This volume provides a snapshot of the current thinking and development perspectives on the installation and design of screw piles within the framework of Eurocode 7. The material included provides background on the various aspects of screw piles, with particular reference to stiff clays: 1. Exptensive description of a multi-million Euros research program on the loading behaviour of screw piles; 2. Geological and geotechnical characterization of Boom clay, and overview of screw pile testing over the last 30 years; 3. Results of the various load tests recently performed on 30 piles: static, dynamic, statnamic, and integrity and outcome of an international prediction event; 4. Tentative translation of the current body of knowledge in terms of potential application rules to be soon ascenrtained at the national level, as required by Eurocode 7. The remarkable aspects of the soil displacement piles covered in this book is an exceptionally low variability of geotechnical parameters,installation performance, and pile capacity calculations.