深部条带开采煤柱失稳特性与冲击危险评价预警.pdf

分类号分类号 TD324 密密 级 公级 公 开开 U D C 单位代码单位代码 10424 学学 位位 论论 文文 深部条带开采煤柱失稳特性深部条带开采煤柱失稳特性 与冲击危险评价预警与冲击危险评价预警 李文帅李文帅 申请学位级别申请学位级别硕士学位硕士学位 专业名称专业名称工程力学工程力学 指导教师姓名指导教师姓名沈沈 宝宝 堂堂 职职 称称教教 授授 山山 东东 科科 技技 大大 学学 二零一六年六月二零一六年六月 万方数据 论文题目论文题目 深部条带开采煤柱失稳特性深部条带开采煤柱失稳特性 与冲击危险评价预警与冲击危险评价预警 国家自然科学基金资助项目（51204102、51374140） 作者姓名李作者姓名李 文文 帅帅 入学时间入学时间 2013 年年 9 月月 专业名称工程力学专业名称工程力学 研究方向矿研究方向矿 山山 岩岩 石石 力力 学学 指导教师沈指导教师沈 宝宝 堂堂 职职 称称 教教 授授 顾顾 士士 坦坦 副教授副教授 论文提交日期论文提交日期2016 年年 6 月月 论文答辩日期论文答辩日期2016 年年 6 月月 授予学位日期授予学位日期 万方数据 INSTABILITY CHARACTERISTICS OF COAL PILLAR AND ROCK BURST UATION AND WARNING IN DEEP STRIP MINING A Dissertation ted in fulfillment of the requirements of the degree of MASTER OF ENGINEERING from Shandong University of Science and Technology by Li Wenshuai Supervisor Professor Baotang Shen College of Mining and Safety Engineering June 2016 万方数据 声声 明明 本人呈交给山东科技大学的这篇硕士学位论文，除了所列参考文献和世所 公认的文献外，全部是本人在导师指导下的研究成果。该论文资料尚没有呈交 于其它任何学术机关作鉴定。 硕士生签名 日 期 AFFIRMATION I declare that this dissertation, ted in fulfillment of the requirements for the award of Master of Engineering in Shandong University of Science and Technology, is wholly my own work unless referenced in acknowledge. The document has not been ted for qualification at any other academic institute. Signature Date 万方数据 山东科技大学硕士学位论文 摘要 摘摘 要要 随着我国煤矿开采逐年向深部发展，冲击地压作为一种特殊的强矿压显现现象而日 趋严峻，给矿井安全、高效生产带来了很大的威胁。受深部高应力、构造应力等复杂应 力场的影响，条带煤柱的受力状态、空间系统结构、力学性质都较浅部发生了巨大的变 化，深部条带煤柱的高应力集中特征使得在进行条带开采时容易诱发冲击地压灾害。本 文以条带开采为背景，采用理论分析、数值模拟及现场试验相结合的研究方法，对条带 开采诱冲机理及冲击危险评价、预警方法进行了研究，取得了以下研究成果 （1）将条带煤柱视为连续分布的 Winkler 弹性地基，将顶板视为置于弹性地基上的 矩形薄板，建立了理想状态下煤柱-顶板力学系统模型；基于弹性力学理论，得出了煤柱 变形与顶板下沉的挠度变化曲线，分析了系统挠度变化影响因素。 （2）基于突变理论，建立了煤柱-顶板系统变形失稳的尖点突变模型，得到了煤柱 失稳的临界有效宽度，分析了系统在理想情况下的煤柱临界有效宽度影响因素，认为一 般情况下，煤柱强度越高，所需要的煤柱有效宽度也就越小，系统稳定性也就越好；构 造应力越小，所需要的煤柱有效宽度也就越小，系统稳定性也就越好。 （3）计算得到了系统失稳所能释放的最大能量。由计算公式可知，系统失稳释放的 能量与顶板、煤柱性质以及外部水平、垂直应力密切相关。 （4）基于 FLAC3D 数值模拟可知 （a）煤柱、顶板垂直应力主要由上覆岩层重力 引起，受构造应力影响较小； （b）相同的埋深条件下，地质构造越复杂，煤柱、顶板积 聚的能量也将更多，发生冲击的可能性也更大； （c）在模拟设定的侧压系数条件下，随 着构造应力的增加，顶板细砂岩岩层 x 方向水平应力增加幅度较明显，而垂直应力增加 幅度不甚明显； （d）随着煤柱弹性模量的增加，煤柱水平方向应力随之增加，垂直应力 基本无变化，弹性应变能的变化基本是由水平应力引起。 （5）基于数量化理论，建立了条带开采冲击危险评价模型，较为客观的评价了安居 煤矿 2304 工作面开采冲击危险性，为条带开采冲击危险提供了一个相对客观的评价模 型。 （6） 基于钻屑法冲击危险预警， 提出了基于多参数临界煤粉量指标的冲击危险预警 方法，避免了仅通过一个临界煤粉量预警指标对所有深度钻孔进行冲击危险预警存在的 较大偏差，从而实现对冲击危险进行准确、可靠的预警。 关键词关键词冲击地压；条带开采；构造应力；冲击危险评价；冲击危险预警 万方数据 山东科技大学硕士学位论文 摘要 ABSTRACT With mining depth of coal mines increasing year by year in China, rock burst as a unique strata behavior for deep mine becomes more serious, which has imposed great threat to the safety and productivity of coal mine. With the influence of complicated stress field, such as high overburden stress and tectonic stress, the stress state, ecosystem spatial structure and mechanical property of deep coal pillars are large different from the shallow ones. The high stress concentration of deep coal pillar makes it easy to induce the rock burst disaster when the strip mining is carried out. In this dissertation, with the background of strip mining, mechanism of rock burst, rock burst assessment and early warning of strip mining were analyzed by the means of theoretical analysis, numerical simulation and field investigation. The main achievements are as follows 1 Strip pillar was regarded as a continuous Winkler foundation and the roof was regarded as a rectangular plate placed on elastic foundation, then a conceptual coal pillar and roof mechanical system model was established. Based on elasticity theory, deflection curve of coal pillar deation and roof sinking was obtained, and the deflection factors of system were analyzed. 2 Based on catastrophe theory, a cusp catastrophic model of coal pillar and roof deation was built up which revealed critical and effective width of coal pillar, and the influencing factors of the critical and effective width of the coal pillar under the ideal condition were analyzed. The results showed that the larger the elastic modulus of coal pillar and the smaller the tectonic stress, the more stable the system generally. 3 The mathematical expression of energy release was obtained once system failed. The results showed that the energy released was mainly influenced by the properties of the roof and coal pillar and the horizontal stress. 4 Based on FLAC3D numerical simulation, the results gained were as follows a Vertical stress in coal pillar and roof was caused mainly by the gravity of overlying strata which was less affected by tectonic stress. b Under the same mining depth, the more complex geological structure was, the greater energy accumulation in the coal pillar and roof would be, and the rock burst impact would be greater. c With the increase of tectonic stress, X-direction stress of roof sandstone strata increased more obviously than the vertical stress. d With the increase of elastic modulus of coal pillar, X-direction stress of coal pillar would increase and the vertical stress had no change. To some extent, the change of elastic strain energy was basically caused by horizontal stress. 5 Based on the quantification theory, a rock burst assessment model of strip mining was established which provided a relatively objective uation for deep strip mining. Rock burst 万方数据 山东科技大学硕士学位论文 摘要 hazard of No. 2304 working face in Anju coal mine was uated by this model. 6 Based on drilling , a rock burst hazard warning based on critical multi parameter coal quantity index was proposed which could improve the accuracy and reduce errors. This would help achieve rock burst warning more accurately and reliably. Keywords rock burst; strip mining; tectonic stress; rock burst assessment; rock burst warning 万方数据 山东科技大学硕士学位论文 目录 i 目目 录录 1 绪论绪论 ................................................................................................................... 1 1.1 问题的提出及研究意义...................................................................................................1 1.2 国内外研究现状...............................................................................................................1 1.3 主要研究内容及技术路线...............................................................................................5 2 深部条带开采诱发冲击危险理论研究深部条带开采诱发冲击危险理论研究........................................................... 7 2.1 条带开采主要诱冲因素...................................................................................................7 2.2 煤柱-顶板系统挠曲线分析............................................................................................10 2.3 煤柱-顶板系统失稳机理................................................................................................14 2.4 算例分析.........................................................................................................................17 2.5 本章小结.........................................................................................................................19 3 深部条带开采诱发冲击危险数值模拟深部条带开采诱发冲击危险数值模拟......................................................... 21 3.1 条带开采冲击危险数值模型.........................................................................................21 3.2 埋深影响下煤柱应力及能量变化规律.........................................................................23 3.3 埋深影响下顶板应力及能量变化规律.........................................................................27 3.4 构造应力影响下煤柱应力及能量变化规律.................................................................29 3.5 构造应力影响下顶板应力及能量变化规律.................................................................33 3.6 煤柱弹模影响下煤柱应力及能量变化规律.................................................................35 3.7 本章小结.........................................................................................................................39 4 深部条带开采冲击危险评价及预警方法深部条带开采冲击危险评价及预警方法..................................................... 41 4.1 条带开采冲击危险评价方法.........................................................................................41 4.2 冲击危险预警方法.........................................................................................................47 4.3 工程实践.........................................................................................................................51 4.4 本章小结.........................................................................................................................57 5 主要结论及展望主要结论及展望............................................................................................. 58 5.1 主要结论.........................................................................................................................58 5.2 展望.................................................................................................................................59 参考文献参考文献 ............................................................................................................. 60 攻读硕士期间的主要研究成果攻读硕士期间的主要研究成果......................................................................... 65 致谢致谢 ..................................................................................................................... 66 万方数据 山东科技大学硕士学位论文 目录 i Contents 1 Introduction.......................................................................................................... 1 1.1 Backgrounds and Signification of Project..............................................................................................1 1.2 Current Study at Home and Abroad.......................................................................................................1 1.3 Main Research Contens and Technical Routes ......................................................................................5 2 Theoretical Study on Danger of Rock Burst Induced by Strip Mining.............................7 2.1 Influence Factors of Rock Burst Danger Induced by Strip Mining........................................................7 2.2 Analysis on Deflection Curve of Coal Pillar and Roof System............................................................10 2.3 Mechanism of Instability of Coal Pillar Roof System .........................................................................14 2.4 Calculation Example............................................................................................................................17 2.5 Brief Summary.....................................................................................................................................19 3 Numerical Simulation of Rock Burst Induced by Deep Strip Mining.............................21 3.1 Numerical Model of Rock Burst in strip mining..................................................................................21 3.2 Law of Stress and Energy Change of Coal Pillar under the Influence of Mining Depth .....................23 3.3 Law of Stress and Energy Change of Roof under the Influence of Mining Depth...............................27 3.4 Law of Stress and Energy Change of Coal Pillar under the Influence of Tectonic Stress....................29 3.5 Law of Stress and Energy Change of Roof under the Influence of Tectonic Stress.............................33 3.6 Law of Stress and Energy Change of Coal Pillar under the Influence of Elastic Modulus..................35 3.7 Brief Summary.....................................................................................................................................39 4 Rock Burst Assessment and Warning of Deep Strip Mining .............................41 4.1 Rock Burst Assessment of Strip Mining.................................................................................41 4.2 Rock Burst Warning ................................................................................................................47 4.3 Engineering Practice ............................................................................................................................51 4.4 Brief Summary.....................................................................................................................................57 5 Main Conclusions and Prospects ........................................................................................58 5.1 Main Conclusions.................................................................................................................................58 5.2 Research Prospects...............................................................................................................................59 References ................................................................................................................................60 Main Achievements during the Master.................................................................................65 Acknowlegements....................................................................................................................66 万方数据 山东科技大学硕士学位论文 绪论 1 1 绪论绪论 1.1 问题的提出及研究意义问题的提出及研究意义 煤炭是我国经济建设有力的能源保障， 从煤炭资源分布来看， 我国煤炭埋深在 1000m 以下的约占煤炭资源总量的 53％。随着浅部资源的枯竭，煤炭开采逐渐向深部及复杂地 质构造环境方向发展，东部矿区尤其明显。为了最大限度的提高煤炭资源采出率，许多 老矿区已经开始着手“三下”压煤的保护开采。 条带开采自 1967 年在我国首次应用以来， 较好的解决了我国数十个矿区“三下”压煤 的保护开采问题。随着煤炭开采向深部转移，条带煤柱的受力状态及力学性质等都较浅 部发生了巨大的变化，深部条带煤柱受采动及地质构造应力叠加因素影响，应力集中程 度较高，使得条带开采时容易发生煤柱失稳诱发冲击。 冲击地压是矿山开采中发生的煤岩动力现象之一。当煤岩系统内部积聚的能量以突 然、猛烈的形式释放时，因冲击弹出的煤岩体对支架等设备造成损坏，严重时会导致人 员的伤亡，某些情况下，冲击地压的发生还会引起矿井瓦斯突出等灾害，对煤矿生产造 成重大经济损失。 掌握深部复杂应力场条件下煤柱应力分布规律，明确深部条带开采诱冲机理，有的 放矢的采取相应预防治理措施，是深部条带开采冲击地压防治的关键。研究深部条带开 采冲击地压机理，对提高煤炭资源回收利用率及其煤矿目前和未来的发展有着重要的意 义。 1.2 国内外研究现状国内外研究现状 1.2.1 冲击地压机理研究冲击地压机理研究 冲击地压发生的机理复杂，不同类型的冲击地压有不同的机理及预测和防治方法。 随着采深增加，深部高应力、构造应力叠加影响下冲击地压发生机理与防治逐渐趋于复 杂。大量工程实践证明，采动与构造应力叠加影响区域应力集中程度较高，冲击地压在 此区域发生的频率也较高。各国学者通过现场及室内试验研究，先后从不同角度提出了 一系列重要的冲击地压理论[1-3]。 冲击地压研究初期，Braener提出的强度理论认为，当煤（岩）所受应力超过其强度 极限时，就会发生冲击地压。根据现场实践，尽管多数情况下煤体应力已经超过其承载 万方数据 山东科技大学硕士学位论文 绪论 2 极限，但其并未诱发冲击。从 20 世纪 50 年代起，通过分析研究“矿体-围岩”力学系统极 限平衡条件，提出了夹持理论[4]。夹持理论认为，一方面，深部煤体变形因坚硬顶底板 对煤体的闭锁作用而受到了限制，导致煤体容易积聚大量弹性应变能；另一方面，由于 摩擦阻力和侧向阻力对煤体滑动的限制，当煤体所受应力突然增大至极限应力或突然释 放时，极有可能发生冲击地压。 上世纪 60 年代，Cook根据刚性压力试验提出刚度理论；20 世纪 70 年代，Black提 出，当矿山负荷系统的刚度小于矿山结构整体刚度时就会发生冲击地压。尽管这一理论 简单明确，但是矿山负荷系统及其相应的刚度、矿山负荷系统及其矿山结构系统刚度峰 值大小较难界定，使得这一理论较难进行应用。另外，矿山负荷系统及其矿山结构本身 可以储存较大能量，这一理论并没将其考虑在内[5]。 通过对南非冲击地压防治情况进行总结，Cook等人提出能量理论，当煤岩体破坏用 于消耗的能量大于所释放的能量时，冲击就会发生。由于能量只是从一种状态转移到另 外一种状态，提出的能量理论从能量相互转化的角度解释了冲击地压发生的原因，使得 结果更加合理、科学。但是能量理论忽略了煤岩体的塑性变化，将其认为是纯弹性介质， 没有明确说明围岩发生破坏的临界条件及其围岩能量在什么条件下释放、释放量大小是 多少，在实际应用过程中有一定的局限性[6]。 波兰和前苏联学者提出冲击倾向性理论[7]，认为煤岩体冲击倾向性达到一定值时冲 击就会发生。 我国学者根据这一理论研究了采用煤样动态破坏时