基于红外热扫描测温技术的冻土分凝冻胀

Research on segregation heave based on infrared thermal scan

为研究后间歇冻结模式下冻土分凝冻胀规律,选取冻胀敏感性粉质黏土,进行了开放系统下不同间歇时间和变温幅度的后间歇冻结试验。采用红外热扫描测温技术获得分凝温度,分析了分凝温度与冷端温度、分凝速率的关系,结果表明:间歇降温阶段,分凝温度降低,分凝速率先增大后减小;间歇升温阶段,分凝温度升高,分凝速率很快趋近于0,分凝冻胀停止。基于试验结果,提出了适用于后间歇冻结模式的分凝冻胀计算方法,将分凝冻胀计算值与实测值进行比较,结果基本吻合。

In order to study on frost heave of freezing soils in continuous-intermittent freezing mode, frost heave tests using frost susceptible silty clay were carried out with variation of time intervals and temperature amplitudes of boundary temperature. The authors acquired segregation temperature by using the technique of infrared thermal scan and analyzed the relation among segregation temperature, boundary temperature and segregation rate. The results indicate that segregation rate increases with the decreasing of segregation temperature, and then decreases in the cooling phase of boundary temperature. Segregation heave pauses with the increasing of segregation temperature because the segregation rate tended to zero quickly in the warming phase of boundary temperature. Based on the tests results, calculation meth- od of segregation heave in continuous-intermittent freezing mode are proposed, the calculated results agree well with the measured results.