A comprehensive study on microstructural behavior of clay under oedometer condition

The present work investigated the macrostructural and microstructural changes in the behavior of two different soil samples collected from Rayaka (Su-1Clay) and Dodka (Su-2Clay) in Vadodara, Gujarat, India, under multi-staged oedometer tests. The microstructural analysis was performed to understand the pore morphology and particle rearrangement for different stress cycles and durations. For interlinking the macroscopic and microscopic data, porosity and void ratio were compared for both levels, and results showed an average deviation of 6%. From the mineralogical data, illite group minerals were predominant in both the samples and similar macroscopic behavior was observed during the multi-staged tests. The pore count was found to be higher during the initial stages of consolidation, as there was no stress involved. The microscopic results for Su-2Clay indicated that the loading patterns, load duration and plane of observations (i.e., parallel or perpendicular to loading) do not influence the circularity of pores and shape ratio. It was observed that the particle rearrangement was influenced by their loading value and duration, plane of observations and loading patterns. As a result, the behavior of most of the particles changed from anisotropic to isotropic as the stress value and time increased.