【作者】 吴海；

【导师】 张农；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2014， 博士

【摘要】 本文采用工程调研、理论分析、物理模拟和数值计算等研究手段，总结归纳了倾斜岩层巷道顶板、底板和两帮及四角的分区变形破坏特征，描述了不同区域内的应力分布特征，阐明了巷道不同区域围岩非均称变形的产生机理，揭示了巷道围岩不同区域不均匀变形的时空演化规律，在此基础上提出了控制倾斜岩层巷道非均称变形的稳定控制技术，并进行工程验证研究。主要结论如下：（1）深部倾斜岩层巷道围岩变形表现出明显的时序性特征。围岩变形破坏的一般顺序依次是巷道顶板和岩层层面相切部位、巷道底板和高帮底角、低帮底角，最后发展到高帮肩角处。力学分析表明，巷道表面切应力方向和岩层倾向夹角越小，非均称变形的显现时间越早，其中巷道高帮表现为拉伸破坏，低帮表现为剪切破坏。（2）参与研制了20MPa-“三向五面”竖向主加载实验系统。系统采用新型模块化设计，采用计算机集成控制和自动采集模型的应力和应变数据。该系统能够对试块进行三个方向5个面的独立伺服加载，每个面主动加载应力为20MPa，各面加载互不干扰，能够根据设计要求较好地实现不同的三维应力状态。模拟试块最大尺度为1000×1000×400mm。（3）利用三维物理模拟实验揭示了深部倾斜岩层巷道围岩变形的非均称特征。开展了30°和45°两种倾角的实验，测试分析均表明：巷道高帮表面变形小，但是内部围岩裂纹发育丰富，横向裂纹沿巷道轴向相互贯穿；巷道低帮表面变形较大，但内部横向裂纹发育相对较少；巷道顶板高帮肩角的变形量小，低帮肩角变形量大；底板变形量表现出高帮底角处侧变形量大，低帮底角侧的变形量小。大倾角时两帮非均称现象更加显著，底板的非均称现象减弱。（4）采用数值模拟揭示了不同倾角下巷道围岩非均称变形的发展态势。采用3DEC数值模拟软件建立了10°到90°角度范围内的14种不同岩层倾角的巷道模型，模拟结果表明：巷道底板变形非均称性随岩层倾角的增加而单调减小，当倾角大于45°后底板变形非均称性趋缓；巷道两帮水平位移随岩层倾角倾角增加而逐渐增加，垂直位移则逐渐减小；顶板位移峰值点在岩层和巷道相切点两侧，并随岩层倾角增加而逐渐向低帮转移，巷道顶板水平位移量逐渐增加，垂直位移量逐渐减小。当岩层倾角小于15°或者大于80°时，巷道围岩的最大主应力等值线呈圆形分布，此时岩层倾角对于巷道主应力分布影响小。当岩层倾角大于15°而小于80°时，以岩层倾向和法向线为坐标系，在每个象限的平分线上有较大的主应力靠近巷道表面。巷道围岩周围的最大主应力等值线呈“四叶草”型分布，其中分布中心在巷道中心。（5）以30°倾角为例研究了围岩应力状态对巷道非均称变形的影响规律。侧压系数等于1时，巷道围岩位移等值线沿通过岩层和巷道切点的岩层法线左右对称，岩层层间滑移离层显现近似的对称特征；侧压系数大于1时，巷道围岩位移区集中在巷道两帮内，层间滑移离层区集中在巷道顶底板内；侧压系数小于1时，巷道围岩位移区集中在巷道顶底板中，岩层层间滑移离层区集中在巷道两帮。巷道围岩位移量、围岩位移范围、层间滑移量、层间滑移范围和巷道围岩应力大小成正比，应力越大变形特征越明显。（6）提出围岩“应力优化-性能提升-结构强化”技术思路，系统创新了控制非均称变形的加固技术。提出了巷道围岩优先加固区的概念，即倾斜岩层在围岩应力作用下早期出现的非均称变形破裂区域，将导致巷道围岩的持续加速变形和结构性失稳，应优先加固。（7）提出采用注浆及注浆锚索深孔注浆相结合的分步全长锚固技术提升围岩力学性能；结合优先加固区和局部支护结构强化技术、“三高”锚固技术和预应力锚索桁架支护结构强化技术控制围岩支护结构的薄弱环节；通过构建内外承载的耦合支护体系及壁后充填技术提高支护结构的强度。（8）结合深部全岩巷道曲江矿-850m东大巷、深部半煤岩巷道曲江矿601巷道和淮南谢桥矿小煤柱沿空巷道三种条件下的倾斜岩层巷道案例给出了工程验证。更多还原

【Abstract】 High intensity of mining status has been existed in China for many years, wheremore and more collieries trying to enter deeper and with the downward speed more than8~10m/a. Certain amount of inclined coal seam exist among them, where theexcavation shows a series of distinctive deformation characteristics like durativeasynchronism and spatial asymmetry. It is obvious that the consequential hiddendangers, like supporting failure or structural instability, will bottleneck the highrecovery of inclined coal seam.Combined measures of engineering research, theoretical analysis, physicalsimulation and numerical calculation are applied in this dissertation and thussuccessfully summarize the deformation and breakage characteristics of different areasof roadway, including roof, floor, sides and corners, there also further analyzes the stressdistribution law of these areas and illuminates the mechanism of unsymmetricaldeformation in different areas, then prosperously reveal the space-time evolution lawof the unsymmetrical deformation in different areas, finally the corresponding stablecontrolling technology for unsymmetrical deformation of roadway buried in inclinedstrata is proposed and also been verified in field application, the main conclusions areshown as follows,(1) Entry’s deformation of inclined deep strata is featured by distinctive timesequence，the general breakage sequence is: Roof, area that tangent to the layer of strata,floor, base angle of higher side and then lower side, and the last one is shoulder ofhigher side. The mechanical analysis manifests that unsymmetrical deformation willshow out sooner as the smaller angle that between the shear stress direction and strata’sinclination.(2) We manufactured Dthree-dimensional and five face vertical primaryload testsystem which is configured by neotype modular design, compute integrated controlling,and automatic strain/stress gathering model, it thus can realize independent load (threedirections and five faces) on the test block, the active load stress of each face can reach20MPa, then ideal different three-dimensional stress state can come true according tothe design requirements. The maximum size of the test block is1000×1000×400mm.(3) Unsymmetrical deformation speciality of deep inclined strata was revealedbased on the three-dimensional physical experiments. There set up two simulatedinclination, namely,30°and45°, results indicated that though deformation of higher rib side was small, interior joints were greatly developed and horizontal joints run throughalong the entry’s axial direction. Deformation of lower rib side was relative large butthe interior horizontal joints were rare. Considering the deformation of entry’s roof,shoulder of higher rib side was relative smaller than the lower rib side. But it showncomplete contrary as to entry’s floor, base angle of higher rib side was relative largerthan lower rib side. This phenomenon tends to be much more dramatic in sides as theinclination increases, however, it tends to mitigate as to floor.(4) Numerical simulation also testified the unsymmetrical deformation ofsurrounding rock, computational software3DEC was adopted here and fourteeninclinations varied from10°to90°had been initiated. The simulated resultsdemonstrated that unsymmetrical deformation decreased versus the increase ofinclinations and it would head for alleviation as the inclination surpasses45°.Horizontal displacement of sides would increase with the inclination’s increasing whilethe vertical shown contrary variation. The peak value of roof’s displacement located atthe both sides of the tangency point between the strata and entry, which also wouldtransfer to the lower rib side as the inclination increases and simultaneously roof’shorizontal displacement increased gradually while vertical displacement decreasedgradually. Under the circumstance that the inclination of strata is less than15°or morethan80°, the contour lines of maximum main stress shown circular distribution and thestress distribution was little influenced by the inclination, when beyond theaforementioned range, however, if build a coordinate system by strata inclination andnormal firstly, then there had relative large main stress located at the quadrant bisector,the stress was close to the surface of roadway, and the contour lines of maximum mainstress shown clover distribution and whose distribution center coincided with theentry’s center.(5) Influence on unsymmetrical deformation which applied by stress state ofsurrounding rock was analyzed when the inclination was30°. Displacement contourlines was symmetrical along the normal line which went through the tangency pointbetween strata and entry under the condition that the side pressure coefficient equaledto1, in addition, the slippage and separation of strata also shown approximate symmetry.The displacement of surrounding rock was concentrate in entry’s sides and slippagearea in the roof and floor if side pressure coefficient surpassed1, if the side pressurecoefficient was less than1, however, the other way around. It was thus obvious that allof displacement value, displacement range, slippage value and slippage range were directly proportional to rock’s stress, the former ones shown distinctive variation aslatter seriously changed.(6) This dissertation also initiated the new technical thoughts of Dstressoptimization-property improvement-structure strengthen, which systematicallyinnovated the reinforcement on unsymmetrical deformation, there also put forward thetheory of priority reinforcement, as what it called, it focused on the priorityreinforcement on the areas where the early formed unsymmetrical deformation located,thus to avoid the continuous deformation and structural instability under the high stressin inclined strata.(7) This dissertation also came up with the technique of step-by-step anchoringmethod to improve mechanical property of surrounding rock, whose kernel was thecombination of grouting and deep hole cable grouting, based on priority reinforcement,regional structural strengthen technique, Dthree highs anchoring technology, andprestressed cable truss structure, vulnerable region can be efficiently supported, and thestrength of supporting structure also can be improved by interior-exterior bearedcoupling system and backfill grouting technology(8) Different engineering practices that concerned inclined strata verifiedaforementioned theoretical results, they were-850m eastern rocky roadway of QujiangMine,601numbered half-coal roadway of Qujiang Mine, and gob-side side entryretaining with little coal pillar retained of Xieqiao Mine, Huainan Mining Group.更多还原