Influence of vertical seismic component on the response of reinforced concrete regular planar frames

The objective of the present paper is to investigate the influence of the vertical seismic component on the response of reinforced concrete regular planar frames. For this purpose, 20 reinforced concrete single-and multi-storey frames with various span lengths are designed according to Eurocodes 2 and 8 and analyzed by means of inelastic dynamic analysis for 20 recorded near-fault ground motions. In particular, two series of time-history analyses are conducted: one taking into account the horizontal seismic component only and a second consid-ering concurrent action of horizontal and vertical components. For each analysis, the values of representative response quantities (axial forces, displacements, plastic hinge rotations) are calculated. The differences of the response quantities resulting from the two series of analyses provide a measure of the vertical seismic component impact on the response of regular planar frames. The whole study demonstrates that the role of the vertical ground motion is quite underestimated by modern seismic codes.