Vibration of Dance Floor 1

[sgdon]

I have seen people adding some percentages of live and superimposed dead loads to the mass of the floor. The model is then run (in Etabs) to obain the eigenvalue, i.e. natural frequency. As we know natural frequency is not a function of external loads, what is the rationale of considering the live loads here?

Thanks

 

[Robertmet]

Somewhere in my dim dark past I remember being at a dance hall . They solved the problems by supporting the building on piles of tires to absorb vibration !...Natural frequency ? a year ago while tearing don the truss bridge here , the used a excavater with jack hammer on the support. They hit the resonant frequency and the whole truss vibrated loudly at about 2 cycles per second !!

 

[miecz]

Robertmet- Thrall's Hall?