Steel Erection Adjustments (late In The Game)

etinul

Hello everybody,

I am a GC and new to this forum and this is my first post. I hope you guys can help me out with a something thats been eating away at me.

I am working on a new three story steel frame building which has moment connections at all columns with 35 bolts at each connection. All the bolts (TC type) have been tightened or "killed" as the erectors like to say. The metal deck has been set and the shear studs installed (no concrete yet). A few days ago, we decided to confirm that the building was plumb and true as the erectors were telling us it was. In any case, we found that the the middle of the building (its rectangular in shape), is about 1" out of plumb from top to bottom ( 35' height). The steel erector says he will install more guy wires to straighten it out.

My concern is that all the TC bolts have been tightened, column base plates grouted, and column butresses filled with concrete. Even if he is able to straighten out the building, will its stay in place once the concrete slabs are poured and he removes the guy wires? Im am concrened beacuse the building is on the property lines of an urban site. 1" will put us dangerously close to the adjacent property.

Any input would be appreciated. Thanks.

joasis

Cable bracing is not typically removed. ever. The engineers place cables and rods to rack or align the frames and structure prior to sheeting, and in many cases, the "diaphram" action of the sheeting is supplemented by the X bracing.

1 inch at a height of 35 feet can be racked out easily, and with no detrimental effect on the structure. Let the steel guy do his job.

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NormW

I know nothing of steel, but have done plenty of production framing. 1/4" over 8' is totally acceptable on these jobs. So 1" over 35' sounds reasonable to me.

I aim for an 1/8", anything further than a 1/4" gets redone or re-racked. If I happen to get it "dead nuts" I brag and strut.

If someone pointed out my 1/4" error, I'd point out his fat ass.

Louisg

Nice post , thanks