The field of experimental unsaturated soil mechanics has grown considerably over the last decade. In the laboratory and in the field, innovative techniques have been introduced into mechanical, hydraulic, and geo-environmental testing. Normally, this information is widely dispersed throughout journals and conference proceedings and it is often difficult to identify suitable equipment and instrumentation for research or professional purposes. In this volume, however, the authors bring together the latest research in laboratory and field testing techniques, and the equipment employed, and examine the current state-of-the-art in a forum devoted solely to experimental unsaturated soil mechanics. The papers published in the proceedings were peer-reviewed by internationally-recognized researchers. The topics tackled by the papers include suction measurement, suction control, mechanical and hydraulic laboratory testing, geo-environmental testing, and field-testing.

Preface. Measurement of matric suction using tensiometric and axis translation techniques; F.A.M. Marinho et al. Indirect measurement of suction; R. Bulut, E.C. Leong. Axis translation and negative water column techniques for suction control; S.K. Vanapalli et al. Vapour equilibrium and osmotic technique for suction control; J. Blatz et al. Mechanical testing in unsaturated soils; L.R. Hoyos et al. Laboratory hydraulic testing in unsaturated soils; F. Masrouri et al. Microstructure investigation in unsaturated soils: a review with special attention to contribution of mercury intrusion porosimetry and environmental scanning electron microscopy; E. Romero, P.H. Simms. Geoenvironmental testing; P. Delage, E. Romero. Field measurement of suction, water content, and water permeability; A. Tarantino et al. Water balance and evapotranspiration monitoring in geotechnical and geoenvironmental engineering; Y.J. Cui, J.G. Zornberg. Monitoring the performance of unsaturated soil slopes; C.W.W. Ng et al. Monitoring large scale tests for nuclear waste disposal; E.E. Alonso et al.

This volume contains the Proceedings of the Second International Workshop on Unsaturated Soils, which was held in Anacapri, Italy, from 23 to 25 June 2004. This meeting was organized by the Department of Geotechnical Engineering of the University of Naples Federico II and the Department of Mechanical and Structural Engineering of the University of Trento, under the auspices of the Technical Committee on Unsaturated Soils (TC6) of the ISSMGE and the Associazione Geotecnica Italiana (AGI). In line with the spirit of the first workshop in 2000, post-graduate and post-doctoral researchers from different universities were invited to present their work. This book contains peer-reviewed papers on unsaturated soils, particularly new developments in laboratory testing, experimental data on compacted and natural soils and constitutive and numerical modelling of unsaturated soil behaviour.