that although micro-shear failure occurred on both sides of the room-type coal pillars,there is a large area of elastic core in the middle,and there will be no overall plastic fracture;therefore,the current remaining room-type coal pillars at Shanghe Coal Mine maintain a stable state overall.If the pillar and room sizes are designed in reverse for mining,the coal pillars will experience significant plastic failure and deformation,leading to instability and triggering mine tremors.The research method has certain reference significance for exploring the stability of remaining room-type coal pillars in similar production coal mines in Yulin.