软岩非线性蠕变损伤特性及锚固机理研究

发布时间：2018-01-07 08:05

本文关键词：软岩非线性蠕变损伤特性及锚固机理研究　出处：《辽宁工程技术大学》2014年博士论文　论文类型：学位论文

【摘要】：蠕变是岩石材料的重要力学特征,许多岩土工程问题都与岩石的蠕变特性有密切关系,岩石蠕变现象给实际工程带来的影响已引起国内外学者的广泛关注。地下工程软岩蠕变特性以及锚固机理是研究的热点问题,文章通过试验研究、理论分析和数值模拟相结合的研究方法,对泥岩的基本力学性能、蠕变特性、非线性蠕变模型、参数辨识以及锚杆锚固界面粘结滑移关系进行了深入的研究,并将研究成果应用于高家梁煤矿软岩巷道支护结构分析中,论文主要工作如下：(1)对泥岩进行常规单轴压缩试验,研究了泥岩的强度和变形特征,获取了其基本力学特征参数。根据泥岩抗压强度确定出蠕变试验中分级加载等级和强度。利用岩石三轴试验仪对泥岩分别进行了单轴和三轴的分级加载蠕变试验,对不同加载路径包括围压恒定、分级增加轴压；轴压恒定、分级增加围压下泥岩的蠕变特性进行了系统研究,得到了不同加载路径和不同应力水平下泥岩蠕变过程的变形特征和蠕变速率的变化规律；(2)将岩石蠕变过程视为线性与非线性蠕变过程的迭加,借鉴元件组合模型的建模方法,将含分数阶微积分的变粘性系数FC元件代替Newton粘壶与Kelvin体、弹簧元件串联,同时引进考虑荷载级别与时间效应的损伤变量,提出一种五元件非线性蠕变损伤模型,较好的模拟泥岩蠕变全过程,尤其是泥岩加速蠕变阶段,并推导出模型的本构方程和蠕变方程；(3)基于分级加载蠕变模型参数多的特点,文中采用具有遗传交叉因子的改进粒子群算法和最小二乘法联合反演的方法,根据泥岩蠕变试验数据,对本文提出的五元件非线性蠕变损伤模型参数进行了辨识,得出了各参数合理数值；(4)为研究端锚粘结式锚杆的锚固机理,进行端锚杆中心拉拔试验。利用配置的5种水泥砂浆分析钢筋和水泥砂浆界面的黏结强度,得到试验的最优配合比。根据室内试验结果,依据荷载传递法推导出端锚杆—砂浆界面历经弹性状态、塑性软化和开裂滑移3个阶段的数学模型；(5)将包含分数阶的五元件非线性蠕变损伤模型的本构方程程序化,实现基于FLAC3D的本构模型二次开发。并结合推导的端锚杆-砂浆界面在弹性状态、塑性软化和开裂滑移3个阶段的数学模型,对高家梁煤矿软岩支护结构进行数值模拟分析。通过FLAC3D软件对巷道支护前后的位移场和应力场进行计算分析,将数值计算结果与现场监测数据进行对比分析,检验了联合支护对软岩巷道变形的控制效果。
[Abstract]:Creep is an important mechanical characteristics of rock materials, many geotechnical engineering problems are closely related to the creep effect, creep of rock for actual engineering has attracted wide attention of scholars at home and abroad. The creep characteristics of soft rock underground engineering and anchoring mechanism is a hot research issue, through experimental research, research methods combining theoretical analysis and numerical simulation, the creep characteristics of the basic mechanical properties of mudstone, the nonlinear creep model, parameter identification and anchoring the interfacial bond slip relationship was studied, and the research results are applied to the analysis of the supporting structure of soft rock roadway in GaoJiaLiang coal mine, the main work is as follows: (1) the conventional uniaxial compression test of mudstone, the strength and deformation characteristics of mudstone, obtain the basic mechanical characteristic parameters which are determined according to the compressive strength of mudstone. Graded loading grade and strength creep tests were carried out. The mudstone grading loading creep test of single axis and three axis by using three axial test of rock, different loading paths including constant confining pressure, grade of axial compression; axial pressure constant grade creep characteristics under confining pressure of mudstone were studied by the different loading paths and different variation of deformation characteristics of mudstone creep stress and creep rate under the level; (2) the creep process of rock creep process as linear and nonlinear superposition, reference modeling method of component model, variable viscosity coefficient FC element containing fractional calculus instead of Newton dashpot with Kelvin, the spring element in series, while the introduction of damage variables considering load level and time effect, this paper presents a new five component nonlinear creep damage model, simulate the whole process of mudstone creep becomes better, Especially the mudstone accelerated creep stage, and derived the constitutive equation and creep equation; (3) the characteristics of graded loading creep model parameters based on multi methods, with a genetic cross factor improved particle swarm algorithm and least square method of joint inversion in this paper, according to the mudstone creep test data, the proposed nonlinear creep the five element damage model parameters are identified, obtained the parameters reasonable value; (4) to study on the anchoring mechanism of the anchor bond type anchor, end anchor pull-out test. Using the configuration of 5 kinds of cement mortar reinforced cement mortar and the bond strength of the interface, get the best mix proportion is presented. According to the indoor based on the test results, derived end bolt and mortar interface after elastic load transfer, the mathematical model of 3 stages of plastic softening and slip; (5) will contain a fractional order A program of this constitutive equation nonlinear creep damage model of five elements, the FLAC3D constitutive model is developed based on the two. Combined with the end of bolt - derived mortar interface in elastic state, the mathematical model of 3 stages of plastic softening and slip, the GaoJiaLiang coal mine soft rock supporting structure for numerical simulation analysis based on the FLAC3D software. The displacement field before and after the supporting and stress field were calculated and analyzed. The numerical calculation results and field monitoring data were analyzed to test the control effect of combined supporting of soft rock roadway deformation.

【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU45

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