冲击地压演化过程及能量耗散特征研究(1).pdf

博士学位论文 冲击地压演化过程及能量耗散特征研究冲击地压演化过程及能量耗散特征研究 Research on Rockburst Evolutionary Process and Energy Dissipation Characteristics 国家“十二五”科技支撑计划（2012BAK09B01） 教育部新世纪优秀人才支持计划（NCET-10-0768） 国家自然科学青年基金项目（50904067，51104156） 作者宋大钊 导师何学秋 教授 王恩元 教授 中国矿业大学 二○一二年五月 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 中图分类号 TD7 学校代码 10290 UDC 622 密 级 公开 中国矿业大学 博士学位论文 冲击地压演化过程及能量耗散特征研究冲击地压演化过程及能量耗散特征研究 Research on Rockburst Evolutionary Process and Energy Dissipation Characteristics 国家“十二五”科技支撑计划（2012BAK09B01） 教育部新世纪优秀人才支持计划（NCET-10-0768） 国家自然科学青年基金项目（50904067，51104156） 作 者 宋 大 钊 导 师 何学秋 王恩元 教授 申请学位 工学博士 培养单位 安全工程学院 学科专业 安全技术及工程 研究方向 冲击地压监测及防治 答辩委员会主席 景国勋 评 阅 人 二○一二年五月 论文审阅认定书 论文审阅认定书 研究生 宋大钊 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 致 谢 致 谢 本论文是在何学秋教授和王恩元教授的悉心指导下完成的,从论文的选题到定稿无 不凝聚着二位导师的心血和汗水。王老师同时也是我的硕士生导师。师从五年来，从专 业学习到论文写作，都得到了二位恩师全方位的指导和培养。导师和蔼的笑容、渊博的 知识、严谨的治学态度、务实的科研作风、孜孜不倦的育人态度、忘我的工作精神，将 使学生受益终生。在博士论文撰写期间，老师对学生严格要求，针对论文中的一些细节 问题与学生进行了深入的讨论和研究，提出了许多宝贵的意见和建议。在此谨向二位导 师致以崇高的敬意和衷心的感谢 特别感谢刘贞堂教授在论文选题及整体构思中给予的支持和帮助,以及五年来在学 业和生活上的关心与帮助 特别感谢李忠辉副教授、刘晓斐副教授、沈荣喜副教授、赵恩来老师、宋晓艳老师、 贾慧霖老师、金佩剑老师及王超老师在论文构思及写作上提供的宝贵意见和无私指导 特别感谢中国矿业大学理学院卢爱红教授、李凯硕士在数值模拟方面提供的支持和 帮助，以及我的师弟冯小军硕士、胡少斌硕士在数值模拟方面的辛勤劳动 特别感谢刘杰博士、李楠博士及薛世鹏硕士在论文实验室及现场实验方面的协助 特别感谢晋明月硕士、董超硕士在论文校对方面所做的大量工作 感谢同门好友徐文全博士、马衍坤博士、欧建春博士，以及安全 09 级博士生刘应 科、蒋靖宇、郭品坤、司俊鸿、王凯、许涛、董梦娟等各位博士，与他们相处的日子充 实快乐，终生难忘，愿在博士学习中结下的友谊之花永远盛开 感谢徐剑坤、陈世海、陈鹏、张鹏、马国强、钱伟华、孙浩博、张近民、蒋文杰、 刘大庆、许金杯、孙珍玉、高芸、何淼、陆智斐、王嗣衡等课题组兄弟姐妹在日常学习、 生活和论文写作过程中的无私帮助 感谢河南义马煤业集团跃进煤矿刘军总工、张国华科长、陈祥坡副科长，山西霍州 煤电新置煤矿王冬辉总工、樊新亭科长、吴学斌科长、谢永强队长、刘国强副队长、罗 兵技术员、董林超技术员等在现场实验中给予的帮助和协作。 特别感谢我的父母家人多年来对我学业的支持和鼓励，论文凝聚着他们殷切的希 望，作者将永远铭记他们的恩情。特别感谢我的女友许飞飞在生活、学习上给予的无微 不至的关心、理解和支持；感谢她与我一同面对困难，一同分享成功的快乐，她始终是 我坚持奋斗的力量源泉。 感谢所引用参考文献的作者，他们卓有成效的工作让我的论文受益匪浅。 感谢各位专家在百忙之中审阅本文，并热切希望得到您的指导和帮助。 I 摘 要 摘 要 冲击地压对煤矿安全和高效生产造成严重威胁。随着采深增加和开采强度不断加 大，我国煤矿冲击地压日趋严重和复杂。冲击地压是煤岩地层受采动影响而发生的动力 灾害现象，是煤岩体在外部应力作用下快速破裂的结果，是典型的能量释放与能量耗散 过程。为此，本文实验研究了煤岩变形破坏过程能量耗散的时域特征；分析了冲击地压 活动域系统（RADS）的时-空演化过程，建立了 MRADS 的动压型冲击地压演化模型； 结合模型研究了 MRADS 在卸压条件下应力场、 能量场的演化规律， 并进行了现场验证。 分析了煤岩破坏过程中的能量类型及转化规律，研究了煤岩单轴压缩破坏能量耗散 的时域特征，并探讨了能量耗散的影响因素。结果表明，煤岩体变形破坏对应其内部能 量的变化，外力做功通过能量的积累、释放与耗散进行自组织调节；电磁辐射能量累计 与对应的耗散能累计服从 y alnxb 的关系，电磁辐射能够较好的反映煤岩内部能量耗 散规律；受载煤岩破坏过程的能量耗散表现出显著的阶段特征，可以作为煤岩破坏状态 及稳定性的有效判据；煤岩体能量耗散的主要影响因素包括材料强度、均质度及能量输 入效率。 提出了冲击地压活动域系统（RADS）的概念，分析了系统时-空二维的熵变及能量 耗散特征；建立了冲击地压活动域系统主体（MRADS）中煤体体元的能量平衡及熵平 衡方程，并对其进行了稳定性分析。结果表明，RADS 中熵流与熵产生反映了系统内部 结构的时-空演化，其代数关系可判定冲击地压是否发生；能量耗散路径不畅导致的弹 性储能的大量聚集，是冲击地压的能量来源。MRADS 煤体体元内能的变化主要取决于 热量的流动和内力的变化，其内部始终自发进行着利用率低的能量类型替代利用率高的 能量的不可逆过程；随着该过程的发展，MRADS 将进入远离平衡态的非线性区域，成 为冲击地压的潜在发生区域；系统的稳定性可通过煤体内热力学过程中某一状态下的超 熵产生来判定。 基于能量耗散建立了 RADS 动压型冲击地压演化模型。 计算得到了 MRADS 内平行 于最大主应力方向周期裂纹的起裂强度及有限区域内的损伤应变能；分析了层状储能结 构的形成及稳定性，计算得到了结构失稳的最小临界载荷及失稳之前内部积聚的弹性 能；分析了不同动力扰动下储能结构的失稳破坏及冲击地压的最终显现。利用老顶来压 与卸压爆破两种典型动力扰动对模型进行了数值模拟验证，基于该模型利用现场煤岩电 磁辐射数据分析了 RADS 演化特征规律。 研究了 MRADS 在水射流卸压条件下应力场、能量场的演化规律，并以电磁辐射为 主要技术手段进行了现场验证。结果表明，水射流割缝卸压破坏了煤体的储能结构，大 幅减小了应力集中、能量积聚的程度和范围，从而使煤层有效卸压并耗散能量，使高应 力区向煤体深部转移，保证了系统区域的稳定性。 II 研究成果对深入认识冲击地压发生机理、提高冲击地压预测及防治的有效性等具有 重要的理论意义及应用价值。 该论文有图 95 幅，表 23 个，参考文献 197 篇。 关键词关键词冲击地压；演化；能量耗散；水射流；卸压 III Abstract Rockburst has posed a serious threat to the coal mine safety and high efficiency production. Along with the increase of mining depth and mining intensity, rockburst has become increasingly severe and complex. Rockburst is a sudden and violent release of energy stored in rock mass and geological structures, results from quick break of coal and rock under their own physical and mechanical changes and external stress, and is a typical irreversible energy dissipation and release process. Thus, this paper attempts to discuss the revolution of rockburst from the point of energy dissipation. The time domain features of energy dissipation during the coal and rock failure process are experimentally studied; on this basis, the time-space evolutionary process of rockburst activity domain systemRADS is analyzed, and a dynamic pressure type of rockburst evolutionary model is built; with the model, the evolution of stress, displacement and energy fields of the system are studied after pressure relief, and site verifications are carried out. The energy types and transation law in coal and rock failure process are analyzed, the energy dissipative characteristics of coal and rock are studied under uniaxial compression process, and the influencing factors are investigated. Results indicate that deation and failure of coal and rock correspond to its internal energy change, and external force work by means of its self-organization of energy accumulation, release and dissipation. The cumulative value of EMR energy and that of corresponding dissipated energy well subject to the of y alnxb, and EMR as a measurable parameter can analyze and invert the internal energy dissipation of coal and rock. The failure process of coal and rock loaded shows significant phased energy dissipation characteristics. The factors that influence the energy dissipation include material strength, homogeneous degree and energy efficiency. The concept RADS is proposed, and the two dimensional spatiotemporal entropy as well as energy dissipation of the system are analyzed. The energy and entropy balance equations of representative volume elementRVE of coal mass in main rockburst activity domain system MRADS are derived based on dissipative structure theory, and the stability are analyzed. Conclusions show that entropy flow and production reflect temporal-spatial evolution of the internal structures in the system; their algebraic relations show a good judgment in rockburst whether or not happens. The massive existence of elastic energy caused by the poor path of energy dissipation is the potential energy source resulting in rockburst. The intrinsic energy change of REV of coal mass mainly depends on heat flow and internal force variation in MRADS; the internal always spontaneous realize a irreversible process with low utilization IV ratio energy alternate that of the higher, with the development of which, MRADS will enter the nonlinear region far from balance state and turn into rockburst potential region. The stability of the system can be judged by a certain state of the excess entropy production during the process of thermodynamics. A dynamic pressure type of rockburst evolutionary model is built based on energy dissipation. The periodic cracks initiation strength parallel to the maximum principal stress direction and damage strain energy in limited area are calculated in MRADS; the ation of the spallation structure and stability are discussed, and the minimum critical load and accumulating elastic energy before are obtained; the failure of the spallation structure under different degrees of perturbation and the generation of rockburst are analyzed. On this basis, two kinds of typical dynamic perturbationmain roof pressure and blasting are numerically simulated for validating the model, and the EMR data are used for site verification to the evolution of RADS. The evolution laws of stress, displacement and energy fields of pressure relieved MRADS are studied theoretically and site verified using EMR . Results indicate that, pressure relief by water jet can greatly reduce the scopes of stress concentration and energy accumulation, which can avoid ing energy-storage structure, and result in dissipating energy of coal seam; it also makes the high press far away from coalface, which ensures the stability of the whole coal mass. The results have important theoretical and practical significance for deep understanding the mechanism and further exploring forecasting and control s of rockburst. The paper contains 95 figures, 23 tables, and 197 references. Keywords rockburst; evolution; energy dissipation; water jet; pressure relief V Extended Abstract Rockburst has posed a serious threat to the coal mine safety and high efficiency production. Along with the increase of mining depth and mining intensity, rockburst has become increasingly severe and complex. Rockburst is a sudden and violent release of energy stored in rock mass and geological structures, results from quick break of coal and rock under their own physical and mechanical changes and external stress, and is a typical irreversible energy dissipation and release process. Thus, this paper attempts to discuss the revolution of rockburst from the point of energy dissipation. The time domain features of energy dissipation during the coal and rock failure process are experimentally studied; on this basis, the time-space evolutionary process of rockburst activity domain systemRADS is analyzed, and a dynamic pressure type of rockburst evolutionary model is built; with the model, the evolution of stress, displacement and energy fields of the system are studied after pressure relief, and site verifications are carried out. 1 The energy types and transation law in coal and rock failure process are analyzed. The deation and failure of coal and rock correspond to its internal energy change, and external force work by means of its self-organization of energy accumulation, release and dissipation. Energy dissipation results in the damage of coal and rock, leading to the lithologic weakening and strength loss, while energy release is the internal reason of the sudden destruction of coal and rock. 2 The energy dissipative characteristics of coal and rock are studied under uniaxial compression process, and the influencing factors are investigated. The cumulative value of EMR energy and that of corresponding dissipated energy well subject to the of y alnxb; EMR can reflect the internal energy dissipation characteristics of coal and rock samples, and invert the internal energy dissipation. Under displacement-control mode, the energy dissipation of coal samples increase steadily during the whole loading process, while that of rock samples have an accelerated trend in the vicinity of the peak load; the failure process of the two can also be divided into six phases like “W“-shape. In the condition of load-control mode, the only energy dissipation of coal samples is steady increasing; besides, rock samples also show four phases, that is, slow rising, rapid increasing, fluctuant rising and rapid falling. The phased characteristics of energy dissipation is closely related to the internal structure changes of coal and rock. Energy dissipation is not only a concrete reflection of the deation and failure, in turn, the latter is an instability phenomena that driven by energy VI dissipation. The factors that influence the energy dissipation include material strength, homogeneous degree and energy efficiency. 3 The concept RADS is proposed, and the two dimensional spatiotemporal entropy as well as energy dissipation of the system are analyzed. Entropy change in fracture zone, the entropy productionS i dcan balance the negative entropy flow S e d, and entropy production is the direct reason that breaks coal mass; in elastic zone, for the non-dynamic ordered MRADS, both the one-way increase of internal and external entropy may cause rock burst, but due to the special environmental conditions underground, as long asSS ei ddcan rockburst occur; in original stress area, coal mass is almost free from mining, and maintains a state of equilibriumSS ei dd, so it can be seen as a “dead“, static stability structure. Energy dissipation in fracture zone, the development of coal mass can be divided into two phases, i.e. load and unload-creep, and the energy mostly transed into dissipated energy; in elastic zone, the existence of vast storage of elastic energy due to the higher confining pressure is a potential energy source of rockburst; in original stress area, the coal mass is under creep state, and the lower mining pressure and higher confining pressure keep the energy change moderate relatively. 4 The energy and entropy balance equations of REV of coal mass in MRADS are derived. The intrinsic energy change of REV of coal mass consists of four parts thermal conductivity, volumetric strain under hydrostatic pressure, the shape and position changes of REV under stress tensor, and external force work. From the point of energy, the intrinsic energy change of REV mainly depends on heat flow and the change of internal force during the slow deation and failure process of coal in MRADS. The deation and failure of coal is a spontaneous irreversible process, along with energy dissipation, with the development of which, MRADS will enter the nonlinear region far from balance state and turn into rockburst potential region. 5 The stability of MRADS can be judged by a certain state of the excess entropy production during the the process of thermodynamics. The evolutionary of MRADS satisfies the minimum entropy production principle, and when the change of entropy production with time is less than zero, the system will be away from the equilibrium state. Later, if0 2 1 d d 2       S t , the system is to be equilibrium state; if0 2 1 d d 2       S t , the system may reach a new stable state by disturbance or fluctuation, and dissipative structure; if0 2 1 d d 2       S t , the system is in a critical state. As a key parameter determining the VII development of MRADS , a small energy disturbance will cause the system far away from equilibrium, and a new ordered structure state, that is dissipative structure. 6 A dynamic pressure type of rockburst evolutionary model is built based on energy dissipation. The periodic cracks initiation strength parallel to the maximum principal stress direction and damage strain energy in a limited area are calculated in MRADS; the ation of the spallation structure and stability are discussed, and the minimum critical load and accumulating elastic energy before are obtained; the failure of the spallation structure under different degrees of perturbation and the generation of rockburst are analyzed. 7 Two kinds of typical dynamic perturbationmain roof pressure and blasting are numerical simulated using FLAC3D for validating the model, based on which, the evolutionary characteristics and laws of RADS are site ve