Aspectos normativos de ações e análises sísmicas em edificações

Abstract

Despite being located in the middle of the stable South American tectonic plate, Brazil is a seismically active country. The effects of seismic actions cannot be ignored in structural designs and the Brazilian standard NBR15421:2006 regulates the procedures for the dynamic analysis of structures in order to establish verification parameters for possible earthquake occurrences in the Brazilian territory. This work presents a review of the basic and fundamental concepts of seismic waves and quakes to understand the seismological factors involved in an earthquake. It also presents concepts of structural dynamics necessary to understand the different methods presented in the design codes, including the definition of the necessary parameters to perform the referred analysis. The definition of the parameters and the seismic analysis methods are reviewed in the Brazilian (NBR15421:2006), American (ASCE 7-16) and European (EN 1998-1:2004) design codes, comparing their procedures and values used in their procedures. The main objective of this work are the seismic analysis of three structural systems in reinforced concrete. The first one consists of an inverted pendulum structure, the second with a 3-storey Shear Building, and consequently 3 degrees of freedom, and the third being the seismic analysis of a 12-storey building on a three dimensional model with computational aid. These structures are analyzed by the Simplified Method, Equivalent Horizontal Forces Method, Spectral Method and Time History Method (Direct Integration), with the help of computational softwares to obtain the necessary data to perform the dynamic analysis, according to the standards presented in this work