砚石台煤矿急倾斜俯伪斜上保护层开采保护范围研究.pdf

砚石台煤矿急倾斜俯伪斜上保护层 开采保护范围研究 重庆大学硕士学位论文 （学术学位） 学生姓名黄光利 指导教师王宏图 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 一四年五月 Study on Protection Scope of Steep-Inclined Upper-Protective Layer with Pseudo-Incline Technique for Yanshitai Coal Mine A Thesis ted to Chongqing University in Partial Fulfillment of the Requirement for the Master’s Degree of Engineering By Huang Guangli Supervised by Prof. Wang Hongtu Specialty Mining Engineering College of Resource and Environment Science of Chongqing University, Chongqing, China May, 2014 中文摘要 I 摘 要 随着煤矿开采向深部发展，矿井灾害不断加剧，煤与瓦斯突出已经严重影响 了矿井的安全高效开采。保护层开采作为矿井多煤层开采防治煤与瓦斯突出最有 效的区域性措施，其关键问题是保护范围的划定。由于现有保护范围的划定是根 据防治煤与瓦斯突出规定的参考值来确定的，在实际生产中存在一定的局限 性，特别是对于急倾斜煤层的开采，工作面采用俯伪斜采煤法，其卸压程度与直 壁工作面存在一定差异，加之煤层埋深、地应力、煤层间距以及煤岩层物理力学 特性等因素影响，使卸压保护范围的划定难度加大。对此，本文以南桐矿业有限 责任公司砚石台煤矿急倾斜俯伪斜 6上保护层开采为研究对象，采用数值模拟分 析和现场考察研究相结合的方法，研究了急倾斜俯伪斜上保护层开采保护范围的 划定方法。根据保护层开采煤岩体变形与瓦斯流动的固气耦合作用，建立了采动 煤岩体变形与瓦斯流动固气耦合数学模型，并进行急倾斜俯伪斜上保护层开采保 护范围的数值模拟计算，最后结合现场考察研究，对比分析确定了砚石台煤矿急 倾斜俯伪斜工作面上保护层开采保护范围的划定方法。论文的主要研究成果和结 论有 ① 针对研究对象，建立了采动煤岩体变形场控制方程和瓦斯渗流场控制方 程；引入采动煤岩体固气耦合变量，得到了采动煤岩体变形与瓦斯流动固气耦合 数学模型；通过验证，证明了该数学模型的正确性。 ② 通过砚石台煤矿 4－6 区急倾斜俯伪斜 6上保护层开采保护范围的数值模 拟计算，得出了 6上保护层采煤工作面开采以后 4被保护层的瓦斯压力分布规律 以及煤层移动变形规律；在此基础上，确定了上保护层开采保护范围的卸压角。 数值计算结果表明基于残余瓦斯压力判别准则得出的 6上保护层开采沿倾向上 边界和下边界的卸压角分别为 81.7 和 78.9 ，沿走向的卸压角为 55.6 ；基于煤层 变形判别准则得到的6上保护层开采沿倾向上边界和下边界的卸压角分别为80.4 和 77.6 ，沿走向的卸压角为 53.2 ；两种方法所得到的结果从数值及分布规律上看 基本一致。 ③ 根据砚石台煤矿 4－6 区急倾斜俯伪斜 6上保护层开采保护范围的现场考 察结果，得到了 6上保护层采煤工作面开采以后 4被保护层的煤层瓦斯压力、钻 孔瓦斯流量和煤层透气性系数的变化规律，划定出了 4被保护层瓦斯动力参数变 化呈现的“四带”分布范围。现场考察结果表明6上保护层开采沿工作面伪斜 方向各处的走向保护范围的卸压角为 47.1 ～74.1 ；沿工作面倾向上边界和下边界 保护范围的卸压角分别为 85.7 和 79.5 ；6上保护层采煤工作面超前于 4被保护 重庆大学硕士学位论文 II 层掘进工作面的合理距离为 114 m。 ④ 对比分析现场考察结果及数值计算结果，二者所得到的卸压角在数值和分 布规律上基本一致，由此说明本文采用的数值模拟计算分析方法来划定 4被保护 层的有效卸压范围是合理可行的；同时，综合分析确定了砚石台煤矿 4－6 区急倾 斜俯伪斜 6上保护层开采对 4被保护层保护范围的划定方法，其卸压角可以根据 数值模拟结果以及现场考察结果来划定，即6上保护层开采沿走向保护范围的 卸压角为 53.2 ～59.8 ；沿倾向上边界保护范围的卸压角为 80.4 ～85.7 ；沿倾向 下边界保护范围的卸压角为 77.6 ～79.5 。 关键词关键词固气耦合，急倾斜，上保护层，保护范围，数值模拟 英文摘要 III ABSTRACT With the deep development of coal mining, coal mine disasters are increasing and coal and gas outburst has seriously affected the safe and efficient mining of the mine. Exploiting protective layer is used as one of the most effective regional measures for preventing of coal and gas outburst, and the key problem is to locate the protection scope exactly. As a result of the traditional protection range is located on the basis of reference values of , there may be deviation in particular cases such as exploiting steep-incline layer with a bow pseudo-incline technique. And combined with the influencing of the factors such as the depth of coal seam, spacing of coal seam, ground stress and physical and mechanical properties of coal and rock, it makes harder to locate the protection scope. As a consequence, this paper takes Yanshitai coal mine of Nantong mining co., LTD as an engineering example and according to combining s of numerical simulation analysis and field investigation research, the locating of protection scope for exploiting steep-incline upper-protective layer was taken into study. Through the establishment of solid and gas coupled mathematical model of coal rock deation and gas flow under mining effecting and its application in numerical calculation for protection scope of exploiting steep-incline upper-protective layer, at the same time according to the results of field investigation, the numerical simulation was verified to be proper and reliable. In the last, by the contrast analysis, to locating the protection scope for exploiting steep-incline upper-protective layer of Yanshitai coal mine was determined. The main conclusion and results of this paper can be drawn that ① Aim at the research objects, coal rock deation control equation and gas seepage control equation were established on the base of assumptions. By importing solid and gas coupling variables, solid and gas coupled mathematical model of coal rock deation and gas flow under mining effecting was established. And through verifying, this mathematical model was proved to be corrected. ② According to numerical calculation for protection scope of exploiting steep-incline 6 upper-protective layer of Yanshitai coal mine with a bow pseudo incline technique, the law of stress and deation in 4 protected layer was gained after 6 upper-protective layer was mined as well as gas pressure distribution in 4 protected layer. The numerical calculation results show that the pressure-relief angles of 6 重庆大学硕士学位论文 IV upper-protective layer located by the discrimination criterion of residual gas pressure are 81.7 and 78.9 along inclined upper and lower boundary respectively and 55.6 along strike and the pressure-relief angles located by the discrimination criterion of coalbed deation are 80.4 and 77.6 along inclined upper and lower boundary respectively and 53.2 along strike. As a consequence, the results of the two s are basically the same between values and distribution. ③ According to the results of field investigation of protection scope for exploiting 6 steep-incline upper-protective layer of Yanshitai coal mine, the change law for 4 protected layer of coalbed gas pressure, gas flow from borehole and permeability coefficient was obtained. And the four distribution range of gas dynamic parameters variation was also drawn out. The field investigation results show that the pressure-relief angles of 6 upper-protective layer are 47.1 ～74.1 along strike and 85.7 and 79.5 along inclined upper and lower boundary. And besides, the reasonable ahead distance for work face of 6 upper-protective layer is 114 m. ④ By the contrast analysis of the results of field investigation and numerical calculation, the pressure-relief angles from two s are basically the same so that it is reasonable and achievable to use numerical calculation to locate the effective pressure relief range of 4 protected layer. Through comprehensive analysis, the pressure-relief angles can be gained according to the results of both field investigation and numerical calculation, which are 53.2 ～59.8 along strike and 80.4 ～85.7 along inclined upper boundary and 77.6 ～79.5 along inclined lower boundary. KeywordsCoupled Solid and Gas, Steep-Inclined, Upper-Protective Layer, Protection Scope, Numerical Simulation 目 录 V 目 录 中文摘要中文摘要 .......................................................................................................................................... I 英文摘要英文摘要 ....................................................................................................................................... III 1 绪论绪论 ........................................................................................................................................... 1 1.1 问题的提出问题的提出 ............................................................................................................................... 1 1.2 研究目的及意义研究目的及意义 ....................................................................................................................... 2 1.3 国内外研究现状国内外研究现状 ....................................................................................................................... 3 1.3.1 煤层瓦斯流动理论的研究现状 ........................................................................................ 3 1.3.2 煤岩变形与瓦斯流动固气耦合理论的研究现状 ............................................................ 4 1.3.3 国内外保护层开采保护范围划定的研究现状 ................................................................ 6 1.4 研究内容及技术路线研究内容及技术路线 ............................................................................................................... 7 1.4.1 研究内容 ............................................................................................................................ 7 1.4.2 技术路线 ............................................................................................................................ 8 2 采动煤岩体变形与瓦斯流动固气耦合数学模型采动煤岩体变形与瓦斯流动固气耦合数学模型 ........................................... 9 2.1 基本假设基本假设 ................................................................................................................................... 9 2.2 采动煤岩体变形场控制方程采动煤岩体变形场控制方程 ................................................................................................. 10 2.2.1 应力平衡方程 .................................................................................................................. 10 2.2.2 几何方程 .......................................................................................................................... 11 2.2.3 本构方程 .......................................................................................................................... 11 2.3 采动煤岩体瓦斯渗流控制方程采动煤岩体瓦斯渗流控制方程 ............................................................................................. 11 2.3.1 瓦斯流动连续性方程 ...................................................................................................... 12 2.3.2 瓦斯渗流运动方程 .......................................................................................................... 13 2.3.3 煤层瓦斯气体状态方程 .................................................................................................. 13 2.3.4 煤层瓦斯含量方程 .......................................................................................................... 13 2.4 采动煤岩体变形与瓦斯流动固气耦合数学模型的建立采动煤岩体变形与瓦斯流动固气耦合数学模型的建立 ..................................................... 14 2.4.1 采动煤岩体固气耦合变量 .............................................................................................. 14 2.4.2 采动煤岩体变形的数学模型 .......................................................................................... 17 2.4.3 采动煤岩体卸压瓦斯流动数学模型 .............................................................................. 17 2.5 定解条件定解条件 ................................................................................................................................. 18 2.5.1 变形场定解条件 .............................................................................................................. 18 2.5.2 渗流场定解条件 .............................................................................................................. 19 2.6 本章小结本章小结 ................................................................................................................................. 20 重庆大学硕士学位论文 VI 3 采动煤岩体变形与瓦斯流动固气耦合模型的数值实现与验采动煤岩体变形与瓦斯流动固气耦合模型的数值实现与验证证 ................... 21 3.1 固气耦合问题的求解方法固气耦合问题的求解方法 ..................................................................................................... 21 3.2 COMSOL Multiphysics 软件简介软件简介 ........................................................................................ 21 3.3 采动煤岩体变形与瓦斯流采动煤岩体变形与瓦斯流动固气耦合模型的数值实现动固气耦合模型的数值实现 ..................................................... 22 3.3.1 固气耦合模型的嵌入 ...................................................................................................... 22 3.3.2 固气耦合模型的设置 ...................................................................................................... 23 3.4 固气耦合模型的验证固气耦合模型的验证 ............................................................................................................. 29 3.4.1 数值计算模型 .................................................................................................................. 29 3.4.2 数值计算结果分析 .......................................................................................................... 30 3.5 本章小结本章小结 ................................................................................................................................. 35 4 急倾斜俯伪斜上保护层开采保护范围的数值模拟分析急倾斜俯伪斜上保护层开采保护范围的数值模拟分析 ......................... 37 4.1 概述概述 ......................................................................................................................................... 37 4.2 数值计算几何模型及基本参数数值计算几何模型及基本参数 ............................................................................................. 38 4.2.1 几何模型的建立 .............................................................................................................. 38 4.2.2 模型的边界条件 .............................................................................................................. 40 4.2.3 数值计算的基本参数 ...................................................................................................... 41 4.3 数值计算结果与分析数值计算结果与分析 ............................................................................................................. 42 4.3.1 基于残余瓦斯压力判别准则的上保护层开采对4煤层的保护范围 .................................... 42 4.3.2 基于变形判别准则的上保护层开采对 4煤层的保护范围 ......................................... 45 4.3.3 两种方法划定结果的对比分析 ...................................................................................... 50 4.4 本章小结本章小结 ................................................................................................................................. 50 5 急倾斜俯伪斜上保护层开采保护范围的现场考察研究急倾斜俯伪斜上保护层开采保护范围的现场考察研究 ......................... 53 5.1 概述概述 ......................................................................................................................................... 53 5.2 现场考察试验概况现场考察试验概况 ................................................................................................................. 53 5.2.1 矿井概况 .......................................................................................................................... 53 5.2.2 上保护层开采的工作面概况 .......................................................................................... 56 5.2.3 上保护层开采保护范围的现有划定方法 ...................................................................... 56 5.3 现场考察内容及试验布置现场考察内容及试验布置 ..................................................................................................... 57 5.3.1 现场考察内容 .................................................................................................................. 57 5.3.2 现场试验布置 .................................................................................................................. 58 5.4 现场考察参数的测定及结果分析现场考察参数的测定及结果分析 ......................................................................................... 62 5.4.1 现场考察参数的测定方法 .............................................................................................. 62 5.4.2 现场考察参数的测定结果及分析 .................................................................................. 63 5.5 现场考察现场考察 6煤层开采对煤层开采对 4煤层保护范围的参数分析煤层保护范围的参数分析 ....................................................... 68 目 录 VII 5.5.1 被保护层 4煤层的残余瓦斯压力与残余瓦斯含量 ..................................................... 68 5.5.2 上保护层 6煤层开采沿工作面走向的保护范围参数 ................................................. 69 5.5.3 上保护层 6煤层开采沿工作面倾向的保护范围参数 ................................................. 71 5.6 急倾斜俯伪斜急倾斜俯伪斜 6上保护层开采保护范围对比分析与划定上保护层开采保护范围对比分析与划定