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Crack growth and electro-conductive properties of expansive soil under drying-wetting cycles
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摘要: 干湿循环引起膨胀土裂隙开展，进而对土体的土水特性产生重要影响。首先进行了不同干密度、含水率状态下均质无裂隙试样的导电性能试验，认为试样电导率与干密度、含水率呈线性关系，可采用多元线性函数进行拟合。用远距离光学显微镜观测了膨胀土裂隙发生发展过程，利用图像灰度熵评价裂隙形态，试验过程中同时测定了试样的含水率和电导率，获得了干湿循环下土体灰度熵-含水率-电导率的关系。结果表明：随着含水率的降低，灰度熵逐渐增大，电导率逐渐减小；含水率对电导率的贡献逐渐降低，裂隙对电导率的贡献逐渐增大。当失水到一定程度时，裂隙对电导率的贡献几乎不变，此时表明裂隙已开展稳定；浸水过程中，裂隙部分闭合，灰度熵减小，电导率增大。经历多次干湿循环的试样，灰度熵和电导率均有所降低，表明土体结构产生了不可逆的改变。Abstract: The soil-water characteristics of expansive soil are influenced by cracks caused by drying-wetting cycles. Electrical conductivity tests were carried out to obtain the soil conductivity without cracks and electrical conductivity had a linear positive correlation with soil dry density and water content. A linear multivariate function was obtained to describe their relationships. A long-distance microscope system was used in observing the crack growth of the expansive soil dynamically under the conditions of drying-wetting cycles and the gray level entropy of image with the cracks was used to evaluate the crack shape. The soil water content and conductivity were obtained and the gray level entropy-water content-conductivity relationship of soil was established under the conditions of the drying-wetting cycles. The gray level entropy increased and conductivity decreased with the crack growth due to water loss. The impacts of water content on the soil conductivity decreased and impacts of cracks on the soil conductivity increased gradually. The impacts of cracks on the soil conductivity kept constant under drying to a certain degree, and the shape of cracks remained stable; the cracks were closed partially due to water absorption. The gray level entropy decreased and the soil conductivity increased. The gray level entropy and the soil conductivity decreased to some extent under the drying-wetting cycles. It was shown that the soil structure was changed irreversibly.
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Keywords:
- cracks /
- gray level entropy /
- conductivity /
- expansive soil
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期刊类型引用(7)
1. 罗舒玉，邓羽松，陈洪松，王金悦，廖达兰. 干湿交替条件下喀斯特峰丛洼地土壤裂隙发育规律. 应用生态学报. 2023(02): 387-395 . 
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2. 张骏，郭杨，陈小川，乐腾胜，高坤，柯宅邦，奚邦禄. 持续浸泡下硬黏土强度劣化试验研究. 水利水运工程学报. 2023(04): 130-137 . 本站查看
3. 许英姿，苏超，刘德志，黄效. 干湿循环下掺根率对膨胀土开裂的影响. 科学技术与工程. 2022(12): 4938-4944 . 百度学术
4. 朱锐，黄英豪，张晨，郭万里，陈皓. 季节性供水渠道边坡稳定性研究. 水利水运工程学报. 2021(01): 124-132 . 本站查看
5. 赵茜，杨金熹，赵晋萍. 冻融和干湿循环对原状黄土渗透系数的影响. 中国地质灾害与防治学报. 2020(02): 119-126 . 百度学术
6. 张卫兵，蒋佳莉. 干湿循环下重塑粉质黏土压缩性劣化规律研究. 建筑科学. 2020(05): 75-82 . 百度学术
7. 周明涛，杨森，秦健坤，熊峰，王泽光，许文年. 土壤裂隙研究的回顾与展望. 土壤通报. 2017(04): 988-995 . 百度学术
其他类型引用(10)
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