Need a book? Engineering books recommendations...

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

Re: soft story

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Sum the stiffnesses of the frames or shearwalls on the lower level.
Do the same for the frames and shearwalls above.

Compare.

You can determine the stiffness using a computer model by putting dummy loads and compare the deflections. Or hand calc.

Usually it's pretty obvious, like when you have a discontinuity at the bottom floor.

"Weak story" is similar, but has to do with strength rather than stiffness

hth,
-gm

On Thu, May 8, 2008 at 10:46 PM, sam2000 . (sam2000) <sam2000(--nospam--at)cyber.net.pk> wrote:
 7 defines soft story as the one where "stiffness" is less than 70% of story above. If stiffness is to be defined as I/L this would mean whenever we have a 16ft 1st floor, we have a weak story, even though all the walls and columns are continuing from the story above? This is frequently the case in multi-story concrete buildings I design. I never thought of 1st story as weak, unless I was missing a wall or something.

I'm afraid I haven't been reading it right. Have I?



Syed A Masroor
Consulting Structural Engineer
Karachi, Pakistan



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