高应力软岩回采巷道预应力锚杆——锚索支护技术研究.pdf.doc

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1、【精品文档】如有侵权，请联系网站删除，仅供学习与交流高应力软岩回采巷道预应力锚杆锚索支护技术研究.pdf.doc.精品文档.武汉理工大学博士学位论文高应力软岩回采巷道预应力锚杆(申请工学博士学位论文)高应力软岩回采巷道预应力锚杆锚索支护技术研究锚索支护技术研究培养单位：土木工程与建筑学院学科专业：岩土工程白启树研究生：白启树武汉理工大学指导老师：夏元友研究员2014 年 3 月分类号密级UDC 学校代码10497 学 位 论 文题 目高应力软岩回采巷道预应力锚杆锚索支护技术研究英 文 Researchonthesupporttechnologyof pre-stressedcable题 目an

2、chorinhighstresssoftrockcoalroadway研究生姓名姓名职称学位指导教师单位名称姓名武汉理工大学邮编 430070学位职称副指导教师单位名称邮编申请学位级别论文提交日期博士学科专业名称2014.3论文答辩日期2014.5学位授予单位武汉理工大学 学位授予日期答辩委员会主席评阅人武汉理工大学博士学位论文武汉理工大学博士学位论文武汉理工大学博士学位论文独 创 性 声 明本人声明，所呈交的论文是本人在导师指导下进行的研究工作及取得的研究成果。尽我所知，除了文中特别加以标注和致谢的地方外，论文中不包含其他人已经发表或撰写过的研究成果，也不包含为获得武汉理工大学或其他教育机构

3、的学位或证书而使用过的材料。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作了明确的说明并表示了谢意。签 名：日 期：学位论文使用授权书本人完全了解武汉理工大学有关保留、使用学位论文的规定，即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，允许论文被查阅和借阅。本人授权武汉理工大学可以将本学位论文的全部内容编入有关数据库进行检索，可以采用影印、缩印或其他复制手段保存或汇编本学位论文。同时授权经武汉理工大学认可的国家有关机构或论文数据库使用或收录本学位论文，并向社会公众提供信息服务。（保密的论文在解密后应遵守此规定）研究生（签名）：导师（签名）：日期(注：此页内容装订在论文扉页

4、)中文摘要煤炭作为我国主要能源在国民经济中占据主足轻重的地位。煤矿回采巷道支护技术作为煤矿生产中的关键一环，如何降低成本、提高工效、减少维护是摆在我们面前的主要课题，目前大型矿井中 80%以上都是煤巷，随着我国煤矿开采强度与规模的不断增大和现代化综合机械化程度的大幅度提高，厚煤层综采放顶煤开采、综采一次性采全高等要求巷道的断面要求越来越大。随着煤矿开采水平的不断加深，高应力软岩巷道支护问题越来越突出，近些年来，锚网索支护技术己成为大断面回采巷道的主要方式。它具有支护强度大、成本低等许多优点，锚网索应用为解决大断面煤层回采巷道支护问题提供了一种有效方法。然而，预应力锚网索支护理论研究远落后于工程

5、实践，特别是对于预应力锚杆与锚索联合支护高应力软岩回采巷道的变形特性还未见报道，为此，论文以马临煤矿 C8煤层回采巷道支护问题为背景，针对高应力软岩回采巷道的流变问题，开展回采巷道围岩变形特征和破坏机理研究，通过流变试验，建立回采巷道锚杆与围岩支护流变本构模型，利用 FLAC3D 数值模拟，研究不同预紧力锚杆与锚索支护高应力软岩回采巷道的变形机理。并将研究成果应用于高应力软岩支护巷道中。通过研究取得了以下成果：1）基于泥质粉砂岩常规三轴压缩试验，通过建立不同围压对软岩峰后软化的力学模型，研究不同围压下泥质粉砂岩的峰后应变软化特征。以广义粘聚力c和广义内摩擦角j来表征的软岩后继屈服面模型，并利用

6、莫尔应力圆确定不同等效塑性剪切应变e 和不同围压s 3条件下广义粘聚力c和广义内摩擦角j。ps2）依据软岩三轴压缩的分级加载蠕变试验曲线的规律与时效特征，建立了高应力下泥质粉砂岩 Burgers粘弹性流变模型，并依据粘弹塑性力学的基本理论，推导了该模型的一维蠕变本构方程，进而借助非线性回归分析辨识了模型参数。对巷道围岩流变分析，得出了巷道围岩位移的粘弹性解，分析了围岩变形与应力、巷道半径、岩性及支护体之间的关系。3）运用 Monte-Carlo 随机数生成方法对回采巷道结构面进行网络模拟，从而对岩体质量进行评价，在此基础上提出回采巷道岩体力学参数估算方法。给出了回采巷道岩体力学参数建议值。4）

7、通过建立高应力软岩回采巷道锚杆锚索与围岩联合支护三维流变本构模型，分析预应力锚杆锚索与围岩的作用机理。采用有限差分数值计算I软件 FLA C3D对高应力软岩回采巷道应力场和位移场进行数值模拟，系统研究高垂直应力和高水平应力作用下软岩巷道锚杆 (索)施加不同预紧力组合时围岩产生的应力场分布特征；不同锚杆间距回采巷道围岩应力场分布特征。给出了围岩变形、应力随着时间推移的变化规律。5)研究了不同支护强度、预紧力对高应力软岩巷道围岩的控制作用，揭示了高应力软岩巷道围岩初期变形破坏具有不可克服性，建立了支护体让压支护的力学模型，分析了不同自由让压距离和不同极限变形量对让压支护效果的影响。6）开展高应力软

8、岩回采巷道预应力锚杆与锚索协调支护研究，提出了预应力锚杆、锚索协调支护的理念，通过预应力锚杆与锚索联合支护形成的组合拱构建了巷道“次生承载层”，从而实现对高应力软岩回采巷道预应力锚杆与锚索联合支护参数优化。研究结果表明：合理的支护密度，必须确保锚杆群支护产生压应力区连成整体并相互叠加形成组合拱对顶板起支撑作用；在支护密度一定时，锚杆的长度是确保锚杆形成的次生承载层的稳定，锚杆长度增加不会改变巷道的支护效果，锚杆长度只需满足顶板形成组合拱的厚度。6）针对高应力软岩回采巷道支护技术存在的问题，将研究成果应用于马临矿 2083回采巷道，通过现场观测，该支护体系能有效地控制回采巷道围岩变形和蠕变，巷道

9、的稳定性大大提高。关键词： 高应力软岩，回采巷道；流变；预应力锚杆锚索；让压支护IIAbstractCoal, the main energy of our country, plays a decisive role in our nationaleconomy. The support technology of mining gateway is regarded as a key link of coalmine production. So, how to reduce cost and raise efficiency is an important issuewhich we a

10、re confronted. Nowadays 80 percent of large-scale mines are coalroadway. With the increase of mining intensity and mechanization degree for coalmine in our country, the roadway section which is required by fully mechanizedtop-coal caving method in thick coal seam and the fully mechanized single mine

11、full-height method become large and large,. Moreover, with the improvement ofcoal mining technology, the supporting problem of high stressed soft rock roadway isbecoming more and more outstanding. In recent years, the bolt-mesh-cable supportingtechnology has been the main method in roadway of large

12、section. As this method haslarge supporting strength, low cost and a number of other advantages, the applicationof bolt-mesh-cable provide an effective approach to solve large section gatewaysupporting problems. However, pre-stressed bolt-mesh-cable theoretical research wasfar behind the engineering

13、 practice. Especially, the deformation characteristics forcombined support of pre-stressed anchor and anchor rope in high stressed soft rockroadway has not been reported. Therefore, with the support problem of Malin coalmine C8 seam gateway as the background, aiming at the rheological problem of hig

14、hstressed soft rock roadway, the study of surrounding rock deformation features andfailure mechanism was carried out in this paper. The rheological constitutive modelsof roadway bolt and surrounding rock was established by rheological test. UsingFLAC3D numerical simulation software, the deformation

15、mechanism of high stresssoft rock roadway under different pre-tightening force of anchor and anchor rope wasstudied, and the results were applied to the high stress roadway supporting system.The following innovative studied results were obtained：1）Based on the result of argillaceous siltstone conven

16、tional triaxial compressiontest, the post-peak strain softening characteristic of argillaceous siltstone at differentconfining stress was studied by establishing the mechanical model of post-peaksoftening soft rock at different confining stress. The soft rock subsequent yieldIIIsurface model was cha

17、racterized by the generalized cohesion( c ) and the generalizedinternal friction angle(j ). Besides, the generalized cohesion(c ) and the generalizedinternal friction angle( j ) at different equivalent plastic shear strain( e ) andpsdifferent confining stress were determined by Mohrs stress circle.2

18、) According to the law curve and time-dependent properties, which had beenobtained by the soft rock graduation loading triaxial compression creep test, Burgersviscoelasticity rheologic model of argillaceous siltstone at high-stress situation wasestablished. On the basis of viscoelastic plasticity me

19、chanics theory, theone-dimensional creep constitutive equation this model was derived, and than themodel parameters were identified with the help of non-line regression. By analyzingthe surrounding rock rheological properties of roadway, the viscoelastic solution ofsurrounding rock displacement was

20、obtained, and the relationship among thesurrounding rock deformation and stress, roadway radius, rock characteristics andsupporting system was studied.3) Using Monte-Carlo generating random number method to simulate thestructural plane of gateway with network, the rock mass quality was estimated.Fur

21、thermore, on the basis of this mehcod, the rock mechanics parameters estimationmethod of gateway was proposed, and the suggested values for gateway rockmechanics parameters were given.4) By establishing the three-dimensional rheological constitutive model ofbolt-cable combination support for high st

22、ressed soft rock roadway, the mechanism ofaction for pre-stressed bolt-cable and surrounding rock was analyzed. Thedisplacement field and stress field in high-stress soft rock gateway were simulated byfinite difference numerical software FLAC3D. The stress field distribution featurescaused by differ

23、ent pre-stress combination which was exerted by bolt or bolt-cable atsoft rock roadway under the condition of high vertical stress and horizontal stress wasstudied. The rock stress field distribution features of roadway at different distanceamong bolts was also studied, and the law of surrounding ro

24、ck deformation and stresschanged with time was given.5)The control action at different support intensity for the high stress soft rockroadway was studied using numerical simulation. The result shows that the initialdeformation of high stress soft rock roadway was insurmountable. So the yieldIVpressu

25、re support is proposed. The yield pressure support mechanics model wasestablished, and the support effects influenced by different yield distance anddifferentlimited deformation amount was analyzed.6) The idea of the secondary load bearing layer which was constructed by thecompound arch composed of

26、bolt-cable combination support was proposed. Moreover,the coordination of prestressing force for bolt-cable combination support wasproposed. The parameter optimization of bolt-cable combination support for highstressed soft rock roadway was achieved. The research results indicate that: Thegenerated

27、compressive zone of bolts group support should connect and overlap to awhole and than made up the arch structure which function was to sustain the roofmust be guaranteed by rational supporting density. Bolts length was an element tomake the secondary bearing stratum steadiness. When supporting densi

28、ty was fixed,the increase of the bolt length will not affect the bolt supporting effect, and the boltslength only required to satisfied the thickness of compound arch which forms atroadway roof.7) Aiming at the existent problems of high-stress soft rock gateway supportingtechnology, the research ach

29、ievements was applied to 2083 gateway of Malin colliery.Through made field measurement, the gateway surrounding rock deformation andcreep were controlled by this supporting system effectively, and the roadway stabilityincreased sharply.Key words: gateway of soft rock; rheology; pre-stressed bolt-mes

30、h-cable; yield stresssupportV目 录第 1章 绪论 .11.1 引言 .11.2国内外研究现状 .21.2.1巷道支护理论研究现状 .21.2.2预应力锚杆（索）支护作用机理研究发展现状 .31.2.3软岩流变特性试验与理论研究 .41.2.4软岩巷道流变特性研究 .51.2.5存在的问题 .61.3论文的主要研究内容 .7第 2章 软岩峰后软化力学特性与流变特性研究 .92.1 软岩的分类及工程性质 .92.1.1软岩的定义 .92.1.2软岩的分类 .92.1.3软岩的工程特性和力学特性 .102.2泥质砂岩三轴压缩试验 .102.3软岩峰后应变软化力学模型 .

31、 112.3.1峰后岩体后继屈服面模型 .122.4软岩流变试验与流变模型研究 .142.4.1 C8煤层泥质粉砂岩流变试验.152.4.2泥质粉砂岩蠕变模型建立 .162.4.3 流变模型参数的辨识方法 .172.5本章小结 .20第 3章 巷道岩体结构特征与岩体力学参数估算 .213.1概述 .213.2巷道岩体结构特征与结构面网络模拟 .213.3 回采巷道顶板力学参数估算 .303.3.1 巷道顶板岩石强度参数 .303.3.2 岩体的质量评价 .333.3.3岩体力学参数估算 .34i3.3.4巷道顶板力学参数 .363.4 本章小结 .36第 4章 回采巷道预应力锚杆锚索支护机理研

32、究 .384.1预应力锚杆与锚索联合支护机理 .384.1.1 锚网索耦合支护的主要作用 .384.1.2 锚网索耦合支护作用 .394.2预应力锚杆支护参数的影响分析 .444.2.1数值模拟模型 .444.2.2预应力锚杆间距对应力场的影响分析 .474.2.3预应力锚杆的布置角度对围岩应力场的影响 .484.3预应力锚杆锚索联合支护对巷道应力场的影响分析 .494.4 本章小结 .53第 5章 高应力软岩回采巷道蠕变控制研究 .545.1蠕变控制总体要求 .545.2软岩巷道围岩流变特性的分析 .555.2.1围岩应力的重新分布及时间效应 .555.2.2巷道围岩应力与变形的流变分析 .

33、575.3巷道锚网索与围岩耦合支护巷道内的流变模型 .615.3.1锚固体的流变模型与本构方程 .615.3.2锚网索与围岩支护流变本构方程 .695.4高应力软岩巷道让压支护的技术研究 .705.4.1软岩工程让压支护现状 .705.4.2让压支护对软岩巷道围岩的控制作用 .715.5锚杆与锚索联合支护（二次支护）巷道流变分析 .735.5.1锚杆（索）预紧力对高应力软岩回采巷道变形影响分析 .735.5.2锚杆（索）支护强度对高应力软岩回采巷道变形影响分析 .775.6本章小结 .80第 6章 高应力软岩回采巷道支护参数优化设计 .816.1锚杆支护参数优化模型 .816.1.1 模型的建立 .