【作者】 何峰；

【导师】 王来贵；

【作者基本信息】 辽宁工程技术大学 ， 工程力学， 2010， 博士

【摘要】 岩石结构是非连续和非均质体,具有非线性、各向异性及随时间变化的流变特性。水是影响岩石蠕变破裂失稳性质的一个重要因素,随着时间的增加,并导致重大岩石工程事故的发生,造成伤亡和重大经济损失,所以开展岩石蠕变破裂与渗流耦合作用规律的研究对岩石工程的长期稳定性具有重要的理论意义和实际应用价值。论文基于前人的研究基础,对煤岩进行了三轴蠕变试验、有限元理论和数值模拟研究,综合分析了岩石工程中各种失稳破坏现象,主要工作如下:(1)对煤岩试件分别进行三轴蠕变试验和蠕变-渗流耦合试验,得出炭质泥岩的长期强度;不同含水率对煤岩试件蠕变特性的影响,确定蠕变模型参数;考虑围压、加卸载及恒压下,渗透率的变化规律;煤岩试件蠕变全过程中对渗透率的影响规律。对于不同岩石和不同的围压、孔压条件下,通过蠕变过程中的渗透性试验,拟合出相应蠕变-渗透率曲线和渗透率-蠕变方程;(2)基于弹性理论的有限元分析基本方程,引入粘弹塑性问题的本构方程,再结合弹性、弹塑性问题的平衡微分方程、几何方程及边界条件,联合建立流变问题的有限元基本方程;并应用最大拉应力理论,建立最大拉应力单元追踪法,模拟流变变形过程中裂纹的萌生、扩展和汇聚,建立蠕变破裂判断准则;同时建立了非线性损伤模型,并进行了岩石损伤过程的有限元模拟。(3)据等效连续介质模型和流变学的理论,建立煤岩体流变场与渗流场耦合作用下的流变模型,推导相应的直接耦合总体控制方程,给出煤岩体流变场与渗流场耦合作用下的有限元分析格式,并进行了有限元程序设计;(4)基于流变试验和蠕变-渗流耦合有限元法,应用FEPG软件平台,编制蠕变破裂模块和蠕变-渗流耦合模块,并应用于层状边坡长期稳定性分析;通过蠕变破裂模块,分别从受法向力作用下蠕变破裂和离层蠕变破裂,分析其各设定监测点随时间演化应力变化规律、不同方向位移变化规律;通过蠕变-渗流耦合模块,分析其监测点水压随时间的变化,位移的变化规律。更多还原

【Abstract】 Rock structure is a non-continuous and non-homogeneous body, whose mechanical properties are nonlinear, anisotropic and rheological properties change with time. Water is an important factor that affects the nature of creep rupture in failure. As time increases, led to the occurrence of major rock projects, cause casualties and significant economic losses, and So to carry out creep rupture and flow coupling rules for long-term stability of rock engineering has great theoretical and practical application value. Based on the previous studies,researchs on the triaxial creep experiment, the finite element theory and numerical simulation of coal and rock, the comprehensive analysis of the rock engineering of instability and failure phenomenon, the main work is as follows:(1) Coal (rock) samples were carried out triaxial creep test and creep– seepage coupling test, what obtain the long-term strength of carbonaceous mudstone , the different moisture content of coal’s (rock) effect on creep properties of specimens, determined parameters of the creep model and when confining pressure,loading and unloading, and constant pressure the changes of permeability and the coal (rock) sample creep law on permeability. For different rock and confining pressure, pore pressure conditions, permeability through the process of creep test, we can get a fitting about the corresponding penetration– creep curve and equation.(2) Based on elastic finite element analysis, introduce constitutive equation of viscoelastic and viscoplastic, and combine the elasticity and plasticity of the equilibrium differential equation, geometric equations and boundary conditions, establish rheological equations. concerned.by application of maximum tensile stress theory, establishes the tracing method of maximum tensile stress and simulates unit process of rheological deformation, cracks initiation, expansion and gathering, and establishes a judgment criterion for the creep rupture.(3) Based on mixture theory and according to the equivalent continuum model and the rheological basic theory, we can establish the rheological model that under the effect of coal (rock) body stress field and seepage coupling, to derive the corresponding equations of the overall direct coupling .Given coal (rock) body of stress coupled with the seepage flow under the action of the finite element analysis format, and we conduct the finite element program’s design and establishment.(4) Based on rheological experiment and the finite element theory on the couple between the creep and seepage flow, two models which were respectively the creep rupture and the couple between creep and seepage were proposed by the FEPG Software Platform, further the two models were applied to investigate the long-term stability of stratified slope. In terms of the rupture of the creep and the abscission layer creep under the normal force loading, stress variation with the time evolution and the displacement variation in different directions on the monitoring points were analyzed by the creep rupture model. Meanwhile by the model of the couple between creep and seepage, water hydraulic variation both with the time and the displacement were conducted.更多还原