Beam modification - reduction in cross sectional area

By evy82 Date 11-04-2008 11:23

Hi all,

I'm trying to find material about modification of structural beams, basically make a hole in one to be able to let a 4" line pass through.
I understand we have to make up for the reduction in cross sectional area by welding around the pipe, does anyone what are the rules on this? or where I can look for this info?

Thanks a lot and rgds,

Evelyn

By Joseph P. Kane (****)

Date 11-04-2008 12:02

evy82

This is a problem for a licensed Structural Engineer (P. E.). Please do not cut any holes without a drawing or sketch signed and sealed by a P. E. Some information on this can be found in the American Institute for Steel Construction "Steel Construction Manual", thirteenth edition. However you will need to have some engineering training to be able to use it,

By jwright650 (*****)

Date 11-04-2008 13:16

I agree with Joe, "beam web penetrations" are done all the time, but are designed with this in mind.

Depending on the situation, some are just round holes through the web, some are reinforced with a short piece of pipe, or flat bar stiffeners, some engineers just want the holes to be smooth without any gouges, and some engineers want the hole to be cut with a particular piece of equipment(ie plasma torch)

...there are many things to consider, so get the approval and a sealed drawing from a licensed engineer like Joe stated.

By swnorris (****)

Date 11-06-2008 01:05

Even if you weld around the pipe, web reinforcement may still be needed. If it is still needed, it will more than likely eliminate having to weld around the pipe. Horizontal reinforcement with flat bars above and below the web penetration is the most effective and efficient method. AISC Design Guide #2...... Steel and Composite Beams with Web Openings is a good reference if you have access to a copy. As Joe and John said, you need this engineered. Keep in mind that you may be required to weld any reinforcement prior to cutting holes, and you may also need to support the beam to prevent the beam from sagging from the heat produced by the cutting and welding processes.

By evy82 Date 11-07-2008 05:06

Gents,
Thanks for your replies
Best Rgds,
Evelyn