vibration longspan trusses soccer arena

[calculor1]

Working on project where a client would like to build an indoor soccer arena over 2 small indoor ice rinks. The trusses for the soccer arena are approximately 75 ft clear span and they are spaced at 5 ft oc. The trusses have double top chord and single bottom chord; the trusses are supported on steel beams which have a maximum span of 15ft. The slab consists of 3" deck with 3" topping slab. My problem using DG11 is that I can't satisfy the natural frequency requirement using, I calculate the natural frequency to around 2.6hz which is significantly less than the minimum recommended. By the way the exterior of the will be a fabric type structure. Anyone have any suggestions?

 

[Archie264]

Yes, I imagine vibration would be an issue in that situation and kudo's to you for checking for it...sometimes that gets overlooked. Having said that, I'm not sure what the solution would be, other than a (perhaps considerably) thicker slab and/or some other way to stiffen the system. I'd be curious to learn how how you decide to address it.