Theory and Design of Seismic Resistant Steel Frames is a state-of-the-art summary of recent developments in the behaviour, analysis and design of seismic resistant steel frames. The book provides advanced students, researchers and professionals in civil and structural engineering with the basic principles upon which the modern seismic codes are based. It deals with all recent developments in seismic design of steel frames, and illustrates how these can be used to improve design rules. The book is much more than a simple background volume, giving the most recent results which can be used to improve the codified recommendations for steel structures in seismic zones. It contains new material which cannot be found in any standard reference book on seismic engineering. The important issues in seismic design of steel frames, such as the evaluation of the local and global ductility, and the evaluation of the q-factor, are fully discussed. In addition, the authors closely examine the influence of second order effects and connnection behaviour. Particular attention is devoted to the problems related to the influence of geometric configuration and of random material variability.