Evaluation of Seismic Safety of Buildings. Report No. 8. Inelastic Response Spectrum Design Procedures for Steel Frames.

摘要

Reported is an evaluation of aseismic design procedures based upon inelastic response spectra. Steel frames of different heights are designed for a desired level of yielding using elastic modal analysis. Responses in terms of maximum ductility ratios are computed for simulated ground motions derived from the design spectrum. Both shear beam models and point hinge models are utilized and compared. Results are given in terms of maximum local and story ductility ratios as compared with the design values. The effect of gravity loads on the computed response and the effect of including such loads in the design procedure and investigated. In general,local ductility ratios exceed the desired design level. The use of seismic load factors to improve performance is investigated. It is concluded that the inelastic response spectrum approach is promising,but that further study and development are necessary before it could be adopted with confidence.