间歇冻结抑制人工冻土冻胀机理分析

Analysis of Mechanism of Restraining Soil Freezing Swelling by Using Intermission Method

阐述了用间歇冻结法控制人工冻土冻胀的机理，通过对冻结细粒土的数值分析，指出与连续冻结相比，间歇冻结在冻结锋面推进速度、冻结区温度、平均冷率和未冻结区的温度梯度等方面有显著不同，这些差异的存在有利于抑制冻胀的产生和发展．结果表明，在一定的冻结温度和间歇冻结方式条件下，即使在冻结敏感土（如粉土）中也可控制冻胀．

The mechanism of restraining soil freezing swelling by using intermission method is analyzed. Based on a numerical analysis for freezing fine grain soil, it is pointed out that by comparing with continuum method, the intermission method shows remarkable differences in advance velocity of freezing front, temperature in frozen area, mean cold rate, temperature grad in unfrozen area, and so on. These differences makes the restraining of freezing swelling occur. At a certain freezing temperature and by intermission method, the freezing swelling can be restrained even if for freezing sensitive soils, such as powder soil. Finally, some general design principles for intermission freezing are proposed.