ML12213A334

SB-0034 - Bechtel Response to Calculation C-CSS-099.20-054, Revision 0

ML12213A334
Person / Time
Site:	Davis Besse
Issue date:	07/27/2012
From:	Office of Information Services
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References
FOIA/PA-2012-0121
Download: ML12213A334 (1)

Text

SB-0034.

Calculation C-CSS-099.20-054, Revision 0:

Page 9: At the top of the page, equation y = Max (0, c-h)

Please explain how this is used in the calculation. Given that c is always less than h, the above equation will always return y = 0.

BECHTEL RESPONSE Please refer to Figure 1 below for a graphical explanation of the meaning of y. As can be seen, the variable y is always measured from the location of the neutral axis, which lies outside of the concrete cross section only when the compression force P is very large (i.e., for demands nearing the compressive capacity of the section). Therefore, for a section under the large compression demand shown in figure 1, the internal compressive force C is obtain by integrating the compressive stress between (c-h) and c.

El mC.

TC Section Compression Strains A-----

_Fle~xure ... c-_

Total Strain

- -4 Neutral axis Figure 1: Strains and demands for a section under large compression demand and moment

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