Prediction of the effects of compaction on granular materials

There is a particular interest, spanning from purely theoretical speculation to practical applications, in establishing a relationship between the micro-mechanical properties of soil, primarily particle shape and grain size composition, and the possibility of improving their macro-continuum equivalent response by means of compaction. However, relationships simultaneously taking into account the role of index soil properties and compaction technique (i.e. method and effort adopted for soil densification) are far from comprehensive. In this paper, two subsequent steps are followed to bridge this gap. A systematic laboratory investigation was carried out subjecting ten samples of sandy materials, each prepared with a carefully studied grading, to a variety of standard compaction methods with progressively increased input energies. The subsequent step consisted of combining the experimental outcomes with data collected from the literature in order to frame the role of compaction energy and soil gradation into a unique comprehensive relationship. Comparison between measured and computed values of dry density show that predictions with estimate errors > 5% are possible.