【作者】 孟波；

【导师】 靖洪文；

【作者基本信息】 中国矿业大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 破裂围岩锚固结构的形成条件及其承载能力对于高应力巷道围岩稳定性控制问题具有至关重要的意义。本文紧紧围绕巷道破裂围岩与锚杆支护相互作用机理这一关键科学问题，综合采用物理模型试验、数值计算、理论分析与工程应用验证等方法开展了系统研究。主要获得了以下成果和结论：（1）研制与完善了“大比尺三维锚固体力学模型试验台”，可以实现对破裂岩体预制以及锚固体受压破坏过程中力学边界条件的模拟与控制；配制了符合破裂岩体力学特性、满足大相似比要求、破坏后仍具有完整性便于裂纹观测以及碎块统计的岩性相似材料。（2）通过模拟实际巷道开挖和返修过程中围岩应力路径预制了破裂岩体。在此基础上，进行不同围岩初始破裂程度、不同锚杆预紧力、不同锚杆密度条件下大比尺、三轴应力条件下破裂围岩锚固体模型试验，得到了破裂围岩锚固体强度随锚固条件的变化规律。探讨了不同锚固条件对破裂围岩锚固体变形破裂特征、分形特征、能耗特征的影响规律，为后续研究组合拱（梁）承载性能奠定了基础。（3）利用数值反演的方法，确定了破裂围岩锚固体强度参数随应变的演化规律，并将之嵌入FLAC^3D计算模型中，获得了巷道破裂围岩组合拱承载能力及其对围岩应力场演化规律的影响。对数值计算得到的不同锚固条件下组合拱承载能力、组合拱内外应力分布以及峰值迁移规律进行了分析，获得了锚固条件及组合拱厚度对组合拱承载能力以及外部围岩稳定性的影响规律。（4）建立了巷道围岩锚固支护结构理论分析模型，获得了一定厚度组合拱（梁）发生结构失稳或强度破坏时极限承载能力表达式。通过对锚固体物理模型试验中锚杆托盘附近岩体破裂形态以及锚固体内部应力分布情况的研究，获得了锚杆控制区范围形态及演化规律，在此基础上推导得到了组合拱（梁）存在需满足的基本条件以及失效形式判据，为破裂围岩巷道组合拱（梁）稳定性控制提供了理论基础。（5）最后，在以上研究的基础上，通过典型的大断面破裂软岩巷道治理工程案例验证了论文结论的合理性和实用性。更多还原

【Abstract】 The forming conditions and bearing capacity are vital to stability control of roadwaysurrounding rock with high stress. Research methods such as physical model test, numericalcalculation, theoretical analysis or engineering application verification were applied to thesystematic research of mutual influential mechanism of fractured rock mass and anchor bolts.Main results and conclusion are as below:(1)"Large scale three-dimensional anchorage unit mechanical model test bed" wasdeveloped and improved, which could simulate and control mechanical boundary conditions ofthe processes of prefabricated fractured rock mass and failure of anchorage unit due tocompression. Anchorage unit similar model material which met the requirement of large ratio ofsimilitude and had integrality after failure for fracture observation and fragment statistic wasdeveloped.(2) Fractured rock mass was prefabricated by simulating stress path of roadway excavationand repairmen process, at the base of which, large scale triaxial fractured surrounding rockanchorage unit model test was carried out under conditions of different surrounding rock initialfissure degree, different anchor bolt pretightening force and different anchor bolt density. Thevariation of fractured surrounding rock anchorage unit strength along with anchorage conditionswas obtained. Influential rule of different anchorage conditions to anchorage unit strength,deformation, failure, fractal and energy dissipation characteristics was discussed, which offeredan important foundation to following study of anchorage structure bearing characteristic.(3) The evolution rule of anchorage unit basic mechanical parameter along with plasticstrain was gained by numerical inversion and finally implanted in FLAC3Dcalculation model,from which roadway fractured surrounding rock combined supporting arch bearing capacity andthe law of its influence to surrounding rock stress field were obtained. Combined supporting archbearing capacity, inner and outer stress distribution and peak stress shifting law under thedifferent anchoring condition from numerical calculation were analyzed. The effect law ofanchoring condition and thickness to combined supporting arch bearing capacity and outersurrounding rock stability was obtained.(4) Theoretical analysis models of roadway surrounding rock anchorage structure wereestablished. Basic condition of combined supporting arch (beam) formation and ultimate bearingcapacity expressions of structure instability or strength failure were obtained. The form andevolution law of anchor bolt controlling zone were obtained with the study of fracturing shape ofrock mass around anchor bolt plate and anchorage unit inner stress distribution from anchorageunit physical model test. Basic forming condition and failure pattern criteria of combined supporting arch (beam) was proposed, which provided theoretical foundation for fracturedsurrounding rock anchorage stability control.(5) Finally, based on the above research, the rationality and practicability of researchconclusions of this dissertation were verified by typical repairing engineering of large sectionroadway with soft and fractured surrounding rock.更多还原