×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Built Up Column w/ 2x8's???

Built Up Column w/ 2x8's???

Built Up Column w/ 2x8's???

(OP)
Does anyone have any design tables or guides for designing bult up columns?

RE: Built Up Column w/ 2x8's???

I use woodworks... works very well.

RE: Built Up Column w/ 2x8's???

Enercalc...its free for the demo version, which is the full blown version.

RE: Built Up Column w/ 2x8's???

(OP)
I'm trying to get 6x6 columns to work for a pole barn addition, here are my parameters:
select str, treated SPF Fc=1400psi  E=1.5x10^6psi
length is 12' w/ fixed base and sidesway permitted so Ke=2.1
loads are snow 85 psf and DL 15 PSL (2/12 monotruss @ 16" oc). each post carries 8500 lbs.
Ke*l/d = 2.1*12*12/5.5 = 55"
classified as a long column so F'c=.3E/55^2 = 149psi

this number seems very small, and a column design table I got from an AWC publication gives 399psi allowable stress for E and Fc listed above w/ 56 l/d but this same publication mentions not to use columns w/ l/d > 50.

with the first method I can get 8x8 to work, does anyone have any advice or find something I am doing wrong? TIA

RE: Built Up Column w/ 2x8's???

Detail the top of the column to be held at 90 degrees to the horizontal, (rather than pinned, which give the Ke of 2.1), thus allowing a lower Ke of 1.2<Ke<2.0. This should help somewhat.

RE: Built Up Column w/ 2x8's???

Beamchek at www.beamchek.com is a very good program for doing all kinds of beams and columns.  Only a $100 or so.

RE: Built Up Column w/ 2x8's???

BTW -

Get rid of the side sway if you can by using shear walls or bracing or whatever.  I show a 6x6 very good with Ke = 1

RE: Built Up Column w/ 2x8's???

(OP)
in the direction parrallel to the wall the columns are fully braced becasue of the wall sheathing. however in the other direction the posts carry LVL beams which support monotrusses at 16" so I can't see how i would prevent sidesway in that direction because of course that is the open area underneath the addition. I'm going to add diagonal 2x6 bracing in the ends walls.

RE: Built Up Column w/ 2x8's???

(OP)
thanks for the beamcheck suggestion, MIke, that helped me verify what I was doing. not sure if i will purchase it or not, seems like a fair price for $150.00

RE: Built Up Column w/ 2x8's???

Try Enercalc...it's free.

RE: Built Up Column w/ 2x8's???

(OP)
thanks, I will try it.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources