eccentric steel beam connection to plate bolted to face of masonry wall

[Ben29]

This is a job where, in hindsight, I wish I didn't take. I designed a steel-framed balcony for an existing restaurant. I was provided an architectural background, which located the post locations. I didn't do any field survey whatsoever, and quite frankly, it wouldn't have done any good since the posts were to be located within existing wood-framed walls that weren't opened up until recently. My drawings say, "verify field conditions prior to construction" about 10 different times. My drawings indicate that shop drawings must be submitted for my approval. No one sent me shop drawings. They just started building.

So they found that they cannot have a post in one location. All the steel is fabricated, so this is a problem for them. Their solution is to clip the end of the steel beam to a steel plate that is eccentrically bolted to an existing CMU block wall. See image below. Quite frankly, I'm not even sure why this block wall is here. I ran numbers on this and it doesn't work.

Won't this connection put an uplift force in the bolts that must be counteracted by the weight of the block wall above? There is no way we have enough block wall above this connection to counteract this weight. am I thinking about this the wrong way?

 

[Ben29]

Here is a view from the exterior of the restaurant. I tried to show where the steel beam wants to frame into the wall.

 

[WinelandV]

I suppose I'll ask the obvious question, which I'm sure you have already asked and they denied: Can the beam be shifted to the left an appropriate amount so that it frames directly into this CMU/block pier?

Please note that is a "v" (as in Violin) not a "y".

 

[XR250]

I can't imagine you getting this to work with a 5.4k load. I agree with Winelandv that the beam need to be shifted. Most of my jobs are field fabricated so I know how easy it is for a good fabricator to change things.

 

[Ben29]

yes, that was my suggestion. and yes, I was denied because they would need to "re-fabricate 7 beams" and the owner is having a conniption. Then the architect got involved and tried to convince me that "it's not alot of load" and that this detail would work. This, of course, drives me insane.

The reason they need to re-fabricate beams is because they installed the exterior posts first without checking the interior conditions. Now I have to drop everything that I'm doing and run down there. And I'm sure they wont' pay me for my time either. Why did we become structural engineers again?

 

[WinelandV]

See the snip below. Can you design an additional beam as shown below that will, essentially, replace the existing lintel?

Please note that is a "v" (as in Violin) not a "y".

 

[XR250]

The reason they need to re-fabricate beams is because they installed the exterior posts first without checking the interior conditions. Now I have to drop everything that I'm doing and run down there. And I'm sure they wont' pay me for my time either. Why did we become structural engineers again?

Sounds like you need to have better boundaries and business practices. I would discuss fees before you even consider heading to the job site. If there's any doubt, ask for a retainer. Also, their emergency is not your emergency.

 

[dhengr]

Ben29:
In my part of the country we call that clay brick, not conc. blk. or CMU. Do you have any idea of the actual make-up of that wall? What is the lintel over the window, could it support part of that beam load in shear? Is there a grouted, reinforced jamb along side that window? How can you come up with a design unless you know these things? Just to put the Arch. and G.C. back in there place, ask for the shop drawings and the field verification notes and dimensions which they forgot to forward for your review. Get paid in advance for this work caused by them shooting a bull. This isn’t really your fault or your problem, so they ought to act at least a little cooperative in getting you the engieering info. you need. Since the Arch. is so cock sure, why didn’t he just o.k. that detail himself?

 

[WinelandV]

dhenger,

I know I was calling that wall/pier CMU - I assumed (perhaps wrongly) that the brick was an architectural feature, and that there were standard CMU blocks behind it. If it really is only the clay brick, then the whole thing (IMO) needs to go back to the drawing board.

Please note that is a "v" (as in Violin) not a "y".