A New Constitutive Model and Its Application for Understanding the Impacts of Extreme Hydroclimatic Events on Geotechnical Systems
Publication: Geo-Congress 2023
ABSTRACT
Extreme hydroclimatic events such as heavy rainfall and drought have occurred frequently in recent years, and their impacts on geotechnical systems must be understood for developing climate-adaptive design procedures. A coupled flow-deformation finite element method that incorporates the variation in stiffness properties and failure due to the change in the degree of saturation is best suited for accurately predicting the impacts. PLAXIS, a finite element software widely used by practicing engineers and researchers, models water flow accurately, but the constitutive model does not consider the change in stiffness and failure criterion due to water flow. In this study, the Mohr-Coulomb (MC) model was first modified by updating the modulus and the yield criterion based on the degree of saturation and/matric suction and then used within PLAXIS to analyze selected geotechnical problems under extreme hydroclimatic events. The modified MC (MMC) model for unsaturated soil was validated using the experimental results for different soils found in the literature. The implementation of the MMC model in PLAXIS 2D through a user-defined soil model (UDSM) was also verified. Finally, the new constitutive model and the existing flow model were used for analyzing selected geotechnical systems in a coupled manner to understand and quantify the impacts of extreme hydroclimatic events on them. The results indicated that extreme hydroclimatic events significantly impact the strength and deformation behavior of deep foundations and the stability of earth slopes.
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Information
Published In
Geo-Congress 2023
Pages: 578 - 587
History
Published online: Mar 23, 2023
ASCE Technical Topics:
- Constitutive relations
- Continuum mechanics
- Deformation (mechanics)
- Engineering fundamentals
- Engineering mechanics
- Finite element method
- Geotechnical engineering
- Geotechnical models
- Hydrologic models
- Mathematics
- Methodology (by type)
- Model accuracy
- Models (by type)
- Numerical methods
- Solid mechanics
- Structural mechanics
- Two-dimensional models
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