In this chapter, an elastoplastic framework for the volumetric behavior of expansive soils based on effective stresses is proposed. This framework is grounded on the volumetric and collapsing behavior of soils developed in Chapters 8 and 9. The hydraulic behavior of the soil is simulated using the porous-solid model developed in Chapter 4. The result is an elastoplastic framework based on the equation of the volumetric behavior of saturated soils presented in Chapter 8 where the value and sign of the compression index depends on the position of the state of stresses and the direction of the increment of the effective stress with respect to the yield surfaces in the plane of effective mean stress against suction. Experimental and numerical comparisons show the ability of the model to simulate the behavior of expansive soils under different stress paths.
Keywords: Collapse upon loading, Compression index, Compression-expansion index, Drying path, Effective stresses, Elastoplasticity, Expansive soils, Loading collapse yield surface, Loading path, Relative density, Suction increase yield surface, Unloading path, Unloading-reloading index, Wetting path.