HUMAN-INDUCED VIBRATIONS OF STEEL-CONCRETE COMPOSITE FLOORS SUBJECTED TO HUMAN RHYTHMIC LOADS

Resumo

The increasing incidence of building vibration problems due to rhythmic activities led to
need of a specific design criterion for rhythmic excitations. This was the main motivation for the
development of a design methodology centred on the structural system dynamical response submitted
to dynamic loads due to human rhythmic activities. This way, this paper investigated the dynamic
structural behaviour of steel-concrete composite floors subjected to the human rhythmic activities,
when the human comfort is considered, incorporating the effect of the people-structure dynamic
interaction, based on the use of biodynamic models representative of the individuals. The dynamic
loads were obtained through experimental tests with individual carrying out rhythmic activities. The
proposed analysis methodology adopted the usual mesh refinement techniques present in the finite
element method (FEM) simulation implemented in the ANSYS program. The investigated structural
system was used based on a health club facility with an adjacent aerobics area. The floor system
consists of long span joist supported by concrete block walls. The floor effective weight was estimated
including people practicing aerobics and also sitting in the health club internal area. The floor effective
weight was estimated to be equal to 3.6 kPa, including 0.6 kPa for people activities. The effective
composite moment of inertia of the joists was selected based on its required strength, i.e.: 1.1x106
mm4. The peak acceleration values were compared to limits proposed by design codes, based on
human comfort and those values were not satisfied. Such fact has indicated that these rhythmic
activities could generate peak accelerations that surpass design criteria limits developed for ensuring
human comfort.