I was looking at some APA test of plywood shearwalls see that the saftey
factors ar for 2.8 to 3.5 for the testing to the ultimate load capacity.
Then I looked at my enercal software that fits with the 2003 IRC and now
plywood shearwall get a R of 6.0 where the 2001 california building code
(1997 UBC) gives them a R of 5.5. the Redundany value reduces the earthquake
forces based on the type of system to be used.(Iknow the R is made by
comittee not by "science") While we use the chosen system at with a safety
factor applied to the ultimate load capacity of that system. I know we
design to a code that is for life safety and looks to design for the big one
at the "near colapse level" . is the difference in the R=5.5 and the 2.8 to
3.5 safety factor made up in reducing the building peroid thru damage so
then the force on the building is less? If I am to design an addition to a
fire station then the importance factor makes sure that everything remains
elastic thus no damage and the facility remains operational?
Tim Rudolph
Pinyon Engineering
Bishop CA
******* ****** ******* ******** ******* ******* ******* ***
* Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
* This email was sent to you via Structural Engineers
* Association of Southern California (SEAOSC) server. To
* subscribe (no fee) or UnSubscribe, please go to:
*
*
http://www.seaint.org/sealist1.asp
*
* Questions to seaint-ad@seaint.org. Remember, any email you
* send to the list is public domain and may be re-posted
* without your permission. Make sure you visit our web
* site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********