Comparative evaluation of the Seismic Bidirectionality according to the Spectral Modal Analysis and Linear Analysis Time History, in Staggered Buildings of Armed Concrete

Authors

Orihuela, Junior

Bermudo, Harol

De La Cruz, Rodrigo

Abstract

In a traditional seismic analysis, the existence of seismic forces acting unidirectionally in two or three independent directions is mainly considered. However, it has been shown that the nature of seismic motion is erratic, i.e., seismic actions act in different directions towards the structure. In the present study, the responses of 4 structural models with a staggered architectural geometry are analyzed using a Spectral Modal Analysis (SMA) and a Linear Time History Analysis (LTHA), with incidence angles with increments every 10° in order to show the effects of the seismic bidirectionality versus the unidirectional one through the maximum responses of the models. The results obtained show that, for the Spectral Modal Analysis (SMA), the largest angle of incidence where the largest responses are presented is 45° for the 4 models, and for the ALTH the angles of incidence are variable. Likewise, in both dynamic analyses, evaluating the seismic bidirectionality, responses of 10 to 40% more than a unidirectional analysis are obtained.