Parametric analysis of vibration in reinforced concrete floors
William Ferreira Miranda1; Graciela Nora Doz de Carvalho1; Suzana Moreira Avila1
1 Universidade de Brasília, UnB, Brasília - DF
doi:10.20906/CPS/CILAMCE2017-0505
Resumo
The advances in structural engineering have been providing structures with large spans with increasingly slender dimensions, however, these become more susceptible to phenomena that until now were not common to them. This occurs in cases of excessive vibration in reinforced concrete structures for certain types of use. In view of the need to satisfactorily provide the good performance of the structures in their service situations, it is sought to understand the influence of the various design decisions on the dynamic parameters of the structure and in its response when submitted to frequent loadings while considering the particularities of the reinforced concrete. Among the structural typologies most used in reinforced concrete floors (slabs supported on beams, flat slabs with and without capitals and waffle slabs), a study will happen regarding which ones are most susceptible to vibrations and which design decisions most affect the dynamic parameters within the same typology. Characteristics of reinforced concrete such as cracking, creep, non-constant reinforcement in the sections, time-varying resistance and modulus of elasticity are fundamental considerations in static analysis. This consideration is often used in floors through the usage of computational tools based on grillage analysis, so this type of computational modeling will be applied in the study of the dynamic parameters in order to make feasible the modeling of real pavements as well as to use this large volume of data originated in the static analysis, during the dynamic verification. Based on the study of these parameters, it is desired to conclude if the ABNT rules, although succinct regarding floor vibrations, is enough to avoid the occurrence of this type of phenomenon, and if excessive vibrations may be the limiting factor of dimensioning in comparison to static deformation and stress.
Palavras-chave: Dynamics; Floor vibrations; Reinforced Concrete; Vibration Frequencies; Grillage analysis