Evaluation of non-uniformity of sandy soil specimens compacted in the field and in the laboratory and its effect on strength and deformation characteristics

Abstract

The specimen of triaxial test used for the soil properties in design of the important fills is prepared by tamping uniformly in a steel mold in which deformation is restrained in laboratory. On the other hand, in the field construction, the compaction machine passes on the fill materials, so a large density distribution is observed in the depth direction in each compaction layer. In addition, since the surface of fill has a small restraining pressure, disturbance due to local shear failure occurs during compaction. In this paper, test fill specimens were retrieved from a full-scale test fill compacted by a small compaction machine in large steel vessel. Result of triaxial test for unsaturated specimen, strength and deformation properties were compared between the specimens compacted in the field and in the laboratory as the same fill material. It is argued that the vertical non-uniformity specimen of strength and deformation properties compacted soil in the field and in the laboratory can be evaluated in the same way by taking into account the effects of shear failure in the field compaction in addition to ρ_d and S_r.