【作者】 张连英；

【导师】 茅献彪；

【作者基本信息】 中国矿业大学 ， 工程力学， 2012， 博士

【摘要】 随着社会与经济发展对能源需求的不断加大,与温度有关的岩土工程问题越来越受到广泛关注,如：地热资源开发、核废料处置及煤炭地下气化等工程。温度与地应力耦合作用下岩石力学性能的研究是解决温度有关的岩土工程问题的基础。本文以煤系岩层中泥岩为研究对象，借助于MTS810电液伺服材料试验系统及配套的高温环境炉、扫描电镜、X射线衍射分析仪等试验手段，应用损伤断裂理论、粘弹塑性理论等，从宏观和细观不同尺度上，对高温作用下泥岩的损伤演化与破裂机理进行了系统的研究。主要工作和研究成果如下：（1）系统测定了常温至800℃高温条件下泥岩试样的全应力-应变曲线，分析得到了泥岩的弹性模量、峰值强度、峰值应变、软化模量等随温度的变化规律，并给出了加载速率对泥岩力学性能的影响，揭示了泥岩随温度升高和加载速率增加的脆延转化特性。（2）基于泥岩试样断口的电镜扫描和X射线衍射分析试验，给出了高温作用下泥岩试样组分结构的变化特征、影响泥岩力学性能的组分因素、试样断口处裂纹的形态及发育变化特征。结果表明，高温作用下泥岩试样的组分与物相变化是导致岩样断口处裂隙的扩展、闭合、晶界破裂形式差异的重要原因，从而呈现了不同温度段泥岩宏观力学性能的变化特征。有效地揭示了高温作用下泥岩宏观破裂特征的微观机制。（3）依据岩石损伤力学与统计强度理论，结合高温作用下泥岩的力学性能，构建了考虑温度及应变率效应的泥岩损伤演化方程和本构模型，并针对所测泥岩岩样的力学特性，给出了相应的损伤本构方程具体参数，本构模型与试验结果具有很好的印证性。（4）通过对常温及高温（700℃）作用下泥岩的分级加载蠕变试验，得到了相应的蠕变曲线，给出了泥岩的蠕变经验方程，并初步建立了考虑温度效应的泥岩蠕变本构模型，包括：泥岩的蠕变方程、卸载方程和松弛方程。研究成果在一定程度上丰富了岩石力学的基本理论，也为高温与地应力耦合作用下岩土工程问题的研究提供重要依据。更多还原

【Abstract】 With the social and economic development, the energy demand is increasing andgeotechnical engineering questions related to temperature attract more and more wideattentions, such as geothermal resource development, nuclear waste disposal and undergroundcoal gasification. Research on rock mechanical properties under the coupled action oftemperature and geostress is the basis to solve geotechnical engineering questions related totemperature. This paper mainly studies mudstone in coal strata by means of experimentalmethods and theoretical methods, including MTS810Electro-hydraulic Servo Material TestingSystem and matched High Temperature Furance, Scanning Electron Microscope, X-rayDiffraction Analyser, damage fracture theory and viscoelastic plastic theory. From the macroand mesoscopic scales, damage evolution laws and fracture mechanisms of mudstone underhigh temperature are studied systematically. The main works and research results are as follow:(1) Whole stress-strain curves of mudstone samples at the temperature from normal to800℃are tested systematically and the change laws of elastic modulus, peak strength, peakstress, peak strain and softening modules of mudstone with an increase in temperature areobtained. In addition, analyse the effect of loading speed on mudstone mechanical propertiesand reveal the features of brittle-to-ductility transformation in mudstone with increasingtemperature and strain speed.(2) According to SEM and X-ray diffraction analysis experiment of mudstone samplesfracture, the change features of component structural, component factor of effects on mudstonemechanical property and morphology and development features of crack in sample fracture areobtained. The results show that: component and phase transformation of mudstone sample athigh temperature are important reasons that cause cracks in sample fractures spread, close andform differences of fractures in grain boundary, and thus present change features ofmacroscopic mechanical property in different temperatures, which effectively revealsmicroscopic mechanisms of mudstone macroscopic fracture features in high temperature.(3) Based on rock damage mechanics and statistical strength theory, combiningmechanical properties of mudstone at high temperature, the damage evolution equation andconstitutive model of mudstone considering effects of temperature and loading speed areesTablelished. And aiming at mechanical properties of tested mudstone, the correspondingdetailed parameters of damage equation are given. Furthermore, constitutive model has a goodagreement with experiment results.(4) Through step load creep experiment of mudstone at normal and high (700℃)temperature, we not only obtain the corresponding creep curves and creep empirical equation of mudstone, but also initially esTablelish creep constitutive model of mudstone consideringtemperature effect, including creep equation, unload equation and relaxation equation ofmudstone.To some extent the research results enrich basic theory of rock mechanics and provideimportant basis for research on geotechnical engineering problems under the coupled action oftemperature and geostress.更多还原