近距离煤层群采空区下底板破坏机理及巷道围岩控制技术.pdf

Study on Floor Failure Mechanism and Control Technology of Roadway Surrounding Rock in the Goaf Under the Close Distance Coal Seam Group Dissertation ted to Xi’an University of Science and Technology In partial fulfillment of the requirement For the degree of Doctor of Engineering By Ren Haifeng Safety Technology and Engineering Dissertation Directed By Li Shugang Professor Jun, 2016 学 位 论 文 独 创 性 说 明 本人郑重声明 所呈交的学位论文是我个人在导师指导下进行的研究工作及其取得 研究成果。尽我所知，除了文中加以标注和致谢的地方外，论文中不包含其他人或集体 已经公开发表或撰写过的研究成果，也不包含为获得西安科技大学或其他教育机构的学 位或证书所使用过的材料。 与我一同工作的同志对本研究所做的任何贡献均已在论文中 做了明确的说明并表示了谢意。 学位论文作者签名日期 学 位 论 文 知 识 产 权 声 明 书 本人完全了解学校有关保护知识产权的规定，即研究生在校攻读学位期间论文工 作的知识产权单位属于西安科技大学。学校有权保留并向国家有关部门或机构送交论文 的复印件和电子版。本人允许论文被查阅和借阅。学校可以将本学位论文的全部或部分 内容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本学 位论文。同时本人保证，毕业后结合学位论文研究课题再撰写的文章一律注明作者单位 为西安科技大学。 保密论文待解密后适用本声明。 学位论文作者签名指导教师签名 年月日 论文题目 近距离煤层群采空区下底板破坏机理及巷道围岩控制技术 专业 安全技术及工程 博 士 生 任海峰（签名） 指导教师 李树刚（签名） 摘 要 为了达到有效控制近距离煤层群采空区下巷道围岩变形的目标，论文采用理论分析、 数值模拟、实验室物理相似模拟、现场工程试验等方法，从研究近距离煤层群下行开采 过程中，上部煤层采空区底板的破坏机理着手，得出了上部煤层底板破坏规律，然后对 下部煤层巷道合理布置进行了研究，再针对巷道的围岩特性提出与之相适应的支护方案， 最后将研究成果工程实践验证。具体如下 建立了压力拱拱脚支承压力计算模型以及压力拱支承压力作用下底板塑性区计算 模型。近距离煤层群下行开采过程中，压力拱将上覆岩层载荷传递到底板，由于上下煤 层间距较近，压力拱对下部煤层及巷道造成一定程度的影响。压力拱拱脚的影响区域大 小、 压力拱的跨度、 压力拱的拱高、 煤层采深等是压力拱支承压力大小的主要影响因素， 这些因素也进一步影响压力拱支承压力对底板的破坏作用。 提出了采空区下伏岩层“拱梁”组合结构模型。当采空区下伏岩层中存在厚硬的 关键层时，关键层表现为梁的特征，对拱的发展起着控制作用。若底板压力拱内存在关 键层， 则在关键层对其附近的煤层及巷道起到保护作用， 若关键层破断后， 其附近岩层、 煤层及巷道会随关键层破段而遭受较大的破坏。 研究了下部煤层巷道布置方式，得出了布置下部煤层巷道的计算模型。当下部煤层 位于上部煤层底板破坏带之内时， 下部煤层巷道虽然无法避开上部煤层底板破坏带的影 响，但可通过调整水平距离避开上部煤层煤柱高应力区的影响。 研究了下部煤层巷道支护方式。当下部煤层巷道离上部煤层煤柱距离较近时，下部 煤层巷道受到非均匀载荷影响，这种情况下宜采用拱形支护。通过理论分析比较了矩形 支护方式和拱形支护方式的受力特点，提出了宜采用拱形支护方式控制巷道围岩变形。 拱形支护体系顶部的弯矩和剪力明显小于矩形支护体系，拱形支护可使最大主应力流线 沿拱形支护体系形成了一个环状压力拱，形成拱效应，充分发挥围岩自我承载能力。 对采空区下巷道破坏情况进行了分区，并给出了不同区域的支护原则。根据上部煤 层采空区下底板破坏带与下部煤层巷道松动圈的位置关系，将采空区下巷道的破坏情况 分为未接触区、部分重叠区和完全重叠区三个区域，给出了判断巷道所处区域的判据公 式。给出了不同区域的巷道支护原则，在未接触区内，既可采用矩形支护，也可采用拱 形支护；在部分重叠区内宜采用拱形支护；在完全重叠区首先考虑拱形支护，当煤层间 距极近时，可考虑采用可伸缩金属支架架棚支护，断面选用拱形。 将研究成果应用于陕西韩城矿业公司下峪口煤矿3号下煤层23305下工作面回风顺槽 的巷道布置和支护方案设计。主要应用成果为运用近距离煤层群下行开采下部煤层巷 道位置计算公式得出该巷道与上部煤层煤柱边缘水平距离大于 41.6m 时， 可避开上部煤 层煤柱支承压力影响区。 运用近距离煤层群采空区下巷道围岩破坏分区判据公式得出该 巷道位于“完全重叠区” 。运用非均匀载荷作用下巷道支护形式确定该巷道采用拱形支 护，根据完全重叠区巷道支护原则采用组合拱设计了支护方案。压力观测和巷道变形量 观测表明，该方案能有效地控制近距离煤层群采空区下巷道围岩变形，证明论文中的近 距离煤层群上部煤层底板破坏、 下部煤层巷道布置以及支护方式等研究成果具有一定的 科学性、合理性。 论文研究得出的近距离煤层群下行开采下部煤层巷道位置计算模型、近距离煤层群 采空区下巷道围岩破坏分区判据公式、非均匀载荷作用下巷道支护形式、采空区下不同 破坏区域巷道支护原则等成果，对近距离煤层群下行开采下部煤层的巷道布置、巷道支 护方案设计等提供了理论依据，具有一定的推广价值。 关 键 词底板破坏；巷道围岩控制；压力拱；近距离煤层群；岩体结构 研究类型应用研究 SubjectStudy on Floor Failure Mechanism and Control Technology of Roadway Surrounding Rock in the Goaf Under the Close Distance Coal Seam Group SpecialtySafety technology and engineering AuthorRen haifengSignature Supervisor Li shugangSignature Abstract In order to achieve the goal of controlling the deation of surrounding rock in the goaf of close distance coal seams. In this paper, theoretical analysis, numerical simulation, laboratory physical similarity simulation, field engineering test and other s are used. The failure mechanism of the upper coal seam floor is obtained from the failure mechanism of the bottom plate of the upper coal seam in the process of downward mining of the close distance coal seams, Then, the reasonable arrangement of the roadway in the lower coal seam is studied, and the supporting scheme is put forward for the characteristics of surrounding rock of the tunnel, and finally the research results are verified by the engineering practice. Specific as follows The calculation model of abutment pressure and the plastic zone calculation model under the action of pressure arch support are established. In the process of downward mining of the coal seams in the near distance, the pressure arch will transfer the overlying strata load to the bottom plate, because the distance between the upper and the lower coal seams is relatively close, the pressure arch will cause a certain degree of influence on the lower coal seam and the roadway. Pressure arch arch foot influenced area size, pressure arch span and pressure arch of arch height, the mining depth of coal seams, is the pressure arch abutment pressure on the size of the main influencing factors, these factors further affects the pressure arch abutment pressure on the bottom of the destructive effect. A combined structure model of the “arch beam“ of the underlying strata in the goaf is presented. When there are thick and hard key strata in the underlying strata of the mined out area, the key layer is the characteristic of the beam, and the development of the arch plays a controlling role. If floor pressure arch in the presence of critical layer, in key layer in the neighborhood of coal and roadway to protective effect, if key stratum fractured, near the rock, coal and roadway will be with the key layer breaking section and suffered considerable damage. The layout of roadway in lower coal seam is studied, and the calculating model of the roadway in the lower coal seam is obtained. When the lower coal seam is located in the upper coal seam floor failure within, the mining of lower coal seam although it is impossible to avoid the upper coal seam floor failure zone, but can be through adjusting the horizontal distance avoid upper coal seam and coal pillar high impact strength. The support s of the lower coal seam roadway are studied. When the distance from the upper coal seam is close to the lower part of the coal seam roadway, the roadway under the lower part of the coal seam is affected by the non uni load. By theoretical analysis and comparison of the characteristics of the rectangular support and the arch support, it is put forward that the arch support should be used to control the deation of the surrounding rock. Arch support system at the top of the bending moment and shear force significantly smaller than that of the rectangular supporting system, arched retaining the maximum principal stress flow lines along the arch support support system ed a cricoid pressure arch, the ation of arch effect, give full play to the surrounding rock self bearing capacity. The destruction of the roadway under the goaf is partitioned, and the supporting principle of different area is given. According to upper coal seam goaf coal seam floor failure and the position relation of the lower coal seam roadway dawsonts moving coil, will adopt the goaf roadway damage divided into non contact area, the overlapping part of the region and fully overlapping area three regions, and gives the judge the roadway located area criterion. The principle of roadway support in different regions is given, which can be used in the non contact area, and can be used in the rectangular support; In the full overlap area, arch type support will be used, when the coal seam has a very close distance, consider using a telescopic metal scaffold erecting shed support section selection of arch. The research results are applied in Hancheng Mining Company Meiyukou Coal Mine No. 3 coal 23305 working face return air along the groove of the roadway layout and support support scheme design. Main application results are By using the calculation ula of the position of the lower coal seams in the lower part of the near distance coal seam group, it is concluded that the horizontal distance between the roadway and the upper coal pillar is more than 41.6m, which can avoid the influence of the support pressure of the upper coal pillar. Based on the ula of the failure zone of surrounding rock of roadway surrounding rock in the goaf of close distance coal seams, the tunnel is located in the complete overlap zone “. The roadway supporting is determined by using the non uni load, and the arch support is adopted. According to the principle of the roadway supporting in the overlap area, the supporting scheme is adopted. Pressure observation and the deation of roadway surrounding rock measurement show that, this scheme can effectively control close distance coal seam group in goaf roadway surrounding rock deation that is scientific and reasonable in the near distance coal seams of the upper coal seam floor failure, lower coal seam roadway layout and supporting way to support the research results. Obtained from this study of close distance coal seam group downward mining lower coal seam roadway location calculation model, close distance coal seam group goaf roadway surrounding rock failure Partition Criterion and non uni load under the action of roadway supporting , and goaf under different failure of roadway area branch principles to support the results, to close distance coal seam group downward mining lower coal seam roadway layout, roadway supporting scheme design provides a theoretical basis and has a certain popularization value. Key words Floor damage; roadway surrounding rock control ; Pressure arch ;Close distance coal seam group; Rock mass structure; ThesisApplication Study 目录 I 目 录 1 绪论........................................................................................................................................1 1.1 选题的背景及意义........................................................................................................1 1.2 国内外研究现状............................................................................................................2 1.2.1 底板岩层结构理论研究现状.............................................................................2 1.2.2 近距离煤层群巷道布置研究现状.....................................................................4 1.2.3 巷道围岩支护理论研究现状.............................................................................5 1.2.4 存在的问题与不足..............................................................................................8 1.3 主要研究内容及技术路线...........................................................................................8 1.3.1 主要研究内容.......................................................................................................8 1.3.2 技术路线...............................................................................................................9 2 近距离煤层群下行开采拱结构分析................................................................................11 2.1 岩层移动中的拱结构..................................................................................................11 2.1.1 压力拱假说.........................................................................................................11 2.1.2 回采工作面压力拱............................................................................................12 2.2 近距离煤层群下行开采压力拱形成机理分析.......................................................13 2.3 压力拱拱脚支承压力分析.........................................................................................14 2.4 岩层结构的拱－梁组合结构模型............................................................................17 2.4.1 拱梁组合结构模型表述................................................................................17 2.4.2 底板拱梁组合结构模型解算.......................................................................17 2.5 本章小结...................................................................................................................... 20 3 近距离煤层群上部煤层采动对底板的破坏分析.......................................................... 22 3.1 工作面回采对底板的破坏作用分析........................................................................22 3.1.1 采空区底板破坏带分析....................................................................................22 3.1.2 压力拱对底板的破坏分析................................................................................23 3.2 工作面支承压力分析................................................................................................. 25 3.2.1 相似模型工作面实验条件................................................................................26 3.2.2 相似条件的确定................................................................................................26 3.2.3 模型铺设.............................................................................................................27 3.2.4 实验方法.............................................................................................................28 3.2.5 相似模拟结果及分析........................................................................................29 3.3 回采对底板破坏作用的数值模拟研究....................................................................32 西安科技大学博士学位论文 II 3.4 采空区上下方压力拱数值模拟研究........................................................................37 3.5 本章小结...................................................................................................................... 44 4 近距离煤层群上部煤层煤柱对底板的破坏分析.......................................................... 46 4.1 采空区周边支承压力的分布特征............................................................................46 4.1.1 煤柱支承压力在底板的传递规律研究.......................................................... 46 4.1.2 煤柱支承压力对底板的破坏分析...................................................................50 4.2 煤柱支承压力对底板破坏作用的数值分析.......................................................... 52 4.2.1 数值模型的建立................................................................................................52 4.2.2 模拟结果及分析................................................................................................53 4.2.3 底板中有关键层时的模拟结果及分析.......................................................... 54 4.3 本章小结...................................................................................................................... 56 5 近距离煤层群采空区下巷道布置研究...........................................................................58 5.1 下部煤层巷道布置原则及布置方式分析................................................................58 5.1.1 下部煤层巷道布置原则....................................................................................58 5.1.2 下部煤层巷道布置方式分析...........................................................................58 5.1.3 下部煤层巷道位置对围岩应力分布影响的数值分析.................................60 5.2 采空区下方拱梁结构对下部煤层巷道的影响因素分析..................................63 5.2.1 采空区下方拱梁结构发展过程造成的底板破坏.....................................63 5.2.2 采空区下方压力拱对巷道稳定性的影响分析..............................................66 5.2.3 拱梁结构对巷道稳定性的影响分析.......................................................... 67 5.3 煤柱支承压力对下部煤层巷道影响分析................................................................68 5.3.1 煤柱支承压力对下部煤层巷道位置的影响分析..........................................68 5.3.2 下部煤层巷道布置位置研究...........................................................................69 5.4 本章小结...................................................................................................................... 71 6 近距离煤层群采空区下巷道围岩控制技术...................................................................72 6.1 采空区下巷道围岩特性及破坏分区研究................................................................72 6.1.1 采空区下巷道围岩变形破坏分析...................................................................72 6.1.2 采空区下巷道围岩破坏分区及判据研究......................................................73 6.2 下部煤层巷道围岩控制技术分析............................................................................76 6.2.1 巷道围岩矿压控制途径.....