单向冻结过程中NaCl盐渍土水盐运移及变形机理研究

发布时间：2018-06-14 15:44

本文选题：盐渍土 + 单向冻结试验　；参考：《岩土工程学报》2017年11期

【摘要】：冻结过程中的水盐迁移机理一直是冻土学研究的热点。通过单向冻结试验,研究了冻结过程中的水盐运移过程及土体变形。研究表明,在土体初始含盐量为0.8%的条件下,土体的冻胀变形显著减小,盐分的存在强烈影响着冻结缘处水分的集聚,盐对土体的冻胀具有抑制作用。在补给不同浓度NaCl溶液的条件下,土体初期的冻胀变形规律一致,随着盐分在冻结锋面处的累积,土体在后续冻结过程中水分迁移动力不足,从而使得土体冻胀过程中冻胀明显减小。基于溶液的性质并考虑盐分对土体冻结温度和未冻水含量的影响,建立了冻结过程中NaCl盐渍土水盐迁移规律及变形的计算模型,计算结果显示,计算模型能够很好地反映含盐土体在冻结过程中的温度、水分、盐分及变形的规律,从而为深入了解盐渍土在冻结过程中的变形机理提供理论参考。
[Abstract]:The mechanism of water and salt migration in freezing process has been a hot topic in frozen soil. The water and salt migration and soil deformation during freezing process were studied by unidirectional freezing test. The results show that when the initial salt content is 0.8%, the frost heave deformation of the soil decreases significantly, and the concentration of water at the freezing edge is strongly affected by the presence of salt, which can inhibit the frost heave of the soil. Under the condition of recharge of NaCl solution with different concentrations, the initial frost heave deformation of soil is consistent. With the accumulation of salt at the freezing front, the water migration power of soil is insufficient in the subsequent freezing process. Thus, the frost heave of soil is obviously reduced during the process of frost heave. Based on the properties of the solution and the effect of salt on the freezing temperature and unfrozen water content of soil, a calculation model of water and salt migration and deformation of NaCl saline soil during freezing process is established. The calculation model can well reflect the rules of temperature, moisture, salt and deformation of salt-bearing soil during the freezing process, thus providing a theoretical reference for further understanding the deformation mechanism of saline soil during the freezing process.
【作者单位】：中国科学院西北生态环境资源研究院冻土工程国家重点实验室;中国科学院大学;
【基金】：国家自然科学基金重点项目(41230630) 中国科学院前沿科学重点研究项目(QYZDY-SSW-DQC015) 国家自然科学青年基金项目(41601074) 中科院寒旱所冻土工程国家重点实验室自主课题(SKLFSE-ZQ-32)
【分类号】：TU448

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