上海交通大学学报 ›› 2020, Vol. 54 ›› Issue (8): 866-872.doi: 10.16183/j.cnki.jsjtu.2019.106

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考虑土水吸附效应的黏土收缩曲线方程

陈盼1(), 向锐2, 魏小棋1,3, 韦昌富1,3, 王吉利1   

  1. 1.岩土力学与工程国家重点实验室 中国科学院武汉岩土力学研究所,武汉 430071
    2.中交城乡建设规划设计研究院有限公司,武汉 430052
    3.桂林理工大学 土木与建筑工程学院,广西 桂林 541004
  • 收稿日期:2019-01-04 出版日期:2020-08-28 发布日期:2020-08-18
  • 作者简介:陈 盼(1984-),男,湖北省孝感市人,副研究员.主要从事非饱和土力学与降雨边坡稳定性方面的研究.电话(Tel.):13477058996;E-mail:pchen@whrsm.ac.cn
  • 基金资助:
    国家自然科学基金(41877269);国家自然科学基金(51939011)

Equation for Soil Shrinkage Curve of Clay Considering Soil-Water Adsorption Effect

CHEN Pan1(), XIANG Rui2, WEI Xiaoqi1,3, WEI Changfu1,3, WANG Jili1   

  1. 1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
    2. China Communications Urban and Rural Construction Planning and Design Research Institute Co., Ltd., Wuhan 430052, China
    3. Guilin University of Technology, Guilin 541004, Guangxi, China
  • Received:2019-01-04 Online:2020-08-28 Published:2020-08-18

摘要:

在干燥条件下土体逐渐失水产生收缩变形,对土体开裂、地基承载力及边坡稳定性产生重要的影响.因此,有效预测含水量变化下土体的体积收缩变形具有重要的意义.本研究提出了能考虑土水吸附效应的全含水量范围内的土体收缩曲线数学方程.该方程能够同时描述脱湿过程中结构性与非结构性黏土的收缩体变.通过考虑土水吸附效应对土体收缩变形的影响,引入1个参数描述低含水量条件下土体收缩斜率,仅用1个方程即可预测从饱和到干燥条件下土体的完整收缩行为,尤其是低含水量条件下土体的体变特性.通过方程的预测曲线与文献中实测数据的对比,证实了所提出黏土收缩曲线方程的可靠性.同时,与现有方程的预测能力进行对比,表明提出的方程能够很好地描述低含水量条件下黏性土的非0收缩段与非0收缩斜率行为,证实了低含水量条件下土体收缩变形预测中考虑土水吸附效应的必要性与重要性.

关键词: 土体收缩, 体变, 干燥条件, 收缩斜率, 非饱和土, 结构性黏土

Abstract:

Soil shrinkage occurs with the decrease of water content in soils under dry conditions, which has a great influence on soil cracking, bearing capacity, and slope stability. Hence, it is important to predict soil shrinkage effectively under the change of water content in soils. A novel mathematical equation is proposed for describing the soil shrinkage behavior within the full water content range considering the soil-water adsorption effect. The proposed equation can be used to characterize the soil shrinkage behavior of structural and non-structural clayey soils under dry conditions. An additional parameter is introduced into the proposed equation for characterizing the slope of soil shrinkage in low water content ranges, in which the effect of soil-water adsorption is considered. Only one equation is needed to predict the complete shrinkage behavior from saturated to zero water content conditions, especially for describing the volume change of soils under low water content. The proposed equation has been validated by comparing the results between the predicted curves using the proposed model and the measured data in literatures. Comparing with existing equations for soil shrinkage curve, the results show that the proposed equation can describe the non-zero shrinkage and non-zero shrinkage slope behaviors very well under low water content conditions. Furthermore, the results show that the soil-water adsorption effect is important and necessary for prediction of soil shrinkage behavior under low water content conditions.

Key words: soil shrinkage, volume change, dry conditions, shrinkage slope, unsaturated soil, structural clay

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