美国钢结构设计手册 LATERAL-FORCE DESIGN.pdfVIP

SECTION 9 LATERAL-FORCE DESIGN Charles W. Roeder, P.E. Professor of Civil Engineering, University of Washington, Seattle, Washington Design of buildings for lateral forces requires a greater understanding of the load mechanism than many other aspects of structural design. To fulfill this need, this section provides a basic overview of current practice in seismic and wind design. It also discusses recent changes in design provisions and recent developments that will have an impact on future design. There are fundamental differences between design methods for wind and earth-quake loading. Wind-loading design is concerned with safety, but occupant comfort and service- ability is a dominant concern. Wind loading does not require any greater understanding of structural behavior beyond that required for gravity and other loading. As a result, the pri- mary emphasis of the treatment of wind loading in this section is on the loading and the distribution of loading. Design for seismic loading is primarily concerned with structural safety during major earthquakes, but serviceability and the potential for economic loss are also of concern. Earthquake loading requires an understanding of the behavior of structural systems under large, inelastic, cyclic deformations. Much more detailed analysis of structural behavior is needed for application of earthquake design provisions, because structural be- havior is fundamentally different for seismic loading, and there are a number of