Water Retention in Soils and Its Implications on Pavement Design

Monday, September 11, 2006 - 3:45pm

About the Event

Water Retention refers to the relationship between the amount of soil water and the energy with which it is held. This relationship is important for characterizing the rate at which water moves through a granular material under both saturated and unsaturated conditions. Important consequences of this relationship are the amount of drainage that may occur through soils, how deep the frost might penetrate, and how strength properties vary seasonally. Pavements are constructed on compacted soils that are typically unsaturated. Several design and maintenance measures are undertaken to maintain unsaturated conditions in the pavement because they provide favorable engineering soil properties. However, the conventional procedures for pavement design are often based on empirical procedures and not on unsaturated soil mechanics principles. The goal of this project is to develop a pavement design method that is consistent with Mn/DOT and AASHTO mechanistic-empirical design framework but is based on the principles of unsaturated soil mechanics. Specifically, we propose to predict shear strength and modulus of unbound pavement materials using index tests, soil water characteristics curves, and simple mechanical tests.


Dr. Satish Gupta, Professor, Department of Soil, Water, and Climate, University of Minnesota