Compacted Soils

Abstract

When unsaturated soils are subjected to drained or undrained compression tests, they approach the saturated compression line with different slopes. This difference in slopes is produced by the amount of collapse of each path. During compression, four main phenomena occur in these materials: first, with the reduction in volume, the degree of saturation increases; second, with the reduction in the size of pores, the soil-water retention curve shifts on the suction axis; third, these two phenomena produce an increase in the suction stress and, finally, this increase in suction stress produces a certain amount of collapse on the sample. In this chapter, a coupled model is employed to simulate the volumetric behavior of compacted soils under different stress paths. The comparison between experimental and numerical results shows the pertinence of the model.

Keywords: Compression, static compaction, Collapse upon wetting, Effective stresses, Coupled model, Undrained tests, Elastoplasticity, Unsaturated soils, Hydromechanical coupling, Retention curves, Suction stress, degree of saturation, Preconsolidation stress, Volumetric behavior, Saturated compression line.