Prediction of the Variation of the Resilient Modulus with Respect to the Soil Suction for Three Granular Materials Using Three Methods

Base-course layers of a pavement structure usually are composed of granular materials which are typically in an unsaturated condition during their service life. Pavements during the last decade have been encouraged to be designed based on the mechanistic methods which use the resilient modulus (M_R) as a key parameter. The soil suction has a significant influence on the M_R of granular materials. In this paper, various equations proposed for predicting the M_R of unsaturated granular materials from the literature are summarized. Three equations proposed for predicting the M_R of granular materials summarized in this paper are selected to provide comparisons between the measured and predicted M_R values of three different granular materials. The strengths and limitations of the three equations are discussed. In addition, the relationship between the M_R and the soil-water characteristic curve (SWCC) is highlighted with recommendation to use it as a tool in the prediction of the M_R for granular materials.