SEISMIC BEHAVIOR AND DESIGN OF STEEL SHORT AND MID-SPAN BRIDGES

This paper provides information on seismic design of short and mid-span steel bridges with spans of up to about ۲۵۰ meters. The current codes on seismic design of bridges, in almost all countries, are based on equivalent static force method and the use of Response Modification Factors, sometimes called reduction factors. The paper first discusses the seismic behavior and the current approach to seismic design of steel bridges. Then, the concept of using Response Modification Factors is discussed. Finally, the Response Modification Factors developed by the author and proposed for inclusion in the specifications for seismic design of steel bridges are discussed and presented.