huangyhg

holes on w beam web.
i have a contractor that needs to drill three 1 3/4" diameter holes side by side on a w10x39. what is the rule of thumb or easy way to analzye this? the beam is almost 17foot long with distributed load and 3 point loads. maybe reinforce the web where the holes are? what is the common way to reinforce the web? or maybe i wont need to reinforce it.
find a job or post a job opening
what do you mean side by side? will there be three holes in the one section? how far apart?
csd
holes centered on the neutral axis do little to bending capacity. check for shear at the section with the holes, if needed, add thickness to the web with a plate welded at the hole location.
if you can locate the holes near the centerline of the beam span (where shear is small) and near the center of the beam depth (where openings make little difference in moment capacity as civilperson pointed out), the overall affect on the beam will be very small.
if still in doubt, check aisc steel design guide #2.
they are probably 4" apart.
aisc steel design guide #2
very good guide to use.
but 1 3/4" holes are pretty small so if you simply space them out a bit it should be no problem.

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