Shrinkage Limit Studies from Moisture Content: Electrical Resistivity Relationships of Soils

Abstract

At the shrinkage limit, the soil is just fully saturated. Shrinkage limit of soils can be perceived as a point of inflection in either direction. While decreasing the water content, from its liquid state to the solid state, a point of inflection is reached (shrinkage limit) when further reduction in water content will not cause a reduction in the volume of the soil mass. While increasing the water content, from a partially saturated state to a fully saturated state and beyond, the electrical resistivity reduces, and from the point of shrinkage limit onwards, there is no further appreciable reduction in electrical resistivity. Earlier studies have proven that shrinkage limit is not governed by plasticity characteristics of the soil. Shrinkage limit is primarily a result of the packing phenomenon governed by the grain size distribution of the soil. This research investigates the relationship between moisture contents and electrical resistivity of well compacted/packed soils. It is shown that electrical resistivity measurements (ER–moisture content profile) of a well packed soil, in an electrical resistivity box, can be a useful tool for predicting the shrinkage limit of the soil. A very good agreement is obtained between Shrinkage limit assessed from standard shrinkage limit test and resistivity–water content profile. The assessment is proven to be valid for contaminated soils too, where in the Atterberg limits get altered. © 2021, King Fahd University of Petroleum & Minerals.