On controlling influence of the line of optimums on the compacted clayey soil behavior

The behavior of compacted clayey soils under wet/dry cycles is examined using the MPK framework proposed by Kodikara (2012). It is hypothesized that at a particular operating net stress, the soils tend to stabilized to a curve controlled by the Line Of Optimums (LOO), referred to as the environmentally stabilized curve. The significance of the LOO is identified as it provides the optimum air content and associated open structure for a soil to undergo swelling and drying reversibly with minimal energy dissipation. Some laboratory data are presented in support of the hypothesis. On the basis of some published case studies, loss of density or decompaction observed in the likely field behavior due to climatic effects is also interpreted.