This proceedings volume for the 4th international conference CIGOS 2017 (Congrès International de Géotechnique - Ouvrages - Structures) presents novel technologies, solutions and research advances, making it an excellent guide in civil engineering for researchers, students, and professional engineers alike. Since 2010, CIGOS has become a vital forum for international scientific exchange on civil engineering. It aims to promote beneficial economic partnerships and technology exchanges between enterprises, worldwide institutions and universities. Following the success of the last three CIGOS conferences (2010, 2013 and 2015), the 4th conference was held at Ho Chi Minh City University of Technology, Ho Chi Minh City (Saigon), Vietnam on 26 to 27 October 2017. The main scientific themes of CIGOS 2017 were focused on ‘New Challenges in Civil Engineering’.

This second volume of a specialty 2-volume works contains 34 papers pertaining to the natural behaviour of diverse geomaterials found in different parts of the world. Each paper is organized along the outline: location and distribution, engineering geology, composition, state and index properties, structure, engineering properties, quality / reliability of data with reference to methods of sampling and testing, and relation to engineering problems. This extensive body of collated knowledge is integrated by three overview papers covering engineering geology, mechanical behaviour and engineering implications. Topics: Overview papers; Marine clays; Eastuarine Clays; Lacustrine clays; Stiff clays; Sands and other cohesionless soils; Residual and other tropical Soils; Weak rock.

The main body of the first volume is taken up by five major keynote papers written by a team of international experts, that survey the enormous advances that have taken place in geotechnical engineering since Skempton's pioneering early work. The second volume contains more than 80 articles that report recent research and advances in practice from around the world. The papers focus on the broad range of geotechnical issues, that most interested Professor Skempton, and are grouped under the headings of: - Soil behaviour, characterisation and modelling - Foundations - Slopes and embankments - Ground performance - The influence of geology on civil engineering.

Plasticity and Geotechnics is the first attempt to summarize and present in a single volume the major achievements in the field of plasticity theory for geotechnical materials and its applications to geotechnical analysis and design. The book emerges from the author’s belief that there is an urgent need for the geotechnical and solid mechanics community to have a unified presentation of plasticity theory and its application to geotechnical engineering.

This volume details recent global advances in laboratory and field testing of unsaturated soils. Coverage includes mechanical, hydraulic, and geo-environmental testing and applications of unsaturated soil monitoring to engineering behavior of geo-structures.