Reasonable Ratio of coring/bolting in RCC cutting through the rebar. 2

[Danish S]

Hello guys,

I have a query that

Question:
What civil engineering code says about the reasonable number or ratio of coring/bolting around an openings in a manner that it cut through the rebar?

Picture below shows a case with damper secured to wall with bolts cut through the steel as marked in red. Opening is 4.2m wide by 2.25m high. In this case, lintel and walls at both side got hooked with broken steel.

Background:
I am part of a Mechanical Contractor working on Tunnel Ventilation. We have to drill holes in order to bolt the ducts around concrete openings. The duct size varies from 3m x 3m to 6m x 6m. During drilling, we encounter steel reinforcement and we have to core to cut through the steel. Due to large openings, the steel quantity is quite high and we have to core through the steel to bolt the ducts.

 

[hokie66]

A structural engineer for your project should be giving you guidance for this, not we random people on the internet. There are good reasons for that reinforcement being there, but there are no rules of thumb as to how much can be sacrificed.

 

[JAE]

Agree wtih that.

And per your original question about "what the code says" - it essentially says that the structural engineer should review it to determine how it affects the structural system.

Check out Eng-Tips Forum's Policies here:
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[msquared48]

I agree too.

You may be required by the SE of record to map the reinforcing pattern using X-ray scanning or similar to locate the rebar.

The SE should then tell you exactly where he will allow the penetrations you need.

The choice of penetration location is not just up to you.

Recently, I had to document where duct penetrations were allowed in a nine story concrete frame building where horizontal penetrations were needed through an existing concrete shear wall that was also functioning as a vertical load transfer element. There was a lot of critical steel in that wall that could not be cut. All the steel in the area of the cut haqd to be located and the critical steel missed.


Mike McCann, PE, SE (WA)

 

[msquared48]

Wun 'n dun I guess, huh?

Mike McCann, PE, SE (WA)

 

[BUGGAR]

As noted by others, the Codes don't cover this. Actually, I believe your Contract should address this. If it doesn't, I see a claim, for or against you. Did you notify owner?