| The present study is related to the incidence of vertical seismic excitation on the structural response of civil engineering structures. Three major research axes were considered: the characteristics of vertical ground motions, the effect of vertical accelerations on steel moment-resisting frames, and finally the effect of the vertical excitation on the sliding response of a gravity dam.; First, a review of previously published work on vertical seismic accelerations is presented. The following aspects are considered: (a) the seismological aspect, (b) historical evidences, (c) experimental evidences, (d) numerical evidences, and (e) codes of practice.; The study on the characteristics of the vertical accelerations was performed on a series of historical accelerograms that were subdivided according to the NBCC (1995) definition of the a/v ratio.; For these series of historical accelerograms, indices such as different measures of duration, predominant period, as well as spectral ordinates were computed and compared. Based on these results, a method consisting of shifting and reducing the horizontal spectrum to obtain the vertical one was proposed. (Abstract shortened by UMI.)... |
