Buried steel beam in 1950s steel building

[TLHS]

Hey all, got a weird one. I'm going to go poke around in the field and dig some holes, but I've been asked for some opinions on a steel building from probably the 50s. It's a single storey portal frame building. They've done an underground scan and it doesn't look like there's an obvious footing, and there's no rebar in the slab. There's a demoed hole in part of the slab away from the columns and I can confirm there's no bar there.

That doesn't mean there isn't grade beam or thickened slab reinforcement that they didn't see, but I'm not aware of it currently.

Oddly, though, they think there's a steel beam under the slab that goes ~3ft out from the column towards the inside of the building. I've had UG scans be confused before, but presuming this is correct has anyone seen this before

?

My initial thoughts are either:

*This was placed and then they poured concrete around it instead of making a reinforced footing.
*This has a tension tie attached to the right hand end of it and the column just bears on a small footing for gravity load. I don't know why they'd go to the trouble of the beam though.

 

[HTURKAK]

Probably yes.. and probably the column extends and rigidly connected to the beam..

Just curious; are the base pl and anchor bolts visible ? Can you post some pictures ?









I cannot give you the formula for success, but I can give you the formula for failure..It is: Try to please everybody.

 

[TLHS]

The base plate and anchors are visible, but it appears to be sitting on top of the same monolitically poured unreinforced slab that makes up the rest of the floor. That doesn't mean there weren't levelling nuts or shims on top of a steel base place that they poured over.

No pictures I can share, unfortunately.

 

[WARose]

Just so we are clear: the beam is in the dirt? If so, that's a potential settlement/failure issue at some point.

If it was embedded in the concrete, I'd think someone was trying to do a shear head (but with just one beam, don't think that would work; also that is something I've typically only seen on elevated slabs).

 

[TLHS]

I'm assuming it's in concrete until I actually dig a hole. There's all sorts of problems if it's just sitting there underground. Don't know yet, though.

 

[TLHS]

Assuming that it's embedded it could also be acting as a tension tie to try and engage unreinforced concrete weight and resist the thrust force at the column. The below is in plan, blue dashed lines would be the concrete it's pulling in. If it's only three feet long, though, it seems like an inefficient way to be doing that.

 

[WARose]

If it's only three feet long, though, it seems like an inefficient way to be doing that.

Agreed. (Not sure when they started using hairpins regularly though.)

My best guesses:

1. Maybe some kind of tie like you were talking about. (Or hairpin.)
2. Half-azzed way of a shear head. (If it is in the slab.)
3. Something to fill a hole with (because Hoffa's body was not yet available).

 

[jerseyshore]

I would lean more to the scan being messed up, but if there is actually a beam under the slab you have to share some pics.