column to existing beam connection
column to existing beam connection
(OP)
Hi FOLKS;
I am designing a project. there is a new column stand on top of existing beam.
the column is w12x45, exiting beam is w36x135.
I don't want weld stiffener on the exiting beam. the beam is 80' long, huge load on top of it.
anyone have idea of it?
Thanks
I am designing a project. there is a new column stand on top of existing beam.
the column is w12x45, exiting beam is w36x135.
I don't want weld stiffener on the exiting beam. the beam is 80' long, huge load on top of it.
anyone have idea of it?
Thanks






RE: column to existing beam connection
BA
RE: column to existing beam connection
RE: column to existing beam connection
lAU668
RE: column to existing beam connection
Sure. However, if your webs are aligned, I would think that there wouldn't be much to be gained that way as you're already spreading the load out over the depth of the column. You'd probably need base plate stiffeners to make substantial gains.
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: column to existing beam connection
RE: column to existing beam connection
I got it
RE: column to existing beam connection
BA
RE: column to existing beam connection
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: column to existing beam connection
see attached picture.
RE: column to existing beam connection
RE: column to existing beam connection
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: column to existing beam connection
I would think that the vertical plates, if spaced close enough over a region would resist the ability to buckle in many ways. Just wondering your opinion :)
RE: column to existing beam connection
I do agree that the assembly would prevent any buckling tending to occur beneath the columns flanges. The question for me, I guess, is do I believe that's where the buckling wants to occur in this situation? I'm not sure that I do. I see the reaction beneath the column as being more like a uniform load beneath the web of the column, skewed towards the flanges. And, if that's the case, how do we know that crippling won't occur at the center-line of the column rather than at the flanges?
This one would be out in no man's land for me. If it were my project and a designer brought me this solution, I'd request something else. If I were reviewing a colleague's project and came across this detail would I go to the mat arguing for it to be changed? Nah.
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: column to existing beam connection
is your opinion like the attached picture?
RE: column to existing beam connection
RE: column to existing beam connection
Has the column changed from W12x45 to W14x61?
Are you concerned about beam web crippling, bearing stress on column or both?
I have the same concerns as KootK. Pre-welded stiffeners may prevent web crippling of the beam but they would not provide reliable bearing under the column flanges due to bolt slip.
BA
RE: column to existing beam connection
I agree with KootK and BA and will try explaining Njkeng’s approach, as I understand it, in different words. His idea was my thought too. Lengthen the column reaction area, down the length of the W36 to reduce the web bearing and crippling potential. A W14x61 col., means d = 13.89", say 14", and I would extend your col. base pl. 8 - 10" beyond each flg., a 34' long col. base pl., down the length of the beam. Weld .5 or .75" stiffener pls. btwn. each col. flg. and the base pl. on the line of the col. and beam webs. This transfers the flg. loads down the beam length and lessens crippling and bearing stresses per unit length on the beam web. My sizes are for descriptive purposes only, since you haven’t told us anything about the loads, moments, etc. I might have some less concern about some light welding on the beam, above its neutral axis, if I could do some min. jacking and shoring under the weld area. Then some half height stiffeners might be put under the col. flgs. and fitted for bearing to the underside of the W36 top flg. Maybe 4" wide, 12-16" high x 5/8" thk. (4 thus).
RE: column to existing beam connection
I do, however, think some of the other posters have raised pertinent points, particularly Kootk and BA. You will need to address them to your satisfaction before you proceed...
Don't forget that your drawing shows these stiffener assemblied perfectly tight, but you need to be able to build tge darn thing! Perhaps opposing shims for the top packer?
RE: column to existing beam connection
RE: column to existing beam connection
Me too. This is one of the jobs that I think the bolted stiffener assembly would be capable of doing.
I assume that OP has rejected the top side stiffener because it projects into occupied space. We'll have to let him confirm or refute that.
I'll be interested to hear what the column load actually is here. Given the transfer length available without doing anything special, I'm surprised that additional measures are required.
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.