采空区空隙分布规律及注浆加固治理

发布时间：2019-02-23 18:03

【摘要】：采空区残留空洞、空隙是采空区二次沉降、煤层自燃、有害气体积聚、矿井突水等灾害的诱因之一。以采动破碎岩石次生岩体平衡结构为主要研究对象,采用理论分析的手段,提出当满足采空区煤柱稳定,关键块的稳定时,老采空区覆岩结构保持稳定的观点。基于岩层碎胀特性推导出不同情况下的垮落带、裂隙带的高度,从而可以得到任意岩性组合条件下导水裂隙带的预测高度,结合岩梁组合运动实现导水裂隙带高度最终确定。在破碎岩石压缩时,轴向载荷较小时,轴向应变增大主要是由破碎岩石位置调整引起的,轴向载荷较大时,轴向变形增大的原因还包括破碎岩石在应力集中条件下进一步破碎成小粒径岩石滑入空隙中。水对破碎岩石压缩变形起到了加速作用,一方面,水充当了破碎岩石间的润滑剂,有利于破碎岩石中颗粒位置调整;另一方面,水充当了破碎岩石进一步破碎的小颗粒的搬运工,加速了小颗粒滑动,填充大粒径碎石之间的空隙。相似模拟研究确定了空隙的分布规律,而破碎岩石压缩实验确定了垮落带空隙率,裂隙带由于闭合效应可注浆空隙很少,可忽略不计;垮落带分为不规则垮落带和规则垮落带,故注浆体积仅计算规则垮落带与不规则垮落带的空隙体积是合理的。规则垮落带的空隙高度以相似模拟的研究结果为准,不规则垮落带的高度为采出厚度的0.915～0.975倍,空隙率以破碎岩石压缩实验确定的空隙率决定,对采空区空隙体积进行预计。结合采空区注浆现场,通过钻孔检测、压浆检测、孔内电视检测、结石体承载性能实验对采空区注浆效果进行了检测,检测结果显示:经过注浆处理后,数据处理中心1#楼场地适宜建设。
[Abstract]:The residual voids and voids in goaf are one of the causes of secondary subsidence, spontaneous combustion of coal seam, accumulation of harmful gas and water inrush of mine. Taking the equilibrium structure of mining broken rock and secondary rock mass as the main research object, using the means of theoretical analysis, this paper puts forward the viewpoint that the overburden structure of the old goaf will remain stable when the coal pillar is stable and the key block is stable in the goaf. The height of collapse zone and fracture zone under different conditions can be deduced based on the characteristics of rock formation breaking and expansion, and the predicted height of water-conducting fissure zone under any lithologic combination can be obtained, and the height of water-conducting fissure zone can be finally determined by combined motion of rock and beam. When the axial load is small, the axial strain increase is mainly caused by the location adjustment of the broken rock, and when the axial load is larger, The reason for the increase of axial deformation is that the broken rock is further broken into small diameter rock and slid into the void under the condition of stress concentration. Water accelerates the compression deformation of broken rock. On the one hand, water acts as a lubricant between broken rocks, which is conducive to the adjustment of particle position in broken rock. On the other hand, water acts as a porter for further fragmentation of small particles of rock, accelerating the slippage of small particles and filling the void between large gravels. Similar simulation studies determine the distribution of the voids, while the void ratio of the collapse zone is determined by the compression experiment of broken rock, and the void rate of the fracture zone can be neglected because of the few grouting voids due to the closure effect. The caving zone can be divided into irregular collapse zone and regular collapse zone, so it is reasonable to calculate the void volume of regular collapse zone and irregular collapse zone only by grouting volume. The void height of the regular collapse zone is based on the results of similar simulation. The height of the irregular collapse zone is 0.915 ~ 0.975 times of the extracted thickness, and the porosity is determined by the porosity determined by the compression experiment of broken rock. The voids volume of goaf is predicted. Combined with goaf grouting site, the grouting effect of goaf is tested by drilling detection, grouting testing, in-hole television testing and bearing capacity experiment of stone body. The results show that: after grouting treatment, The data processing center 1# building site is suitable for construction.
【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】：TD325.3

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