Soil Degradation‒Consolidation Models

This chapter introduces the soil degradation‒consolidation theory, drawing upon the concepts covered in Chaps. 2 , 3 , and 4 . It offers a comprehensive overview of several degradation‒consolidation models and their practical relevance to landfilled MSW and NGHs. The chapter begins by outlining several degradation‒consolidation models specifically tailored to skeleton-degradable soils, subsequently deriving governing equations and establishing a finite element numerical solution framework. The chapter then focuses on the degradation and stabilization behaviors of landfilled MSWs with HFWC and LFWC, detailing various degradation and stabilization indicators and exploring anaerobic and aerobic degradation stabilization behaviors. Validations of the established theoretical models and evaluations of degradation stabilization behaviors in HFWC MSW landfills are accomplished through large-scale bioreactor experiments and field surveys. Furthermore, the characteristics of two-dimensional landfill slopes are examined, analyzing the coupling effects of landfill gas (LFG) production and deformation due to the degradation of MSW on the landfill slope stability. Additionally, LFG pressure distributions, horizontal and vertical displacement distributions, and deformation patterns are analyzed. Moreover, NGH degradation and consolidation behaviors are explored by the numerical model and validated by centrifugal hypergravity modeling. Notably, the degradation‒consolidation theory describes solid skeleton deformation, liquid and gas flow, solute migration, and heat transport, facilitating its widespread applications to multifield coupling processes within porous media. Leveraging diverse biochemical degradation models, the degradation‒consolidation theoretical framework demonstrates direct applicability to various skeleton-degradable soils.