动压影响底板巷道大变形力学机理及围岩控制技术研究.pdf

煤炭资源与安全开采国家重点实验室自主研究课题资助SKLCRSM08X01 博士学位论文 动压影响底板巷道大变形力学机理 及围岩控制技术研究 Large Deation Mechanism and Control Technology of Surrounding Rock around Roadway in Floor Strata Influenced by Mining 作者娄培杰 导师谢文兵 教授 中国矿业大学 二○一四年四月 万方数据 中图分类号 TD353 学校代码 10290 UDC 622 密 级 公开 中国矿业大学 博士学位论文 动压影响底板巷道大变形力学机理 及围岩控制技术研究 Large Deation Mechanism and Control Technology of Surrounding Rock around Roadway in Floor Strata Influenced by Mining 作 者 娄培杰 导 师 谢文兵教授 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 矿山压力及其控制 答辩委员会主席 高明中 评 阅 人 二○一四年四月 万方数据 130 学位论文原创性声明学位论文原创性声明 本人郑重声明所呈交的学位论文 动压影响底板巷道大变形力学机理及围岩控制技 术研究 ，是本人在导师指导下，在中国矿业大学攻读学位期间进行的研究工作所取得的 成果。据我所知，除文中已经标明引用的内容外，本论文不包含任何其他个人或集体已 经发表或撰写过的研究成果。对本文的研究做出贡献的个人和集体，均已在文中以明确 方式标明。本人完全意识到本声明的法律结果由本人承担。 学位论文作者签名 年 月 日 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 万方数据 论文审阅认定书论文审阅认定书 研究生 娄培杰 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 万方数据 致谢致谢 本论文在导师谢文兵教授的悉心指导和关怀下得以顺利完成。师从五载，导 师优秀的人格品质、深厚的专业功底、严谨的治学风范、儒雅的性格魅力都在无 形中影响和感染着我，这成为我人生中一笔弥足珍贵的财富。在此，谨向导师致 以深深的敬意。 特别感谢中国矿业大学张农教授、周华强教授、茅献彪教授、徐金海教授、 许家林教授、柏建彪教授等，以及安徽理工大学高明中教授，山东科技大学谭云 亮教授。诸位老师在论文选题和创作过程中给予了细致、认真的指导，特别想对 你们说声谢谢。 衷心感谢师母五年中在学习、生活等各个方面的关心和照顾。 非常感谢师兄荆升国老师在我的专业学习、生活、论文完善方面的指导和帮 助，相伴五年，从您身上学习到很多优秀品质和科研态度。 非常感谢王其洲博士在论文修改方面提出的宝贵意见。 非常感谢师弟李亚运、范洪飞、刘家启、赵金帅、刘晨晨硕士在矿压观测期 间辛勤、艰苦的协助。另外感谢实验室其它师弟，在论文写作过程中给予的帮助 和支持。 非常感谢杨峰老师在论文写作最困难的时候给予的宝贵意见。 非常感谢芦岭矿掘进矿长张晓更，技术科蒋科长、丁科长及区队其它技术人 员。 还要感谢为我辛勤付出的父母，感谢你们对我的全力支持，无怨无悔。 从辞职考博到论文完成整整五年，期间经历了痛苦、彷徨、心酸和艰辛，但 始终坚持到最后，谨此特别感谢爱人梁书玲女士，独自承担家庭重任，在我屡遭 挫折时给予我的精神动力。 特别诚心感谢论文所引文献全部作者。 最后，感谢各位专家、学者在百忙之中评审本论文，并殷切希望得到您的指 点和赐教。 万方数据 万方数据 I 摘摘 要要 淮北矿区芦岭煤矿二水平主要开拓和准备巷道不受采动影响时， 巷道维护状 况良好， 但在受到煤层开采的扰动时， 变形强烈， 不但巷道受影响的超前距离长， 而且影响程度也大，巷道的变形和破坏极为严重，几乎所有底板巷道都要经过多 次翻修，造成巷道维护困难，严重影响了矿井的正常生产秩序。 本文采用理论分析、实验室试验、数值模拟和工业性试验相结合的综合研究 方法，系统分析了动压影响底板巷道围岩大变形力学机理、采场底板应力分布规 律及底板破坏深度、动压影响底板巷道围岩变形破坏规律，以及不同支护方式下 动压影响底板巷道围岩稳定性时空演化规律。主要研究成果如下 （1）通过引入岩体强度软化模量 b cc pbep Q qq ss ee - - ，建立静、动压条件下考虑应变 软化条件时圆形巷道围岩弹塑性力学分析模型。然后推导出静、动压条件下的巷 道围岩破裂区、塑性区、弹性区三区应力、位移新解。新解算例表明，应变软化 模量对围岩“三区”范围影响显著，能够更为客观地反映静、动压条件下巷道围 岩强度随应变增加而降低的特性。若岩石力学参数选择合理，则从理论上可以得 到更为合理的解析解。 通过提高破裂区岩体残余强度， 可以有效控制破裂区半径， 并可以作为今后动、静压巷道布置、支护设计施工的有效依据。 （2）通过岩石力学试验，得到芦岭矿Ⅱ82 采区石门砂岩岩块的单轴抗压、 抗拉、抗剪强度。通过分析采动岩体的力学特性和运用 roclab 软件对采动岩体 力学参数进行优化。通过 X 射线衍射实验可知该巷道围岩所含膨胀性岩石组份 极少，基本可以排除物化膨胀型的变型力学机制。通过现场调查可知该巷道附 近没有断层、褶曲等地质构造，岩层结构较好，没有特别软弱的夹层，层理、节 理也不发育，基本可以排除结构变形型力学机制。认为该巷道变形仅为单一的应 力扩容型变型力学机制，属于 IID 工程偏应力型软岩； （3） 基于圣维南原理， 将采场底板支承压力进行线性简化， 引入分区函数x， 求得工作面走向底板支承压力分布不同区域的集度q，并在此基础上求得底板应 力分量 x s、 y s 、 xy t 的积分表达式，并据此分析底板走向支承压力的分布规律； （4）假设采动应力场为弹性薄板中间矩形开孔问题，在基于 Westergaad 应 力函数的采场围岩应力计算模型基础上求解得到采场附近应力场。 从传统的采场 附近应力场简化公式求得①平面应力条件下采场边缘主应力值 1 s、 2 s、 3 s， 边界方程r、采场底板岩体最大破坏深度值h，并根据上述公式求得 8煤开采底 板最大破坏深度 m h；②平面应变条件下采场边缘主应力值 1 s、 2 s、 3 s，边界方 程r、采场底板岩体最大破坏深度值 h，并根据上述公式求得 8煤开采底板最 万方数据 II 大破坏深度 hm； （5）提出一种“大、小塑性区”条件下留设底板巷道合理位置的计算公式 22 x 2 c 1 11 1 mp m 11 0 1.57 4 h nh r n 1 11 K K bbbb m ccccccc b ci H L R QAQACQAK rD mKQAKqKQA g sssssss s - - ----- -- 该公式即考虑采场底板塑性区范围又考虑动压影响底板巷道塑性区半径。 据 此，求得 II82 采区石门理论位置为距采场底板38.66m； （6）通过数值模拟分析得到巷道围岩内部大变形活动规律该类巷道先后 受到工作面超前支承压力和工作面后方老顶破断、回转的影响，巷道围岩不同部 位、不同深度均产生极不均匀变形，该极不均匀变形极易导致 U 型棚或一次锚网 承载结构结构性失稳，由“弱结构”部位继而引发整体结构性失稳。 （7）提出二次锚网索支护中结构补强锚索作用机理为针对单一锚杆支护 承载结构的薄弱位置进行结构补强，可以提高原有支护方式中锚杆组合拱的厚 度，改善了围岩的自承载能力，大幅度增强了锚网索支护承载结构的稳定性和承 载能力。 提出棚索耦合支护中结构补强锚索作用机理为 针对棚式支护被动承载结构 的薄弱部位进行结构补强，大幅提高了 U 型棚帮部结构稳定性和承载能力，既充 分利用 U 型棚的高强护表能力，又充分发挥锚索主动承载性能，大幅度提高了 U 型棚支护承载结构的稳定性和承载能力。 （8）基于以上研究，提出两套巷道支护方案①棚索耦合底板锚网索注 浆；②二次锚网索结构补强底板锚网索注浆。矿压观测表明两套方案均能比 一次锚网支护更好的控制该类巷道围岩的极不均匀大变形，减小巷道表面位移， 降低维护成本，具有较大的推广应用价值。 该论文有图 78 幅，表 33 个，参考文献 165 篇。 关键词关键词动压；底板巷道；大变形；围岩控制 万方数据 III Abstract Luling coal mine, huaibei mining area two level of the main development and preparation of roadway is not affected by mining, roadway maintenance in good condition, but by coal bed mining disturbance, deation, advance roadway affected not only the distance is long, but also big influence degree, deation and failure of tunnel is very serious, almost all floor roadway after many renovations, cause roadway maintenance difficulties, seriously affected the normal production order of mine. Based on the theoretical analysis, laboratory test, numerical simulation and industrial test the integrated research s of combining systematic analysis of the dynamic pressure influence mechanism of large deation mechanics, stope floor of roadway surrounding rock stress distribution and floor damage depth, the dynamic pressure influence floor of roadway surrounding rock deation and failure regularity, under different supporting and the dynamic pressure influence the space-time evolution of floor roadway surrounding rock stability.The major achievements of this thesis are given as below 1By introducing rock mass strength softening modulus b cc pbep Q qq ss ee - - , the elastic-plastic mechanical analysis model of round roadway surrounding rock with consideration of strain softening condition under static pressure and mining pressure was set up. Then, the stress and new displacement explanation of elastic-plastic three area of roadway surrounding rock under static pressure and dynamic pressure were deduced. The new explanation example shows that strain softening modulus has remarkable impact on surrounding rock “three areas” scope, which can objectively reflect the features of roadway surrounding rock strength decrease along with strain increase under static pressure and dynamic pressure. This is the mechanical mechanism of large deation for this kind of roadway. If reasonable rock physical and mechanics parameters are selected, then more reasonable analytic solutions can be obtained in theory. By improving residual strength status of fracture zone, the fracture zone radius can be effectively controlled. It is the mechanical mechanism of the roadway surrounding rock stability control, which can provide effective gist for 万方数据 IV the roadway arrangement and supporting design construction under static pressure and dynamic pressure. 2By conducting the tests of indoor rock physical and mechanical properties, the uniaxial compressive, tensile and shearing strengths of sand rock mass at Ⅱ82 mining area crosscut in Luling Coalmine were obtained. The shearing strength curve of sand rock was gained by matching. By analyzing the mechanical properties of mined rock mass and optimizing the mechanical parameters of mined rock mass with roclab software, the reliable mechanical parameters of rock mass was offered for the further numerical modeling establishment. Based on the analysis of rock constituents experiment, it can be concluded that the swelling rock constituents are precious few contained in roadway surrounding rock. This is merely single stress dilatation deation mechanical mechanism rather than materialization dilatation deation mechanical mechanism. Thus, it belongs to deviatoric stress soft rock of IID project. 3On the basis of saint venant principle, linear simplification of stope floor abutment pressure was made. Partitioning functionx was introduced to calculate the intensities of floor abutment pressure distributions at different zones in working face direction. Based on the above, the integral representations of floor stress components x s, y s and xy t were computed. Then, the distribution law of abutment pressure in floor direction was analyzed. 4Provided that mining stress field involves rectangle trepanning in the middle of elastic sheet, stress field nearby stope can be computed based on stope surrounding rock stress calculation model of Westergaad stress function. By simplified ula from stress field nearby traditional stope, it can be obtained ①under plane stress, principal stress value on the edge of stope 1 s, 2 s and 3 s, boundary equation r as well as maximal destruction depth value of stope floor rock mass h. According to the above equations, the maximal destruction depth value of mining floor in 8 Coal m h22.03m was obtained. ②under plane strain, principal stress value on the edge of stope 1 s, 2 s and 3 s, boundary equationr as well as maximal destruction depth value of stope floor rock mass h. According to the above equations, the maximal destruction depth value of mining floor in 8 Coal h20.83 m m was obtained. 5The computational ula of floor destruction depth under the condition of “big and small plastic zone” was proposed where both plastic zone radius of dynamic pressure influenced floor roadway and plastic zone range of stope floor were 万方数据 V considered. The theoretical burial depth of II82 mining area crosscuts had the distance of 38.66m from stope floor, which was in line with field reality. 22 x 2 c 1 11 1 mp m 11 0 1.57 4 h nh r n 1 11 K K bbbb m ccccccc b ci H L R QAQACQAK rD mKQAKqKQA g sssssss s - - ----- -- 6By adopting strain softening model in discrete element software UDEC, the mechanical model of stope and dynamic pressure influenced floor roadway was made, distribution features of stope floor abutment pressure were analyzed and following variation laws were acquired. The first is the variation law of floor fracture zone distribution along with working face advancing distance L. The second is that of floor fracture development along with working face advancing distance L. Through comprehensive comparison of influence laws of dynamic pressure on floor roadway surrounding rock equivalent stress, displacement, destruction line and fracture development, the internal activity law of dynamic pressure influenced floor roadway surrounding rock was given. In summary, this kind of roadway is influenced by lead abutment pressure of working face floor as well as upper roof fracture and revolving in the back of working face. There is uneven deation for roadway surrounding rock from different parts at different depths, which can easily cause structural instability of support or abutment structure. Furthermore, “weak structure” part then triggers overall structural instability and global deation. 7The distribution law of surrounding rock equivalent stress, displacement and plastic zone is in organic connection with that of anchor rod axial force and failure zone wholly. By analyzing mechanical state of mining rock mass, supporting efficiency under different supporting ways was explained. In the same way, supporting efficiency under different supporting ways can be used to analyze mechanical state of mining rock mass. The supporting abutment behaviors of floor roadway at different parts involved transfer in different mining stages in working face. However, the stress was increased and supporting abutment property was improved as a whole. The action mechanism of structural reinforcement anchor rope means structural reinforcement was made aiming at the weak location of single anchor rod supporting abutment structure to increase the thickness of anchor rod compound arch 万方数据 VI from original supporting way, enhance self-abutment capacity of surrounding rock and substantially reinforce the abutment capacity and structural stability of anchor net supporting abutment structure. The action mechanism of structural reinforcement anchor rope on U-steel frame supporting roadway means structural reinforcement was made aiming at the weak location of shack supporting passive abutment structure to sharply improve the abutment capacity and structural stability of U-steel frame support sides. In this way, highly intensive surface-protected capacity of U-steel frame support was fully used and active abutment property of anchor rope was fully displayed so to sharply improve the abutment capacity and structural stability of U-steel frame supporting abutment structure. Suppose that there is the same stress for dynamic pressure influenced floor roadway, the supporting effect of shack-rope coupling supporting is better than twice supporting of high-strength anchor-net-rope. Thus, beneficial reference can be provided for choosing reasonable supporting ways under the same condition. 8On the basis of detailed investigation into Ⅱ82 mining area crosscuts geology, mining conditions and reasons of roadway surrounding rock failure, two sets of testing programs of roadway stability controlling technology were proposed in combination with theoretical analysis and numerical simulation Scheme of high①-strength stability supporting at U- steel frame Scheme of high②-strength stability supporting at anchor net supporting section The long-term mine pressure observation station was arranged for the test roadway to observe surface displacement. The monitoring results suggest that under the conditions of the similar geology, mining conditions, construction techniques and forces, the support effect of shack-rope coupling plus floor grouting is better compared with twice structural reinforcement of anchor-net-rope plus floor grouting, which can control the extremely uneven deation of dynamic pressure influenced roadway surrounding rock to larger extent and reduce roadway surface displacement quantity by a large margin. In addition, the service length of developing system roadway can be prolonged with bigger promotional value. keywords mining pressure; roadway in floor strata; large deation; control of surrounding rock 万方数据 VII Extended Abstract Roadway influenced by mining pressure is common heavily stressed roadway influenced by mining in coal mines. There is large deation, large ground pressure and difficulty in supporting for this kind of roadway when influenced by mining. Thus, the supporting cost was raised substantially and the difficulty in mining carryon was caused severely influencing the normal production of mines. The maintenance problems were particularly prominent. How to solve the supporting of this kind of roadway is not only one of the relatively complicated engineering technological problems in underground construction in current world, but also is one of the key problems in underground resource mining. The maintenanc