The Effect of Sequential Excitations on Asymmetrical Reinforced Concrete Low-Rise Framed Structures

Abstract

In the current research, the elastoplastic behaviour of symmetrical and asymmetrical reinforced concrete buildings is explored by dynamic analysis. The used ground excitations are of sequential type, which is found in the literature to possibly strongly affect the dynamic structural behaviour. The contemporary seismic codes neglect the impact of sequential earthquakes on the seismic response, highlighting a scientific gap necessary to be studied. Within the scope of this study, ordinary 3D reinforced concrete low-rise building frames are forced to sequential ground excitations, as well as to a respective single-occurrence corresponding ground excitation, for comparability reasons. In the present dynamic analyses, the two horizontal directions of the excitations, along with the vertical one, are included in the analysis input. The nonlinear behaviour of reinforced concrete sections under strong strain is considered in the present analyses. The geometrical in-plan asymmetry of the 3D models is expressed by a simply defined ratio. Selected unitless resulting plots of the current dynamic analyses are presented and appropriately discussed given the relative geometrical asymmetry. The role of sequential ground excitations on the dynamic response is recognized, along with the role of simple geometrical symmetry or asymmetry, in the resulting response plots. Thus, useful conclusions are acquired, pointing to remarks on the geometrical structural design helpful for the development of recommendations of seismic provisions.