沿空留巷巷道底板破坏规律及控制技术研究.pdf

太原理工大学硕士研究生学位论文 I 沿沿空空留留巷巷巷巷道道底底板板破破坏坏规规律律及及控控制制技技术术研研究究 摘摘要要 沿空留巷是一次采煤技术的重大改进，具有诸多优越性。但由于沿空 巷道在留巷过程中， 采空区顶板上覆岩层回转下沉， 巷道受力持续时间长、 应力集中较大、采动影响强烈；且沿空留巷巷道在整个服务期间要经历上 下工作面两次回采的动压影响，在复杂的应力变化下，导致沿空留巷巷道 变形普遍较大。严重的底鼓会使巷道断面变小、通风困难、影响设备及井 下工人的通行。 本文以关岭山煤矿 15206 工作面沿空留巷巷道严重底鼓为研究背景， 采用现场调研、室内实验、理论分析、数值模拟和现场监测等方法，对沿 空留巷回采巷道破坏规律及控制技术进行深入研究，得出以下结论 （1） 通过理论分析沿空留巷顶板运移规律及不同阶段下沿空留巷巷 道的底板破坏机理，得出底板变形的主要原因，阐述了沿空留巷各阶段底 板破坏过程。联系岩石蠕变特性，分析沿空留巷各阶段底板的蠕变变形特 征。并运用多目标综合评价方法层次分析法，通过构造判断矩阵，求 得各地质因素的权重集，权重分配值符合矿区实际煤层条件。 （2） 以关岭山煤矿 15206 工作面沿空留巷为工程背景，首先进行钻孔 窥视，分析该矿围岩岩性和节理裂隙，其次现场取样进行岩石力学实验， 测定围岩力学参数。并结合上述测定的围岩参数，取层次分析法研究中影 响权重较大的部分因素，采用单因素分析法进行数值模拟研究，对不同因 素下沿空留巷底板破坏规律趋势进行研究。研究发现硬顶软底岩性下沿空 留巷巷道底鼓最严重；巷道埋深越大，底鼓量越大，且增加速率越快；充 万方数据 太原理工大学硕士研究生学位论文 II 填体宽度对巷道底鼓影响较小；留巷宽度的增加会导致底鼓量稍微增加， 增加幅度较小。 （3） 对关岭山煤矿 15206 工作面沿空留巷底鼓量进行理论计算，得出 总底鼓量理论值为 616.86mm，而蠕变影响下的底鼓量占的比重为 19.96。 并利用数值模拟计算，建立 Cvsic 蠕变模型，假设工作面回采时超前和滞后 影响范围外，巷道围岩受力环境稳定，巷道变形主要为蠕变变形，分别在 巷道底板中心线处、充填体侧底板和实体煤侧底板建立位移测点进行底鼓 量的监测。模拟结果得出，沿空留巷在二次回采超前影响阶段，充填体侧 底板的总底鼓量大于实体煤侧，充填体侧底板总底鼓量为 339.94mm，充填 体侧底板蠕变变形量所占比重为 16.16，实体煤侧总底鼓量为 220.88mm， 实体煤侧底板蠕变变形量所占比重为 17.20；而巷道中心线处底板，岩层 蠕变更加剧烈，最大底鼓量为 502.26mm，其蠕变变形量占总底鼓量比重可 达到 23.92。 与理论计算蠕变影响下的底鼓占比相差不大， 具有参考意义。 且对模拟结果分析发现，沿空留巷巷道底鼓量随时间变化曲线遵循典型蠕 变曲线类似的变形规律， 也分为四个阶段 快速底鼓阶段、衰减底鼓阶段、 稳定底鼓阶段和加速底鼓阶段。 （4） 通过对关岭山煤矿 15206 工作面沿空留巷巷道顶板下沉量、底鼓 量和两帮移近量进行位移监测，观测浇筑前和浇筑后巷道的围岩变形，验 证前文得出的底鼓量理论计算值和数值模拟值。并针对该矿实际地质条件， 提出三种加强底板治理的方案，采用数值模拟的方法，对比分析各方案， 确定最优底鼓控制方案为帮角锚杆底板注浆锚杆，为该矿今后的底鼓治理 提供一些借鉴之处。 关关键键词词沿空留巷，底鼓机理，层次分析法，蠕变破坏规律，现场监 测，底鼓控制 万方数据 太原理工大学硕士研究生学位论文 III STUDY ON THE DESTRUCTION RULE AND CONTROL TECHNOLOGY OF FLOOR SLAB ALONG LANEWAYS ABSTRACT Retaining lanes along the road is a major improvement in coal mining technology and has many advantages. However, due to the rotation and sinking of overlying strata on the roof of the goaf during the process of retaining roadways along the empty roadway, the stress of the roadway is long, the stress concentration is large, and the influence of mining is strong; and the roadways along the empty roadway are to be experienced during the entire service period. The impact of dynamic pressure on the two working faces of the upper and lower working face, under complex stress changes, leads to a generally larger deation of the roadway along the left-hand roadway. A serious kick drum can make the roadway section smaller, make it difficult to ventilate, and affect the passage of equipment and underground workers. In this paper, the background of the roadway at the roadway of the 15206 working face in Guanlingshan Coal Mine is taken as the research background. Field investigation, indoor experiments, theoretical analysis, numerical simulation and on-site monitoring s are adopted. The in-depth study of technology led to the following conclusions 1 Through the theoretical analysis of the movement law of the roof along the empty culvert and the failure mechanism of the floor of the roadway in the different lanes, the main reasons for the deation of the floor are obtained, and the failure process of the floor of the roadway along the empty lane is described. In connection with the creep characteristics of rocks, the creep 万方数据 太原理工大学硕士研究生学位论文 IV deation characteristics of the floor slabs at each stage of the roadways are analyzed. Using the multi-objective comprehensive uation -AHP, through the construction of the judgment matrix, the weight set of each geological factor is obtained, and the weight distribution value is consistent with the actual coal seam conditions in the mining area. 2 Taking the retaining lane along the 15206 face of the Guanlingshan Coal Mine as the engineering background, the drilling peek was first pered to analyze the lithology and joint fractures of the surrounding rock of the mine. Second, on-site sampling was pered for rock mechanics experiments to measure the surrounding rock mechanics parameters. Combined with the above-mentioned parameters of the surrounding rock, the factors that have a greater weight in the AHP study are used. The single-factor analysis is used to conduct numerical simulation studies, and the trend of floor failure of gob-side lanes under different factors is studied. It is found that the floor drum is the most serious roadway in hard-bottom soft-bottom lithology; the deeper the roadway depth, the greater the amount of kick drum, and the faster the rate of increase; the width of the filling body has less influence on the roadway floor drum; An increase in width will result in a slight increase in the amount of kick drums and a smaller increase. 3 The theoretical calculation of the bottom drum volume of the roadway along the 15206 working face of the Guanlingshan Coal Mine was carried out, and the theoretical value of the total floor drum was 616.86mm, while the proportion of the kick drum under the influence of creep was 19.96. In addition, the Cvsic creep model was established using numerical simulation calculations. Assuming that the working face is outside the range of influence of advance and lag, the stress environment of roadway surrounding rock is stable, and the deation of the roadway is mainly creep deation. They are respectively at the center line of the roadway floor and the backfill body. The side bottom plate and the solid coal side bottom plate establish displacement 万方数据 太原理工大学硕士研究生学位论文 V measurement points to monitor the amount of the bottom drum. The simulation results show that the total amount of bottom heave at the side of the backfill is greater than that of the solid coal side in the lead-in effect of secondary recovery along the empty goaf. The total floor heave of the bottom side of the backfill is 339.94 mm, and the bottom floor of the backfill body is creep deed. The proportion of the amount is 16.16, the total side of the physical side of the coal drum is 220.88mm, the proportion of the actual side of the coal floor creep deation is 17.20; and the floor of the roadway center line, the rock layer is more severe creep, the maximum kick drum The amount is 502.26mm, and its creep deation amount accounts for 23.92 of the total kick drum weight. There is no significant difference in the proportion of kick drums under the influence of theoretical calculation creep. According to the analysis of the simulation results, the curve of the amount of kick at the roadway along an empty roadway follows the typical deation law similar to that of a typical creep curve. It is also divided into four stages fast kick stage, decay kick stage, and stable kick stage. And accelerate the kick stage. 4 Displacement monitoring of the roadway roof subsidence volume, floor drum volume, and the displacement of the two gangs in the roadways along the 15206 face of the Guanlingshan Coal Mine are conducted to observe the deation of surrounding rock before and after the pouring, verifying the previous text. The amount of theoretical calculations and numerical simulations of the amount of kick drums. In view of the actual geological conditions of the mine, three kinds of plans for strengthening the floor treatment are proposed. Using numerical simulation s, comparative analysis of each program, to determine the optimal kick control program for the help angle bolt bottom grouting bolt, for the mine The bottom-line governance in the future provides some lessons. KEY WORDSgob-side entry retaining; bottom drum mechanism; AHP; creep failure; site monitoring; bottom drum control 万方数据 太原理工大学硕士研究生学位论文 VI 万方数据 太原理工大学硕士研究生学位论文 VII 目目录录 第一章绪论 .................................................................................................................... 1 1.1 研究背景及研究意义 .......................................................................................... 1 1.1.1 研究背景 ....................................................................................................... 1 1.1.2 研究意义 ....................................................................................................... 2 1.2 国内外研究现状 .................................................................................................. 2 1.2.1 沿空留巷围岩变形研究现状 ....................................................................... 2 1.2.2 沿空留巷底鼓研究现状 ............................................................................... 3 1.2.3 沿空留巷底鼓防控技术研究 ....................................................................... 4 1.2.4 研究现状的局限性 ....................................................................................... 5 1.3 主要研究内容及技术路线 .................................................................................. 6 1.3.1 研究内容 ....................................................................................................... 6 1.3.2 研究方法及技术路线图 ............................................................................... 7 第二章沿空留巷底板破坏机理及影响因素研究 ........................................................ 9 2.1 沿空留巷底鼓机理研究 ...................................................................................... 9 2.1.1 沿空留巷上覆岩层运移规律 ....................................................................... 9 2.1.2 沿空留巷底板破坏力学机理 ..................................................................... 11 2.2 基于层次分析法的沿空留巷底鼓影响因素分析 ............................................ 14 2.2.1 层次分析法简介 ......................................................................................... 14 2.2.2 层次分析法影响因素分析 ......................................................................... 14 2.2.3 影响因素权重结果分析 ............................................................................. 19 2.3 本章小结 ............................................................................................................ 19 第三章沿空留巷底板破坏数值模拟研究 .................................................................. 21 3.1 沿空留巷工程背景 ........................................................................................... 21 3.1.1 煤层及工作面概况 .................................................................................... 21 3.1.2 沿空留巷巷道支护 .................................................................................... 22 3.2 围岩钻孔窥视分析及力学测定 ....................................................................... 25 3.2.1 围岩钻孔窥视分析 .................................................................................... 25 万方数据 太原理工大学硕士研究生学位论文 VIII 3.2.2 围岩力学参数测定 .................................................................................... 32 3.3 沿空留巷底板破坏数值模拟研究................................................................... 33 3.3.1 不同顶底板岩性下沿空留巷底鼓数值模拟研究 .................................... 35 3.3.2 不同埋深下沿空留巷影响底鼓因素数值模拟研究 ................................ 37 3.3.3 不同充填体宽度下沿空留巷影响底鼓因素数值模拟研究 .................... 38 3.3.4 不同留巷断面尺寸下沿空留巷影响底鼓因素数值模拟研究 ................ 39 3.4 本章小结............................................................................................................ 41 第四章沿空留巷底板蠕变破坏规律研究 ................................................................. 43 4.1 关岭山煤矿沿空留巷底鼓理论计算............................................................... 43 4.2 Cvsic 数值模型的建立过程 ............................................................................. 45 4.3 数值模拟结果分析........................................................................................... 47 4.3.1 掘进阶段数值模拟结果分析 .................................................................... 47 4.3.2 一次回采阶段数值模拟结果分析 ............................................................ 49 4.3.3 二次回采阶段数值模拟结果分析 ............................................................ 52 4.4 本章小节........................................................................................................... 55 第五章现场监测及沿空留巷底鼓治理 ..................................................................... 57 5.1 浇筑前监测数据分析....................................................................................... 57 5.2 浇筑后监测数据分析....................................................................................... 59 5.3 底鼓治理方案数值模拟研究........................................................................... 62 5.3.1 底鼓治理方案确定 .................................................................................... 62 5.3.2 底鼓治理数值模拟结果分析 .................................................................... 64 5.4 本章小节........................................................................................................... 69 第六章主要结论与不足 ............................................................................................. 71 6. 1 主要结论.......................................................................................................... 71 6. 2 存在不足.......................................................................................................... 72 参考文献 ..................................................................................................................... 75 致谢 ............................................................................................................................. 81 附录 A攻读硕士学位期间发表的学术论文 ......................................................... 83 附录 B攻读硕士学位期间参与的科研项目.......................................................... 83 附录 C沿空留巷底鼓影响因素重要性评分表...................................................... 84 万方数据 太原理工大学硕士研究生学位论文 1 第第一一章章 绪绪论论 1.1 研研究究背背景景及及研研究究意意义义 1.1.1 研研究究背背景景 中国是煤炭资源大国，占据我国产能结构消耗的主导地位[1-2]。我国煤炭生产中多 以留设煤柱的方式保障生产安全，导致煤炭资源的大量浪费，且传统的双巷掘进方式已 经不能满足井下的高产高效生产。与此同时，由于过往对浅埋煤层的开采，现阶段，煤 炭开采不断向深部转移，矿方盲目的加大保护煤柱宽度以维持巷道的安全稳定，造成更 多的煤炭资源损失。且对于高瓦斯矿井，原有的通风方式难以解决上隅角瓦斯问题[3]。 因此，为解决以上矿井生产问题，沿空留巷开采方式应运而生。 沿空留巷是指将上一工作面的顺槽通过一定支护手段，留作下一个工作面的回采顺 槽使用的一种开采技术。其优越性主要有（1）不留设煤柱，减少资源浪费，增加资 源采出率；（2）解决采掘接替慢的难题，减少孤岛工作面产生；（3）留巷后回采巷道 形成“Y”型通风，能有效解决瓦斯超标问题[4-7]。 经过井下不断实践，已充分证明，沿空留巷是一次采煤技术的重大改进，具有诸多 优越性[8]，但在实践生产过程中发现，沿空留巷支护技术还不完善，仍存在诸多不足之 处，且以往支护设计中总是忽略底板的支护，尤其在深部开采中，受高地应力和侧向支 承应力等复杂影响，巷道的底鼓问题严重影响着正常的矿井生产。不仅会导致巷道变形 较大，进而影响到整个矿井的通风问题，而且为了维持巷道稳定会增大经济投入，给煤 矿造成较大经济损失。研究表明，底板变形在一次回采至二次回采期间最为剧烈，底鼓 量有时可达数百毫米，占整个巷道掘进、回采过程中，顶底板总移近量的 70以上。随 着底鼓量继续加大，当下一工作面回采前，为保证留巷的继续安全使用，巷道需通过卧 底等方式进行底鼓治理，但治理效果较差，且经济投入过大。因此，沿空留巷底鼓问题 应该受到重视[9]。 调研发现， 采用沿空留巷开采方式时， 特别是处于巷道围岩比较破碎的前提条件下， 由于多次采动影响， 采空区顶板回转下沉， 对留巷巷道产生较长时间、 较大强度的影响； 且留巷巷道的一帮为实体煤，另一帮为充填体，其力学环境与一般的回采巷道有很大不 万方数据 太原理工大学硕士研究生学位论文 2 同。这些因素导致沿空留巷巷道围岩变形剧烈，尤其是往往被忽视的底板部分，将会产 生较大的破坏变形[10-12]。而且，沿空留巷巷道底板受力呈非对称性，其破坏变形亦呈非 对称性。在工程实践中，围岩支护应考虑整体结构的稳定，减少支护薄弱部分，也减少 不必要的支护浪费[13-15]。因此，盲目的进行底板治理，不但导致支护效果不明显，围岩 稳定性无法得到保障，而且会造成大量的资源浪费。故根据底板破坏特征及主要影响因 素，设计与之相匹配的支护方案尤为重要。 1.1.2 研研究究意意义义 自上世纪末以来，各国学者开始对巷道底鼓进行研究，已经在底鼓机理和控制技术 方面取得了较大研究成果 [16-27]。但这些底鼓理论和控制技术研究主要针对深部软岩巷 道或动压巷道，对沿空留巷巷道底鼓问题的研究则少之又少，人们对于沿空留巷底鼓机 理仍然认识不清，沿空留巷底鼓问题仍未找到有效的治理方法，煤矿工作人员对底板的 支护常常具有很大的盲目性，主观性和经验性。而煤炭行业作为一个高危行业，这样的 盲目性，主观性和经验性是极不可取的。 实际工作中多数沿空留巷矿井采用反复卧底的方式解决底鼓问题，这种方式可短暂 恢复巷道的使用，但不能从根本上解决底鼓问题，反而导致围岩破碎区域增大，在二次 回采过程中，致使巷道底板所受应力扰动更加剧烈，底鼓问题更为突出[28-30]。本文通过 分析留巷巷道服务期间底板岩层受力及变形规律，研究沿空留巷底鼓机理和底鼓的主要 影响因素，提出解决底鼓的防治方案，为沿空留巷底鼓治理提供理论依据。 1.2