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

Re: Allowable Compressive stress-ACI 530

[Subject Prev][Subject Next][Thread Prev][Thread Next]
David Williams wrote:

> I'm designing a 12'-6" tall reinforced CMU wall using 12" block (actually
> the wall is taller than that, but it'll have a lateral support @ 12.5').  I
> have to use allowable stress design  (local building code requirement).
> Equation 2-17 in subsection 2.3.3.2 is used to calculate allowable
> compressive stress in the masonry due to axial loading.  The equation uses a
> ratio of h/r which is the ratio of the effective height of the wall to the
> "radius of gyration" of the member.
>
> My question is: How is the radius of gyration to be calculated?  Is it the
> height of the wall divided by the square root of 3?
>
> TIA
>
> David L. Williams, P.E.
> Snyder Engineering, Inc.
> Columbia, MO  65202
>
>

>From the Masonry Designers' Guide for 12" CMU

Face shell mortar bedding r=5.08 in.
Full mortar bedding r=4.29 in.

--
Davis G. Parsons II, PE RA AEI
a practical structural engineer
in Fort Worth, Texas



* 
*   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