北京科技大学学报Issue(12)：1567-1574,8.DOI:10.13374/j.issn1001-053x.2014.12.001
卸荷岩体细观损伤演化的核磁共振测试
Meso-damage evolution of unloading rock mass based on nuclear magnetic resonance technology
摘要
Abstract
To investigate the meso-damage evolution characteristic of unloading rock mass, unloading confining pressure tests on marble specimens were first conducted under initial confining pressures of 10, 20 and 30 MPa. Then nuclear magnetic resonance tests were performed on the unloaded specimens. The stress-strain curves, transverse relaxation time T2 distribution, rock porosity, and nuclear magnetic resonance imaging pictures of the unloaded specimens were obtained. It is found that the deformation of the unloaded specimens changes from elastic to plastic with the increase of unloading confining pressure ratio. As the unloading confining pressure ratio increases, the size of small microcracks increases, and the number and size of large microcracks also increase. When the unloa-ding confining pressure ratio is less than 90%, the damage of rock mass is mainly caused by the increase in number of microcracks. But when the unloading confining pressure ratio exceeds 90%, the damage of rock mass is caused by the sharp increase in number and size of microcracks. The rock porosity increases with the increase of unloading confining pressure ratio, and the growth rate becomes greater. The development processes of the number, size and structure of microcracks in the rock specimens under different initial confi-ning pressures and different unloading confining pressure ratios can be directly visualized by nuclear magnetic resonance imaging pictures.关键词
岩石力学/损伤/核磁共振/卸荷/孔隙度/围压比Key words
rock mechanics/damage/nuclear magnetic resonance/unloading/porosity/confining pressure分类
建筑与水利引用本文复制引用
胡振襄,周科平,李杰林,高峰,王明球..卸荷岩体细观损伤演化的核磁共振测试[J].北京科技大学学报,2014,(12):1567-1574,8.基金项目
“十二五”国家科技支撑计划资助项目(2013BAB02B05) （2013BAB02B05）
国家自然科学基金资助项目(51274253) （51274253）
中国博士后科学基金资助项目(2013M542138) （2013M542138）
