多煤层煤柱底板应力分布规律及其应用.pdf

国家重点基础研究发展计划（973 计划） （2013CB227904） 国家建设高水平大学公派博士研究生联合培养项目（201206420027） 国家自然科学基金青年科学基金项目资助（51404251） 教育部科技项目创新团队资助（IRT_14R55） 江苏高校优势学科建设工程资助项目 博士学位论文 多煤层煤柱底板应力分布规律及其应用 Stress Redistribution Law of Floor Strata under Chain Pillar and Its Application in Multi-seam Mining 作 者张念超 导 师张 农教授 中国矿业大学 二〇一六年五月 万方数据 中图分类号 TD322 学校代码 10290 UDC 622 密 级 公开 中国矿业大学 博士学位论文 多煤层煤柱底板应力分布规律及其应用 Stress Redistribution Law of Floor Strata under Chain Pillar and Its Application in Multi-seam Mining 作 者 张念超 导 师 张农教授 申请学位 工学博士 培养单位 矿业工程学院 学科专业 采矿工程 研究方向 巷道围岩控制 答辩委员会主席 许家林 评 阅 人 盲 审 二〇一六年五月 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 论文审阅认定书论文审阅认定书 研究生 张念超 在规定的学习年限内，按照研究生培养方案的要 求， 完成了研究生课程的学习， 成绩合格； 在我的指导下完成本学位论文, 经审阅，论文中的观点、数据、表述和结构为我所认同，论文撰写格式符 合学校的相关规定，同意将本论文作为学位申请论文送专家评审。 导师签字 年 月 日 万方数据 致致 谢谢 论文即将完成，读博伊始的一幕幕从眼前闪过，2009 年本科攻博开始，一晃七 年，24 岁的青年小伙变成了 31 岁的中年大叔，见证了煤炭行业的强盛和衰败，让 我意识到除了丰富自己别无他择。感恩遇到导师张农教授，跟随七年，除了学到丰 富的专业知识，更被导师那渊博的学识，严谨的治学态度和高尚的做人风格所熏陶 感染。博士求学期间，导师在学术、精神和物质方面给予了我巨大的支持与帮助。 论文的撰写过程中，导师在选题和思路上都给予了登高博见的点拨，让学生深刻的 体会到学无止境。张老师，请允许我向您深深的鞠一躬，以表达我对您最诚挚的感 谢和最衷心的祝福，您是我一生学习的目标和榜样。 感谢许兴亮副教授，郑西贵副教授，李桂臣教授，韩昌良老师，赵一鸣老师， 司光耀博士，孙元田博士，王化洋硕士，崔光俊硕士，李井硕士，王龙辉硕士在论 文撰写期间给予的热情指导和大力帮助。冯晓巍博士，王洋博士，潘东江博士，马 百龙硕士，张天池硕士，李井硕士，徐华君硕士，董昭禄硕士，杨林硕士，谢正正 硕士，兰一天硕士，杨力硕士，甘江硕士在论文的数据分析和排版等方面给予了建 设性的意见；博士求学期间王成副教授，阚甲广副教授，钱德雨博士，李宝玉博 士，于宪阳博士，薛飞博士，吕创新博士，谢军峰硕士，许幸福硕士，刘聪硕士， 司文硕士，胡程程硕士，徐晓勇硕士给予了我生活上的帮助，在此表示衷心感谢。 论文的工程现场取自澳洲昆士兰大学博士联合培养期间与Vale Australia下属煤 矿Integra Underground Mine的科研项目。在此衷心感谢Joan Esterle教授和她的Vale- UQ中心还有Huilin Xing副教授及他的数值模拟小组对我巨大的学术指导和生活帮 助。刘岩，高晋芳，刘向冲，韩志婷，李琴，Valerie，Stephanie，Areeba你们都给我 了美好的异国回忆。同时，衷心感谢Integra Underground Mine对论文数据的支持。 感谢父母，一直默默支持，对于这个三十尚不立的儿子，从未有过任何怨言， 爸妈，儿子向您磕头致谢了。 感谢岳父母的信任，敢于把自己女儿交给一个三十岁还在画大饼的女婿。 感谢老婆高群不但给了我一个聪明可爱的女儿更重要的是勇于挑起家中的经济 重担，我无以为报，只能为你奉献终生，奋斗终生。 感谢 IceFrog 开发的 Dota 游戏，陪我度过了这些年的风风雨雨，你的陪伴让我 本应该五年毕业的顺利延期到七年。不过我相信小姨说的话，一切挫折都是化了妆 的祝福。我相信走过迷途才知道大道的珍贵，才会更加奋力的冲向最前。 最后，衷心感谢在百忙之中参与论文评审和答辩的专家评委们，祝愿你们工作 顺利，身体健康，万事如意 张念超 2016.04.28 万方数据 I 摘摘 要要 多煤层开采矿井，随着上部煤层的逐渐采空，遗留下了各种各样的残留煤柱， 在原岩应力场和采动应力场的相互影响下，对底板岩层产生损伤破坏，下部煤层尤 其是极近距离和近距离煤层开采面临难题。为此，本论文选取反映岩石材料拉伸破 坏和剪破坏的最大主应力和最大剪应力为评价指标，并辅以底板岩层中垂直应力和 水平应力的分布状态描述，考虑围岩岩性状况（围岩岩性、煤层倾角和间距） 、围岩 应力状况（岩层侧压系数和煤层深度）和人为影响因素（煤柱宽度和煤层采高）的 影响，采用无量纲化应力的研究手段，通过理论分析、实验室测试、数值模拟和工 程验证的方法，结合提出的“应力临界线”和“间深比”概念，研究了多煤层开采 煤柱下底板岩层的应力分布规律。研究成果不仅具有重要的理论意义，而且具有重 要的工程应用价值。具体成果如下 （1）现场调研了Integra Underground Mine煤矿多煤层开采的地质力学状况，提 取了研究底板岩层应力分布特征的相关地质力学资料；取样进行实验室力学性能测 试，得到了该矿岩石力学参数。 （2）视煤岩体为弹性介质，建立了是否考虑采空区垮落顶板对底板岩层损伤破 坏的两种模型， 推导了两模型中底板分别为单一岩层和多层岩层时任一点的应力公式； 辅以数值模拟对比分析，发现不考虑采空区垮落顶板的模型中，顶板覆岩重量完全由 煤柱承担，导致底板应力集中区影响过大，不符合工程实践，因此，采空区垮落顶板 对底板岩层的损伤破坏是研究煤柱下底板岩层应力分布不可或缺的影响因素， 但采空 区垮落顶板对底板岩层的应力集中梯度影响远小于荷载煤柱的影响，因此，煤柱底板 应力分布规律研究应以煤柱对底板岩层的损伤破坏为主， 以采空区垮落顶板的影响为 辅。 （3）基于无量纲化的应力集中系数，提出“应力临界线”概念，得到煤柱下垂 直应力、水平应力、最大主应力和最大剪应力的应力临界线分布分别呈“纺锤形” 、 “共轭犄角形” 、 “双耳鼎形”和“葫芦形” 。 （4）数值模拟详细研究了煤柱下底板岩层岩性，煤层倾角和岩层侧压系数三个 因素对底板应力分布演化的影响，得到了层状岩体的界面效应，用于解释煤层巷道 顶底板应力集中现象，指导岩石巷道层位优化选择；发现45岩层倾角具有特殊 性，垂直应力、最大主/剪应力的最大应力集中系数值以45为界，当倾角增大或者 减小时，最大应力集中系数都会增大；侧压系数的变化对岩性较强的岩层产生的影 响大于岩性较弱的岩层，高侧压系数会对采动影响产生抑制作用。 （5）通过叠加煤柱下底板岩层垂直应力、水平应力、最大主/剪应力的应力集中 区，得到底板应力分区模型，分析了各分区的应力集中情况和破坏形式，给出了多煤 万方数据 II 层开采分类中极近距离煤层开采、近距离煤层开采、单一煤层开采的判据。 （6） 提出煤层 “间深比” 概念， 以最大主/剪应力临界线为评价指标， 得出以-ln间 深比为判据的多煤层开采分类，与底板岩层分区模型的判据基本吻合；考虑底板岩 层为不同岩性， 拟合出煤层间深比和煤柱宽高比与下部煤层回采巷道最佳布置位置的 函数方程，同时给出函数方程优化巷道位置的步骤，采用数值模拟验证了函数方程准 确有效。 （7）研究成果成功应用于 Integra Underground Mine 煤矿多煤层开的 Middle Liddell 煤层、Lower Liddell 煤层和 Hebden 煤层。 该论文有图 103 幅，表 38 个，参考文献 200 篇。 关键词关键词多煤层开采；底板应力分布；应力临界线；间深比；数值模拟 万方数据 III AbstractAbstract Multi-seam longwall mining is considered to be the future of excavating the underground coal in most of the coal countries, such as China and Australia. As upper seam was mined out, chain pillars were left generating severe interaction to the floor strata and the lower coal seam mining, especially for the ultra-close seam mining. This paper presents detailed research on the stress redistribution of the floor strata under the chain pillar of multi- seam longwall mining with the ology of field investigation, analytical derivation, laboratory test, numerical simulation and industrial implementation. The maximum principal stress and the maximum shear stress were employed to uate the stress redistribution patterns of the floor strata under the chain pillar, which were also described by the vertical stress and horizontal stress. Two original definitions of the stress threshold contour and interburden-to-overburden were put forward according to the nondimensionalize analysis . Considering the strata attribute rock properties, dip angle of coal seam and interburden thickness, the strata stress state the lateral stress coefficient and depth of the upper coal seam and the man-made influence the coal pillar width and mining height in this reserach, the stress interaction and redistribution of the floor strata under the upper pillar was studied detailedly. The conclusions can provide theoretical framework of a design overview and practical basis for similar mining conditions in other coalfields. The total figures, tables, and references are 103, 38 and 200, respectively, in this dissertation. Keywords Multi-seam mining; Floor strata stress redistribution; Stress threshold contour; Interburden-to-overburden; Numerical simulation 万方数据 IV Extended Abstract Multi-seam longwall mining is considered to be the future of excavating the underground coal in most of the coal countries, such as China and Australia. As upper seam was mined out, chain pillars were left generating severe interaction to floor strata, which makes it hard for the lower coal seam mining, especially for the ultra-close seam mining. This paper presents detailed research on stress redistribution of the floor strata under the chain pillar of multi-seam longwall mining with the ology of field investigation, analytical derivation, laboratory test, numerical simulation and industrial implementation. The maximum principal stress and the maximum shear stress were employed to uate the mechanical state of the floor strata with definitions of the stress threshold contour and interburden-to-overburden. Considering the strata state, such as rock properties, dip angle of coal seam and interburden thickness, the strata stress, such as the lateral stress coefficient and depth of the upper coal seam, and the man-made influence, for example, the coal pillar width and mining height in numerical simulation, detailed mining interaction to the floor strata from the upper pillar was studied. The conclusions can provide theoretical framework of a design overview and practical basis for similar mining conditions in other coalfields. The key findings are as follows, 1 Multi-seam mining of geological and mechanical conditions were investigated in Integra Underground Mine. The geomechanical data of stress redistribution of the floor strata was researched. Rock parameters were indicated by the laboratory test. 2 Built the mechanical models of whether considering the caving roof strata damaging the floor strata with isotropic and transversal isotropy layer floor and derive the equations assuming the strata are elastic materials. With numerical simulation comparison, the model of ignoring the caving roof strata makes the whole load working on the chain pillar which is unrealistic for the stress influence too severe. Therefore, the other model of considering the caving roof strata is essential in the study of the stress redistribution of the floor strata under a chain pillar. However, it was found that the stress concentration beneath a chain pillar is usually significantly larger than that under a gob, and its impact on underlying seams is proportionally greater. So this paper mainly studied the stress beneath a chain pillar. 3 Based on the nondimensionalized stress concentration coefficient, the stress threshold was mentioned whose shape of vertical stress, horizontal stress, the maximum principal stress and the maximum shear stress is “spindle”, “conjugated corner”, “ding with two ears” and “calabash”, respectively. 万方数据 V 4 The influence of the stress redistribution of the floor strata properties, dip angle of the coal seam and the lateral stress coefficient was simulated and analyzed. The interface effect of transversal isotropy layer was mentioned which can be used to interpret the stress interaction in the floor and roof strata below and above a gateroad and opitimise the layout of rock roadways in floor strata. Also the 45 angle was indicated a special boundary of the vertical stress, the maximum principal stress and the maximum shear stress. The lateral stress affects the strata of a stronger stiffness than a weaker stiffness and depresses the mining interaction. 5 The division model of the floor stress concentration was derived by overlapping the stress concentration zones of vertical stress, horizontal stress, the maximum principal stress and the maximum shear stress. The damage pattern was also discussed. Moreover, the criterion of the multi-seam mining of ultra-close mining, multi-seam mining and single seam mining was given by the division model. 6 The criterion of multi-seam mining with the minus natural logarithm of interburden- to-overburden was found the same with the criterion of the above division model, uating with the threshold of the maximum principal stress and the maximum shear stress. With mudstone and sandstone isotropy floor, the fitting equations of interburden-to-overburden, the width-to-height of a chain pillar and the optimization location of the gateroad were solved. The equations of the maximum pricipal stress threshold are as follows  If the floor strata are soft mudstone, the fitting equations of interburden-to- overburden, the width-to-height of a chain pillar and the optimization location of the gateroad gives, 0.26620.2070.257 x4.2583-49.028171.33 mmphhh fwxwxw    If the floor strata are hard sandstone, the fitting equations of interburden-to- overburden, the width-to-height of a chain pillar and the optimization location of the gateroad shows, 22 2 2 x0.9435 5.6872 10.177- 9.6434 58.63 110.99 23.835 147.26 314.71 smphh hh hh fwwx wwx ww    （） （） （） The equations of the maximum shear stress threshold are as follows  If the floor strata are soft mudstone, the fitting equations of interburden-to- overburden, the width-to-height of a chain pillar and the optimization location of 万方数据 VI the gateroad gives, 323 322 32 32 x0.6626 4.6995 9.7434 5.541- 9.2328 65.114 133.66 74.702 41.301 289.63 589.47 331.49 61.114 428.01 874.1 534.45 mmshhh hhh hhh hhh fwwwx wwwx wwwx www     （） （） （） （）  If the floor strata are hard sandstone, the fitting equations of interburden-to- overburden, the width-to-height of a chain pillar and the optimization location of the gateroad indicates, 0.18830.27720.350.372 x-1.198622.114-139.04314.66 smshhhh fwxwxwxw   7 For particular case of Integra Underground Mine in Sydney basin, Australia, the fitting equations were calculated for the multi-seam mining of the Middle Liddell seam, Lower Liddell seam and Hebden seam. The result shows the equation works effectively and efficiently. The total figures, tables, and references are 103, 38 and 200，respectively, in this dissertation. Keywords Multi-seam mining; Floor strata stress redistribution; Stress threshold contour; Interburden-to-overburden; Numerical simulation 万方数据 VII 目目 录录 摘摘 要要 .................................................................................................................................... I 目目 录录 ................................................................................................................................ VII 图清单图清单 ................................................................................................................................. XI 表清单表清单 ........................................................................................................................... XVIII 变量注释表变量注释表 ...................................................................................................................... XXI 1. 绪论绪论 .................................................................................................................................. 1 1.1 研究背景及意义 .......................................................................................................... 1 1.2 国内外研究现状 .......................................................................................................... 3 1.3 存在的主要问题 ........................................................................................................ 11 1.4 研究方法及内容 ........................................................................................................ 12 1.5 研究技术路线 ............................................................................................................ 13 2 多煤层开采地质条件分析多煤层开采地质条件分析 ............................................................................................. 15 2.1 矿井地质概况 ............................................................................................................ 15 2.2 煤系地层赋存状况 .................................................................................................... 17 2.3 岩石力学性能测试 .................................................................................................... 24 2.4 本章小结 .................................................................................................................... 25 3 煤柱底板岩层的理论模型和界面效应研究煤柱底板岩层的理论模型和界面效应研究 ................................................................. 27 3.1 研究评价指标概述 .................................................................................................... 27 3.2 底板岩层应力分布理论模型 .................................................................................. 31 3.3 数值模拟验证理论模型 .......................................................................................... 40 3.4 层状岩体的界面效应 ................................................................................................ 57 3.5 本章小结 .................................................................................................................... 59 4 煤柱底板岩层应力分布及分区研究煤柱底板岩层应力分布及分区研究 ...................................................................