Introduction

Geotechnical research into the field of Unsaturated soils started in the 50’s with some funding papers including Croney, Coleman and Bishop’s pioneering contributions and its development started to be significant 20 years ago, following the venue of the UNSAT’95 - First International Conference on Unsaturated Soils held in Paris in 1995, as a consequence of a series of successful Conferences on Swelling soils with the last one held in Dallas (1992).

This series of conferences sponsored by the TC6/TC106 Technical Committee of ISSMGE on Unsaturated soils was afterwards followed by a series of successful Regional Conferences that started in Singapore in 2000 with the Asia-Pacific series, followed by the European one started in Durham (UK) in 2008 and, finally, the Pan-American series started in Cartagena de las Indias (Colombia) in 2013.

In the meantime, research into the behaviour of unsaturated soils expanded in a spectacular manner in terms of laboratory/in-situ investigations and conceptual/numerical modelling, aiming at solving practical engineering problems based on sound analyses of coupled multi-physics phenomena that became less mysterious thanks to the sound and deep investigations carried out all over the world in a constantly increasing number of research groups.

In this exciting context, there is no doubt that the forthcoming E-UNSAT 2016 in Paris, will attract interesting contributions and foster fruitful discussions from researchers from Europe and overseas.