Re-examination of compaction parameters of fine-grained soils

The reported methods for prediction of compaction parameters of fine-grained soils are critically re-examined in this paper. It is shown that correlations involving just any one index property do not yield satisfactory prediction of optimum moisture content and maximum dry unit weight of soil at any rational compactive effort. By defining a fine-grained soil by its liquid limit and plastic limit, the interrelationship between compaction energy and compaction parameters is brought within a definite framework. Plastic limit is found to influence the maximum dry unit weight of soil to a greater extent than the liquid limit at all energy levels considered in the study. On the other hand, the optimum moisture content-compaction energy-index property relationship is more complex. The degree of accuracy of optimum moisture content prediction is improved when separate correlation equations are used for low-to-medium plastic and highly plastic soils.