【作者】 李冲；

【导师】 徐金海；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2012， 博士

【摘要】 软岩巷道支护问题至今没有完全解决，特别是高应力泥化软岩巷道支护难度大，往往需要返修多次才能控制巷道长期稳定，严重影响生产安全和浪费大量巷修费用，软岩巷道稳定性控制已成为煤矿亟待解决的重大技术难题。本文以曲江矿850m东皮带大巷（高应力泥化软岩巷道）为工程背景，围绕高应力泥化软岩巷道稳定性控制问题，综合运用数值模拟、理论分析、实验室试验、现场监测和工业性试验等方法，对软岩巷道让压壳网壳耦合支护机理与技术进行系统研究，取得了如下主要创新成果：（1）进行了泥质粉砂岩三轴蠕变试验，建立了泥质粉砂岩蠕变全过程的粘弹塑性蠕变模型，并推导出该蠕变模型的本构方程；采用FLAC3D软件，分析并得到了高应力泥化软岩巷道流变规律以及塑性区分布规律。（2）提出了让压壳的概念，给出了让压壳的构筑条件、支护作用特点、支护内涵，并推导出让压壳厚度的计算式，分析了软岩巷道让压壳支护强度，确定了东皮带大巷让压壳支护强度与厚度。（3）建立了全长锚固预应力锚杆支护力学模型，系统研究了短细密锚杆支护作用机理，推导出锚杆轴应力和剪应力计算式；推导出围岩沿锚杆轴向、径向和环向的应力计算式，分析并得到了预紧力、锚杆长度、直径与锚杆轴应力和剪应力的关系；分析并得到了锚杆长度与预紧力对围岩应力的影响规律；采用FLAC软件，分析并得到了锚杆长度与支护密度对软岩巷道围岩变形的影响规律。（4）提出了让压壳网壳耦合支护技术，分析了让压壳网壳耦合支护原理，提出了“限压让压、让压抗压、限让适度、让抗协调”的二次支护原则，给出了让压壳网壳耦合支护技术关键与控制方法；推导出软岩巷道预留让压空间的计算式，并确定了东皮带大巷预留让压空间大小为38cm。（5）将高应力泥化软岩巷道围岩划分为让压壳（在破裂区内）、破裂区、塑性区及弹性区，基于粘弹塑性理论，考虑围岩蠕变与扩容，推导出塑性区半径、破裂区半径以及让压壳半径的计算式及各分区应力表达式，分析了让压壳变形以及变形过程中能量释放，确定了东皮带大巷让压壳网壳耦合支护强度与时机。（6）依据软岩巷道让压壳网壳耦合支护理论与技术，确定了曲江矿850m东皮带大巷围岩控制方案与参数，并进行了工业性试验。现场应用表明，采用“合理断面形状及尺寸+卸压控顶施工技术与工艺+让压壳+预留让压空间+锚索补强+网壳衬砌支架”的施工技术和支护方式较好地控制了850m东皮带大巷围岩有害变形，确保东皮带大巷长期安全稳定。更多还原

【Abstract】 The problem about support of soft rock roadway has not been solved completelyyet. It is difficult to support especially in mudding soft rock roadway with high stress,we often rework several times in order to control the long term stability of roadwaywhich affects production safety seriously and wastes high cost of roadwaymaintenance, thus to control the stability of soft rock roadway has been a significanttechnical problem which needs to be resolved immediately. In this paper, we choose850m east belt main roadway of Qujiang coal mine (mudding soft rock roadway withhigh stress) as the engineering background and apply comprehensively numericalsimulation, theoretical analysis, laboratory experiment, field monitoring, industrialexperiment and other methods around the problem about controlling the stability ofmudding soft rock roadway with high stress. We make a systematical study ofyielding shell reticulated shell coupling support mechanism and technology in softrock roadway and obtain following innovation achievements:(1) We make a triaxial creep test of argillaceous siltstone, establish a viscoelasticplasticity creep model of the whole creep process of argillaceous siltstone and deducethe three dimensional constitutive equation about this creep model; we utilize Flac3Dto analyze and obtain the creep law and plastic zone distribution law in soft rockroadway with high stress.(2) We put forward the concept of yielding shell and the construction condition,support action characteristics and support connotation of yielding shell are given. Wededuce the formula for the thickness of yielding shell, analyze the support strength ofyielding shell in soft rock roadway and determine the support strength and thicknessof yielding shell in east belt main roadway.(3) We establish the mechanical model of full size grouted prestressed boltsupport, study systematically the support mechanism of bolts which are short, thin andarranged densely, deduce the formula for the axial stress and shear stress of bolt; wededuce the formula for the surrounding rock stress along the axial direction, theradial direction and the ring direction of bolt, analyze and obtain the relationshipbetween pre tightening force of bolt, length of bolt, diameter of bolt and axial stressof bolt, the shear stress of bolt; we analyze and obtain the influence law ofsurrounding rock stress by bolt length and bolt pre tightening force; we use Flacanalyze and obtain the influence law of the deformation of soft rock roadway surrounding rock by bolt length and support density.(4) We put forward the yielding shell reticulated shell coupling supporttechnology, analyze the yielding shell reticulated shell coupling support principle, putforward the secondary support principle that we should restrict, yield and resist stress.Meanwhile, moderate restriction and yielding are needed, yielding should coordinatewith resistance. The yielding shell reticulated shell coupling support technology andmethod are given. We deduce the formula for the reservation yielding space in softrock roadway and determine the reservation yielding space in the east belt mainroadway is38cm.(5) We divide the mudding soft rock roadway surrounding rock with high stressinto yielding shell (which is in fractured zone), fractured zone, plastic zone and elasticzone. We base on viscoelastic plastic theory, consider the creep and dilatancy ofsurrounding rock, deduce the formulae for the radius of plastic zone, the radius offractured zone and the radius of yielding shell and the expression of each division. Weanalyze the deformation of yielding shell and the energy release during deformationprocess, determine the yielding shell reticulated shell coupling support strength andtime in the east belt main roadway.(6) According to the yielding shell reticulated shell coupling support theory andtechnology in soft rock roadway, we determine the control method and parameters ofsurrounding rock in the850m east belt main roadway of Qujiang coal mine and makesome industrial tests. The field application shows that using the constructiontechnology, which consists of rationalizing the shape and size of section, yielding roofcontrol construction technology and process, yielding shell, reserving yielding space,anchor reinforcement and reticulated shell lining stent, and support method cancontrol the harmful deformation of surrounding rock in the850east belt mainroadway, ensure the long term security and stability of the east belt main roadway.更多还原