Numerical Prediction of Expansive Soil Behavior in Changing Climate

The prediction of expansive soil shrinkage/swelling response to climate cycles is of great importance for geotechnical engineers. The climate change is anticipated to cause significant changes in the hydrological cycles that consequently results in higher risk of damage to the structures constructed on expansive soils. In this study, a single stress state variable framework was adopted to describe the void ratio as a function of effective stress for soils in unsaturated state. A two-dimensional finite element model that couples variably saturated flow and stress-strain analysis was developed to simulate the behavior of expansive clay subject to change in soil moisture content. The developed numerical model was used to assess the impact of climate change on the behaviour of Regina Clay in the city of Regina, Saskatchewan. The results indicated that the frequency of large expansive ground heaving events is considerably higher under critical future Regina climate scenario compared to historical climate.