Towards improving the seismic hazard map and the response spectrum for the state of RN/Brazil

Petrus Gorgônio Bulhões Da Nóbrega,Bruno Rammon Silva Souza,Selma Hissae Shimura Da Nóbrega

doi:10.1590/s1983-41952021000300002

Petrus Gorgônio Bulhões Da Nóbrega, Bruno Rammon Silva Souza + Show 1 more

Open Access

https://doi.org/10.1590/s1983-41952021000300002

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Abstract

Abstract Although Brazilian seismic activity is defined as low to moderate, it is known that intraplate earthquakes can also be associated to high intensities. In Brazil, the state of Rio Grande do Norte (RN) is one of the most seismically active areas, but there is no specific study to evaluate the seismic hazard in this region. This paper presents analyses towards improving the seismic hazard map, the peak ground acceleration value and the response spectrum of RN. The methodology is based on Probabilistic Seismic Hazard Analysis, comparing the results to the design criteria defined in the Brazilian code NBR 15421:2006 (Design of seismic resistant structures – Procedure). The analyses show that, in general, the code sets conservative values for the peak ground acceleration and for the design response spectrum; however, related to this last one, the shape is quite different.

Highlights

The expression “hazard”, in common words, means the situation or agent that can cause harm, damage or an adverse effect to humans, properties, or the environment
The seismic hazard analysis, which is associated to the evaluation of the potential earthquake consequences, is important and proposed as the main theme of this paper, focusing the Rio Grande do Norte (RN), a state of the Brazilian Northeast region
The purpose of the analyses is to evaluate if the design criteria presented by NBR 15421 are consistent with the RN reality, whether in terms of the maximum acceleration values, or in the form and values of the design response spectrum

Summary

Introduction

The expression “hazard”, in common words, means the situation or agent that can cause harm, damage or an adverse effect to humans, properties, or the environment. The hazard is real, if it occurs here and or potential, when it may happen in short, medium or long term, depending on the nature of its causes. In this context, the seismic hazard analysis, which is associated to the evaluation of the potential earthquake consequences, is important and proposed as the main theme of this paper, focusing the Rio Grande do Norte (RN), a state of the Brazilian Northeast region. Its geology and geographic position, in the middle of an extensive tectonic plate, contributes to a greater seismic stability than that

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