Eurocode 7 and reliability-based design

This chapter outlines how reliability-based geotechnical design is being introduced in Europe through the adoption of Eurocode 7, the new European standard for geotechnical design. Eurocode 7 is based on the limit state design concept with partial factors and characteristic values. This chapter traces the development of Eurocode 7; it explains how the overall reliability of geotechnical structures is ensured in Eurocode 7; it shows how the limit state concept and partial factor method are implemented in Eurocode 7 for geotechnical designs; it explains how characteristic values are selected and design values obtained; it presents the partial factors given in Eurocode 7 to obtain the appropriate levels of reliability; and it examines the use of probability-based reliability methods, such as firstorder reliability method (FORM) analyses and Monte Carlo simulations, for geotechnical designs and the use of these methods for calibrating the partial factor values. An example is presented of a spread foundation designed to Eurocode 7 using the partial factor method, and this is followed by some examples of the use of probabilistic methods to investigate how uncertainty in the parameter values affects the reliability of geotechnical designs.