Modeling soil compaction under uniaxial compression

Knowledge about soil compaction is increasingly important within agriculture and for environmental protection. The objective of this study is to modify a previous two-parameter model to generalize it to account for preconsolidation effect. A three-parameter model for the relationship between soil bulk density and applied stresses during compaction is presented. It relies on the physical approach of the previous two-parameter model and satisfies the same boundary conditions. The proposed model is applied to compaction data of four silt loam and loam soils. A good fit to data is obtained for a wide range of applied stresses, including stresses less than the preconsolidation stress. The proposed model is compared with the three-parameter version of a recent model. The performances of the two models are similar. The root mean square errors for the four soils ranged between 0.004 to 0.011 for the recent equation and 0.005 to 0.018 for the proposed model. The advantage of. the proposed model is that it releases the physically unrealistic constraint in the recent model that the maximal bulk density of a compacted soil is equal to its particle density.