Analysis of deep moisture barriers in expansive soils. I: Constitutive model formulation

Expansive soils cause important economical losses in many arid or semiarid countries in the world. Considering the large economic impact, relatively few efforts have been devoted to develop analytical methods that may help practitioner engineers to adequately design civil infrastructure on this type of soil. A rational design method should be able to quantify the heave or subsidence of the soil associated with the suction changes during water diffusion, as well as the contact pressures on soil-structure interfaces. Accordingly, in this and in a companion paper, the problem of volume changes due to nonpermanent water flow in expansive soils is studied and applied to the case of vertical moisture barriers. In this paper, a constitutive model for expansive soils is proposed. This model is an extension of that developed by Alonso in 1990, in the sense that it can take into account the behavior of expansive soils. The advanced model is evaluated by comparing the numerical results with experimental data. © 2006 ASCE.