Prediction of Swell-Shrink Movements of Pavement Infrastructure

Two well-known models available in the literature are used in this paper to predict the swell-shrink related soil movements of expansive soils. Both models are based on unsaturated soil properties and they were used for the predictions of total soil movements that included both swell and shrinkage related soil movements. Field data collected from three instrumented pavement sites located in Fort Worth, Paris and San Antonio in Texas provide measured soil movements in real field conditions. Pavement subgrades instrumented with suction probes and moisture content sensors provided measurements that were used in the prediction models. Both models were used to predict the swell-shrink movements of the pavements for various depths of subgrades and these predictions are compared with the field measured total movements. Predictions showed a good match when shallow subgrades ranging from 2 to 3 ft depth are considered for the prediction analysis. Reasons for the good match due to shallow depths lower than active depths are explained.