Floor Vibration in Steel Mezzanine
Floor Vibration in Steel Mezzanine
(OP)
Running a steel vibration analysis to get the ap/g down to under 0.5% usually results in much heavier sizes which can be rather expensive. Most clients don't want to pay for that. How important is it to meet that criteria? For example, would there be a noticeable difference between 0.8% and 0.5%?
Thanks for any help.
Thanks for any help.






RE: Floor Vibration in Steel Mezzanine
RE: Floor Vibration in Steel Mezzanine
Do you want me to design it for good vibration criteria, or not?
It is ultimately a serviceability issue. It's the same as asking for L/720 or code minimum deflections.
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: Floor Vibration in Steel Mezzanine
1) You explaining the situation to your client.
2) Your client accepting the risk.
If your framing is such that it would make sense, your client can roll the dice and then possibly add a mass damper to the girders at some point in the future to remedy any vibration issues that arise. I know at least one marquis structural firm that will routinely include a mass damper on their feature stair designs even when those stairs have been designed for vibration. It's just so hard to predict vibrations issues that it's prudent to give yourself an easy way to fix them should problems arise.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Floor Vibration in Steel Mezzanine
RE: Floor Vibration in Steel Mezzanine
Kootk, I'm not too familiar with how a mass damper would be installed or what it even looks like. Could you explain how that would work?
RE: Floor Vibration in Steel Mezzanine
Elsewise, you could specify on your drawings that when renovated for office space they need to add an additional couple inches of concrete. The 50psf reduction in live load would afford you quite a bit of additional concrete thickness. But it's hard to enforce.
RE: Floor Vibration in Steel Mezzanine
The detail below is the one that I was thinking of. Pretty low tech really. Still, if you pitch a mass tuned damper on an industrial mezzanine, expect to see some raised eyebrows.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Floor Vibration in Steel Mezzanine
RE: Floor Vibration in Steel Mezzanine
Did you consider the Ecospan system to develop composite action? Those studs that vulcraft came up with are a pretty good idea.
RE: Floor Vibration in Steel Mezzanine
Yeah, I imagine that would vibrate. Discuss it with the owner but remember that your name is attached to it as well. What happens when the owner's engineer finds a new job two years from now and his replacement, knowing nothing of the history and tired of hearing tenants' complaints, pulls your phone number off the drawings and calls you up to "fix" your design? A bit far-fetched, perhaps, but if the design is to be skinnied down for budgetary purposes make sure you protect yourself with documentation.
That said, since you mentioned it might be used for offices in the future my recommendation is to try to convince the owner to let you beef it up now. Office workers are particularly prone to noticing vibration and if they are to be used for offices someone will never hear the end of it. My $.02 worth.
RE: Floor Vibration in Steel Mezzanine
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Floor Vibration in Steel Mezzanine