Evaluating Soil Shrinkage Behavior Using Digital Image Analysis Process

In this paper, the shrinkage behavior of silty clay soil widely found in Warangal is characterized under free evaporation condition over a wide range of suction. As a part of the research evaluation, a comprehensive laboratory test program was framed and conducted on the samples collected from Warangal. Slurries of soil samples were subjected to desaturation by evaporation, and the change in the sample dimension was captured with camera still images and Vernier caliper. The captured images were processed and used for quantifying the overall volume change. The shrinkage behavior was represented as soil shrinkage curve (SSC), and the curve exhibited three zones. The proportional or normal shrinkage was dominant with volume of water lost from the pores equaling the volume change in the sample. The structural and residual shrinkage phase indicated the loss of water from both inter- and intra-aggregate pore spaces with gradual increase in time. The study showed the existence of bimodal porosity in low plasticity soil and also discusses the reliable efficiency of the proposed experimental procedure to study the shrinkage behavior of soils with low plasticity.