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.