Comparing experimental and numerical modeling of desiccation of clayey soils

Abstract

This paper aims to present an understanding and prediction of the drying shrinkage behavior of clayey soils through a combined approach involving experimental investigations and numerical simulations. Initially, desiccation experiments were conducted on fully saturated slurry as well as pre-consolidated clayey soils. The experimental results indicate that the deformation observed in the fully saturated slurry during the drying shrinkage process is related to its moisture loss. Therefore, this research directly employed the Fredlund’s function to estimate the shrinkage volumetric strain. Subsequently, a constitutive model for the hydraulic mechanical properties of clay was developed based on a stress state variable framework, and simulations were performed for the desiccation experiments involving fully saturated slurry. The drying experiment conducted on pre-consolidated clayey soils revealed that these soils does not deform during the drying process, and external loading emerges as a critical factor influencing their deformation. As moisture is lost from pre-consolidated clay, an internal suction gradient develops, thus, suction distribution was derived by integrating Darcy’s law with SWCC. Ultimately, this research provides a theoretical explanation for the deformation processes associated with clay drying through numerical modeling while highlighting differences in clay drying behavior between varying initial states.

Highlights

A constitutive model describing the hydraulic and mechanical behavior of clay under controlled environment was established through the stress state variables framework.

The experimental relationship between the physical variables in desiccation of material was established.

For pre-consolidation specimens, the desaturation process was relatively slow in clayey soil due to low permeability, the high-water pressure gradient was generated with a significantly heterogeneous suction distribution in the clayey soils during the drying process.