Thermo-Hydro-Mechanical model of vegetation based on an extended Barcelona Basic Model (BBM-VEG)

1. Home
2. Publications
3. Online Library
4. Thermo-Hydro-Mechanical model of vegetation based on an extended Barcelona Basic Model (BBM-VEG)

The effects of vegetation in unsaturated soils are often simulated by modifying soil strength parameters, such as cohesion or friction angle. However, this simplification fails to represent the progressive nature of root-soil interaction during loading. To address this limitation, this study develops an extended Barcelona Basic Model (BBM-VEG) that incorporates vegetation effects into the thermo-hydro-mechanical (THM) framework for unsaturated soils. The model introduces a strain-dependent root reinforcement parameter (Rp_veg), linked to root mass fraction and activation strain, which dynamically alters the soil stiffness and strength. The yield surface evolves with suction and root effects, allowing for the simulation of strain hardening and softening in vegetated soils. It also integrates suction-dependent elastoplasticity and Bishops effective stress for coupled hydromechanical behavior under both drained and undrained conditions. Compared to previous models, BBM-VEG captures the progressive mobilization and degradation of root reinforcement as a function of strain, allowing for a more realistic prediction of stress-strain behavior and strength enhancement in rooted soils. Validation against experimental triaxial tests on rooted soil demonstrates its capability to simulate both initial stiffness and peak strength under varying root densities, highlighting its robustness in modeling vegetated soils.

3rd International Workshop on Soil-Vegetation-Atmosphere Interaction (RootS2025)

1d. Coupled numerical thermo-hydraulic modelling of soil-vegetation-atmosphere interaction