Abstract: Soil resistivity is one of the basic physical indices to evaluate soil characteristics, which is related to soil structure, mineral composition, moisture content and other factors. In this paper, the resistivity of silty clay samples under different degrees of compaction and desorption-absorption moisture paths are tested through laboratory tests. The effects of degree of compaction and desorption-absorption moisture paths on the resistivity changes of silty clay samples and their influencing mechanisms are investigated. Finally, Gunzel and Waxman models were used to compare and analyze the test results. The most suitable resistivity structure model for the silty clay in the dehumidification and hygroscopic process is identified. The results show that the decrease rate of resistivity is greater with the increase of volumetric water content under the condition of lower degree of compaction. Under the same moisture content, the resistivity of the soil sample on the desorption-absorption moisture path is greater. The fitting results show that the Gunzel and Waxman models have higher fitting accuracy.

Key words: Unsaturated Soil, Resistivity, Degree of Compaction, Desorption Absorption , Moisture Absorption Moisture Path