The principles and concepts for unsaturated soils are developed as extensions of saturated soils. Addresses problems where soils have a matric suction or where pore-water pressure is negative. Covers theory, measurement and use of the fundamental properties of unsaturated soils--permeability, shear strength and volume change. Includes a significant amount of case studies.About the Author: D.G. Fredlund is the author or coauthor of over 460 refereed journal articles, conference proceedings, technical papers, and chapters in edited collections. In 1993, he coauthored Soil Mechanics for Unsaturated Soils, the first major text on unsaturated soil mechanics published. He has served as a research consultant to the Government of Hong Kong, U.S. Army Corps of Engineers, and Saskatchewan Highways, and presently is head of the Golder Unsaturated Soils Group, Canada. H. Rahardjo is head of the Division of Infrastructure Systems and Maritime Studies at the School of Civil and Environmental Engineering at Nanyang Technological University in Singapore. He is the coauthor of Soil Mechanics for Unsaturated Soils and over 200 technical publications.