摘要：Purple soil is widely distributed in the Three Gorges Reservoir area, and its resistivity can represent the basic parameters of soil conductivity. In recent years, due to the frequent occurrence of arid climate, soil moisture evaporation and soil shrinkage and deformation have been caused. We conducted a series of indoor drying experiments to explore the resistivity characteristics of the purple soil during shrinkage. The test results show that: (1) The changes in soil mass and water content during the dry shrinkage process can be divided into rapid evaporation and deceleration rate stage. The soil mass and water content in the early drying period decrease rapidly, and then the decline rate slows down. (2) The change in the axial / transverse shrinkage rate of the soil can also be divided into a rapid shrinkage stage and a deceleration rate stage, and the slope of the curve in the rapid shrinkage phase is larger. (3) AC resistivity decreases with the increase of current frequency, water content, and zinc content. With the development of drying, tensile stress is generated in the soil, which promotes contraction and deformation of the soil. (4) The conductive path of soil is divided into the first conductive path (soil and water), the second conductive path (water), the third conductive path (soil). The main reason for the lack of cracks in the soil is due to the large thickness of Vaseline and the soil. The research results can provide theoretical support for the determination of soil resistivity under dry shrinkage conditions.
关键词：Purple soil;resistivity;water content;drying shrinkage;current frequency
