A NEW METHOD TO PREDICT SWELLING USING A HYPERBOLIC EQUATION

Light buildings founded on expansive soils may be subjected to undesirable cracking resulting from differential swelling and/or shrinking of the soil. The prediction of probable heave of these soils under given surcharge loads is therefore becoming important in day-to-day soil engineering practice. Several detailed investigations have been made in the past to characterise swelling-swelling pressure-time relationships for expansive clays. These relationships and other methods to predict swelling have had only a limited success since problems involving swelling behaviour are complex and can only be solved by an approach based on the observed properties of these soils. An attempt is made in this study to predict the maximum swelling from the observed behaviour over a short interval of time. The approach is based on a hyperbolic equation. The test data obtained from several tests have been analysed to examine the validity of the hyperbolic equation. Published data have also been analysed to verify the validity of the equation and the analyses show a good agreement between predicted and observed maximum swelling. /Author/TRRL/