深部硬岩脆-延性转化行为的细观损伤模型  

Micromechanical Damage Model for the Brittle-Ductile Transition in Deep Hard Rock

作　　者：胡坤 赵伦洋 李鹏飞 刘思利 陈曦 HU Kun;ZHAO Lunyang;LI Pengfei;LIU Sili;CHEN Xi(Faculty of Architecture and Civil Eng.,Huaiyin Inst.of Technol.,Huaian 223021,China;School of Civil Eng.and Transportation,South China Univ.of Technol.,Guangzhou 510641,China;Inst.of Civil Eng.,Jiangsu Open Univ.,Nanjing 210036,China)

机构地区：[1]淮阴工学院建筑工程学院,江苏淮安223021 [2]华南理工大学土木与交通学院,广东广州510641 [3]江苏开放大学建筑工程学院,江苏南京210036

出　　处：《工程科学与技术》2024年第3期11-20,共10页Advanced Engineering Sciences

基　　金：江苏省高等学校基础科学面上项目(22KJB560012);国家自然科学基金项目(42001053);“淮上英才计划”驻淮优秀博士人才项目。

摘　　要：既有试验研究表明,在压缩荷载作用下,围压对低孔隙率硬岩的强度、破坏模式、剪胀性等具有重要影响。在围压不断增大的条件下,硬岩的破坏特性将呈现由脆性向延性转变的趋势。本文基于细观力学方法分析硬岩的脆-延性破坏机理,探究脆-延性转化过程中非弹性变形、损伤与围压的定量关系,继而构建细观损伤力学模型以描述深部硬岩在不同压缩荷载作用下的脆-延性转化力学行为。为了验证所构建模型的合理性和有效性,通过UMAT子程序将其嵌入有限元软件Abaqus模拟低孔隙率砂岩(围压10~120 MPa)和Tavel石灰岩(围压10~150 MPa)在常规三轴加载下的力学行为。对比发现,数值模拟结果与试验数据具有较好的一致性,说明细观损伤力学模型能够较好地捕捉硬岩随着围压增加表现出的从脆性到延性转化的力学特性,也初步表明基于细观力学的分析方法可以为解译深部岩石的力学行为提供理论支撑。Objective This comprehensive exploration delves into the intricate domain of confining pressure’s influence on the mechanical complexities found in low-porosity,resilient rocks under compressive loading.It seeks to elucidate the transition from brittleness to ductility induced by in-creasing confining pressure.Additionally,it sheds light on the variations in strength,failure modes,and shear dilation across a wide range of con-fining pressure conditions in these rocks.As confining pressure increases,a transformative process unfolds,leading to a dramatic shift in the fail-ure characteristics of these rocks—From the fragility of brittleness to the flexible embrace of ductility.The paper aims to unravel the intricate mechanism of the brittle-ductile transition by delving into the micro-mechanical landscape.This detailed expedition meticulously charts the nu-anced relationship among non-elastic deformation,damage evolution,and the pervasive influence of confining pressure.Arising from the intrica-cies of our micro-mechanical analysis is a skillfully crafted micro-damage mechanics model,serving as a guide through the challenging terrain of hard rocks under compressive loading.Methods In our meticulous mechanical scrutiny,we intentionally choose the representative elementary volume(REV),characterized by the volu-minousΩand the peripheral boundaryΩ,as the focal point of our investigative efforts.The articulation of micromechanical constitutive equa-tions is meticulously forged by the nuanced contemplation of microstructural idiosyncrasies and indigenous mechanical properties.The distinct-ive elementary volume emerges as an amalgamation of an isotropic rock matrix and a profusion of penny-shaped microcracks.Its examination is steeped in the resolution of the Eshelby inclusion problem,unfurling the tapestry of the aforementioned heterogeneity.The formulation of mi-cromechanical constitutive equations is carefully crafted through thoughtful consideration of microstructural idiosyncrasies and inherent mechan-ical prope

关 键 词：脆性-延性转化 围压效应 摩擦滑移 损伤临界值 细观力学模型 

分 类 号：TU2[建筑科学—建筑设计及理论]