| 锦屏大理岩单轴压缩过程中的微结构演化 |
| |
| 引用本文： | 封陈晨,李傲,王志亮,王浩然.锦屏大理岩单轴压缩过程中的微结构演化[J].水文地质工程地质,2022,49(6):90-96. |
| |
| 作者姓名： | 封陈晨 李傲 王志亮 王浩然 |
| |
| 作者单位： | 合肥工业大学土木与水利工程学院, 安徽 合肥 230009 |
| |
| 基金项目： | 国家自然科学基金雅砻江联合基金资助项目（U1965101）；国家自然科学基金项目（12272119） |
| |
| 摘 要： | 为了研究锦屏大理岩受载过程中内部孔隙结构的演化规律，文章先对其进行矿物成分测定和单轴压缩试验；随后对施加不同轴压后的试样开展了核磁共振（nuclear magnetic resonance，NMR）测试，并分析相应试验结果；最后，根据NMR孔隙度参数，建立起试样损伤度、有效应力比系数与轴压比之间函数关系。结果表明:大理岩内部孔隙分布具有多尺度特性；加载过程中核磁共振 T 2谱分布曲线整体向右移动，小尺寸孔隙占比减少而中等尺寸孔隙占比增加；岩样内部孔隙具有多重分形结构，小孔占比影响孔隙的分形维数和连通性。当小孔占比小时，孔隙结构相对简单，分形维数较低；当小孔占比大时，孔隙结构则较复杂，分形维数增大。大理岩孔隙度和损伤度均随荷载增加呈指数增大，且损伤和未损状态下有效应力比也增大。此项研究对揭示岩石损伤与破坏机理具有重要指导意义，同时在岩石损伤检测方面也具有一定参考价值。
|
| 关 键 词： | 大理岩 核磁共振 孔隙度 分形维数 损伤度 |
| 收稿时间： | 2022-04-12 |
A study of mineral compositions and micro-structure characteristics for the Jinping marble |
| |
| Affiliation: | School of Civil Engineering, Hefei University of Technology, Hefei, Anhui 230009, China |
| |
| Abstract: | To study the evolution law of internal pore structure of Jinping marble under loading, the mineral composition and uniaxial compression test were first conducted. Then, the nuclear magnetic resonance (NMR) tests were carried out on the samples subjected to different axial pressures, and the corresponding test results were further analyzed. Finally, the functional relationships of the damage degree and effective stress ratio with the axial compression ratio were established according to the NMR porosity parameters. It is found that the pore distribution in the marble has multi-scale characteristics. During the loading process, the T2 spectrum distribution curve of NMR shifts to the right as a whole, and the proportion of small-sized pores decreases while the proportion of medium-sized pores increases. There exist multi-fractal structures of pores inside the rock samples, and the fractal dimension and connectivity of pores are affected by the small pore proportion. When the small pore proportion is low, the pore structure is relatively simpler and the fractal dimension is lower. When the small pore proportion is high, the pore structure is more complex and the fractal dimension increases. Both the porosity and damage degree of the marble increase exponentially with the increase of load, and the effective stress ratio of damaged and undamaged state also increases. This study has important guiding significance for revealing the mechanism of rock damage and failure, and also own certain reference value in rock damage detection. |
| |
| Keywords: | |
|
| 点击此处可从《水文地质工程地质》浏览原始摘要信息 |
|
点击此处可从《水文地质工程地质》下载全文 |
|
