基于细观力学的饱和脆性砂岩各向异性损伤机理与本构模型研究

项目名称： 基于细观力学的饱和脆性砂岩各向异性损伤机理与本构模型研究

项目编号： No.51209188

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 水利科学与海洋工程学科

项目作者： 谢妮

作者单位： 中国地质大学（武汉）

项目金额： 25万元

中文摘要： 饱和脆性岩石的细观损伤本构模型是岩石力学领域前沿基础性研究课题之一。本项目采用室内试验、理论建模和数值分析相结合的方法，研究饱和脆性岩石孔隙水压力作用下的各向异性损伤演化机理与本构模型。以三峡库区典型脆性砂岩为研究对象，运用扫描电镜(SEM)获取砂岩的典型细观结构，为确定初始损伤参数提供依据；利用MTS试验系统对饱和砂岩进行不同孔隙水压力作用下的三轴压缩试验，并同步进行声发射和超声波速测试，揭示饱和砂岩各向异性损伤演化规律和破坏机理；基于试验结果，采用细观力学均匀化方法，融合不可逆热力学理论、弹塑性理论，建立严格基于尺度扩展的饱和脆性岩石细观损伤模型；研发可计算三轴压缩及不同应力路径下岩石力学响应及损伤演化的程序，为饱和脆性岩石的变形破坏分析提供理论依据，研究成果可广泛应用到核废物地质处置、二氧化碳地质封存、深埋长大引水隧洞群开挖、坝基以及涉水岩质边坡等众多与饱水岩石相关的岩石工程领域。

中文关键词： 各向异性损伤；细观力学；声发射；超声波速；饱和砂岩

英文摘要： Micromechanics-based damage model for saturated quasi brittle rocks is one of the most fundamental researches in the field of rock mechanics and geotechnical engineering. This project employs synthesis approaches of indoor test, theoretical modeling and numerical simulation, to study the anisotropic damage evolution and constitutive equation of saturated brittle rocks under interstitial fluid pressure. Typical brittle sandstones from Three Gorges reservoir is selected as the study object. SEM (Scanning Electron Microscope) is used to investigate the typical microstructures of the studied sandstone and provide references for the determination of initial damage parameters. Triaxial compression tests combined with synchronous acoustic emission and ultrasonic velocity tests under different interstitial fluid pressures are conducted on saturated sandstones using MTS testing system, so that the anisotropic damage evolution and failure mechanism of saturated sandstone can be revealed. Based on testing results, homogenization method used in micromechanics, the irreversible thermodynamics and elastoplasticity theory are adopted to establish the micromechanics-based damage model for saturated brittle rocks by strictly following the upscaling procedure. Afterwards, computational program which is capable of calculating the

英文关键词： Anisotropic damage；micromechanics；acoustic emission；ultrasonic velocity；saturated sandstone