Thorough investigation of vertical seismic excitation effects on a high detailed bridge

Field evidences of recent earthquakes show that many bridge damages are due to the direct compression or tension in columns and also some of the flexural and shear failures that are probably caused because of the variation in axial forces of columns. Investigations show that these damages could not be occurred only due to the horizontal seismic excitations, and thus the vertical component of earthquake excitations must be the main reason that is usually ignored in design and analysis processes. In this study in order to accurateyl investigate the importance of vertical seismic excitation, a series of nonlinear time history analyses are conducted on a detailed three-dimensional model of a multi-span simply supported bridge using a suite of representative ground motions of the region. The results showed the impressive influences of vertical excitation on the bridge responses during the seismic excitations. Thus it is very imperative to extend practical methods in future studies considering the vertical seismic excitation besides horizontal excitations during design and analysis processes

Keywords:

bridge , vertical seismic excitation , nonlinear time history analysis