基于介电特性的冻土检测方法研究

Study on frozen soil detection method based on dielectric properties

文章在冻土组分的介电特性原理基础上,对空气、水、冰及干土的温度-介电特性进行了实验研究。研究发现,在温度变化过程中,冻土总介电常数的变化主要取决于水和冰相变,空气和干土对总介电常数影响基本可忽略。基于这一特性,提出了利用空气、固态土、水和冰介电常数的差异检测冻土的方法,并进行了典型土壤冻结介电特性实验。实验结果表明,土壤冻结过程中介电常数变化在数值上较为明显且容易辨别。因此,采用基于介电特性的平面电容传感器检测冻土的方法是可行的。

On the basis of principle of dielectric properties of frozen soil components,laboratory study on the temperature-dielectric properties of air,water,ice and dry soil were carried out.It is found that the variation of frozen soil total dielectric constant depends on the phase transition of water and ice in the process of temperature change,and the influence of air and dry soil on soil total dielectric constant is negligible.Based on these characteristics,a method for detecting frozen soil by using the difference of dielectric constant of air,solid soil,water and ice is proposed,and taking the experiment for the dielectric properties of typical frozen soil.The experimental results show that the variation of the dielectric constant of soil freezing process is more obvious and easy to distinguish,therefore,it is feasible to use the capacitive sensor based on dielectric characteristics to detect the frozen soil.