BASE PLATE WELD
BASE PLATE WELD
(OP)
I have a moment frame building and the column is taking a pretty healthy moment around 600 k-ft. To resist this large of a moment with a 20" pipe i have to use 1 3/4" weld to the base plate. This weld seems way to large to be excecuted in the field but i dont know of another solution.
Any suggestions?? Your help is much appreciated
Any suggestions?? Your help is much appreciated






RE: BASE PLATE WELD
RE: BASE PLATE WELD
RE: BASE PLATE WELD
You are right i spoke wrong this would be shop welded but steel seems very large. Me being green in this area would a full penetration weld theoretically require half of the thickness?? Sorry for my confusion. Thanks
RE: BASE PLATE WELD
RE: BASE PLATE WELD
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: BASE PLATE WELD
What's the pipe wall thickness?
RE: BASE PLATE WELD
That was my orginal thought but i have went through how the moment was developed three times and get the same answer. Seems large...
The pipe is very large itself 20" diameter 1 1/4" thickness
RE: BASE PLATE WELD
The tricky part will not be the weld, but the design of the baseplate and its anchorage to the foundation.
As far as the modeling goes, you might look at the footing rotation to see if your moment will actually be developed. This will hurt your structure's deflection but might help your structure's stresses. And it should be a more reasistic model.
RE: BASE PLATE WELD
And yes i am wary of a fillet that large ITS HUGE!!!
Thanks for your input
RE: BASE PLATE WELD
1-1/4 thick "pipe" wall?
Try to change the connection to spread the laod out, and try to limit the fillet to 1/2 inch.
(Euro design (thickness across the throat) or US standard (length of the fillet leg)?)
RE: BASE PLATE WELD
Using LRFD:
Shear Yield Deff = 30.2 * Fy/Fexx * t
Shear Rupture Deff = 22.6 * Fu/Fexx * t
For A500 Gr B material Fy=46, Fu= 58 and assuming Fexx=70 ksi, a 1 7/16" fillet weld would develop the plate. To me at least, your calc doesnt seem too far off if you are stretching the capacity of the section.
RE: BASE PLATE WELD
The weld is a weld that is all around the pipe so the only variable i can design to is the weld thickness, and im using US standard design.
Galambos,
Thank you for the input and im pretty confident in my number using this process just was trying to think so a solution to avoid the big of a weld.
RE: BASE PLATE WELD
A 1.75" fillet has a cross sectional area of 1.53 sq-in.
If you used a CJP with a 3/8" root and prepped the pipe with a 30° bevel it would only require 1.01 sq-in of weld. Although you'd need to back that up with some size a fillet.
Or you could meet in the middle with a PJP weld reinforced with a fillet.
RE: BASE PLATE WELD