摘要
土体中的未冻水含量影响冻土的物理力学性质,也是评价冻土中水分迁移的重要指标.利用核磁共振技术对含有不同浓度硫酸钠溶液的兰州黄土的未冻水含量进行测试,并分析了温度、含盐量对未冻水含量的影响.同时,测试了不同含盐量下黄土的液塑限及液塑限含水率下土体的冻结温度,计算了不同含盐量下的未冻水含量并与实测值进行比较,给出了不同含盐量下幂函数方程wu=at-b中的参数值.在此基础上,分析了-5、-10、-15和-20℃条件下未冻水含量随含盐量的变化规律,建立了4个温度下不同含盐量区间的未冻水-含盐量拟合公式.
Unfrozen water content not only influences the physical and mechanical properties of frozen soil,but also is an important evaluation index of water migration. The moisture content of Lanzhou loess which contains different concentrations of sodium sulfate was measured by pulsed nuclear magnetic resonance（ NMR）. The influence of temperature and salinity on the unfrozen water content was analyzed. We simultaneously test the liquid and plastic limits of the samples containing different concentrations of sodium sulfate,and the freezing points of different water content of liquid and plastic limit. Based on the above data,the unfrozen water content was calculated according to wu= at^- b so as to compare with the test value and the fitting parameters of the power function formula are also figured out. Then the temperature：- 5 ℃,- 10 ℃,- 15 ℃ and- 20 ℃ are chosen to analyze the relationship between unfrozen water content and salt content. The result shows that the change of unfrozen water content is not obvious in the mass,but the value becomes a maximum when the salt content is2%. As a result,the fitting formulas based on different salinity ranges are established at the above temperature.
出处
《冰川冻土》
CSCD
北大核心
2016年第4期963-969,共7页
Journal of Glaciology and Geocryology
基金
国家自然科学基金项目(41371090
41672310)
甘肃省科技重大专项计划项目(143GKDA007)
冻土工程国家重点实验室自主课题(SKLFSE-ZT-08)资助
关键词
硫酸钠
盐渍土
未冻水含量
液塑限
核磁共振
sodium sulphate
saline soil
unfrozen water content
liquid and plastic limit
nuclear magnetic resonance
