Análise de parâmetros globais de projeto em edifícios com estrutura de concreto armado

Abstract

The verification of reinforced concrete buildings is carried out by local analysis and by global analysis. In the local analysis are evaluated the effects of deformations in the isolated elements. Already in the overall analysis of the behavior is evaluated considered the structure as a whole. Normally, this overall verification is done through design parameters, which allow to maintain control of problems that can affect the safety or performance of buildings of reinforced concrete. By means of computer systems, it’s possible to obtain, fairly quickly, a series of parameters that offer virtually complete diagnostic of the answers that the structures will present when external actions submitted, like the wind or the vertical loads. Howeverit is not enough process structural models and get results, it is necessary to interpret what these mean and verify its validity. Therefore, this study was done with the intention to contribute with the referring studies the overall analysis of the structures, based on the design parameters to know: 𝛾𝑧 and 𝑅𝑀2𝑀1 coefficients, overall critical load factor of buckling, horizontal displacements, fundamental frequency and acceleration. Are studied several cases of idealized structures, with the objective to evaluate the relation between these parameters and propose simplified equations for calculating the overall critical load factor and the fundamental frequency from the 𝛾𝑧 coefficient. Furthermore, are analyze some real building structures aiming to evaluate the proposed equations and draw comparisons with the limits recommended by Brazilian standards. For the processing of structures were used two analysis programs, the TQS and the SAP2000. Generally speaking, the equations that relate the 𝛾𝑧 coefficient with the critical load factor and with the fundamental frequency showed satisfactory results. For displacement and acceleration, could not establish equations due to inexistence of relation of these as the 𝛾𝑧. As for the normative limits, found to be that even structures that fulfill the safety criteria for the overall instability, nevertheless these may present problems related to excessive horizontal displacements and vibrations perceptible to the human being.