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Contractor Cored Through Transfer Beam - What's the next step?

Contractor Cored Through Transfer Beam - What's the next step?

Contractor Cored Through Transfer Beam - What's the next step?

(OP)
Hi everyone,

Without approval, the contractor has cored through a PT transfer beam. We now have to perform an assessment on the structural integrity of the beam.

What are the major things I need to be looking at when assessing the potential failure of this transfer beam?

I have personally looked at the cores and God only knows how they didn't hit any PT or rebar...

I have requested photos of the beam's soffit at the exit points.

After running a few numbers, the loss of area in shear seems to be fine in terms of capacity, but I'm wondering if there are any other concerns I have overlooked.

Background info:
[img http://i.imgur.com/0GEy6jz.png?1]

[img http://i.imgur.com/7XThNPt.png?1]

RE: Contractor Cored Through Transfer Beam - What's the next step?

Section loss here is minimal and well placed. You just need to find a reliable way to confirm that the reinforcement hasn't been damaged and you should be good to go.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Contractor Cored Through Transfer Beam - What's the next step?

(OP)
I looked over the core samples thoroughly and nothing had been hit.

I can only assume they are the correct cores though.

RE: Contractor Cored Through Transfer Beam - What's the next step?

Well, I guess the contractor gets the 'idiot' award, but it could have been a lot worse. Missing the PT and both transverse and longitudinal rebar was fortunate.

I would check inside the resulting holes in the beam - to make sure that no rebar or PT was indeed cut. I have seen removed cores with no signs of cut rebar, only to have the holes show cut rebar - 'hidden' in the cores due to the width of the annular cutting teeth (about 3 or 4 mm).

65mm diameter cores across a 2400mm wide band seems to be a very small loss of shear area. If it was new construction and the plumbing called for 1 x 65mm sleeve through the beam width would you be doing any thing additional? Probably not.

I would check your resulting shear capacity and compare it to your factored demand, and assuming you have a healthy margin, move on.

Then send the contractor an invoice for your time!

RE: Contractor Cored Through Transfer Beam - What's the next step?

(OP)
No worries, Thanks for the replies KootK & Ingenuity. The numbers stack up and there are no signs of any cracking on the soffit.

However, I was blown away by the response of the contractor when I was looking at the cores and said they hadn't seemed to hit anything.

"I've done well then..."

And to think Brisbane had their third biggest earthquake since records began the next day!

RE: Contractor Cored Through Transfer Beam - What's the next step?

Yep, Some contractors do some idiotic things.

We found this RC column - that supported 12 floors over - 50% of the area was chipped so a dumb-waiter sheave beam could be installed. Some column longitudinal bars had buckled!



I noticed you guys got rattled by some 5+ Magnitude shakes.

RE: Contractor Cored Through Transfer Beam - What's the next step?

Make sure water entry and corrosion is not an issue with the repair.

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