深部高应力半煤岩巷变形机理及跨界高强支护技术

    Deformation mechanism of deep high stress semi coal rock roadway and cross-border high-strength support technology

    • 摘要: 针对深部高应力半煤岩巷围岩变形持续时间长、变形量大及支护构件损伤破断等围岩控制难题,以渝阳矿N3702运输巷为工程背景,综合采用现场测试、理论分析、数值模拟和工程试验的方法,对半煤岩巷围岩变形机理和控制对策展开研究。通过巷道矿压监测与松动破坏范围测试,量化了半煤岩巷的矿压显现特征,揭示了半煤岩巷顶板泥页岩抗变形能力弱、锚索锚入坚硬硅质灰岩的深度较浅甚至未锚入、巷道所处高应力环境且其轴向近乎垂直于最大水平主应力是造成矿压显现剧烈的根源;基于自然垮落拱理论的成拱形态、锚杆组合梁和悬吊理论的组合压缩作用与悬吊作用,阐明了矩形断面巷道锚杆锚索支护时顶板低位“显形压缩梁”结构和高位“隐形压缩拱”结构的形成机制;在分析锚索锚固段所处位置岩性、自由段长度及锚尾施加预紧力大小对“梁-拱”锚固结构承载能力影响规律的基础上,提出了矩形断面半煤岩巷以锚杆配合锚索为主体支护构件的跨界高强支护技术方案,并开展了现场应用。实践结果表明:该技术有效地控制了深部高应力半煤岩巷持续变形,保证了围岩与支护构件的稳定与安全。

       

      Abstract: Aiming at the surrounding rock control problems of deep and high stress semi coal and rock roadway, such as long deformation duration, large deformation and damage and breakage of support components, taking N3702 transport roadway of Yuyang Coal Mine as the engineering background, the deformation and instability mechanism and control countermeasures of surrounding rock of semi coal and rock roadway are studied by means of field test, theoretical analysis, numerical simulation and engineering test. Through roadway ground pressure monitoring and loose damage range testing, the characteristics of ground pressure appearance of semi coal rock roadway were quantified, and it was revealed that the weak deformation resistance of shale on the roof of semi coal rock roadway, the shallow depth of anchor cable anchoring into hard siliceous limestone, the high stressenvironment where the roadway is located and its axis is nearly perpendicular to the maximum horizontal principal stress were the root causes of severe ground pressure appearance. Based on the arch forming form of the natural caving arch theory, the combined compression effect and suspension effect of the bolt composite beam theory and the suspension theory, the formation mechanism of the low level “apparent compression beam” structure and the high level “invisible compression arch” structure of the roof during the bolt and anchor cable support of the rectangular section roadway is expounded. Based on the analysis of the influence law of the location lithology of the anchorage section of the anchor cable, the length of the free section and the preload applied by the anchor tail on the bearing capacity of the beam-arch anchor structure, a cross-border high-strength support technical scheme with the anchor bolt and anchor cable as the main support components in the rectangular section semi coal rock roadway is proposed, and the field application is carried out. The practice results show that the technology effectively controls the continuous deformation of deep high stress semi coal rock roadway, and ensures the stability and safety of surrounding rock and support components.

       

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