考虑干湿循环累积损伤的膨胀土土水特征研究
Research on SWCC of Expansive Soil Considering Cumulative Damage Effect of Dry Wet Cycle
朱翔 1赵迎澳 2张景伟 2刘云龙2
作者信息
- 1. 黄河科技学院工学部,郑州 450006
- 2. 郑州大学土木工程学院,郑州 450045
- 折叠
摘要
为探明干湿循环中膨胀土裂隙发育对其土水特征的影响,制备经历不同次数干湿循环的柱状土样,并对其土水特征曲线进行测定.结合CT扫描结果,基于裂隙的分形特征构建土柱截面和整体损伤变量,通过其变化规律阐明裂隙发育对土水特征的影响.结果表明:裂隙的分形维数沿深度方向逐渐减小,大体呈线性变化规律,不同循环次数下裂隙的开展过程具有相似性;基于裂隙分形维数构造的损伤变量能够较好描述干湿循环对膨胀土的累积损伤效应,土柱的整体损伤变量随干湿循环次数逐渐增加,且增速逐步提高;提出的基于土柱整体损伤变量进行修正的Fredlund-Xing模型能够较好拟合裂隙膨胀土的土水特征曲线.研究成果能够为后续裂隙膨胀土的渗流和工程应用研究提供理论支持.
Abstract
In order to investigate the influence of the cracks generated in the cyclic drying and wetting process on the soil water characteristics of the expansive soil,the soil water characteristics curves of column soil samples subjected to 0 to 3 drying and wetting cycles were tested.Combined with the CT scan results,the cross-section and overall damage variables of the column soil samples were constructed based on the fractal characteristics of cracks.Then the influence of cracks development on soil water characteristics of expansive soils was demonstrated through the changing disciplines of the damage variables.The research results indicated that the surface fractal dimensions of the crack approximately decreased gradually and linearly along the depth.Also,the crack development process showed similar trend in different drying and wetting cycles.The damage variables constructed based on the fractal dimension of the cracks could well describe the cumulative damage effect of drying and wetting cycles on the expansive soil.The overall damage variables of the soil column gradually increased with the number of drying and wetting cycles,and the growth rate gradually increased.The proposed Fredlund-Xing model modified based on the overall damage variables of soil column could well describe the soil water characteristic curve of cracked expansive soil.The research results presented in this study could provide theoretical support for the subsequent research on the seepage and engineering properties of cracked expansive soils.
关键词
膨胀土/干湿循环/裂隙/土水特征曲线Key words
expansive soil/drying and wetting cycle/crack/soil water characteristic curve引用本文复制引用
基金项目
国家自然科学基金(42107196)
河南省自然科学基金(212300410280)
出版年
2024
NETL
NSTL
维普
万方数据