摘要
针对水溶液物理化学特性,利用热力学原理,建立了冰水化学势能平衡方程。基于理想成冰模型,依据土体孔隙分布特征,推导了不同孔径中水分冻结公式。在此过程中引入有效应力原理,建立了负温下未冻含水量与温度的关系。据此,提出计算不同温度下水分冻结的通用公式,并通过试验验证,证明了此公式的合理性与准确性。研究表明:未冻含水量与冻结温度之间呈现指数函数递减;外荷载的增大、含盐量的增加均会导致未冻含水量与温度曲线向坐标右侧移动,而土孔隙变小引起未冻含水量曲线逆时针旋转;孔隙中冰晶会延缓水分冻结趋势,该作用随着孔径的减小而愈发明显。
The balance equation of ice and water chemical potential was built by taking advantage of the thermodynamic principle for the physicochemical characteristics of water solution.Moreover,the formula of water freezing in different pore sizes was deduced according to the pore distribution characteristics of soil under the assumption of the ideal ice-forming model.In this process,the principle of effective stress was introduced to build the relationship between unfrozen water content and temperature in low temperature.Based on this,a general equation to determine water freezing in soils at different temperatures was proposed.Besides,the rationality and accuracy of this equation have been proved through experimental verification.The results show that the unfrozen water content decreases with freezing temperature exponentially.The increase of the external load and the increase of salt content will cause the curve of unfrozen water content-temperature to move rightward in the coordinate,while the decrease of soil pore sizes results in the anticlockwise rotation of the unfrozen water content curve.The ice crystal in the pores in the soil delays the process of water freezing and the impact of ice crystals on water freezing is increasingly obvious with the decrease of pore size.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2018年第1期123-129,共7页
Journal of the China Railway Society
基金
国家自然科学基金(41601068
41230630)
西南石油大学科研"起航计划"(2015QHZ025)
关键词
未冻含水量
冻结温度
化学势
冰液接触面自由能
孔径分布
unfrozen water content
freezing temperature
chemical potential
the free energy on ice-water interface
pore size distribution
