Case Study: Comparing Measured and Finite Element Modelled Footfall Vibration Levels in a New Research Building

Résumé

Occupant footfalls are often the most critical source of floor vibration on the elevated floors of buildings.  In research facilities employing high resolution electron microscopes, this issue can be critical.  Modifications to reduce vibration impacts in completed buildings typically require major changes to the mass, stiffness or damping of the floor system. As such, vibration impacts on sensitive equipment need to be addressed during the design stage. There are various methods available for predicting vibration levels from footfalls. The Finite Element (FE) approach presented in The Steel Construction Institute (SCI) P354 and The Concrete Centre (CCIP) 016 methodologies, which considers the interaction of many modes, is generally accepted to be more accurate than other methodologies that rely on simple beam theory.  A case study is presented where measurements were performed on bare concrete floors, prior to completion of the Brimacombe Building addition at the University of British Columbia. The facility requires a low vibration environment to support world leading quantum materials research. The measured vibration levels are compared with the values predicted by the SCI P354 and CCIP 016 methodologies to assess the accuracy of the prediction methodology in the absence of damping inherent in completed buildings.