Workout Room Vibration - No Aerobics or weights

[Nickel05]

We're currently designing a three story high-end office building with a small workout room on the first elevated floor. The structure is steel composite beams with long spans in short bays (30' girder spans and 58' beam spans). The workout room itself has three treadmills and two stationary bikes. The room is only 27'x27' so it's doubtful it will ever see any type of "aerobics" or high impact class.

The issue we're having is if we follow the DG11 recommendations for aerobics we're killing the structure. We know the owner wants a high-end building and would not be pleased with any vibration in the surrounding offices, but we're wondering if we truly fall under the aerobic restraints. Is there some happy medium between Rhythmic and Walking analysis that we could use and still maintain the dignity of the structure without killing the budget?

Any thoughts would be appreciated.

 

[strucguy]

Make sure to design all your bays for a minimum fundamental natural frequency of 9 Hz and an acceleration limit of 0.06 g. Using the criteria for aerobics is an overkill in this specific case.

 

[msquared48]

Depending on how "High End" the owner wants to make it, would it be possible to vertically and laterally separate the workout room from the rest of the structure since it is on the first floor?

Mike McCann
MMC Engineering

 

[Nickel05]

strucguy - I agree it's overkill. We use Floorvibe and I can change the frequency and acceleration limit as you've suggested. Should I still be considering it as Rhythmic?

msquared48 - there is a basement garage below so that's probably not an option.

Thanks

 

[UcfSE]

There's plenty of room for aerobics or some other exercise class, even if its a small class. How do you know the owner would not accept a lease from such a class in a few years?

 

[Nickel05]

UcfSE - it's a private workout room for employees of the building Owner. It's possible they would consider it but highly unlikely.

 

[Archie264]

It might be tough to minimize vibrations in a 58' span to the point that they aren't noticeable. Frankly, it sounds like a challenging problem.

 

[strucguy]

I second Archie264's opinion. Try reducing your bay sizes by adding columns. Tell Arch that the beams can get insanely heavier and deeper if they don't comply. Also, it would be a good idea if the owner can be brought to the table to clarify expectations. Give in writing the design criteria being used to address vibration and ask them if they have any issues with it. Also, suggest owner to hire a vibration consultant if they need additional guidance. We learnt this the hard way.

 

[hokie66]

Agree with Archie264 and strucguy. The architect and owner need to look at the layout of the parking garage. It sounds like your column spacing requires spanning across a traffic aisle and parking on both sides. This seems to be common in the US, but it does not lead to an efficient structural system. Put the columns between the cars, and you will save a lot of headroom, and make the structure stiffer and more economical.