沿空留巷充填区域直接顶受力状态探讨与应用

摘要

针对综采放顶煤、复合顶板等松软破碎顶板沿空留巷直接顶稳定控制难题,根据沿空留巷顶板活动的时空特征,建立了沿空留巷充填区域直接顶弹性损伤力学模型,推导了充填区域直接顶应力分布表达式,研究了充填区域直接顶应力分布演化规律,进而得到了充填区域直接顶拉应力范围和水平错动范围计算式及相应的演化规律.结果表明:充填区域直接顶受力状态受基本顶回转下沉角和直接顶损伤变量的影响,随着基本顶回转下沉角的增加,拉应力作用范围逐渐减小,水平错动范围逐渐增大.结合新元煤矿3107工作面沿空留巷的工程地质条件,提出了分区域动态加固沿空留巷充填区域直接顶的控制对策,工程应用表明,沿空留巷充填区域顶板下沉量得到了有效地控制,沿空留巷围岩稳定性较好.%In order to overcome the problems with the immediate roof control of gob-side entry retaining (GER) in a fully-mechanized top-coal caving longwall,a compound roof longwall and other soft cracked longwall,an elastic damage mechanics model of immediate roof above roadside backfill area (IRRBA) in GER was established,the stress distribution expression of IRRBA in GER was deduced,and the stress distribution evolution of IRRBA in GER was researched based on the space-time movement characteristics of IRRBA in GER.Then,the tensile stress depth and horizontal dislocation region calculation formulas of IRRBA in GER,and the corresponding evolution laws were obtained.Results show that the stress state of IRRBA in GER are associated with the main roof rotation angle and the immediate roof damage variable,and that the tensile stress depth decreases and the horizontal dislocation region increases with the increase of main roof rotation angle.Combined with the 3107 longwall engineering geological conditions of Xinyuan Colliery,the dynamic regional consolidation control countermeasures for IRRBA in GER were put forward.Field practice shows that the application of control countermeasures has achieved an expected effects for the subsidence of IRRBA and surrounding rock stability control in GER.