Please note, the reduction factor, Ri, is intended to correct the Internal Pressure Coefficient, GCpi, as a function of Total Area of openings, Aog, and unpartitioned internal volume, Vi, for partially enclosure buildings.
If you evaluate the
Lim Ri(Vi, Aog), when Aog → ꝏ, then Ri ≈ 1.0
Lim Ri(Vi, Aog), when Aog → 0, then Ri ≈ 0.5
Thus, for very large area of openings, Ri will be closer to 1.0
And for very reduced area of openings, Ri will be closer to 0.5
You probably need to verify the deduction of your Vi, Aog, and the enclosure classification of your building.
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Gustavo Escorcia Ing., P.E., M.ASCE
Structural Engineer
STV / Ralph Whitehead and Associates
North Chesterfield VA
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Original Message:
Sent: 03-20-2023 11:12 AM
From: Mohammed Awez
Subject: REDUCTION FACTOR Ri FOR INTERNAL PRESSURE
Thanks Gustavo Noted !
Infact 2016 and 2022 have shown 22800
However I am having merely no reduction if apply the values as per 22800 even my unpartioned volume quite huge? Will this equation ever gives a reduction ?
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Mohammed Awez Aff.M.ASCE
Design Engineer
DUBAI
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Original Message:
Sent: 03-20-2023 09:35 AM
From: Gustavo Escorcia
Subject: REDUCTION FACTOR Ri FOR INTERNAL PRESSURE
Mohammed,<o:p></o:p>
<o:p> </o:p>
The denominator in the square root of the Reduction Factor equation for Large Volume Building is twenty-two thousand eight hundred (22,800) ft * Aog (sf), as is shown on ASCE 7-05 equation 6-16. <o:p></o:p>
<o:p> </o:p>
Please try to use the third printing of ASCE 7-10, which incorporates errata identified through March 15, 2013. In this third printing of the standard, the equation for Reduction factor for Large Volume Buildings (Eq. 26.11-1), matches the one shown on ASCE 7-05 (6-16).<o:p></o:p>
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Gustavo Escorcia Ing., P.E., M.ASCE
Structural Engineer
STV / Ralph Whitehead and Associates
North Chesterfield VA