Floor Vibration 1

[RDM]

Can anyone recommend a good reference for analysis of floor vibration for steel bar joists supporting a concrete floor slab? Thanks.

 

[Taro]

A good one is AISC Steel Design Guide 11, "Floor Vibrations Due to Human Activity", by Thomas Murray, et al.

 

[dzyn]

Taro, I'm in the midst of trying to design a floor system for a church sanctuary using design guide 11. I'm finding it next to impossible to meet the 0.05% acceleration limit using a damping ratio of 0.02. (The church will have movable seating.) I'm all ready using 5" (NW) concrete total thickness on 1 1/2" steel deck. The steel keeps getting heavier and/or beam spacing tighter to get even close. Any suggestions? Do you know if this is typical for this type of system to meet the strict vibration criteria? The floor below is devided into classrooms, do you think it is wise to adjust my damping ratio to .03 in this case -i.e. ceilings and duct work below?

 

[emceditor]

dzyn,

Besides increasing mass, try maximizing the joist spacing. The more load per joist the lessor the vibrations. Check with the Architect whether you can have a contact ceiling. That helps too. I prefer a 6 1/4" normal weight concrete slab on composite deck on composite wide- flange steel beams spaced at 6-ft to 8-ft o/c for churches.