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为利用核磁共振(NMR)技术更快地测试得到冻土中未冻水的含量,首先对传统的单试样测试方法进行了分析,探究了其实验时间过长的原因.然后,基于传热学中的集总参数法,研究了小体积试样在空气中以自然对流传热为冷却方式的温度变化特征.根据试样温度与时间的对应关系,提出了多试样连续测试法.最后,以一种黏土为例,分别利用多试样连续测试法和单试样测试法测量了土样冻结过程中NMR信号强度随温度变化的关系.实验结果表明:二者的测量结果非常接近,但连续测试法耗费的时间非常少.综合比较两种利用NMR技术所耗费的时间和实验结果的精确程度,多试样连续测试法是可行的.
In order to obtain the content of unfrozen water in frozen soil by nuclear magnetic resonance (NMR) technique, the traditional single sample test method was firstly analyzed to explore the reasons why the experiment time is too long.Then, According to the lumped parameter method, the temperature change characteristics of small volume sample in natural convection heat transfer in air are studied. According to the correspondence between sample temperature and time, a multi-sample continuous test method is proposed. , Taking a kind of clay as an example, the relationship between NMR signal intensity and temperature was measured by multi-sample continuous test method and single sample test method respectively.The experimental results show that the measurement results of the two are very close, However, the continuous test method takes very little time.Comprehensive comparison of two kinds of time spent using NMR technology and the accuracy of experimental results, multi-sample continuous test method is feasible.