深部薄煤层双侧沿空留巷支护技术及巷旁支护材料研究.pdf

深部薄煤层双侧沿空留巷支护技术及巷旁支 护材料研究 重庆大学硕士学位论文 （学术学位） 学生姓名张 适 指导教师曹树刚 教 授 专 业采矿工程 学科门类工 学 重庆大学资源及环境科学学院 二 O 一五年五月 Research on Support Technology and Supporting Materials of Double Side Entry Rataining under Deep Thin Coal Seam Mining A Thesis ted to Chongqing University in Partial Fulfillment of the Requirement for the Master’s Degree of Engineering By Zhang Shi Supervised by Prof. Cao Shugang SpecialtyMining Engineering College of Resources and Environmental Science of Chongqing University, Chongqing, China May, 2015 中文摘要 I 摘 要 随着浅部资源的逐渐减少和枯竭，地下开采由浅到深已经成为必然趋势。但 是，随着开采深度的增加，将面临地质环境趋于复杂、高瓦斯压力、高地应力、 高温以及软岩控制等一系列技术难题等。在复杂生产环境下，传统的“U”型通风 方式易造成工作面上隅角瓦斯积聚和超限问题，严重制约着矿井的高效、安全生 产，很大程度上限制了深部开采的规模和速度。通过沿空留巷技术，实现采煤工 作面“Y”型通风可有效解决上述瓦斯积聚和超限问题。目前据大多数矿井使用单 侧的沿空留巷方案，即在巷道一侧留设支护体。如果在巷道两侧留设支护体，即 双侧采空沿空留巷，两侧的工作面推进后，巷道可作为瓦斯抽采巷继续使用，将 实现更大的经济价值。然而，目前针对深部薄煤层开采双侧采空沿空留巷技术尚 不成熟，其应力复杂状态、围岩破坏特征、稳定性控制等是沿空留巷采矿亟待研 究的问题。 采用自行研制的可旋转平面应力试验台进行相似材料模拟试验，研究了两次 采动影响下双侧采空沿空留巷上覆岩层运动规律、破断特征和支承压力分布特征； 基于二次沿空留巷力学作用原理，提出了深部薄煤层双侧采空沿空留巷力学模型； 然后，通过分析沿空留巷基本顶关键块 B 的受力情况、上覆岩层运动规律和沿空 留巷稳定性控制因素，对煤矿巷内支护和巷旁支护进行了优化设计。由于巷内支 护技术相对成熟，本文着重研究了巷旁支护材料选型及其在受载下的变形破坏规 律，为巷旁支护现场试验材料的选择提供了可靠依据。主要获得如下研究结论 ①通过相似材料模拟试验， 获得了多次采动薄煤层开采条件下上覆岩层移动规 律。与中厚煤层开采后的顶板变形及破断规律不同，薄煤层采空区直接顶垮落后 能够充满采空区，使得上覆岩层的运动没有足够的空间。据此得到的岩层破断角 以及最大离层高度等上覆岩层移动规律对薄煤层沿空留巷围岩控制、巷内和巷旁 支护参数的选择具有重要的参考价值。 ②基本顶关键块的结构状态对沿空留巷的稳定性控制有着极其重要的影响， 是确定该类开采条件下影响留巷稳定性的主要因素，由理论分析得知，不同阶段 采动对关键块稳定性影响具有差异性。 ③通过分析现有沿空留巷巷内支护和巷旁支护的缺陷及其不足的原因，提出 了具有刚度耦合、协同变形、可共同承担上覆岩层荷载等优点的巷旁支护和巷内 支护技术。 ④对巷旁支护材料变形特征及力学响应的研究表明， “矸石袋锚网”支护系 统在前期具有一定的回缩量，能起到让压作用；随着矸石体进一步压缩，在后期 重庆大学硕士学位论文 II 能够提供较大的支撑力，满足深部薄煤层沿空留巷巷旁支护在材料变形和强度方 面的要求。 关键词关键词薄煤层，双侧采空，沿空留巷，力学模型，巷旁支护体 英文摘要 III ABSTRACT Because the shallow resource gradually decreases and exhausts, underground mining from shallow to deep has become an inevitable trend. However, with the increasing of mining depth, a series of technical problems have to be solved, such as complicated geological environment, high gas pressure, underground stress and temperature, soft rock control and so on. In such intricate environment, the traditional “U” type ventilation system which easy to causes gas accumulation and transfinite on the top corner of working face seriously affects the efficient production and limits the scale and speed of deep underground coal mining. By using the gob-side entry retaining technology, it can achieve the “Y” type ventilation system of work face which will tackle the problem above. The regular way of gob-side entry retaining is to layout support on one side of roadway. If there are supports on both sides, namely, “double side goaf” gob-side entry retaining, the roadway can be used for gas extraction which will create great economic value. Whereas such technology is rarely used in deep extremely thin coal seam mining. The study about the complexity of stress state, failure characteristics and control of surrounding rock need to be carried out. By using the self-developed rotating plane stress similar material simulation test system, the characteristic of movement and damage and the distribution of abutment pressure during “double side goaf” gob-side entry retaining are studied. Through mechanic analyze, the mechanical model of “double side goaf “gob-side entry retaining of the deep thin coal seam is proposed. Then according to the analyses of the key block B of basic roof, the movement of overlaying state and the stability factors of support, the designing of gob-side entry retaining both inside and beside are optimized. For the entry support is relatively mature, this thesis is forced on the selection of supporting materials, the laws of deation and breakage of them. Such research provides bases for in suit gob-side entry retaining. Some main conclusions are drawn as follows ① Through similar material simulation experiment, the movement law of overlying strata of deep extremely thin coal seam under repetitive mining was clearly observed. Unlike the deation and breakage of roofs of medium thickness and thick coal seam, the immediate roof can almost fill the gob. For this reason, there is not sufficient space for upper state to de. Accordingly, the rock breaking angle, the 重庆大学硕士学位论文 IV maximum depth of abscission layer and other parameters which were acquired through the experiment are important for the control of surrounding rock and the roadway support of gob-side entry retaining in thin coal seam. ② The stability of key block institutional state of basic roof have extremely important influence on the lower support of gob-side entry retaining. It is also the key factor to analyze whether success of gob-side entry retaining is being achieved. By theoretical analysis, different stages of mining have different effects on the stability of key blocks. ③ Through summarizing and studying the defects and deficiencies of typical gob-side entry retaining, the entry and roadside supporting technology which has the advantages of coupling stiffness, harmonious deation and can jointly bear the upper load is proposed. ④ According to the analysis of the deation and mechanical response of supporting material, the “waste bag, bolt and metal mesh” supporting system can be compressed at early stage that results in stress relieve. While it provides rapidly increasing bearing force with the further compaction which can satisfy the requirements of deation and strength of gob-side entry retaining in deep thin coal seam mining. Keywordsthin coal seam; double-side-gob ; gob-side entry retaining; mechanical models; lane-beside filling body 目 录 V 目 录 中中文摘要文摘要 .......................................................................................................................................... I 英文摘要英文摘要 ....................................................................................................................................... III 1 绪绪 论论 ...................................................................................................................................... 1 1.1 研究的背景和意义研究的背景和意义 .................................................................................................................. 1 1.2 国内外研究现状国内外研究现状 ...................................................................................................................... 2 1.2.1 沿空留巷上覆岩层运动规律研究现状 ........................................................................... 2 1.2.2 国内外沿空留巷技术研究现状综述 ............................................................................... 4 1.2.3 我国沿空留巷技术当前所面临的问题 ........................................................................... 5 1.3 主要研究的内容和技术路线主要研究的内容和技术路线 .................................................................................................. 6 1.3.1 主要研究的内容 ............................................................................................................... 6 1.3.2 研究的技术路线 ............................................................................................................... 7 2 煤岩物性及力学响应差异性研究煤岩物性及力学响应差异性研究 ........................................................................... 9 2.1 引言引言 .......................................................................................................................................... 9 2.2 矿井概况矿井概况 .................................................................................................................................. 9 2.2.1 矿井位置 ........................................................................................................................... 9 2.2.2 主采煤层概述 ................................................................................................................... 9 2.3 试验巷道工程地质条件试验巷道工程地质条件 ........................................................................................................ 11 2.3.1 试验巷道煤层状况 ......................................................................................................... 11 2.3.2 煤层顶底板情况 ............................................................................................................. 11 2.4 煤岩物性及力学响应差异性测试煤岩物性及力学响应差异性测试......................................................................................... 11 2.4.1 煤岩试件制备 ................................................................................................................. 11 2.4.2 试验条件 ......................................................................................................................... 12 2.4.3 差异性测试内容 ............................................................................................................. 14 2.5 本章小结本章小结 ................................................................................................................................ 21 3 双侧采空沿空留巷相似模拟试验研究双侧采空沿空留巷相似模拟试验研究 ............................................................... 23 3.1 引言引言 ........................................................................................................................................ 23 3.2 相似模型的建立相似模型的建立 .................................................................................................................... 23 3.2.1 相似原理 ......................................................................................................................... 23 3.2.2 相似准则 ......................................................................................................................... 24 3.2.3 相似比讨论 ..................................................................................................................... 24 3.3 相似材料的选取相似材料的选取 .................................................................................................................... 25 重庆大学硕士学位论文 VI 3.3.1 相似材料选取原则 ......................................................................................................... 26 3.3.2 相似材料试件的制作与养护 ......................................................................................... 26 3.3.3 模型材料承载及变形规律 ............................................................................................. 27 3.3.4 试件破裂特征分析 ......................................................................................................... 28 3.3.5 相似材料与实际煤岩体性能比较 ................................................................................. 28 3.4 模型制作与监测方法模型制作与监测方法 ............................................................................................................ 29 3.4.1 相似材料用量 ................................................................................................................. 29 3.4.2 位移及应力测点布置 ..................................................................................................... 29 3.5 七号煤层七号煤层上上覆岩层位移及应力演化规律覆岩层位移及应力演化规律 ............................................................................ 32 3.5.1 上覆岩层运动演化过程 ................................................................................................. 32 3.5.2 七号煤层开采应变演化过程 ......................................................................................... 34 3.5.3 上覆岩层沉降过程 ......................................................................................................... 37 3.6 八号煤层八号煤层上上覆岩层位移及应力演化过程覆岩层位移及应力演化过程 ............................................................................ 37 3.6.1 上覆岩层位移及应力演化过程 ..................................................................................... 37 3.6.2 八号煤层采动应变演化过程 ......................................................................................... 41 3.6.3 双侧采空沿空留巷岩层沉降位移分布及演化过程 ..................................................... 42 3.7 不同采动条件影响下不同采动条件影响下““两带两带””发育特征发育特征 ............................................................................ 44 3.8 本章小结本章小结 ................................................................................................................................ 45 4 双侧采空沿空留巷上覆岩层移动规律研究双侧采空沿空留巷上覆岩层移动规律研究 .................................................... 47 4.1 引言引言 ........................................................................................................................................ 47 4.2 双侧采空留巷上覆岩层运动规律双侧采空留巷上覆岩层运动规律 ........................................................................................ 47 4.2.1 采场上覆岩层移动破坏形式 ......................................................................................... 47 4.2.2 采场上覆岩层竖向运动规律 ......................................................................................... 47 4.2.3 上覆岩层沿推进方向运动规律 ..................................................................................... 48 4.3 双侧采空留巷基本顶破断形态研究双侧采空留巷基本顶破断形态研究 .................................................................................... 49 4.3.1 单侧沿空留巷期间基本顶结构 ..................................................................................... 49 4.3.2 双侧采空沿空留巷期间基本顶结构 ............................................................................. 51 4.4 双侧采空沿空留巷关键块双侧采空沿空留巷关键块 B 力学模型力学模型 ................................................................................ 52 4.4.1 单侧沿空留巷关键块力学模型及稳定性分析 ............................................................. 52 4.4.2 下区段开采时关键块力学模型及稳定性因素分析 ..................................................... 61 4.4.3 双侧采空留巷关键块力学模型及稳定性因素分析 ..................................................... 64 4.5 本章小结本章小结 ................................................................................................................................ 68 5 双侧采空沿空留巷支护优化设计双侧采空沿空留巷支护优化设计 ......................................................................... 69 5.1 引言引言 ........................................................................................................................................ 69 目 录 VII 5.2 巷内支护优化方案巷内支护优化方案 ................................................................................................................ 69 5.2.1 巷内支护现状分析 ......................................................................................................... 69 5.2.2 巷内支护优化设计 ......................................................................................................... 70 5.3 巷旁支护优化设计巷旁支护优化设计 ................................................................................................................ 71 5.3.1 巷旁支护现状分析 ......................................................................................................... 71 5.3.2 “矸石袋锚网索”充填体压密性能研究 .................................................................... 72 5.3.3 破碎矸石承载中的高密度圆台体 ................................................................................. 76 5.4 本章小结本章小结 ................................................................................................................................ 80 6 结论与展望结论与展望 ..................................................................................................................