Wednesday, February 13, 2008

RE: ASCE 7-05 Cantilevered Columns

There are cantilevered columns / inverted pendulums in ASCE 7-05 at the back
of the table but with the response modification factors in the code they have
you are practically designing with a base shear equal to the building weight.


-----Original Message-----
From: Larry Hauer [mailto:lrhauer@hotmail.com]
Sent: Wednesday, February 13, 2008 12:35 PM
To: seaint@seaint.org
Subject: ASCE 7-05 Cantilevered Columns

I'm trying to determine if structral systems that use to be acceptable under
the '97 UBC are even allowed under the '07 CBC/ASCE. Per table 12.2-1 of the
ASCE 7-05, section G, it appears that for Seismic Design Catagories D and E,
(most of Southern California), the following structural systems are no longer
permitted as lateral load carrying sytems:

A wide flange cantilvered column system out of a concrete grade beam at
grade, (i.e. front of garage, etc.).

A pile foundation system supporting light wood framing above, (i.e. two story
residence), unless it is a "Special reinforced concrete moment frame"- i.e.
cantilevered concrete piles no longer allowed.

Am I missing something here, or do these systems go the way of the buggy
whips.

Larry Hauer S.E.


________________________________

Connect and share in new ways with Windows Live. Get it now!
<http://www.windowslive.com/share.html?ocid=TXT_TAGHM_Wave2_sharelife_012008>


******* ****** ******* ******** ******* ******* ******* ***
* 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
******* ****** ****** ****** ******* ****** ****** ********