综采面高强度采动影响下浸水煤柱的稳定性研究.pdf
硕士学位论文 综采面高强度采动影响下浸水煤柱的综采面高强度采动影响下浸水煤柱的 稳定性研究稳定性研究 Study on the stability of soaking coal pillar under the influence of high-strength mining in fully mechanized mining face 作 者王中伟 导 师巨 峰 研究员 中国矿业大学 二零一九年五月 万方数据 学位论文使用授权声明学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定,同意本人所撰 写的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一, 学位论文著作权拥有者须授权所在学校拥有学位 论文的部分使用权,即①学校档案馆和图书馆有权保留学位论文的纸质版和电 子版,可以使用影印、缩印或扫描等复制手段保存和汇编学位论文;②为教学和 科研目的,学校档案馆和图书馆可以将公开的学位论文作为资料在档案馆、图书 馆等场所或在校园网上供校内师生阅读、浏览。另外,根据有关法规,同意中国 国家图书馆保存研究生学位论文。 (保密的学位论文在解密后适用本授权书)。 作者签名 导师签名 年 月 日 年 月 日 万方数据 万方数据 中图分类号 TD323 学校代码 10290 UDC 密 级 公开 中国矿业大学 硕士学位论文 综采面高强度采动影响下浸水煤柱的稳定性研 究 Study on the stability of soaking coal pillar under the influence of high-strength mining in fully mechanized mining face 作 者 王中伟 导 师 巨峰 申请学位 工学硕士 培养单位 矿业学院 学科专业 采矿工程 研究方向 矿山压力与岩层控制 答辩委员会主席 柏建彪 评 阅 人 盲审 二○一九年五月 万方数据 致谢致谢 时光如梭,眨眼间,三年硕士生涯就要结束了。想到即将离开熟悉的学校、 敬爱的师长、可爱的同学们,离愁不觉涌上了心头,有太多的不舍在心间积聚。 硕士研究生三年,在导师巨峰研究员的指导下,不管是在科研还是为人处世 方面,我都学到了很多,巨峰研究员虽然是一位年龄仅有 36 年的青年导师,但 他知识积累渊博、 学术视野开阔、 治学态度严禁、 做人品质优秀、 工作态度认真, 他的这一切优点不仅在这三年里潜移默化地影响着我,而且我坚信,在未来的日 子里将会继续影响着我,他将是我一路前行的启明灯。 三年来, 导师巨峰研究员给与了我无私的指导和帮助。 工作中, 他循序渐进、 踏踏实实、一步一个脚印带领着我充实度过每一天的科研之路,让我在学习的过 程中既知其然,也知其所以然;生活中,虽然他总是夜以继日地忙碌着,但是总 会刻意抽出时间来关心我们的学习和生活。在论文的整个研究过程中,巨老师在 论文选题上给予了高瞻远瞩的指导,在技术路线的设计上给予了高屋建瓴的点 拨, 在论文的框架结构以及遣词造句上给予了匠心独运的指导。论文从选题到成 稿,一字一句无不饱含着导师的心血与智慧。没有导师的悉心指导和帮助,论文 是不可能得以顺利完成的。值此毕业论文完成之际,我心怀感激和敬佩,感谢巨 老师在研究生期间对我孜孜不倦的教诲和无私帮助与关怀, 在此对导师巨峰研究 员致以崇高的敬意和由衷的感谢,也要感谢导师在生活、做人、做事上给予的启 示和帮助。 感谢张凯教授、陈彦龙副教授、黄艳丽教授、周楠副教授、马立强教授、曹 胜根教授对毕业论文思路和具体内容提出的建议和指正, 在这里我向他们道一声 辛苦和感谢 特别感谢黄鹏博士后对我毕业论文的全程指导及帮助,从我开始准备开题, 到做实验,及毕业论文的构思撰写,黄鹏博士后一直在全心全意的帮助我。可以 说黄鹏博士后是我硕士毕业论文的第二指导老师同时,也感谢黄鹏博士对我日 常的照顾和帮助谢谢师兄 感谢课题组肖猛博士对我毕业论文实验章节及理论章节的指导; 感谢何泽全 硕士、 李开源硕士对我毕业论文的格式排版及错别字查找;感谢宁湃硕士对论文 研究现状的整理修改及对图表标题的翻译; 感谢何泽全硕士和郭志文硕士在我做 实验过程中对我的帮助。非常感谢课题组师兄弟对我的帮助。 感谢郭帅博士、李百宜博士、高瑞讲师、张云博士、宁耀圣硕士、王靖超硕 士、钱万雄硕士、宋天奇硕士、孔国强硕士在我毕业论文撰写期间对我的鼓励和 帮助。 万方数据 感谢女友闫峰女士对我一贯的支持,对我的不离不弃,你对我无微不至的照 顾是我一直前行的动力。谢谢你,亲爱的。 感谢父母,他们给我生命、养育我长大、教我做人,在我心烦气躁时给予理 解和包容,并安慰和鼓励,他们是我坚实的后盾,不断奋斗的动力。 最后,感谢各位专家和教授在百忙之中评审本文,并期待得到更多的指导和 启迪。 万方数据 I 摘摘 要要 小纪汗煤矿是一个水文地质比较复杂的矿井,正在开采的 2主采煤层是主 要含水层,在工作面采掘过程中地下水涌出量非常大。地下水对煤柱的稳定性影 响很大,在水的长期浸泡下煤柱的力学性质弱化、强度降低,因而使煤柱的稳定 性也随之降低。且小纪汗煤矿是一个以大采高综采技术为主的现代化高产矿井, 工作面推进速度较快,矿压显现相当剧烈,对煤柱稳定性的影响相当大。本文在 此背景下,研究了推进速度和煤层含水率对区段煤柱稳定性的影响,其相应研究 成果可以为矿井水影响下的区段煤柱稳定性控制提供必要的理论基础。 (1)由实验可知,煤体峰值强度、弹性模量随含水率和加载速率的增大呈 现先增大后减小的变化趋势,存在临界含水率和临界加载速率;加载速率和含水 率较小时,煤体在峰值强度附近发生脆性破坏,加载速率和含水率较大时,发生 延性破坏,含水率越大,这种现象越明显,但当含水率较大时,煤体随加载速率 变化的破坏都属于延性破坏。 (2)由模拟结果可知,随着煤层含水率和工作面推进速度的增加,煤柱水 平位移量先减小后增大,垂直应力先减小后增大,塑性区面积先减小后增大,因 此,存在临界含水率和临界推进速度,使得区段保护煤柱稳定性达到最高。 (3)由理论分析可知,煤层含水直接影响区段煤柱的极限强度,当煤层含 水率为临界含水率时,区段煤柱的极限强度最高,煤柱稳定性最高;工作面推进 速度影响工作面老顶破断步距,当推进速度处于临界推进速度时,工作面老顶破 断步距最小,来压时工作面的支架阻力最小,煤柱承受压力最小,因此,区段煤 柱的稳定性最高。 引入含水率对煤体强度的弱化因子和推进速度对煤体所受应 力集中系数的影响因子,将二者影响下的区段煤柱应力集中系数重新定义为 11K,从而利用现有煤柱留设宽度模型推导出含水和工作面推进速度 影响下区段煤柱的合理留设宽度。 该公式能大体估算出不同含水率和工作面推进 速度下区段煤柱的合理留设宽度。 (4)提出了疏放煤层含水至临界含水率状态和改变工作面推进速度至临界 推进速度这两种针对性的方法,通过现场测试得到,工作面推进速度处于临界推 进速度时,工作面老顶破断步距最小,保护煤柱的损伤最小,煤柱稳定性最高; 煤层含水率处于临界含水率时,区段保护煤柱的强度最高,抗压能力最强,煤柱 两帮鼓出量最小。 本文以实验、 理论及现场相结合的方法研究了区段保护煤柱在不同含水率和 工作面推进速度下的应力、变形特征,推导了含水煤体在不同加载速率下的损伤 万方数据 II 本构方程、分析了煤柱的失稳机理、推出了区段保护煤柱的失稳判据、提出了相 应的煤柱稳定性控制措施, 研究结果可以为西部煤矿工作面开采设计提供一定的 理论支撑。 本文有图 58 幅、表 10 个、参考文献 84 篇。 关键词关键词煤层含水率;工作面推进速度;煤体强度;区段煤柱 万方数据 III Abstract Xiaojihan Coal Mine is a mine with complex hydrogeology. 2 main mining seam is the main aquifer, and the amount of groundwater gushing out in the mining process of the working face is very large.. Groundwater has a great influence on the stability of coal pillars. Under the long-term immersion of water, the mechanical properties of coal pillars are weakened and the strength of coal pillars is reduced, so the stability of coal pillars is also reduced.And Xiaojihan Coal Mine is a modern high-yield mine with large mining height and fully mechanized mining technology as its main technology. The working face advances rapidly, the strata pressure appears intensely, and the strong strata pressure occurs frequently, which has a great influence on the stability of coal pillars. Under this background, this paper studies the influence of advance speed and water content of coal seam on the stability of section coal pillar, and the corresponding research results can provide the necessary theoretical basis for the stability control of section coal pillar under the influence of mine water. (1) The experimental results show that the peak strength and elastic modulus of coal increase first and then decrease with the increase of water content and loading rate, and there are critical water content and critical loading rate. And with the increase of loading rate and water content, the failure of coal mass near the peak strength gradually changes from brittle failure to ductile failure. The larger the loading rate, the larger the water content, the more obvious this phenomenon is. (2)The simulation results show that the horizontal displacement and the vertical stress and the area of plastic zone of coal pillar decreases first and then increases, with the increase of the water content of coal seam and the advancing speed of working face. Therefore, there are critical water content and critical advancing speed, which make the stability of protective coal pillar reach the highest level. (3)the theoretical analysis show that coal seam water content directly affects the ultimate strength of coal pillars. When the water content of coal seam is critical, the ultimate strength of coal pillars is the highest and the stability of coal pillars is the highest. The advancing speed of working face affects the weighting strength of working face. When the advancing speed is at the critical advancing speed, the weighting strength of working face is the smallest and the stability of coal pillars is the highest. By introducing the weakening factor of water content on the strength 万方数据 IV of coal body and the influence factor of advancing speed on the stress concentration factor of coal body, the stress concentration factor of coal pillar in the section affected by the two factors is redefined as 11K.So ,the reasonable reserved width of section coal pillar affected by moisture content and advance speed of working face can be deduced by using the existing width model of coal pillar reserved. The ula can roughly estimate the reasonable setting width of coal pillars under different water content and advancing speed of working face. (4)Put forward two pertinent s that draining the water content of the coal seam to the critical water content state and changing the advancing speed of the working face to the critical advancing speed, and then tests the feasibility of these two s on the spot. Through field testing, it is found that when the advancing speed of the working face is at the critical advancing speed, the weighting of the working face is the weakest, the damage of the protective coal pillar is the smallest, and the stability of the coal pillar is the highest; when the water content of the coal seam is at the critical water content, the strength of the protective coal pillar is the highest, the compressive capacity is the strongest, and the outburst of two sides of coal pillar is the smallest. There are 58 figures, 10 tables and 84 references in this paper. Key words coal seam water content; working face advancing speed; coal body strength; section coal pilla 万方数据 V 目目 录录 摘摘 要要 ........................................................................................................................... I 目目 录录 .......................................................................................................................... V 图清单图清单 .........................................................................................................................IX 表清单表清单 ..................................................................................................................... XIII 变量注释表变量注释表 .............................................................................................................. XIV 1 绪论绪论 ........................................................................................................................... 1 1.1 研究背景与意义 ..................................................................................................... 1 1.2 国内外研究现状 ..................................................................................................... 2 1.3 研究内容与技术路线 ........................................................................................... 11 2 不同加载速率下浸水煤体的力学特性不同加载速率下浸水煤体的力学特性 ................................................................. 13 2.1 实验方案 ............................................................................................................... 13 2.2 不同含水率对煤体强度的弱化作用 ................................................................... 19 2.3 不同加载速率对浸水煤体力学特性的影响 ....................................................... 28 2.4 不同加载速率下浸水煤体的本构关系 ............................................................... 37 2.5 本章小结 ............................................................................................................... 42 3 采动影响下浸水煤柱稳定性数值模拟采动影响下浸水煤柱稳定性数值模拟 ................................................................. 44 3.1 数值计算模型建立 ............................................................................................... 44 3.2 不同含水率下煤柱的变形破坏规律 ................................................................... 49 3.3 不同推进速度下煤柱的变形破坏规律 ............................................................... 54 3.4 本章小结 ............................................................................................................... 59 4 高强度采动影响下浸水区段煤柱的失稳机制分高强度采动影响下浸水区段煤柱的失稳机制分析析 ............................................. 61 4.1 煤柱稳定性的影响因素 ....................................................................................... 61 4.2 高强度采动影响下浸水煤柱失稳机理 ............................................................... 62 4.3 高强度采动影响下浸水煤柱合理留设宽度 ....................................................... 66 4.4 高强度采动影响下浸水煤柱失稳判据 ............................................................... 70 4.5 失稳判据实例计算 ............................................................................................... 71 4.6 本章小结 ............................................................................................................... 72 万方数据 VI 5 工程实例工程实例 ................................................................................................................. 73 5.1 11215 工作面概况 ................................................................................................. 73 5.2 11215 工作面矿压显现情况 ................................................................................. 76 5.3 煤柱稳定性控制措施 ........................................................................................... 79 5.4 高强度采动影响下浸水煤柱变形监测................................................................ 80 5.5 本章小结 ............................................................................................................... 83 6 结论与展望结论与展望 ............................................................................................................. 84 6.1 主要结论 ............................................................................................................... 84 6.2 展望 ....................................................................................................................... 85 参考文献参考文献 ..................................................................................................................... 87 作者简介作者简介 ..................................................................................................................... 93 学位论文原创性声明学位论文原创性声明 ................................................................................................. 94 学位论文数据集学位论文数据集 ......................................................................................................... 95 万方数据 VII Contents Abstract ...................................................................................................................... III Contents .................................................................................................................... VII List of Figures .............................................................................................................IX List of Tables ........................................................................................................... XIII List of Variables....................................................................................................... XIV 1 Introduction ............................................................................................................... 1 1.1 Research Background and Significance ................................................................... 1 1.2 Present Research Status............................................................................................ 2 1.3 Research Contents and Technical Route ................................................................ 11 2 Mechanical Properties of Water-immersed Coal at Different Loading Rates .. 13 2.1 Experimental Scheme............................................................................................. 13 2.2 Weakening Effect of Different Water Content on Coal Strength ........................... 19 2.3 Effect of Different Loading Rates on Mechanical Properties of Water-immersed Coal .............................................................................................................................. 28 2.4 Constitutive Relationship of Immersed Coal at Different Loading Rates ............. 37 2.5 Summary ................................................................................................................ 42 3 The Numerical Stability of Coal Pillar Mining under the Influence of Immersion ................................................................................................................... 44 3.1 Establishment of Numerical Calculation Model .................................................... 44 3.2 Deation and Failure Law of Coal Pillar under Different Water Content ........ 49 3.3 Deation and Failure Law of Coal Pillars at Different Propulsion Velocities . 54 3.4 Summary ................................................................................................................ 59 4 Analysis of Instability Mechanism of Soaking Section Coal Pillar under the Influence of High-strength Mining ........................................................................... 61 4.1 Influencing Fact