tailieunhanh - Seismic Design of Steel Bridges

Seismic Design of Steel Bridges Introduction Seismic Performance Criteria • The R Factor Design Procedure • Need for Ductility • Structural Steel Materials • Capacity Design and Expected Yield Strength • Member Cyclic Response 39 Ductile Moment-Resisting Frame (MRF) Design • Introduction • Design Strengths • Member Stability Considerations • Column-to-Beam Connections Chia-Ming Uang University of California, San Diego Ductile Braced Frame Design Concentrically Braced Frames • Eccentrically Braced Frames Keh-Chyuan Tsai National Taiwan University Stiffened Steel Box Pier Design Introdcution • Stability of Rectangular Stiffened Box Piers • Japanese Research Prior to the 1995 Hyogo-ken Nanbu Earthquake • Japanese Research after 1995 Hyogo-ken Nanbu Earthquake. | Uang C. Tsai K. Bruneau M. Seismic Design of Steel Bridges. Bridge Engineering Handbook. Ed. Wai-Fah Chen and Lian Duan Boca Raton CRC Press 2000 39 Seismic Design of Steel Bridges Chia-Ming Uang University of California San Diego Keh-Chyuan Tsai National Taiwan University Michel Bruneau State University of New York Buffalo Introduction Seismic Performance Criteria The R Factor Design Procedure Need for Ductility Structural Steel Materials Capacity Design and Expected Yield Strength Member Cyclic Response Ductile Moment-Resisting Frame MRF Design Introduction Design Strengths Member Stability Considerations Column-to-Beam Connections Ductile Braced Frame Design Concentrically Braced Frames Eccentrically Braced Frames Stiffened Steel Box Pier Design Introdcution Stability of Rectangular Stiffened Box Piers Japanese Research Prior to the 1995 Hyogo-ken Nanbu Earthquake Japanese Research after 1995 Hyogo-ken Nanbu Earthquake Alternative Schemes Introduction In the aftermath of the 1995 Hyogo-ken Nanbu earthquake and the extensive damage it imparted to steel bridges in the Kobe area it is now generally recognized that steel bridges can be seismically vulnerable particularly when they are supported on nonductile substructures of reinforced concrete masonry or even steel. In the last case unfortunately code requirements and guidelines on seismic design of ductile bridge steel substructures are few 12 21 and none have yet been implemented in the United States. This chapter focuses on a presentation of concepts and detailing requirements that can help ensure a desirable ductile behavior for steel substructures. Other bridge vulnerabilities common to all types of bridges such as bearing failure span collapses due to insufficient seat width or absence of seismic restrainers soil liquefactions etc. are not addressed in this chapter. Seismic Performance Criteria The American Association of State Highway and Transportation Officials AASHTO .