Estimation of the compaction characteristics of soils using the static compaction method

Abstract

Ground improvement using mechanical stabilization is commonly applied by performing the standard Proctor compaction test, which requires a significant quantity of soil, usually obtained from open pits. A static compaction test is an alternative laboratory compaction test. Although researchers have shown that the results of miniature size static compaction tests are comparable with that of standard Proctor tests in terms of the maximum dry density and the optimum water content, no attempt has been made to compare the two fundamental properties of the compacted soil: undrained shear strength and hydraulic conductivity. The scope of this investigation was to estimate the level of static compaction energy required to (1) obtain a compaction curve similar to that of the standard Proctor test; (2) reconstruct compacted soils using the standard Proctor and static compaction tests at the optimum water content; and (3) compare the undrained shear strength and hydraulic conductivity of compacted soils. The compacted soils at the predetermined energy level were subjected to hydraulic conductivity tests using the rigid-wall falling-head permeability method. Undrained shear strength tests were performed by employing a high-capacity laboratory vane shear apparatus on compacted samples of both the standard Proctor and static compaction tests. The present investigation revealed that the static compaction test, requiring about only 10% of the soil necessary to perform the standard Proctor method, provides comparable results in regard to hydraulic conductivity and undrained shear strength.