Static Method to Determine Compaction Characteristics of Fine-Grained Soils

Engineering projects such as roads, earthen dams, embankments, and trench backfills require soil compacted at higher dry unit weight. In a majority of geotechnical projects, compaction of soils is involved with increasing strength and decreasing compressibility and permeability. The Proctor compaction test forms one of the most popular and important tests in geotechnical engineering practice. The moisture content-dry unit weight relationship of the soil obtained from the standard Proctor test forms the basis for specification and field compaction control. Standard Proctor test, also known as the dynamic compaction test requires considerable time and effort and has few imperfections. This study examined the possibility of determining the equivalent static pressure to the standard Proctor test to obtain the optimum moisture content, OMC, and maximum dry unit weight, of fine-grained soils. For this, a static compaction pressure test was devised in the Proctor mold itself to statically compact the soil at different water contents. The equivalent static pressure so determined will simplify the compaction procedure and will also result in considerable saving of time, money, and effort, especially so when dealing with highway and earth embankment projects.