BEHAVIOUR OF STEEL STRUCTURES IN SEISMIC AREAS is a comprehensive overview of recent developments in the field of seismic resistant steel structures. It comprises a collection of papers presented at the sixth International Specialty Conference STESSA 2009, held in Philadelphia, Pennsylvania, USA, in August 2009. The latest progress in both theoretical and experimental research on the behaviour of steel structures in seismic areas is presented under the followings themes:- Performance-Based Design of Structures;- Seismic, Wind and Exceptional Load;- Material Behaviour;- Member Behaviour;- Connection Behaviour;- Global Behaviour;- Analytical and Experimental Methods;- Mixed and Composite Structures;- Passive and Active Control;- Strengthening and Repairing;- Codification;- Design, Fabrication and Practice.The intention of the book is to transfer the findings of scientists and experts involved in research, codification and application to the common practice. This book provides a complete framework of the most recent trends in the field of steel structures in seismic areas, with particular reference to the utilisation of multi-level performance based design concepts, the analysis of factors influencing the steel structure behaviour during strong ground motions, minimizing earthquake damage, seismic retrofit, the collapse behavior of steel structures, recent develpments in advanced large-scale experimental techniques, and the utilization of large-scale seismic testing facilities.The book is a valuable resource for engineers, scientists, and Ph.D. students in Civil Engineering, Earthquake Engineering, Structural Engineering, Steel Construction, Steel Development, and Building Disaster Prevention.