Probabilistic Limit States Design of Moment-Resistant Frames Under Seismic Loading

This paper focuses on the development of a methodology for the optimal probabilistic limit states design of seismic-resistant steel frames. A mechanism for allowing the designer to include the effects of uncertainties and multiple design objectives in the design process is described. The frame's performance is assessed on the basis of its statistical response to gravity loads alone, gravity loads plus a family of moderate earthquakes, and finally, gravity loads combined with an ensemble of rare severe earthquake ground motions. Design objectives include the frame volume, minimum story drifts and maximum dissipated energy. The methodology is illustrated via the design of a three story, single bay, moment resistant steel frame using a computer-aided design system called DELIGHT. STRUCT.