Soil–environment interactions modelling for expansive soils

Abstract

Water content and matric suction changes in unsaturated expansive soils due to environmental variations contribute to the overall volume changes (shrinkage or swelling). The soil movements cause tilt in trees, highway surfaces, building foundations and pipelines and pose problems to the functionality of the infrastructure. In this paper, a modulus of elasticity-based method approach (MEBM) proposed by Adem and Vanapalli (2013a) is tested for modelling the soil–environment interactions for a test site with an expansive soil deposit that was modelled by Ito and Hu (2011) for 1 year. In the MEBM, the soil suction changes in the active zone and the associated modulus of elasticity were estimated and used as key parameters in a volume change constitutive relationship to model the soil–environment interactions over time. The MEBM approach reasonably models the water content and matric suction changes over time and the swelling–shrinkage movements. The study results are encouraging for extending the simple MEBM in practice for rational design purposes of both the sub- and superstructures constructed in or on expansive soils.