基于声发射的脆性岩石单轴压缩损伤演化与本构模型  

Damage evolution and constitutive model of brittle rock under uniaxial compression based on acoustic emission

作　　者：刘冬桥[1] 郭允朋 李杰宇 凌凯 杨园园 张树东 LIU Dongqiao;GUO Yunpeng;LI Jieyu;LING Kai;YANG Yuanyuan;ZHANG Shudong(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《中国矿业大学学报》2023年第4期687-700,共14页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(52074299,41941018);中央高校基本科研业务费项目(2021JCCXSB03)。

摘　　要：为了研究脆性岩石损伤演化特征并建立能够准确描述脆性岩石应力-应变全过程的损伤本构模型,对玄武岩、花岗岩和砂岩3种脆性岩石开展了单轴压缩声发射试验,基于声发射能量表征岩石损伤变量,并借助Logistic函数模拟了该损伤变量演化全过程,进一步结合损伤力学理论与有效介质理论,建立了能够模拟单轴压缩下脆性岩石变形全过程的分段本构模型.研究表明,1)基于声发射能量表征的损伤演化曲线可分为3个过程:初始几乎无损伤、损伤缓慢开始、损伤急剧陡增.2)Logistic函数可以很好地模拟基于声发射能量表征的脆性岩石损伤演化过程.3)进一步建立的损伤本构模型可以较好地描述脆性岩石单轴压缩应力-应变全过程,理论模型曲线与试验数据吻合度高.4)本构模型中参数a和r分别反映了岩石的初始损伤程度与损伤演化速率,a越大,初始损伤程度越低,峰值强度越高;r越大,损伤变量发展速度越快,最大损伤演化速率D′m越大.Uniaxial compression acoustic emission tests were performed on three types of brittle rock:basalt,granite,and sandstone.The goal was to study the damage evolution characteristics of brittle rocks and establish a damage constitutive model that can accurately describe the whole stress-strain process.The whole process was simulated with the Logistic function based on the acoustic emission energy to characterize the rock damage variable.Furthermore,a piecewise constitutive model which can simulate the whole process of brittle rocks deformation under uniaxial compression was established by combining damage mechanics theory and effective medium theory.The results show that:1)The damage evolution curves based on acoustic emission energy can be divided into three stages,including an initial stage with almost no damage,a slow damage stage,and a sharp damage stage.2)The Logistic function accurately can well simulate the damage evolution process of brittle rocks based on acoustic emission energy.3)The damage constitutive model developed further better describes the complete deformation process of brittle rocks under uniaxial compression,and the theoretical model curve is in good agreement with the experimental data.4)Parameters a and r represent the initial damage degree and damage evolution rate,respectively.Larger a values typically correspond to a lower initial damage degree and higher the peak strength.The larger r,the faster the damage variable develops,and the greater the maximum damage evolution rate“D′_m”.

关 键 词：岩石力学 声发射能量 Logistic函数 损伤演化 本构模型 

分 类 号：TU45[建筑科学—岩土工程]