摘要
土-水特征曲线(SWCC)在非饱和土力学中扮有重要的角色,是非饱和土力学研究的核心问题。以西北地区黄土中含有的典型硫酸钠盐为变化因素,采用滤纸法测得了兰州黄土及不同含盐量黄土状硫酸钠盐渍土的基质吸力并绘制土-水特征曲线,通过试验测试和理论分析来解释硫酸钠盐分对黄土状硫酸钠盐渍土基质吸力的影响规律,以期为工程实践提供一定的理论依据。结果表明:相同含水率下硫酸钠盐渍土的含盐量越高,基质吸力越大。以非饱和土力学理论和表面物理化学理论为基础,考虑了土中的盐分对基质吸力的毛细部分及吸附部分的影响,得到了土中含盐量与基质吸力关系的半经验公式。利用该公式计算得到不同含盐量硫酸钠盐渍土的土-水特征曲线,计算曲线与试验曲线吻合程度较高,表明该公式可以很好地描述盐渍土中不同含盐量与基质吸力的关系。
Soil-water characteristic curve(SWCC)is a curve describing the relationship between soil matric suction and water content,which is the core of unsaturated soil mechanics research. Matric suction is an important stress state variable of unsaturated soil,which controls the balance between soil structure and shrinkage membrane,and is an important factor affecting mechanical properties of unsaturated soil. Loess containing sodium sulfate is widely distributed in Northwest China,and has been widely used in engineering practice. The relationship between the matric suction of loess and the content of sodium sulfate is studied by experimental test and theoretical analysis,and the law of the matric suction of loess like sodium sulfate saline soil affected by sodium sulfate is obtained. Taking the typical sodium sulfate contained in loess in Northwest China as the variable factor,the matric suction of Lanzhou loess and sodium sulfate saline soil with different salt content was measured by filter paper method,and the soil water-characteristic curve was drawn. The results show that the existence and content of sodium sulfate have a great influence on the matric suction of loess,and the higher the salt content of sodium sulfate saline soil is,the greater the matric suction is. The influence of sodium sulfate on the matric suction of loess is different under different water content:when the water content is high,the influence of sodium sulfate on the matric suction of loess is small;when the water content is low,the influence of sodium sulfate on the matric suction of loess is great. Based on unsaturated soil mechanics theory and surface physicochemical theory,assuming that the salt solution in soil does not affect the pore structure of soil,considering the influence of salt solution in soil on the capillary part and adsorption part of matric suction,a semi empirical formula is obtained,which can be used to calculate the relationship between salt content in soil and matric suction. The Kelvin radius and the thickness of adsorb
作者
姜浩
邴慧
JIANG Hao;BING Hui(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《冰川冻土》
CSCD
北大核心
2021年第2期497-509,共13页
Journal of Glaciology and Geocryology
基金
国家自然科学基金项目(41371090)资助。
关键词
土-水特征曲线
滤纸法
硫酸钠盐渍土
基质吸力
含盐量
soil-water characteristic curve
filter paper method
sodium sulfate saline soil
matric suction
salt content
