2012 Volume 68 Issue 2 Pages I_299-I_306
Compacted soil is widely used for earth structures. However, the mechanism of compaction has not been explained, so it is difficult to grasp distributions of stress, void ration, and soil moisture within compacted earth structure. Therefore, estimation of safety and stability of compacted earth structures exposed to natural disaster is complicated. Compaction is decreasing void ratio by applying stress under certain water content and pushing air out of soil mass. Thus, the mechanics of unsaturated soil, which includes air within void, is needed for understanding of compaction. In this study, we regarded compaction as compression and expansion phenomenon of unsaturated soil under drained air and undrained water conditions and formulated it in initial-boundary-value problem. Here, the influences of permeability and soil water retention characteristics on compaction were considered and static compaction tests were simulated. Moreover, multi-layered compaction was examined.