Relationship between different compaction energies and swelling characteristics on clayey soils

In this study, the relationship between the swelling characteristics of clayey soils and different compaction energies has been investigated. Proctor tests were conducted on three different clayey soil samples provided from two different regions in the Kozan and Sarıçam districts of Adana province, and the optimum moisture content and maximum dry unit weight were determined. Clayey soil samples, recompacted with various compaction energies at the determined optimum moisture content, were subjected to free swelling tests by placing them in consolidation rings. It was found that swelling characteristics are dependent on the energy variation, and a direct relationship exists between compaction energy and swelling percentage as well as swelling pressure. It was observed that with an increase in compaction energy, both the swelling pressure and swelling percentage of clayey soils increased. It was also concluded that the variation rates of swelling percentages and swelling pressures, depending on compaction energy, varied according to the plasticity index. When the graphs between compaction energies and swelling characteristics were examined, it was found that when the compaction energy was increased by 500 kN-m/m3, the swelling percentage of sample B, which had the highest plasticity index, increased by 300%, and the swelling pressure increased by 277%. Sample A, with a lower plasticity index, exhibited an increase of 121% in swelling percentage and 158% in swelling pressure, while sample C, with the lowest plasticity index, showed an increase of 120% in swelling percentage and 115% in swelling pressure. Consequently, a positive correlation between the plasticity index and swelling characteristics was established.