摘要
节理裂隙对岩石的力学特性具有重要影响.本文选取花岗岩试件作为研究对象,通过单轴压缩试验及CT扫描,研究了花岗岩试件中节理的发育扩展情况,并根据二值化处理后CT扫描图像的像素点统计量,确立了花岗岩试件的损伤变量D,推导了损伤本构方程,并将建立的损伤本构方程进行编程嵌入有限元软件;采用三维重构软件对加载前花岗岩岩芯扫描层图片进行了三维重构,提取了花岗岩试件内部的节理特征,用于数值模拟分析中节理的确定.采用数值模拟方法分别研究了不考虑节理与损伤本构、只考虑节理和只考虑损伤本构关系3种情况下,单轴压缩作用下岩芯的塑性区和应力-应变关系等力学特性.研究表明,后两种情况下得到的岩石单轴抗压强度接近,但只考虑损伤本构关系的方法,避免了数值模拟时节理存在导致的网格划分困难,具有高效方便的优点,且能揭示试件的实际受力特性,具有较大的实用价值.
The joints and fissures have an important effect on the mechanical properties of rock.Uniaxial compression test and CT scanning were used to study the crack propagation of granite core in loading process.The damage variable D was determined by pixel statistics of joints to that of the two-dimensional binary image,and the damage constitutive relation was deduced and programmed in finite element software.Three-dimensional reconstruction of joints was conducted on the binary two-dimensional scanned images,and implanted to the model of rock core in numerical simulation.Three cases(no joints and no damage constitutive relation,only joints and only damage constitutive relation)were designed for numerical simulation,the plastic areas and the relations of stress-strain were gained.The results showed that the compressive strength of the latter two are close,but the equivalent method of damage constitutive relation avoids the difficult of meshing on joints in numerical simulation,it is very convenient and efficient,and the actual mechanical properties of rock are revealed perfectly,it has great practical value.
作者
谭文辉
王鹏飞
王建林
刘景军
马学文
TAN Wenhui;WANG Pengfei;WANG Jianlin;LIU Jingjun;MA Xuewen(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 10083,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2020年第6期1489-1498,共10页
Journal of Basic Science and Engineering
基金
国家重点研发计划项目(2017YFC0804103)
国家自然科学基金重点项目(51534002)
关键词
CT扫描图像
力学特性
损伤本构
单轴压缩
节理
三维重构
数值模拟
CT scanned image
mechanical property
damage constitutive relation
uniaxial compression
joint
three-dimensional reconstruction
numerical simulation
