A blog post by Aleksandar Pavic

The New Civil Engineer has just published a piece with me talking about the rapidly developing tension between the need for the lean design of long-span building floors in a climate emergency and their vibration serviceability. It’s a rather fundamental tension, though, caused by a simple application of the 2nd Newton’s Law dictating that lighter structures will vibrate more with all other things being equal. Hence modal mass in the denominator of all acceleration calculation formulas.

Of course, this tension can be resolved by making building floors with much shorter spans, but it is often forgotten that such a strategy also has many very serious shortcomings related to human factors in buildings, space utilisation, cost and time to build, architectural appeal, foundations, etc. This is why floor spans kept growing and growing in the last 50 years, regularly reaching 15m+ nowadays in many developments.

The brand new VSimulators and floor active mass dampers are two not previously tried and now commercially available innovations related to floor vibration serviceability. Both were commercially and operationally launched in 2021. They are potential game-changers by enabling both long spans and lean design of omnipresent building floors of which the world needs 230bn m2 (one Paris every week) by 2040. They can tackle the two most difficult elements of the contemporary floor vibration problem:

1) VSimulators can help establish a new generation of objective floor vibration serviceability criteria pertinent to humans to replace their currently erratic counterparts based on often too crude, relaxed, and scientifically not proven R-factors for which there is growing evidence that they may lead to unexpected problems with modern lightweight and code-compliant floors, and

2) Floor active mass dampers can replace huge amounts of structural mass and stiffness to control resonant floor vibrations by providing an unprecedented high level of damping only where and when needed in a manner and in such large amounts that were previously not possible.

VSimulators virtual view of a generic open plan office featuring long floor spans