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# Question Regarding initial eccentricity of walls...

• To: <seaint(--nospam--at)seaint.org>
• Subject: Question Regarding initial eccentricity of walls...
• From: "Gulbrandsen, Peter W" <PGulbrandsen(--nospam--at)bonestroo.com>
• Date: Tue, 10 Jun 2003 15:32:36 -0500

Title: Question Regarding initial eccentricity of walls...

I am designing an assumed 8 thick, 12 tall, and 50 long reinforced concrete wall with #5 bars @ 12 both ways.  I am trying to calculate the design strength of the wall with an approximate 20 psf wind load (bending), 90 psf dead load (axial), and 40 psf live roof load (axial)

I am going through the ACI 318-02 (especially example on 21-12) notes and cant figure out how to calculate the initial eccentricity (Mu/Pu) and therefore the final eccentricity of the wall.  I am having trouble because I need an eccentricity for the factored load combinations (Mu), and if [eccentricity = (Mu/Pu)] then I will have separate eccentricities for each load combination. Furthermore, if I change the eccentricity for each load combination the (Mu/Pu), which I believe is the eccentricity, changes.  The values also dont seem to converge like I thought they might.

Any help or guidance would be greatly appreciated.

Peter Gulbrandsen