Abstract:

The two-dimensional consolidation problem of unsaturated soils is studied. If water and air in the pores can be regarded as a mixed fluid in unsaturated soils with , the deformations of unsaturated soils become the consolidation process of two-phase with soil skeleton and mixed fluid. Regarding the compressibility of the mixed fluid in pores, mixed fluid continuity equations are established. Then the stress-strain and mixed fluid pressure can be computed by mixed fluid continuity equations and balanced equations. If the suction and pore-air pressure are required, the water continuity equation should be established first to compute the pore-water pressure. A numerical example shows that the pore-air pressure is a minor factor in the consolidation process of unsaturated soils because the changing of the mixed fluid pressure is consistent with that of pore-water pressure; the deformation process is similar to that of embankment construction. Therefore, the approach is reasonable and very important to pragmatize computation of consolidation deformation.

Key words: unsaturated soil, two-dimensional consolidation, mixed fluid, suction