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.
