Contractor Error Introduced Sweep in Steel Beam

[MagicFarmer]

Good afternoon,

I am currently reviewing a construction deficiency and was hoping for some additional guidance. The contractor has installed a heavy W760 that spans ~8.0 m and has introduced a sweep in the top flange of approximately 25-50 mm and has installed the precast concrete floor. This exceeds the Permissible Variation in Straightness limitation of L/1000 in ASTM A6.

With this limitation in mind I am unsure how to proceed without removing the attached floor slab and having the structural steel contractor plumb the beam. Do you have any additional resources or suggestions on how one might proceed?

Thank you,
MF

 

[ahypek]

Don't really know much about your exact situation but I wouldn't plumb it. I'd install an adjacent beam, if necessary provide temporary shoring, and remove it.

 

[Lomarandil]

My understanding is that it's not that straightness can't exceed that limit, just that's the standard practice limit that can be accommodated in the field without going back for the EOR's blessing.

Are you the EOR for this job? If not, my first step would be to go ask them to review their calcs with the current condition in mind. For a beam with continuous top flange support (from the precast deck), there's a good chance it's OK structurally.

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The name is a long story -- just call me Lo.

 

[WARose]

The contractor has installed a heavy W760 that spans ~8.0 m and has introduced a sweep in the top flange of approximately 25-50 mm and has installed the precast concrete floor.

What do you mean by "sweep"? I'm not sure I get the situation here.

 

[Lomarandil]

Sweep typically refers to lateral displacement of the beam (especially the compression flange) between supports.

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The name is a long story -- just call me Lo.

 

[MotorCity]

Is the sweep at midspan? Does it affect the beam end connections? Does it affect the connections to the precast floor?
Does it induce torsion into the beam that affects its integrity? If the answer to all of those questions is "no", I don't see a need for corrective action. If it needs to be straightened, I would consider using heat straightening. However, if you plan to straighten it, I would think you need to provide separation between the precast floor and the beam in order to allow the beam to move.