A New Approach to Measure Soil Shrinkage Curve

Abstract

Abstract The shrinkage curve is widely used to characterize soil deformation during drying. Over the years, several methods have been developed to measure soil shrinkage curves. However, these methods suffered from several limitations and were rarely used because of difficulties in accurate soil volume measurement during drying. In this study, a simple method is proposed to measure soil shrinkage curves. The soil volume is measured using a photogrammetric technique from which a three-dimensional (3D) model of the soil specimen during drying can be accurately reconstructed. The soil volume is calculated based on the reconstructed 3D model. Meanwhile, a digital balance is used to record the soil weight for the back-calculation of soil water content, which will be used for the shrinkage curve construction. The overall volume measurement error was evaluated to be 0.35 % and 0.43 % through tests on aluminum cylinders and a saturated soil, respectively. With the proposed method, a series of tests were performed to measure the shrinkage curves of a soil mixture (i.e., Fairbanks silt and Kaolin at a ratio of 1:1). Results from these shrinkage tests indicate that the proposed method is cost-effective, accurate, and reliable for soil shrinkage curve measurements.