Recalibration of low seismic excitations in Brazil through probabilistic and deterministic analyses: Application for shear buildings structures

Abstract

Brazil has a low level of seismicity compared to several other regions in the world; however, some significant earthquakes occurred. In this article, four techniques have been used to define new seismic inputs: probabilistic seismic hazard, elastic spectra, synthetic spectra, and artificial accelerograms. To carry out the probabilistic analysis, new seismogenic zones for southeast Brazil established in 2018 have been implemented. Elastic response spectra follow the Brazilian code, whereas the synthetic response spectra have been defined by using attenuation equations. Finally, the artificial accelerograms have been developed using analytical models. Modified Brazilian elastic response spectra by considering the results of the probabilistic seismic hazard analyses are proposed. Artificial accelerations, consistent to the non-modified and modified elastic response spectra, show that for non-modified spectra the structural response increases of ~2.50 times. Data for seismogenic zones and specific analytical equations to obtain the probability of non-exceedance of the spectral accelerations have been adapted for this study. An application for shear buildings was analyzed. © 2022 fib. International Federation for Structural Concrete.