1.辽宁工程技术大学;2.国家能源集团神东煤炭集团有限责任公司 大柳塔煤矿
TD353
1.Liaoning University of Engineering and Technology;2.National Energy Group Shendong Coal Group Limited Liability Company, Daliuta coalmine
为研究沿空留巷开采过程中工作面顶板覆岩垮落结构和裂隙演化规律与传统留煤柱开采的差异，以大柳塔煤矿52605和52606工作面为工程背景。通过两组相似材料模拟实验，模拟两种工况开采过程，并记录岩层移动及裂隙演化。研究结果表明，柔模砼墙沿空留巷时，一次采动留巷结束形成的裂隙率小于二次采动，而传统留煤柱开采后煤柱两侧工作面覆岩裂隙形成演化规律接近。两种开采方式形成的裂隙率、裂隙类型、垮落范围和垮落角存在差异，柔模砼墙沿空留巷工作面覆岩裂隙率为5.0756%、垮落范围为覆岩50m内、垮落角位于31°~86.9°范围之间，以离层裂隙为主。留煤柱开采工作面覆岩裂隙率为2.8604%、垮落范围为覆岩40m内、垮落角位于50°~52°之间，以沿垮落倾角发育的剪切裂隙为主。沿空留巷工作面砼墙两侧开采结束后，砼墙顶板岩层未发生剪切滑落，形成铰接结构。而留煤柱工作面煤柱两侧开采结束后岩层整体切落,上覆岩层在砼墙及煤柱两侧形成结构差异明显，对于沿空留巷工作面的砼墙载荷分布形成显著的集中应力作用。
In order to study the difference of the roof caving structure and crack evolution between gob-side entry retaining and traditional coal pillar mining. Taking the 52605 and 52606 working faces of Daliuta Coal Mine as the engineering background.Through two groups of simulation experiments of similar materials. The mining process under two working conditions was simulated, recorded the process of overlying rock movement and fracture evolution. Research shows that, the crack rate formed at the end of primary mining is less than that of secondary mining when using gob-side entery retaining with flexible formwork concrete wall. But, after traditional coal pillar mining, the formation and evolution law of overlying rock fissures on both sides of coal pillar is similar. There are differences in crack rate, crack type, caving range and caving angle between the two coal mining methods. The crack rate of the overlying rock in the gob-side roadway retaining face of flexible formwork concrete wall is 5.0756%, the collapse range is within 50m, and the collapse inclination angle is in the range of 31°and86.9°. The crack rate of the overlying rock in the leaving coal pillar mining face is 2.8604%, the collapse range is within 40 m, and the collapse dip angle is between 50°and 52°, mainly the shear cracks developed along the caving dip angle. After the end of mining concrete wall in the face of gob-side entry retaining , the rock layer on both sides of the roof of the concrete wall does not slip, forming a hinged structure. On the other hand, after the mining is completed. the overlying rock layers on both sides of the coal pillar in the staying coal pillar mining face are cut off as a whole. The overlying strata form obvious structural differences on both sides of the concrete wall and coal pillar, which forms a significant concentrated stress effect on the load distribution of the concrete wall in the gob-side roadway retaining face.
