Compacted soils are relevant to many geotechnical applications, from earth dams to infrastructure embankments, nuclear waste disposal and rammed-earth buildings. Every geotechnical structure made of compacted soils will include sections that remain partly saturated at least for a period of its service life. Improved understanding of this fast growing area can contribute to the improved design of earth structures/fills by maximizing the use of locally sourced soils, with consequent gains in safety, cost and sustainability of future building practice. The sixteenth Géotechnique Symposium in Print focused on the study of compacted unsaturated soils, which are at the core of geotechnics and have been at the forefront of research for many years, providing a unique scientific forum for the exchange of the latest knowledge and best practice between academia and industry. This book brings together all the Symposium papers from leading international researchers, published in Geotechnique, the keynote speeches presented at the Symposium, at the Institution of Civil Engineers on 20 June 2011, and a selection of questions posed by delegates during the Symposium, together with answers from presenters. Partial Saturation in Compacted Soils provides a comprehensive overview of recent advances in unsaturated soil mechanics, ranging from material testing to modelling and analysis of engineering boundary value problems, providing further insight into the rapidly developing topic of unsaturated soil mechanics and its application to compacted fills and serving as an invaluable reference for engineers and researchers for years to come.