New Methods for Characterizing and Modeling the Engineering Behavior of Expansive Soils

Abstract

Expansive soils experience alternating swelling and shrinkage due to variations in soil suction, thereby creating long-term challenges for the integrity of civil infrastructure. Conventional design approaches typically rely on constant soil parameters and do not account for transient and cyclical changes in soil suction and variable hydraulic conductivity. This keynote lecture presents a new conceptual framework for characterizing expansive clays (Ito et al., 2022a) and a suction-based predictive model for estimating volumetric deformations (Ito et al., 2022b). The new framework integrates the water retention curve, the swell–shrink curve, and the hydraulic conductivity curve to develop a soil property function. The numerical modeling simulations closely matched ten years of field monitoring data, demonstrating the validity of the new approach for predicting periodic movements at and near ground level.