Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Question regarding seismic joints

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Thanks, Mark. I suspect you are correct about pressure from developers. I have been thinking more about this. My addition is to an existing building that was not originally designed for seismic loads, just wind. The system is such that it will almost definitely not stand up to the code prescribed loading. Should the design earthquake occur, the existing building would likely fail and possibly impact the addition, which makes me ask the question: what am I accomplishing by providing this seismic joint? Perhaps I am protecting the EXISTING BUILDING from the addition. Or perhaps I am providing increased protection to the combined building during a smaller event. But, logically, I am not preventing pounding in the event of the design earthquake. Any thougts?


From: Mark Gilligan <MarkKGilligan(--nospam--at)compuserve.com>
Reply-To: <seaint(--nospam--at)seaint.org>
To: "INTERNET:seaint(--nospam--at)seaint.org" <seaint(--nospam--at)seaint.org>
Subject: RE: Question regarding seismic joints
Date: Fri, 23 Apr 2004 02:35:39 -0400

The reality is that if adjacent buildings are not seperated enough they
will pound together.  Pounding buildings can either damage columns thus
leading to collapse or the pounding can increase the acceleration that each
structure sees.

The formulas are compromises that are expected to control but not eliminate
damage.

Many jurisdictions (both on the East coast and the West coast)  have turned
a blind eye to these seperation provisions at property lines.  Just think
how developers would respond to reducing the floor platein a tall building
because of seismic joints.  The fact that separation joints are not
mentioned for seismic design catagories B and C might be influenced by
these same pressures.

You should keep these three points in mind whenever deciding the size of
seismic joints.

Mark Gilligan

******* ****** ******* ******** ******* ******* ******* ***
*   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(--nospam--at)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
******* ****** ****** ****** ******* ****** ****** ********

_________________________________________________________________
MSN Toolbar provides one-click access to Hotmail from any Web page ? FREE download! http://toolbar.msn.com/go/onm00200413ave/direct/01/


******* ****** ******* ******** ******* ******* ******* ***
*   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(--nospam--at)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 ******* ****** ****** ****** ******* ****** ****** ********