Analysis of accidental loads on garage floors

Resumo

The focus of the paper is the analysis of live loads used for garage floors considering the recommendations of national and international regulations on the load values to be applied on those floors. The Brazilian regulation NBR 6120/1980 [1], on the subject, does not specify concentrated loads while Euro Code [2] and IBC [3] international regulations recommend that distributed and concentrated loads shall be considered. Currently, waffle slabs are widely used in garage floors. In this context, considering the standards of the most used vehicles in the country, certain questions arise: are the values of the distributed loads given by regulations suitable for slab design? Or is it necessary to correct these loads to account for concentrated loads on the order of 8.5 kN corresponding to a utility vehicle tire? The objective of the present study is to find answers for those two questions through parametric analysis involving the main parameters of a waffle slab, which are: side ratio  (lambda), spacing between the main ribs and, scheme of slab support (one-way or two-way). The set of simulations shows that the loads recommended by the mentioned regulations need to be corrected when used in garage floors to reproduce the effect of the loads concentrated in the tires of utility vehicles.