特厚煤层错层位外错式沿空掘巷、区段间相邻巷道联合支护的机理研究

There search in this paper was conducted aimed at the problems such as leaving small coal pillar along gob side entry, roadway support and skip-mining. It is the first time to put forward outer stagger arrangement roadway driving along goaf and support technology in extra-thick coal seam. At first, we study on the stability of the triangular bottom coal brought by the different height of the slope of stagger position and overburden strata movement features, Which realized the coupling of triangular bottom coal and overburden strata movement in variation of stress and zoning of the entity coal and determined the reasonable position of outer stagger arrangement roadway driving along goaf. On this basis, the paper puts forward the joint support scheme of adjacent roadway by using the three - dimensional spatial relationship of adjacent roadway between sections. We studied on the anchorage zone of different supporting parameters of entity coal side of roadway and mechanical response of combined excavation zone of adjacent roadway. The technical system of the joint adjacent roadway support which we researched and determined its support mechanism is established. Finally, combined with the actual engineering background, the research results are verified by field test. It is expected that the research results will solve the technical problems of gob-side entry driving in extra-thick coal seam, improve the supporting mechanism of floor roadway and the difficult situation of roadway support in thick coal seam floor and expand the application range of full-seam mining adopted roadway layout of stagger arrangement.

本项目拟对特厚煤层沿空掘巷小煤柱留设、巷道支护、需要跳采等问题展开研究，首次提出在特厚煤层中应用错层位外错式沿空掘巷技术。研究中，首先对错层位不同起坡高度带来的三角底煤稳定性与上覆岩层运动变化展开研究，实现三角煤体与覆岩运动在实体煤侧的应力与分区变化的耦合，确定错层位外错式沿空掘巷的合理位置。在此基础上，利用区段间相邻巷道的立体化空间关系，首次提出相邻巷道的联合支护技术方案，先后对起坡段巷道实体煤侧不同支护参数的锚固区、沿空掘巷支护参数对相邻巷道的联合锚固区力学响应展开研究，建立区段间相邻巷道联合支护技术体系，研究并确定其支护机理。最后，结合实际工程背景对研究成果进行现场实测验证。预期研究成果即可解决特厚煤层沿空掘巷的技术难题，又可完善底板巷道的支护机理，改善厚煤层底板巷道支护困难的现状，同时拓展了错层位巷道布置采全厚采煤法的应用范围。

本项目针对错层位外错式沿空掘巷展开研究，对相邻两巷“一高、一低、立体化”空间结构特点巷道布置与联合支护方案展开研究。首先，对错层位外错式沿空掘巷特有的三角煤体结构稳定性展开研究，分别建立了极限平衡力学模型与顶板作用下底板破坏深度力学模型，从而实现三角煤体稳定性的全空间判别准则；在此基础上，结合三角煤体稳定性对实体煤在侧向应力作用下的稳定性进行了研究，确定了错层位外错式沿空巷道布置的方法，即沿空巷道既要布置在稳定煤体区域，且要避开上覆破碎顶煤区域，形成在煤层厚度纵向上的综合布置方案；最后，利用相邻两巷立体化空间关系，提出“联合锚固区”的概念，给出沿底巷道顶板支护方案与参数的确定方法。本项目达到预期目标，形成了错层位外错式沿空掘巷新方法，可为我国普遍存在的厚煤层提供新的参考方案。