动载扰动下巷道锚固承载结构冲击破坏机制及控制技术.pdf

分类号分类号 学校代码学校代码 U D C 密密 级级 煤炭科学研究总院 博士学位论文 动载动载扰动下扰动下巷道锚固承载结构巷道锚固承载结构冲冲 击破坏击破坏机制及控制技术机制及控制技术 作者姓名 焦建康 学科专业 采矿工程 导师姓名 鞠文君 研究员 完成时间 二〇一八年五月 万方数据 分类号分类号 学校代码学校代码 U D C 密密 级级 China Coal Research Institute A dissertation for doctors degree Burst Burst FailureFailure MMechanism and echanism and C Control ontrol T Technology of echnology of R Roadway oadway A Anchorage nchorage B Bearing earing S Structure under tructure under D Dynamic ynamic L Load oad D Disturbanceisturbance Author’s Name Jiao Jiankang Speciality Mining Engineering Supervisor Prof. Ju Wenjun Finished time May，2018 万方数据 煤炭科学研究总院学位论文原创声明煤炭科学研究总院学位论文原创声明 本人郑重声明此处所提交的学位论文动载扰动下巷道锚固承载结构冲击 破坏机制及控制技术 ，是本人在导师指导下，在煤炭科学研究总院攻读博士学 位期间独立进行研究工作所取得的成果。据本人所知，论文中除已注明部分外不 包含他人已发表或撰写过的研究成果。 对本文的研究工作做出重要贡献的个人和 集体，均已在文中以明确方式注明。本声明的法律结果将完全由本人承担。 作者签名 日期 年 月 日 煤炭科学研究总院学位论文使用授权书煤炭科学研究总院学位论文使用授权书 动载扰动下巷道锚固承载结构冲击破坏机制及控制技术 系本人在煤炭科 学研究总院攻读学位期间在导师指导下完成的学位论文。 本论文的研究成果归煤 炭科学研究总院所有，本论文的研究内容不得以其他单位的名义发表。本人完全 了解煤炭科学研究总院关于保存、使用学位论文的规定，同意学校保留并向有关 部门送交论文的复印件和电子版本，允许论文被查阅和借阅，同意学校将论文加 入中国优秀博硕士学位论文全文数据库和编入中国知识资源总库 。本人 授权煤炭科学研究总院，可以采用影印、缩印或其他复制手段保存论文，可以公 布论文的全部或部分内容。 本学位论文属于（请在以下相应方框内打“√“; 保密□,在 年解密后适用本授权书 不保密□ 作者签名 日期 年 月 日 导师签名 日期 年 月 日 万方数据 摘 要 I 摘 要 冲击地压是威胁我国煤矿安全高效开采的主要矿井灾害之一。统计表明，大 部分冲击地压发生在回采巷道中。 目前， 针对冲击地压的研究主要集中发生机理、 预测预警和解危措施方面。 由于冲击地压发生机理的复杂性， 影响因素的多样性， 发生地点的不确定性，已有的研究成果并不能完全避免冲击地压的发生。作为冲 击地压的最后一道防线， 预紧力锚杆支护系统与其作用范围内围岩共同形成的锚 固承载结构决定了巷道围岩的整体稳定性。对于动载冲击地压巷道，锚固承载结 构不仅承受较大静载，还受到频繁动载的扰动，其冲击破坏机理与静载巷道不尽 相同。本文以开采深度大、采动应力高、受顶板动载扰动，且煤岩层具有冲击倾 向性等综合特征的义马矿区冲击地压巷道为工程背景，采用现场实测、实验室试 验、理论分析及数值模拟相结合的方法，围绕动载扰动下巷道锚固承载结构冲击 破坏特征、破坏机理以及控制技术开展了系统研究。论文取得的主要研究成果如 下 （1）开展了义马矿区冲击地压巷道地质力学测试和典型冲击破坏实例实测 分析，总结了动载冲击巷道冲击破坏特征和原因。结果表明义马矿区动载扰动 冲击地压巷道冲击破坏特征主要表现为①巷道围岩瞬时变形量大；②巷道底鼓 严重；③变形破坏程度和震源能量正相关；④冲击破坏之前，巷道围岩缓慢变形 严重；⑤锚杆支护体系严重失效。冲击破坏后的巷道表现为围岩节理、裂隙扩展 贯通，强度和完整性弱化，锚固系统锚固性能（锚固力、预紧力）降低，锚固界 面粘结劣化失效， 锚杆产生塑性变形， 杆体内部晶粒扭曲、 畸变， 晶粒产生剪切、 滑移，晶粒被拉长，金相组织紊乱，抗拉强度、延伸率和冲击吸收功普遍降低。 巷道冲击破坏的主要原因为 高原岩应力和采动应力叠加形成的高静载应力集中、 坚硬顶板脆断形成的动载扰动、 巷道围岩外碎内脆‖的结构特性以及锚杆支护参 数不合理导致的锚固承载结构承载能力低。 （2）建立了动静载联合作用下回采巷道数值模型，采用数值模拟方法分析 了动载扰动作用下巷道锚固承载结构动载响应特征及冲击破坏演化过程。 结果表 明 动载产生的反复压拉作用， 极易造成锚固岩体扩容变形破坏或锚固系统失效， 导致锚固承载结构冲击破坏；应力波在深浅部围岩产生的动载应力差，是顶板锚 固承载结构变形破坏的主导因素， 不同深度围岩动态响应差异是巷帮锚固承载结 构变形破坏的主导因素；锚固承载结构冲击破坏演化过程为顶板动载扰动→浅 部围岩损伤变形破坏→锚固系统失效→锚固承载结构失去对深部围岩控制→围 岩损伤破坏范围骤增→深部围岩能量瞬时释放→锚固承载结构冲击破坏。 动载扰 万方数据 摘 要 II 动下巷道锚固承载结构的冲击破坏是在采动静载和动载驱动下的力学破坏过程， 伴随着能量的消耗、释放与转化。 （3）提出了动载扰动下锚固承载结构冲击破坏准则和判据，基于响应面法 实验设计和数据分析功能， 定量研究了单因素以及多因素交互作用对锚固承载结 构稳定性的影响，结果表明动载扰动冲击地压巷道锚固承载结构冲击破坏必须 满足应力和能量的双重“超载”条件，必要条件是顶板动载和巷道围岩静载叠 加强度大于锚固承载结构的承载能力，即应力超载；充分条件是矿震余能和巷 道围岩释放的弹性能量大于锚固承载结构冲击破坏耗能， 且有盈余能量并可转化 为冲击动能，即能量超载。围岩强度、震源距离、震源强度、原岩应力、支护强 度等单因素和各因素交互作用对锚固承载结构变形量都有显著影响， 不同组合条 件下锚固承载结构的破坏模式可分为锚杆断裂型、锚固脱粘型、岩体主导型和复 合型。 （4）提出了动载扰动冲击地压巷道锚固围岩控制技术，主要包括“降载- 抗冲-吸能”稳定性控制原理、 “深部卸压-浅部强支-巷表防护”多层次控制技术 以及新型抗冲击锚杆支护材料。围岩卸压可以降低应力集中的程度和范围，降低 深部围岩冲击破坏时能量释放的大小，增大动载传播的距离和衰减系数，减缓矿 震动载对锚固承载结构的扰动，降低锚固承载结构发生冲击破坏的风险。针对不 同锚固承载结构破坏模式，采用加长或全长高预应力锚固、超高强度长短锚杆协 同支护以及全断面支护， 可以有效提高冲击地巷道锚固承载结构自身的抗冲击性 能和吸能特性。研发出的新型超高强、高冲击韧性套接锚杆的破断载荷与 SKP22-1/1770 型锚索相当， 但套接锚杆的平均延伸率 （19.5） 与冲击吸收功 （128J） 远超锚索。 （5）开展了动载冲击地压锚固承载结构稳定性控制现场实践。采用人工爆 破模拟矿震动载检验控制效果，围岩质点振动、锚固围岩损伤电磁波 CT 扫描、 围岩变形和锚固系统受力等矿压监测结果显示爆破产生的动载扰动，造成监测 点位置围岩张性拉伸损伤破坏，且锚固范围内浅部围岩损伤破坏大于深部。由于 锚固围岩的损伤破坏，大部分锚杆、锚索轴力突降，轴力损失率随着震源距离的 增大呈乘幂关系衰减，随预紧力的增大呈减小趋势。在爆破动载作用下，监测区 域巷道围岩未发生冲击破坏，巷道位移和锚杆（索）受力均在允许范围内。 关键词关键词冲击地压 锚杆支护 巷道 锚固承载结构 动载扰动 冲击破坏 万方数据 Abatract I ABSTRACT Rock burst is one of the main disasters that threaten the safe and efficient mining in Chinese coal mines. Statistical analysis shows that most of rock bursts occur in mining gateways. The existing research on rock burst has focused on the occurrence mechanism, forecast and controlling strategies, which can not completely prevent rock burst due to the complexity of occurrence mechanism, the diversity of influencing factor, and the uncertainty of bursting location. As the last barrier to prevent rock burst, anchorage bearing structure plays a crucial role in stability of roadway surrounding rock, which is composed of pre-tensioned bolt support system and its reinforced rock. The failure mechanism of bursting roadway is not the same as that of static loading roadway, as the anchorage bearing structure not only bears large static load but also dynamic load in bursting roadway. In this paper, based on the bursting roadway in Yima mining area with large mining depth, high mining-induced stress, dynamic load disturbance in roof and high rock burst tendency of coal, burst failure characteristics, failure mechanism and control technology of anchorage bearing structure under dynamic load disturbance have been studied by comprehensive s of field measurement, laboratory test, theoretical analysis and numerical simulation. The main conclusions and innovative results are as follows 1 The geomechanical field test of surrounding rock of bursting roadways in Yima mining area was carried out, and the bursting characteristics and reasons of anchored rock were statistically analyzed. The main bursting characteristics are ① Large transient deation of surrounding rock; ② serious floor heave;③ The degree of deation and failure positively related to the energy of source; ④ serious slow-deation of surrounding rock before bursting failure; ⑤ Serious failure of bolt support system. The roadway after rock burst is characterized as the propagation and coalescence of discontinuities in surrounding rock, the reduction of strength and integrity of surrounding rock and the decrease of anchoring perance. The decrease of anchoring perance is manifested as the degradation of bond in anchoring interface, the plastic deation of bolts, the drop of tension strength, extensibility and impact absorbing power of bolts, and the damage of microstructure in bolts which is characterized by that the grains in bolts are distorted and elongated with shearing and sliding, and the metallographic structure is disordered.The main reasons are concentration of high static-loading stress, dynamic load disturbance in roof, structural characteristics of “external fragile and internal brittle“ and unreasonable bolt supporting system. 2 The numerical model of gateway under combined effect of dynamic and static loads was established. And the dynamic-loading response and evolution process of bursting failure for anchorage bearing structure was numerically analyzed. The results are as follows the failure of anchored rock by expansion deation or anchoring system are easily resulted from repeated effect of compression and tension induced by dynamic load, finally causing bursting failure of anchorage bearing structure; The main failure factor of anchorage bearing structure is the stress difference at different depths of surrounding rock induced by stress wave for roof, 万方数据 Abatract II while the main factor is the difference of dynamic response for rib. The evolution process of bursting failure of anchorage bearing structure is illustrated as the dynamic-loading disturbance in roof→ the damage in shallow surrounding rock → the failure of anchoring system→ the disabled control of anchorage bearing structure to deep surrounding rock→ the sudden increase of the damage range of surrounding rock→ the instantaneous release of energy in deep surrounding rock → the bursting failure of anchorage bearing structure. 3 The criterion of bursting failure for anchorage bearing structure under dynamic load was put forward. The influences of single factor and interaction of multiple factors to stability of anchorage bearing structure were quantitatively analyzed using response surface . The results are as follows the bursting failure of anchorage bearing structure will happen when both satisfying the dual overload conditions of stress and energy. The stress overload is necessary condition, which means the superposition of the dynamic and static load in surrounding rock is greater than the bearing capacity of anchorage bearing structure. And the energy overload is sufficient condition, which means the superposition of residual energy from mine earthquake and elastic energy released from surrounding rock is larger than that needed for bursting failure of anchorage bearing structure, with the surplus energy converted to bursting kinetic energy. The amount of deation for anchorage bearing structure is heavily influenced by the single factor such as the strength of surrounding rock, the source distance, the source intensity, in-situ stress, supporting strength and their interactions. The failure modes of anchorage bearing structure can be categorized as bolt breaking, anchorage debonding, rock dominating and the compositing mode under different combinations of influencing factors. 4 The control system of anchored rock for bursting roadway was put forward, including stability controlling principle of reducing load - resisting burst-absorbing energy‖, multilevel controlling technologies of releasing pressure for deep rock - strong support for shallow rock- protection for surface rock‖ and new anti-bursting bolts material. Releasing pressure for deep rock can reduce the degree and scope of stress concentration, reduce the magnitude of energy release during the burst failure of deep surrounding rock, increase the distance and attenuation coefficient of dynamic load propagation, slow down the disturbance of the rock vibration load on the anchorage bearing structure, and reduce the risk of burst failure of the anchorage bearing structure.For different failure modes, the ability of resisting burst and absorbing energy of anchorage bearing structure are effectively improved by means of lengthened or full-length anchorage with high prestress, the combined support of long and short bolts with super high strength and full-section support. The breaking load of newly developed connected bolt, which has a super high strength and high impact toughness, equals to that of SKP22-1/1770 type cable, with the average elongation 19.5 and the impact absorbing power 128J far larger than cable. 5 The field practice of stability control for anchorage bearing structure under dynamic load was carried out. The control effect was verified by mine earthquake simulated by artificial blasting. The monitoring result shows that under the dynamic load resulted from blasting, the monitoring area is failure by tension, with the shallow 万方数据 Abatract III damage greater than the deep in anchored rock. Due to the failure of anchored rock, the axial forces of most of bolts and cables drop suddenly. The loss rate of axial force decreases not only with the increase of pretensioned force, but also exponentially with the increase of distance to source. Under the effect of blasting load, rock burst has not occurred in the monitoring surrounding rock, with the deation of roadway and the forces of bolts and cables both within the allowable range, which verifies the rationality of theoretical analysis and controlling strategies. Key Words rock burst; bolt support; roadway; anchorage bearing structure; dynamic load disturbance; burst failure 万方数据 目 录 I 目目 录录 第 1 章 绪论 .............................................................................................................. 1 1.1 选题背景及意义 .................................................................................................. 1 1.2 国内外研究现状及分析 ..................................................................................... 3 1.2.1 冲击地压巷道锚固围岩承载原理 .................................................................................3 1.2.2 冲击地压巷道锚固承载结构动态破坏机理 .................................................................5 1.2.3 冲击地压巷道稳定性控制技术 .....................................................................................7 1.2.4 冲击地压巷道围岩支护材料 .........................................................................................9 1.3 存在的主要问题 ............................................................................................... 11 1.4 研究内容、方法及技术路线 ........................................................................... 12 1.4.1 研究内容及方法 .......................................................................................................... 12 1.4.2 技术路线 ...................................................................................................................... 13 第 2 章 义马矿区动载冲击地压巷道冲击破坏特征 ................................. 15 2.1 义马矿区冲击地压巷道工程地质概况 ........................................................... 15 2.1.1 井田地质条件 .............................................................................................................. 15 2.1.2 地应力分布 .................................................................................................................. 17 2.1.3 巷道围岩强度及结构特性 .......................................................................................... 18 2.2 巷道冲击破坏特征 ........................................................................................... 21 2.2.1 巷道支护形式 .............................................................................................................. 21 2.2.2 巷道冲击破坏统计 ...................................................................................................... 22 2.3 巷道冲击破坏典型实例分析 ........................................................................... 24 2.3.1 冲击破坏前后围岩结构和强度 .................................................................................. 25 2.3.2 冲击破坏后锚固系统锚固性能 .................................................................................. 27 2.3.3 冲击破坏后锚固界面粘结劣化 .................................................................................. 29 2.3.4 冲击破坏前后锚杆杆体力学性能 .............................................................................. 30 2.3.5 冲击破坏前后锚杆金相组织结构分析 ...................................................................... 31 2.4 巷道冲击破坏原因分析 ................................................................................... 32 2.5 本章小结 ........................................................................................................... 35 第 3 章 动载扰动下锚固承载结构冲击破坏演化过程 ............................ 37 万方数据 目 录 II 3.1 预应力锚杆（索）作用下巷道锚固承载结构特征 ....................................... 37 3.1.1 巷道围岩采动应力及围岩强度 .................................................................................. 37 3.1.2 锚固承载结构的形成及承载特性 .............................................................................. 39 3.2 动载冲击地压巷道锚固承载结构数值模型的建立 ....................................... 40 3.2.1 模拟目的与内容 .......................................................................................................... 40 3.2.2 数值模型的建立 ...............................................................................