Evaluation of floor vibration properties using measurements and calculations

Abstract

Timber floor constructions are very common in the Nordic countries, for instance in single- and multifamily buildings. But building with wood is increasing in popularity for other building categories and there is wider interest in increasing the span width of wooden joist floors. Static and vibrational performance become crucial for serviceability of timber floors and often limit the design; however, constructors and designers want to increase the floor span width. To meet these challenges, reliable design methods are required and have therefore become a focus in many countries.

This paper presents results from a number of measurements of different joist floor constructions. Parameters measured have also been calculated according to given equations and relevant methods. Both calculations and measurements include 17 laboratory objects and four field objects. The objects represent a huge variety of solutions and therefore a large spread of results. The main reason for the selection of floor solutions was to expand the possibilities and test the methods more than tuning current solutions into satisfactory floor vibration perception.

The data and resulting analysis in this paper highlight benefits and limitations concerning relevant parameters for evaluation of floor vibration perception. According to this work, it is not possible to verify the Eurocode method with respect to accuracy, and the link to perception of floor vibrations is rather low. Another method should be used or developed for the future. Results presented in this paper show that sufficient accuracy may be achieved using parameters from the Hu and Chui (2004) method. Experiences from Norway over the last five years are also promising regarding evaluation of floor vibration perception using this method. However, attention should be given to floors with significantly lower damping properties and/or significantly higher (modal) masses. Damping properties or an alternative parameter taking a longer time interval of the vibrations into account should be considered.