富水条件下泥岩巷道长时变形失稳机理研究

发布时间：2019-06-29 19:29

【摘要】：富水条件下泥岩巷道长时变形失稳破坏已成为煤矿井巷安全控制亟需解决的问题之一。论文以芦岭煤矿㧟590西轨大巷变形破坏工程案例为背景,针对富水条件下泥质裂隙岩体长时变形问题,综合运用现场测试、理论分析、实验研究等方法,分析了不同矿物组分岩样水化过程中微观结构演变特征及泥质裂隙岩体中水化作用与渗流-应力耦合的相互影响机制,从微观层面揭示了富水条件下泥质裂隙岩体长时变形的力学机理;通过引入带应变触发的非线性粘性元件,改进已有流变模型,得到了适用于富水条件下泥质裂隙岩体长时变形的增量式本构方程。取得了如下创新成果:(1)岩石微观结构受其矿物组分、胶结状况、粒径分布、孔隙分布及细观非均匀性等因素综合影响。(2)水化作用对泥质裂隙岩体微观结构的改变主要表现为粘土矿物吸水发生膨胀、溶蚀和泥化效应,改变程度与其孔隙结构密切相关。(3)水化作用对泥质裂隙岩体复杂孔隙结构的改变趋势因其矿物组分不同而异;浸水导致泥质裂隙岩体某一孔径范围孔隙体积比例发生改变;泥质裂隙岩体渗透率K值同时受孔隙率n及孔径分布状况影响。(4)富水条件下,泥质裂隙岩体的长时变形是由于泥质裂隙岩体的流变特性受到渗流-应力耦合、水化作用以及二者相互影响的综合作用所致。泥质裂隙岩体的流变性是其长时变形的基础;水化作用与渗流-应力耦合相互关联、促进,水化作用依靠于泥质裂隙岩体的孔隙结构,又借助渗流-应力耦合导致孔隙结构产生新的改变,进而促进泥质裂隙岩体进一步水化;膨胀、溶蚀、泥化效应致使泥质裂隙岩体微观结构发生改变,宏观上表征为力学性能弱化(力学参数改变),致使相应的本构关系为一随水化程度而不断变化的方程;膨胀应力以及泥质裂隙岩体固体骨架结构形态的改变均会导致其有效应力发生改变。
[Abstract]:Under the condition of rich water, the long-term deformation and instability of mudstone roadway has become one of the urgent problems to be solved in the safety control of coal mine roadway. Based on the engineering case of deformation and failure of western rail roadway in Luling Coal Mine, aiming at the long-term deformation of muddy fracture rock mass under the condition of rich water, the microstructure evolution characteristics of rock samples with different mineral components and the interaction mechanism between hydration and seepage-stress coupling in muddy fracture rock mass are analyzed by means of field test, theoretical analysis and experimental research. The mechanical mechanism of long-term deformation of muddy fracture rock mass under the condition of rich water is revealed from the microscopic level. By introducing the nonlinear viscous element with strain trigger, the existing rheological model is improved, and the incremental constitutive equation suitable for the long-term deformation of muddy fracture rock mass under the condition of rich water is obtained. The following innovative results have been obtained: (1) the microstructure of rock is comprehensively affected by its mineral composition, cement condition, particle size distribution, pore distribution and meso-heterogeneity. (2) the effect of hydration on the microstructure of muddy fracture rock mass is mainly due to the expansion, dissolution and muddy effect of clay minerals. The change degree is closely related to its pore structure. (3) the change trend of complex pore structure of muddy fracture rock mass due to hydration varies with its mineral composition; Water immersion leads to the change of pore volume ratio in a certain pore size range of muddy fracture rock mass, and the permeability K value of muddy fracture rock mass is affected by porosity n and pore size distribution at the same time. (4) under the condition of rich water, the long-term deformation of muddy fracture rock mass is caused by seepage-stress coupling, hydration and the comprehensive interaction between them. The rheology of muddy fracture rock mass is the basis of its long-term deformation, hydration and seepage-stress coupling are related to each other, and hydration depends on the pore structure of muddy fracture rock mass, and the pore structure is changed by means of seepage-stress coupling, thus promoting the further hydration of muddy fracture rock mass. The microstructure of muddy fracture rock mass is changed by expansion, dissolution and mud effect, which is characterized by weakening of mechanical properties (change of mechanical parameters), resulting in the corresponding constitutive relation as an equation that changes continuously with the degree of hydration, and the change of expansion stress and solid skeleton structure shape of muddy fracture rock mass will lead to the change of effective stress.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD322

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