基于细观裂纹扩展演化的岩石损伤本构模型研究  

A new damage constitutive model of rock considering microscopic crack growth

作　　者：李盛南 肖俊 李玉 刘新喜 梁桥[1] 常锦 刘杰[1] LI Shengnan;XIAO Jun;LI Yu;LIU Xinxi;LIANG Qiao;CHANG Jin;LIU Jie(School of Architectural Engineering,Hunan Institute of Engineering,Xiangtan,Hunan 411104,China;School of Civil Engineering,Changsha University of Science and Technology,Changsha,Hunan 410114,China;School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]湖南工程学院建筑工程学院,湖南湘潭411104 [2]长沙理工大学土木工程学院,湖南长沙410114 [3]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《岩石力学与工程学报》2023年第3期640-648,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52108405);湖南省自然科学基金项目(2022JJ40122);湖南省教育厅科研基金项目(21B0659)。

摘　　要：为准确表征岩石细观裂纹扩展演化过程的力学特性。基于唯象理论,将岩石细观结构概化为完整岩石微元体、裂纹扩展损伤微元体和孔隙三个部分;利用微元体间的静力平衡关系,构建岩石细观受力模型。在此基础上,根据岩石裂纹扩展演化特征,提出利用生物阻滞增长模型表征岩石裂纹扩展长度;基于几何损伤理论,建立裂纹扩展长度与损伤的定量关系,构建岩石裂纹扩展损伤演化方程;并利用断裂力学求解裂纹扩展损伤微元体的实际应力;通过将裂纹扩展损伤和损伤微元体实际应力引入岩石细观结构静力平衡方程,考虑软岩压密阶段非线性变形的影响,建立基于细观裂纹扩展演化的岩石损伤本构模型;最后,提出模型参数的确定方法,并探讨模型参数对岩石力学性质的影响规律。结果表明:该模型能较好表征岩石裂纹扩展过程的应力应变特征,与实验结果吻合度较高,且模型参数物理意义明确。This paper aims to establish a damage constitutive model that can accurately characterize the mechanical properties of the evolution process of microscopic crack propagation in rocks.Firstly,based on phenomenological theory,the rock mesostructure is generalized into three parts:complete rock micro-elements,crack propagation damage micro-elements and pores.Using the static equilibrium relationship between these three parts,a mesoscopic force model of fractured rock is constructed.Secondly,according to the crack propagation characteristics of rock,a bio-blocking growth model is proposed to characterize the crack propagation length.Based on the geometric damage theory,the quantitative relationship between crack growth length and damage is established,and the damage evolution equation of crack propagation of rock is established.Thirdly,the actual stress of crack propagation damage element is solved by fracture mechanics.Then,by introducing the damage variable of crack propagation and the actual stress of crack propagation damage microelement into the mesostatic equilibrium equation of rock,and considering the influence of nonlinear deformation in the compaction stage of soft rock,a damage constitutive model of rock considering the microscopic crack propagation evolution is established.Finally,a method determining the model parameters is proposed,and the influence of model parameters on the mechanical properties of the rock is discussed.The results show that the model can better characterize the stress-strain characteristics the crack propagation process of rock,which is in good agreement with the test results,and the physical meaning of the model parameters is clear.

关 键 词：岩石力学 岩石损伤 本构模型 裂纹扩展 断裂力学 非线性变形 

分 类 号：TU45[建筑科学—岩土工程]