穿层钻孔采动分区失效机制及控制研究

The failure mechanism and stability control of the lateral cross-seam boreholes are studied in the process of large-scale mining and lateral strata movement. Drilling stress evolution, fracture expansion, fracture surface slip and deformation and failure mechanism of drilling in homogeneous rock mass, soft - hard, hard - soft - hard, soft - hard - soft and other different combinations of rock under compressed stress and shear stress are studied using combination monitoring system of fiber grating ，acoustic emission and CCD camera shooting. The influence of mining height，drilling angle，roof structure on the stability of borehole is simulated to quantitatively analyze the dominant factors of drilling failure. The characteristics of perforation drilling division are studied by means of deep and long panoramic borehole camera and fiber grating monitoring system on-site fine detection and numerical simulation. Establishing the casing - buffer layer - surrounding rock mechanics to analyze the stress - strain characteristics of casing under uniform and non - uniform load. The casing - buffer layer - surrounding rock mechanics model is established to analyze the stress - strain characteristics of casing under uniform and non - uniform load. In the final ,the method of controlling the stability of lateral cross-measure boreholes is formed by combining the failure mode and the failure characteristics of the mining. The research results provide theoretical basis for the design and protection of various types of boreholes, such as gas drainage and coal and gas co-mining.

项目以井下穿层钻孔受大范围开采及顶板运动影响，采动破坏失效及稳定控制为研究对象。采用声发射监测和高分辨率CCD摄像相结合的方法，研究均质岩体、软-硬、硬-软-硬、软-硬-软等不同组合岩体中钻孔受压及受剪作用下，钻孔应力演化、裂隙扩展及其变形破坏的规律；模拟分析钻孔倾角、采高、顶板岩性结构等因素对钻孔稳定性的影响，量化分析钻孔失稳破坏的主控因素，结合深长全景钻孔窥视和数值模拟，分析穿层钻孔受采动影响全过程应力演化及分区破坏特征；建立套管-垫层-围岩力学模型，利用20MPa-“三向五面”竖向主加载试验系统、现场精细探测，研究套管在均匀和非均匀载荷作用下应力和变形规律，分析不同结构穿层钻孔采动分区破坏模式和破坏特征，形成穿层钻孔稳定性控制方法。研究成果将为卸压瓦斯抽采、煤与瓦斯共采等各类钻孔设计及保护提供理论依据。

项目以受大范围开采及顶板运动影响的井下穿层钻孔为研究对象。采用理论分析、物理模拟及数值计算等方法，通过不同煤岩组合体钻孔试验，得到了不同煤岩组合体抗压强度、声发射振铃计数、声发射能量与钻孔孔径之间的关系，分析了不同钻孔煤岩组合体裂隙发育规律。研究了钻孔布置、结构及围岩性质对钻孔稳定性的影响，分析了钻孔套管变形破坏的三大原因是岩层的层间滑移、非均布挤压和离层，其主要的变形破坏形式有层间剪切滑移变形导致的剪切变形坏、径向挤压变形导致的挤压变形破坏。建立了钻孔在挤压和剪切变形下的破坏判据，分析了原岩应力、钻进方向、套管外径、壁厚、岩层剪切滑移量等因素对钻孔稳定性的影响规律。研究了抽采钻孔的变形破坏分区域特征，分为挤压破坏区、压剪过渡区、剪切破坏区，并比较研究了不同区域破坏机理及破坏形式的不同。针对不同区域的破坏特征，提出了相应的控制对策。项目的研究成果，对瓦斯高效抽采与矿井安全保障具有普遍的理论价值和实践指导意义。依托项目研究成果，发表SCI/ EI论文5篇；获得江苏省科学进步一等1项（排名第2）、中国煤炭工业协会科学技术一等奖1项（排名第8）；申请发明专利3项，授权发明专利1项；参加国内国际学术交流6人次；培养硕士研究生2名。