magic equation(r) for rcc rectangular column
Category:bug report

General Notations:
P = Factored Load in KN
Mx = Factored Moment I I to X – axis in KN.m.
My = Factored Moment I I to Y – axis in KN.m.
B = Column Dimension I I to X – axis in mm.
D = Column Dimension I I to Y – axis in mm.
For Example:
Fck = 20 N/mm^2
Fy = 415 N/mm^2
Area of steel in mm2 (four faces)
As = 3.703*P – 0.0296*B*D + 57.544* D*Mx /P+57.544* B*My/P+ 115087.2*Mx*My/(P*P)
Note : IF the value for component marked underlined is ZERO or less than ZERO.Then the Equations become as under.
As =7192.95*Mx /B+7192.95* My/D+ 14385902*Mx*My/(P*B*D)


#1 submitted by admin on Wed, 06/17/2009 - 12:44
Attachment:magic equation(for all codes).xls (111 KB)

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#2 submitted by raveeleo on Thu, 06/18/2009 - 07:51
Category:task» bug report
Assigned to:rg.gupta» raveeleo
#3 submitted by karunaagrawal on Tue, 06/23/2009 - 07:37


It is actually a wonderful and clicking tool for column design and saves a lot of energy, time and in turn has a lot money value.
The equation works for change of grade of steel, but not for the change of grade of concrete. Could you throw some light, as we are designing columns in M35 and higher grades. And steel Fe415 is out of date, while Fe500 and higher grades are in vogue these days. Thanks,