Simplified Method to Predict Compaction Curves and Characteristics of Soils

Improvements of the soils in sites are usually necessary to achieve the desired strength, compressibility and hydraulic conductivity of soils. Generally, improvement in compaction is preferred and applied in sites. The compaction curve and associated characteristics, namely maximum dry unit weight and optimum moisture content, should be determined in the laboratory by using Proctor test procedures. However, a number of Proctor tests need to be carried out for projects like earth dams, embankments and highways. In this paper, a simplified and dependable way of obtaining compaction characteristics and compaction curves at different compaction energy levels for preliminary designs is introduced. For this purpose, Proctor compaction tests were conducted with different soils and at different compaction energy levels apart from using extensive results found in the literature. It was found out that by only getting the compaction characteristics from plastic limit an approximate compaction curve can be obtained from family curves. The approximate compaction curve compares well with the tested values too. Maximum dry density predicted is 0.986 times the maximum dry density at plastic limit, whereas predicted optimum moisture content is 0.99 times the actual optimum moisture content.