| 双孔结构非饱和压实土微观结构演化模型 |
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| 引用本文： | 蔡国庆,吴天驰,王亚南,刘祎,李舰,赵成刚.双孔结构非饱和压实土微观结构演化模型[J].岩土力学,2020,41(11):3583-3590. |
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| 作者姓名： | 蔡国庆 吴天驰 王亚南 刘祎 李舰 赵成刚 |
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| 作者单位： | 1. 北京交通大学 城市地下工程教育部重点实验室，北京 100044；2. 北京交通大学 土木建筑工程学院，北京 100044 |
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| 基金项目： | 国家自然科学基金项目（No. 52078031, No. 51722802, No. U1834206）；中央高校基本科研业务费项目（No. 2020CZ002）；北京市自然科学基金（No. 8202038） |
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| 摘 要： | 在最优含水率干侧压实的黏土一般具有明显的双孔结构，其集聚体间孔隙（又称宏观孔隙）和集聚体内孔隙（又称微观孔隙）对土体宏观水力和力学特性影响差异显著，同时，水-力耦合作用下两种孔隙的演化规律也存在明显不同。双孔结构非饱和土对应的孔径分布函数为双峰孔径分布形式，该分布函数可通过叠加宏观孔隙和微观孔隙的单峰孔径分布曲线得到，并通过平移量、缩放量和分散度3个演化参数对双孔结构土的孔隙演化规律进行描述。通过构建在力学及水力加、卸载过程中演化参数与孔隙比之间的关系，提出了适用于描述变吸力下非饱和压实土的微观结构演化模型。分别基于所开展的桂林红黏土压汞试验数据和文献中的米尼亚卢博瓦膨胀土试验数据，对所建立的微观结构演化模型进行参数标定，并通过模型预测结果与试验结果的对比，验证了所建立模型的适用性。
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| 关 键 词： | 非饱和土 双孔结构 双峰孔径分布函数 孔径演化 |
| 收稿时间： | 2020-01-09 |
| 修稿时间： | 2020-04-13 |
Model of the microstructure evolution of unsaturated compacted soils
with double-pore structure |
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| CAI Guo-qing,WU Tian-chi,WANG Ya-nan,LIU Yi,LI Jian,ZHAO Cheng-gang.Model of the microstructure evolution of unsaturated compacted soils
with double-pore structure[J].Rock and Soil Mechanics,2020,41(11):3583-3590. |
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| Authors: | CAI Guo-qing WU Tian-chi WANG Ya-nan LIU Yi LI Jian ZHAO Cheng-gang |
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| Institution: | 1. Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China;
2. School of Civil Engineering and Architecture, Beijing Jiaotong University, Beijing 100044, China |
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| Abstract: | Clay compacted at the dry side of optimal moisture content generally has a distinct double pore structure, inter-aggregate pore (also called macroscopic pore) and the intra-aggregate pore (also called microscopic pore). The significant difference of their influences on mechanical responses and water retention behaviors of soils leads to the discrepancy on the evolution rules of these two types of pores. The pore size distribution function of unsaturated soil with double pore structure is the bimodal pore size distribution form, which can be obtained by superposing the unimodal pore size distribution curves of macroscopic pores and microscopic pore. The evolution parameters of translation degree, scaling degree and dispersion degree, are adopted to describe the pore evolution rule of soils with double pore structure. Based on establishing the relationship between the evolution parameter and the porosity during mechanical and hydraulic loading and unloading, a model of the microstructural evolution of soils with dual-pore structure suitable for describing unsaturated compacted soils under variable suction was proposed. Based on the results of mercury intrusion tests on Guilin red clay and the test data of Minia Lubois expansive soil in the literature, the established model parameters were calibrated. The applicability and prediction accuracy of the model was verified by comparing the simulation results with test results. |
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| Keywords: | unsaturated soil double-pore structure bimodal pore size distribution function pore size evolution |
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