×
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

Seismic Expansion Joints

Seismic Expansion Joints

Seismic Expansion Joints

(OP)
My firm is located in an area where every building ends up in Design Category "D". We typically try to exhaust all options before using moment frames because of the IMF or SMF requirement for this Design Category.

Every now and then we will have a scenario where we want to split a building into two separate structures (expansion joint) due to building geometry, inadequate diaphragm strength, re-entrant corners, etc.

Which leads me to my question. When both or even one of these structures uses IMF or SMF the lateral deflections become a huge issue with regard to expansion joints.

Are expansion joints typically sized for inelastic displacements (i.e. using cd * elastic displacements)?

Example:
50 foot tall buidling(s)
building one displacement=2" w/ cd=5.5 yields delta=11
building two displacement=2" w/ cd=5.5 yields dela=11
per IBC building separation=sqrt((11^2)+(11)^2)=15.55


How do you deal with an expansion joint this large?

Any thoughts or experiences would be greatly appreciated

RE: Seismic Expansion Joints

Lap jointed ?
MikeHydroPhys

mdshydroplane

RE: Seismic Expansion Joints

(OP)
Although it is not ideal, a lap joint will work for the floor, but what about the walls?

RE: Seismic Expansion Joints

Several companies make expansion joint covers that are designed to cover expansion joints (both seismic and thermal joints) in buildings and allow traffic across them.  The covers are used anywhere that traffic is expected to cross the joint.  

The following is the website of one company that makes Expansion Joint Covers.

http://www.balcousa.com/balcoexpansion/index.html

Hope this helps.

Thane

RE: Seismic Expansion Joints

(OP)
Thanks for the web page. I've used similar joint covers in the past. I'm just trying to check my philosphy and approach about sizing expansion joints for inelastic displacments. Any additional thoughts or comments are greatly appreciated.

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