Pre- and post-construction characterization of an embankment fill material

Each compaction method significantly affects the engineering properties of compacted soils by producing its own distinctive internal structure. Independently of the mechanics and type of compaction energy applied in field, the design requirements for embankments construction should satisfy standard Proctor moisture-density criteria. The aim of this paper is to investigate the pre- and post-construction strength of a clayey silt used as fill material on an experimental embankment built along the Po river, Italy. After seven years of the embankment construction, undisturbed specimens were obtained from the embankment body. Suction controlled triaxial test were conducted on the retrieved samples in order to determine the post-construction shear strength. The results have been compared with the obtained by Vasallo (2003) on samples compacted by using standard Proctor method. The experimental procedures, the post-construction results and the comparison with the pre-construction parameters are presented and discussed in the paper.