Evaluation of Seismic Performance of Moment Resisting Frames considering Vertical Component of Ground Motion

Abstract

The design of structures to withstand seismic loading is primarily governed by horizontal ground motion, and the effects of vertical ground motion have long been deemed unimportant or secondary. However, an emerging body of evidence suggests that vertical ground motions have great destructive potential, especially for certain site conditions.Using nonlinear dynamic analyses, the seismic performance of frames is evaluated by simultaneously applying the horizontal and vertical components of earthquake motion. Three special moment frames are subjected to 15 recorded near-field earthquake motions and the results of the analyses are used for performance evaluations, based on FEMA 350 guideline. It is found that, within the elastic range of response, considering the vertical component of ground motion, does not alter the dynamic structural response significantly, however, some tangible differences emerge in nonlinear range of response once the horizontal component of ground motion is accompanied by the vertical component.