Modelling the behavior of inundated collapsible soils

Abstract

The properties of collapsible soil exhibit a lot of sensitivity toward the increase of water content, especially when the soil is close to the dry state. The inundation of collapsible soils induces a considerable drop in the void ratio (e) (ie, collapse potential, Cp, increase), which in return affects the dry unit weight (γd), friction angle (ϕ), and shear strength of the soil. The presented study employs large numbers of sandy and silty specimens of collapsible soils with different initial conditions (gathered from the literature) to develop a correlation that evaluates Cp of the soil (ie, settlement) due to inundation. The developed relationship accounts for the soil's initial properties such as the void ratio (e0), degree of saturation (Sr), and pressure applied to the inundated specimens. The presented model reflects the significant influence of Sr on Cp of inundated soil which considerably decreases by the increase of Sr. The determined properties of inundated collapsed soil, such as e and ϕ, are employed to construct the post‐inundation stress‐strain curve (ie, mobilized shear strength) of the soil based on the concepts of the conventional triaxial test. Comparisons between predicted and measured stress‐strain curves of inundated collapsible soils are presented for validation.

Keywords

• collapse potential
• collapsible soil
• constitutive model
• stress‐strain curve