土的电阻率室内测试技术研究

LABORATORY MEASUREMENT TECHNIQUES OF THE ELECTRICAL RESISTIVITY OF SOILS

土的电阻率可反映土的组成和结构特征。室内测试是研究土电阻率的主要方法之一。本文在分析影响电阻率因素的基础上,总结了国内外现有土电阻率测试的原理与方法,介绍了作者研制的一种实用土电阻率测试仪,并通过典型试验,论证了该测试仪器的可行性,可以在室内土电阻率测试试验中应用。

The electrical resistivity of soils is dependent on solid components, pore water, microstructure and environmental characteristics of soils. Therefore, electrical resistivity of soils is affected by various factors, including soil type, water content, saturation, temperature and pore fluid property et al. The soil electrical resistivity can be measured non- destructively by placing electrodes on the soil surface, applying a voltage and measuring the current. In the laboratory measurements of soil electrical resistivity, the number of electrodes （ two electrodes or four electrodes ）, current types （ DC or AC ） and the frequency of the used AC should be considered. Practical aspects of these methods and arrangements are discussed in this paper. Based on the analyses of the theory of soil electrical resistivity and laboratory measuring techniques, the authors introduce a new practical device for the laboratory measurement of electrical resistivity, which uses two electrodes and lower frequency AC. Pilot test results show the equipment is effect and feasible in measurement of soil electrical resistivity.