直角梯形板破断与应力传播对底板跨采巷道支护规律研究

发布时间：2019-05-28 03:39

【摘要】：我国很多矿区都存在近距离煤层群采动影响底板巷道的稳定问题,尤其是受跨采影响的底板巷道围岩破坏机理复杂,支护困难,因此近距离跨采巷道稳定性控制十分困难。底板巷道受近距离煤层群采动影响实际上是采动过程中的动静压交替作用下的巷道破坏问题,从而造成巷道维护困难,进而影响煤矿安全生产的重要原因之一。论文以仲恒煤矿10304采面倾斜长壁开采为工程背景,综合运用室内试验、理论分析及数值模拟等手段,对大倾角直角梯形采场关键层破断机理及传播规律进行研究,探究了倾斜煤层采动影响的巷道围岩压力分布规律和传播原理,实现巷道合理的分区段分层次支护。主要研究内容及结论:利用弹性薄板理论建立了倾斜状态下直角梯形薄板关键层力学模型,并采用康托洛维奇方法求解得到两邻边固支两邻边简支直角梯形薄板关键层的弯曲下沉解析解和应力分布表达式,对倾斜直角梯形关键层应力演化规律进行理论分析,探讨了工作面煤体应力值的变化规律;运用PFC数值模拟研究,倾斜直角梯形采面底板的应力分布规律及跨采底板裂隙发育规律。结果表明:底板应力峰值集中在采面的中部附近,在高应力区底板裂隙更为发育,结合底板与煤层距离的不同,建立力学模型分析不同层位状态条件下底板应力的大小及传播规律。利用PFC模拟软件对跨采巷道上方的应力状态进行监测和分析并提出合理的支护方案。结合倾斜直角梯形的应力演化规律和超前支承压力的影响,分析推导工作面煤壁的载荷动态分布表达式,在底板应力传播的基础上综合分析巷道稳定性,并利用数值模拟监测分析应力传播规律并确定仲恒煤矿底板巷道12轨道运输石门分区支护的界定,在及时支护和永久支护的基础上提出主动支护和被动支护结合的双耦合支护方式来应对跨采的围岩变形调动深部岩层自身的承载能力,来保证跨采的安全以提高生产率。
[Abstract]:In many mining areas of our country, there is a problem that the mining of close coal seam group affects the stability of floor roadway, especially the failure mechanism of surrounding rock of floor roadway affected by span mining is complex and the support is difficult, so it is very difficult to control the stability of near distance mining roadway. In fact, the influence of floor roadway by mining of close coal seam group is actually the failure problem of roadway under the action of dynamic and static pressure alternately in the mining process, which leads to the difficulty of roadway maintenance and then affects the safety of coal mine production. Based on the inclined long wall mining of 10304 mining face in Zhongheng Coal Mine, this paper studies the breaking mechanism and propagation law of key strata in large inclination right angle ladder stope by means of laboratory test, theoretical analysis and numerical simulation. The pressure distribution law and propagation principle of roadway surrounding rock under the influence of inclined coal seam mining are discussed, and the reasonable hierarchical support of roadway is realized. The main research contents and conclusions: based on the theory of elastic thin plate, the mechanical model of the key layer of right angle ladder thin plate in inclined state is established. The analytical solution and stress distribution expression of bending and subsidence of the key layer of straight angle ladder thin plate with fixed support and simply supported adjacent edge are obtained by using Kantorovich method, and the stress evolution law of the key layer of inclined right angle ladder is analyzed theoretically. The variation law of coal body stress value in working face is discussed. PFC numerical simulation is used to study the stress distribution of inclined right-angle ladder mining floor and the development of cracks across mining floor. The results show that the peak stress of the floor is concentrated near the middle of the mining face, and the crack of the floor is more developed in the high stress area, which combines the difference of the distance between the floor and the coal seam. A mechanical model is established to analyze the magnitude and propagation of floor stress under different horizon conditions. The stress state above the roadway is monitored and analyzed by PFC simulation software, and a reasonable support scheme is put forward. Combined with the stress evolution law of inclined right angle ladder and the influence of leading support pressure, the dynamic distribution expression of load on coal wall of working face is analyzed and deduced, and the stability of roadway is comprehensively analyzed on the basis of stress propagation of floor. The stress propagation law is monitored and analyzed by numerical simulation, and the definition of stone gate partition support for 12 track transportation of floor roadway in Zhongheng Coal Mine is determined. On the basis of timely support and permanent support, a double coupling support method combining active support and passive support is put forward to cope with the deformation of surrounding rock and mobilize the bearing capacity of deep rock strata, so as to ensure the safety of cross mining and improve productivity.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD353

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