ADEQUACY OF ACCIDENTAL ECCENTRICITY IN ACCOUNTING FOR THE EFFECTS OF THE TORSIONAL COMPONENT OF EARTHQUAKES ON THE SEISMIC DAMAGE

摘要

The influence of the torsional component of earthquake excitations on the response of reinforced concrete (R/C) structures is the aim of this work. The structure that is going to be examined is asymmetric in plan and regular in elevation 5-storey R/C building. In most studies, seismic input is modeled only using the translational components of the ground acceleration, while the torsional one is ignored. This is due to the observation that the torsional component has minimal effect on low-rise buildings. Hence, the accelerometers used would not measure it, leading to a lack of records. Nowadays, technology provides such instruments and relative records have been made available. Indicative of this is that design response spectra for rotational components are introduced in the design codes. In this paper, nonlinear dynamic time history analyses of the selected R/C building are performed (a) considering the torsional component of the excitation and (b) without it. From the numerical results it is shown that the impact of torsional component in structural response must be taken into account. Moreover, the extracted results indicate that the provided by Eurocodes values for the accidental eccentricity can effectively capture the effects of the torsional component on the seismic damage.