Design Live Load for Elevated Tennis Courts

[conradlovejoy]

Trying to run some prelims to win a bid for an site expansion so I don't have tons of info. Part of the expansion is to add parking below grade and use the deck as tennis courts. I feel that the closest category in ASCE7 is the "bowling alleys or other recreational areas" at 75psf. I feel this is justifiable, however I am concerned that the worst case could be that at some random point the courts are used for some public assembly that would more fit into a 100psf category. Has anyone else ever had a similar issue when trying to justify LL?

 

[dik]

I would think 100 psf minimum... but, dynamics would be a much bigger issue.

Dik

 

[conradlovejoy]

The rationale behind not using 100 is that 98% of the time (or more) there will be about 12 people on the deck. The rationale for using 100% is that other 2% when they might use the courts for some ceremony or whatnot. It feels overly conservative to punish the design for 'maybes' like that. The "occupancy" is for approximately ten to twenty people to be playing tennis at one time...not to have a public gathering. I can see it both ways and know that increasing the live load 25psf will have a pretty sizable effect on the design.

 

[jayrod12]

I would think as dik said deflection and vibration would be the largest issue. I would likely design it for the 100 psf and then not need to worry about those issues knowing that for 98% of the time it would be no where near loaded.

 

[hokie66]

I doubt that it will make much difference, costwise. Formwork, placement, finishing all the same. Maybe a bit extra in concrete and/or reinforcement. So I would just use 100.

 

[oldestguy]

Then along comes a new owner that wants to park cars there.

 

[dik]

OG... then use 50 (for parking garages)? If long spans, then vibration will likely govern... I'd still use 100...

Dik

 

[JAE]

If you read the commentary in ASCE 7 they admit that most of the live load requirements are much higher than what is typically found on the various types of floors.
But then they state that the loading requirements are there for the reason that sometimes the floors do get heavily loaded and you need to design to the less frequent, but potential (probable) and occasional heavier loading.

So your 100 psf would probably be what I'd do.

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[KootK]

I like 100 psf too but I think that can be a "last legs" design with serviceability etc off the table. Ideally, your vibration control at more reasonable loads would still govern. What's your proposed system? Two way RC? Precast? TJI?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[MotorCity]

If there are spectator stands or bleachers, I am onboard with 100 psf or more. If there are JUST tennis courts with people only (no type of carts or vehicle access)40 psf or so sounds more reasonable to me.

 

[thaidavid40]

I'm willing to bet money that the member proportions needed to handle the deflections and vibrations at 75psf will actually meet the 100psf design allowance.
Dave

Thaidavid