Coring through concrete beam

[asixth]

Hi guys,

I have a situation where an existing 600 x 190 beam (24" x 8") needs to be cored so services can pass through. My thoughts are that I should try to do this in a low shear region because the beam is not going to be scanned to determine the location of the shear ligs.

And I should core approximatley within the middle third of the depth, this way I will avoid any tensile steel and the compressive stress block should not be affected depending on the depth of the neutral axis.

What do others think of this logic.

 

[hokie66]

asixth,

Based on your photograph, I would guess that the section of concrete you are planning to core through is not a beam at all, but just a dropped soffit to receive the head for a movable partition. I think the joists at 1450 centres span the 8500 between the 900 deep beams.

 

[asixth]

hokie,

Maybe, it appears like what you have described when looking over the existing structural drawings, that the 450 deep beams span to the 900 deep beams with then span onto the columns.

I will post the drawings on tuesday when I get back to work.

 

[TXStructural]

It looks like the concrete through which the duct penetrates, the same one you are looking to core, is a diaphragm brace for the beams. Is there a load path which indicates load is going into this member, or out of this member?

It sounds like someone needs to review the plan to determine the function of the member. With a hole the size of the duct, I doubt there is any flexural load on this member.

 

[csd72]

http://findarticles.com/p/articles/mi_qa5379/is_200303/ai_n21327928/

http://products.ihs.com/cis/Doc.aspx?AuthCode=&DocNum=266936

 

[swivel63]

low shear, tension zone.

 

[asixth]

thanks to all those for their contributions so far. I have attached the structural drawings. The beam I want to core through runs transversly between B10 and B12. It hasn't got the size marked on plan but it is a 600 x 290 (24" x 12") with two significant penetrations that I assume will have been designed for. The beam hasn't been marked on plan or shown on elevations so I am hoping it is a soffit downturn to pick up the partition.

I ran a quick model to determine what magnitude of forces are going through that member and there is significant positive moment due to the curvature of the floor system. Saying that, the shear isn't of significant magnitude.

I don't think there should be a problem with coring through this beam provided I stay away from the tension steel and the neutral axis. And I have the slab x-rayed to map the exact locations of the steel.

 

[hokie66]

It is just a distribution rib, really just there for architectural reasons. Although it may be picking up some load due to geometry, it would not have been designed that way, and I would not hesitate to cut through it.

 

[kslee1000]

Maybe you can locate it on the HVAC/Piping drawings.