高压力作用下深部黏土冷却过程及其特征研究

发布时间：2018-04-26 23:31

本文选题：深部黏土 + 冻结过程　；参考：《岩土工程学报》2016年10期

【摘要】：深部黏土的埋深决定着深部黏土在进行人工冻结期间所承受的地压力的大小,而较大的地压力将会影响冻结壁形成时冻结温度的大小以及冻结壁的冷生构造,从而影响冻结壁的强度与稳定性。本研究通过对高压力作用下的深部黏土在不同含水率状态下进行冷却过程试验,分析了压力大小对不同饱和状态的深部黏土冷却曲线形式及初始结晶温度、冻结温度及过冷度的影响。结果表明:深部土的冻结温度、初始结晶温度以及过冷度都与土体所承受的压力密切相关。不论是非饱和状态、饱和状态还是过饱和状态下的深部黏土,其冻结温度都随土体所承受压力的增大而减小,而初始结晶温度则随压力的增大呈起伏状变化。利用物质结晶理论,进一步分析后认为冻结过程主要是自由孔隙水的相变过程;而压力作用会通过改变土体中土颗粒对孔隙水分子的吸附作用,改变土体中自由水的含量,进而改变土体冻结过程中潜热释放量的大小,最终影响土体冷生构造。
[Abstract]:The depth of the deep clay determines the pressure of the deep clay during the artificial freezing, and the larger earth pressure will affect the freezing temperature and the cold structure of the frozen wall during the formation of the frozen wall. Thus, the strength and stability of the freezing wall are affected. In this paper, the cooling process of deep clay under high pressure under different water content is studied, and the cooling curve and initial crystallization temperature of deep clay under different saturation state are analyzed. The effect of freezing temperature and undercooling. The results show that the freezing temperature, initial crystallization temperature and undercooling of deep soil are closely related to the pressure of soil. The freezing temperature of deep clay in unsaturated state, saturated state or supersaturated state decreases with the increase of soil pressure, while the initial crystallization temperature fluctuates with the increase of pressure. Based on the theory of material crystallization, it is considered that the freezing process is mainly a phase change process of free pore water, and the pressure effect will change the content of free water in soil by changing the adsorption of soil particles to pore water molecules. And then change the amount of latent heat release in the process of soil freezing, and finally affect the cold structure of soil.
【作者单位】：中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;中国科学院大学;
【基金】：国家自然科学基金面上项目(41671069);国家自然科学基金项目(41630636) 冻土工程国家重点实验室基金项目(SKLFSE-ZT-31)
【分类号】：TU442

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