Steel Column Reinforcing
Steel Column Reinforcing
(OP)
I have an existing column with additional load coming down due to a new mechanical unit (about 2500#) on the roof. The existing column was already over stressed due to the existing loads (as per my calculations by about 10%). The column is an HSS4x4x1/4 (14'-8" tall) w/ 28k DL and 13K LL (existing loads). I am assuming the column to be fully unbraced.
Would reducing the unbraced length by providing braces be the way to go or can I reinforce the column in some other way. The owner prefers not to replace the column due to various medical equipment around the column.
Would reducing the unbraced length by providing braces be the way to go or can I reinforce the column in some other way. The owner prefers not to replace the column due to various medical equipment around the column.






RE: Steel Column Reinforcing
RE: Steel Column Reinforcing
You could potentially weld an angle to each corner to increase the buckling resistance.
RE: Steel Column Reinforcing
DaveAtkins
RE: Steel Column Reinforcing
If you use 14.67' unbraced length, you get an allowable capacity, using 13th ed. ASD, of 37.75k (you have 41k +2.5k add'l) - so you are overstressed by 9% w/o the new load and 15% w/the new load. If you use LRFD, you have a capacity of 56.7k. Your Pu is 54.4k + 3k add'l for a total Pu of 57.4k. Now you are ok w/o the new load and over capacity by 1% with it. That looks fine to me.
RE: Steel Column Reinforcing
RE: Steel Column Reinforcing
RE: Steel Column Reinforcing
RE: Steel Column Reinforcing
Are there any code regulations for strength of built-up columns?
RE: Steel Column Reinforcing