Static Compaction Test and Determination of Equivalent Static Pressure

Abstract

Soil compaction is a vital part of the construction process. The compaction curve between moisture content and dry unit weight should be prepared for all types of soil in the project area, before earthwork commences as it forms the basis for specification and field compaction control. The relationship between moisture content and dry unit weight of the soil is a function of the compactive effort. The modified Proctor test, the reduced modified Proctor test, the standard Proctor test and the reduced standard Proctor test are dynamic methods which use different compactive efforts. These tests require considerable time and effort, and also these have some imperfections. In the present study, a laboratory procedure is devised to determine the relationships between moisture content and dry unit weight by using static compaction method for different static pressures. The static compaction pressure test is devised in the Proctor mould itself to statically compact the soil at different water contents. This method is less laborious, and the time involved is less. For this, seven fine-grained soil samples of various plasticity characteristics were tested. The analysis shows that the relation between water content and dry unit weight in static compaction for different static pressure is parabolic in nature. In this study, the equivalent static pressures to the modified Proctor test, the reduced modified Proctor test, the standard Proctor test and the reduced standard Proctor test are determined, to obtain the maximum dry unit weight and the optimum water content corresponding to the four different compactive efforts.