Seismic collapse capacity-based evaluation and design of frame buildings with viscous dampers using pushover analysis

A simplified procedure is developed for estimating the seismic sidesway collapse capacity of frame building structures incorporating linear and nonlinear viscous dampers. The proposed procedure is based on a robust database of seismic peak displacement responses of viscously damped nonlinear single-degree-of-freedom systems for various seismic intensities and uses nonlinear static (pushover) analysis without the need for nonlinear time history dynamic analysis. The proposed procedure is assessed by comparing its collapse capacity predictions on 1,190 different building models with those obtained from incremental nonlinear dynamic analyses. A straightforward collapse capacity-based design procedure aimed at achieving a predetermined probability of collapse under maximum considered earthquake event is also introduced for viscously damped structures without extreme soft story irregularities.