基于FDR技术的土体质量含水率和干密度快速检测方法

A method for quick detection of soil moisture content and dry density rapidly based on frequency domain reflectometry technology

为解决现有烘干法和环刀法测定土体质量含水率和干密度存在的周期长、扰动大的问题,提出一种基于频域反射(FDR)技术的快速无损检测方法。基于介电常数、电导率与质量含水率和干密度的关系式,利用电导率与介电常数的拟合关系,推导出质量含水率和干密度的求解公式。参数率定试验和模拟土体填筑的模型试验表明,提出的质量含水率与干密度快速测定方法合理可行,具有较高的测试精度。

The traditional method to determine the soil moisture content and dry density, which uses the oven drying combined with the cutting-ring, has the problems of long testing period and sampling disturbance, thus a rapid non-destructive testing method was proposed based on the frequency domain reflectometry(FDR) technology in this study. Firstly, based on the relationships of dielectric constant and bulk electrical conductivity with the soil moisture content and dry density, and by using the fitting relationship of dielectric constant and bulk electrical conductivity, the solving equations for soil moisture content and dry density were derived. After that, both the calibration test and model test that simulated the layered filling construction were conducted to verify the applicability of the proposed method. It is found that the proposed mothed to detect the soil moisture content and dry density is feasible with high accuracy.