Parking Structure- One column and four beams

[JOHN2021]

I am new to the forum.

I am designing a two level parking structure. In the middle of it, I have four steel beams coming to one concrete column on the same level. With that many beams, do I need to have corbels to support them and if so, is it possible to have two corbels supporting two beams and the other two beams connect directly to the column with some steel to concrete type connections?

 

[MIStructE_IRE]

A sketch will help you get some useful responses.

 

[Agent666]

I think it will be a case of whatever you can get to work both from a strength perspective and also detailing perspective as things can get pretty congested with some combination of corbels/weld plates/bolting through columns from all four sides. I don't think you'll find any guidance that needs to be adhered to in these situations.

Perhaps giving some beam sizes/reactions and column size/reinforcement might offer some further insight on the best arrangement?

Obviously at the uppermost level you could consider taking the beams onto the top of the column, or have one direction of beams continuous over the column with the others framing into the sides of the first beam. But at the first level things are a bit more complicated but having some idea of the proportions and other constraints will help guide a solution.

 

[KootK]

I think that your proposed solution is quite clever. A four way corbel does create a congestions issue but, then, to some degree so does a four way embed connection, depending on the size of the column. Your setup should avoid all of that nicely. I don't love steel in parking structures in general but that's an issue for another thread.

 

[KootK]

I'm picturing something like this.

Precast columns? A precaster will likely be able to provide corbels on all four sides and that would probably have durability advantages. That said, on two of the column sides, the corbels may wind up being secondary pour elements which always makes me a bit nervous for high load applications.

 

[Agent666]

The other thing with corbels is to be wary of the fact that they need to be accommodated under the beams, potentially eroding clearances for vehicles, most parking structures have beams pushed right down to minimum clearances required for vehicles. You don't want them to be projecting into the zones used by traffic clearances and creating an issue with any chance vehicles might come into contact.

The other way I've seen it done locally is a welded hollow square plate sleeve with studs internally between longitudinal column bars, with web plate type connections welded onto the column on site. This is also quite good form a tolerance perspective as you can vary the length of the fin plate to suit the final set out or add slotted holes to suit. Using loose link ties you can build the column shear reinforcement through the plate zone without clashing with the studs (cannot slot full stirrup sets down into the sleeve depth without hitting the studs). Hopefully that makes sense, if not I can draw a sketch.

 

[PROFR]

John,
You can use typical concrete corbels from two sides. On the other perpendicular sides, you can use rebar plate cast into the concrete and then weld steel bracket (yard welded) to it. To minimize rebar congestion, lower the steel corbel slightly so that the tension corbel steel from the two sides is at different levels. Correct the levels later by welding a plate to the top of the steel section. See screen shot below. Keep in mind when designing the column that the maximum column moments do not happen when all four corbels are loaded with the live load.

 

[dik]

I'd likely use weld plates for all 4 connections... corbels are costly to construct.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

Me too... but, look at Toronto Lakeshore Drive and see what happened to the concrete... have to be careful about how you do things...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik