Constitutive Models for Skeleton-Degradable Soils

This chapter focuses on developing stress‒strain constitutive models specifically tailored to skeleton-degradable soils, including soils subjected to particle breakage, NGHs, and MSW. The discussion begins with an overview of the classical Modified Cam-Clay model for normally consolidated soils and the unified hardening (UH) model for overly consolidated soils. Considering soil phenomena such as compressive hardening, friction, and shear contraction and dilation, the above classical models are then adapted to analyze the complex behaviors of skeleton-degradable soils. Furthermore, new state variables are introduced to facilitate the development of stress‒strain constitutive models for skeleton-degradable soils. In particular, the constitutive model for soils subjected to particle breakage emphasizes the influence of particle size distribution variations on the stress‒strain relationship. Meanwhile, the constitutive model for NGHs highlights the significant influence of depressurization and hydrate decomposition rates on volumetric strain behavior. Finally, the constitutive model for MSW considers the influence of degradation on waste hardening behavior. Additionally, parameter sensitivity analyses are conducted to evaluate model variations, and simulated results are rigorously compared with experimental data to validate the effectiveness of the newly developed constitutive models.