Columns in a parking garage

[SAMO]

I wonder if it is necessary to consider a horizontal point load of certain magnitude to account for the possibility of impact due to a car crash into a column in a parking garage?
I'd like to know the code has considered this point.

Thanks

 

[damstructural]

Guess you'd have to call that "drive live." I couldn't resist that one.

It would seem prudent to check for an impact load. I have a design guide for steel parking structures at home. I'll check it and get back to you. Seems to me that steel columns would be more vulnerable than concrete.

 

[structuresguy]

Good question, you wouldn't want the building to come down becuase a column buckled after a car impact. However, I suspect that the load required to fail a column would be substantially higher than a car hitting it at nominal speeds. After all, the car would crush and reduce the impact deceleration force. And concrete is much stronger for loads of very short durations (impact) than under static loading.

I would also be interested if you find any code requirements for parking garage columns. I know you have to design guardrails for impact force, but have never seen a requirement for columns, or other structural members.

 

[damstructural]

Your question forced me to read through my Steel-Framed Open-Deck Parking Structure Design Guide (AISC). I've never done a parking structure, but if I did, it would probably be concrete. There's some good info in this manual, especially regarding prestressed decks.

Anyway, they recommend an impact design load for barriers, what I jokingly refer to as a "drive live load", of 10 kips applied on a 1 SF area at a height of 18 inches. They quote the National Parking Association as the source of the recommended load. National Parking Association? I guess there's an organiziation for everything. They may have more info for columns.

Good Luck

 

[SimpleStructures]

Samo,

Yes, this must be considered in the design if women will be parking in the facility. Fun aside, the column must be designed to resist vehicular impact unless there is no way for a vehicle to hit the column. You will find that tightly spaced column ties are required in the lower half of the column to resist the Code force cited by Damstructural. One way around this is to add bollards in front of the column to resist stray vehicles.

Good luck!

 

[CSEllc]

As far as I know, It is not a "Code" requirement...but it would be the prudent thing to do.