×
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

Lateral resisting system problem
2

Lateral resisting system problem

Lateral resisting system problem

(OP)
I have designed a single story steel frame structure with metal stud infill.  I used threaded rod cross bracing to resist lateral loads.  The contractor comes back and request that we use shearwall system.  I'm having trouble getting the lateral load from the diaphragm (metal deck) into the shearwall without turning the stud infill into a gravity loadbearing system (connection from top of wall to beam to deck).  I think one option would be to ensure that all dead load be in place before attaching the sheathing.  The only problem is selecting a transfer mechanism from the deflected beam (gravity) to the wall below (lateral stability).  Any help on this would be greatly appreciated.

RE: Lateral resisting system problem

2
I don't recall seeing any lateral collector or axial capacity in most light gage steel double tracks.  Even if they did, how could you connect them - never heard of slotted hole connections for screws.

What you might do is require a tube collector to be placed just below the main beam with a gap large enough to accommodate the vertical deflections of the roof beam.

Then, attach the stud wall top track to the underside of the tube.  The gap between the tube and the beam would be small enough that any lateral force dragging in from the roof beam would be transfered to the tube via bending in the columns (or you could install some shear plates at each end of the beam/tube to avoid the small column bending).  

Then sheath the walls.

You would have to take perpendicular component wind forces from the stud wall into the tube, which would span laterally from column to column.  Some additional wind columns might be necessary.

This costs more for the tube, but you save money in not having a slip track, and not having X-braces.

RE: Lateral resisting system problem

(OP)
JAE,

Thanks

RE: Lateral resisting system problem

Check with the Steel Network http://www.steelnetwork.com/ They have developed gage metal connectors and some can transfer in plane shear into your walls with what they call "stiffclips".  They have a decent technical support staff as well.

RE: Lateral resisting system problem

Any thought about moment frames or knee-braced frames.  Knee bracing can 'easily' be framed around with metal studs

RE: Lateral resisting system problem

It seems like installing steel tubes and possible wind columns would cost more than a slip track.  You can get a slip track with slotted vertical holes.  You would use only one track and the studs get screws in each flange to the track through the slotted holes.  Then you can transfer in-plane forces but still have the vertical slip for gravity.  They have tested values for the out-of-plane stud reaction on the track as well for up to 54-mil track.  You can calculate a value for 68-mil if you need it.

Dietrich  Click on deflection connectors, when the pdf opens go to number 4 slotted SLP-TRK.

RE: Lateral resisting system problem

Can't speak for all building codes but FBC requires full blocking for wood / metal stud shearwalls.  Since you can't attach the sheathing to the track, you would be required to provide either strap or stud blocking below the track for your perimeter sheathing attachment.  Wouldn't this put the studs into weak axis bending carrying the shear up into the track?  Also, I didnt see any value for in-plane allowable loads. Not sure how strong the track is in-plane transfering shear through the slots

Not saying this wouldn't work, just saying its not a simple load path.

RE: Lateral resisting system problem

Correct, there is no inexpensive simple load path.  There are alternates.

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