Impact Load from Car/SUV on a concrete column
Impact Load from Car/SUV on a concrete column
(OP)
I am designing a 3 story wood structure with parking underneath. The structure is open at the parking level, and I have one post in the structure that is critical to the structure. If it failed, the structure could collapse, and it is exposed to vehicle traffic. Does anyone have an idea of how much impact load I should be designing the column for. I know that it is F=MA, but is there a code requirement for size of the vehicle, and speed that needs to be designed for. I don't think it makes sense to look at bollard design, as bollards can fail and deflect, whereas this post needs to remain standing.
Any thoughts would be much appreciated!
-Mike
Any thoughts would be much appreciated!
-Mike






RE: Impact Load from Car/SUV on a concrete column
I'd design a protective system to armor the column. I've seen steel plates embedded into the concrete columns with shear studs used in mill take a lot of hits from forklifts without excessive damage.
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RE: Impact Load from Car/SUV on a concrete column
RE: Impact Load from Car/SUV on a concrete column
RE: Impact Load from Car/SUV on a concrete column
I am at worst picturing an SUV going 15 MPH and hitting this.
I am right now looking at a 14 x 14 concrete column. The column will be attached to a steel beam at the top which is into the floor diaphram, and then creating a thickened slab, maybe 10 feet by 10 feet around the column to create a reaction at the base. I would then run the column as a simply supported beam, and run the load case of perhaps a 20 kip load at 4-feet up from the base, dead load. I know these numbers are kind of out of left field, but I am looking to see if I am in the right ballpark with this. Just gut feeling is that this all seems reasonable.
Thank you for sending along that article, I will check that out as well.
RE: Impact Load from Car/SUV on a concrete column
TTFN (ta ta for now)
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RE: Impact Load from Car/SUV on a concrete column
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RE: Impact Load from Car/SUV on a concrete column
Having said that, my columns have always been at least 16" square, and as part of a concrete structure with concrete floors above.
Perhaps you could design the supported beam for more robustness, similar to earthquake and blast design principles, so that the entire building retains some integrity with damage to that column.
RE: Impact Load from Car/SUV on a concrete column
Anyway I came across this link on ET Link, which doesn't say much. If you're really worried and can't use a bollard, how about a steel jacket?
RE: Impact Load from Car/SUV on a concrete column
I think that the "threat" in these situations is mostly a bumper impact induced shear failure from relatively slow moving vehicles. The 15 MPH SUV as you say. Consequently, were I to do anything, I would probably pound the bottom three feet of column full of ties. That, combined with integrity reinforcing compliance above, strikes me as reasonable. In your particular case, some ductility and/or reserve capacity in the connection between your concrete column and the steel beam above probably makes sense too.
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.
RE: Impact Load from Car/SUV on a concrete column
Added: I used PWF since the structure is wood...
Dik
RE: Impact Load from Car/SUV on a concrete column