Smart questions
Smart answers
Smart people
Join Eng-Tips Forums
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

Join Eng-Tips
*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.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

vcueto80 (Structural) (OP)
23 Mar 10 14:41
Have a one-story, rectangular light-frame building (wood) in a Seismic Design Category D region. Since I am in Category D I want to detail for seismic loads(Have 3x framing in shearwalls per SDPWS section 4.3.7 item 3c, >350plf for ASD). In section 12.10.2.1(ASCE 7-05) for collector elements the Overstrength Factor can be ignored. Then in Table 12.2-1 Seismic Force-Resisting Systems(ASCE 7-05) page 120 for Light-framed walls the Overstength Factor is 2.5 (flexible diaphragm).

I have read in a previous post "When to use Overstrength Factor," since ASCE 7-05 does not really state when to use the load combinations in section 12.4.3.1. Somewhere I read the OS factor is for critical connections.

My question is why can the collector element use a different load combination which does not include the OS factor and the shear wall use an OS factor since both are critical and tied to each other??
 
slickdeals (Structural)
23 Mar 10 15:10
The collector beams are designed for the overstrength factors, while the shear walls are not.

A collector "collects" and transfers the load to the lateral load system and hence, is deemed a critical member in the load path. As a result, it gets an overstrength factor. Connections are the same way as well. Connections are designed to remain elastic during a seismic event so that the member yielding/buckling can dissipate the energy. You don't want your connection to fail before the member.
vcueto80 (Structural) (OP)
23 Mar 10 15:27
According to ASCE 7-05 section 12.10.2.1 the collector element for light-frame shear walls does not use an overstrength factor. But for shear walls an OS factor is given in Table 12.2-1

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!

Back To Forum

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close