D14.A.4 Column Design
Columns are designed for axial force and biaxial bending at the ends. All active loadings are tested to calculate reinforcement. The loading which produces maximum reinforcement is called the critical load and is displayed. The requirements of SABS 0100-1 clause 4.7 are followed, with the user having control on the effective length in each direction by using the ELZ and ELY parameters as described in table 12A.1. Bracing conditions are controlled by using the BRACE parameter. The program will then decide whether or not the column is short or slender and whether it requires additional moment calculations. For biaxial bending, the recommendations of 4.7.4.4 of the code are considered.
Column design is done for square, rectangular and circular sections. For rectangular and square sections, the reinforcement is always assumed to be arranged symmetrically. This causes slightly conservative results in certain cases.
Using parameter TRACK 1.0, the detailed output below is obtained. TRACK 0.0 would merely give the bar configuration, required steel area and percentage, column size and critical load case.
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C O L U M N N O. 1 D E S I G N R E S U L T S
M30 Fe450 (Main) Fe450 (Sec.)
LENGTH: 3000.0 mm CROSS SECTION: 715.0 mm X 380.0 mm COVER: 40.0 mm
** GUIDING LOAD CASE: 1 END JOINT: 2 SHORT COLUMN
DESIGN FORCES (KNS-MET)
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DESIGN AXIAL FORCE (Pu) : -14.6
About Z About Y
INITIAL MOMENTS : 0.00 0.00
MOMENTS DUE TO MINIMUM ECC. : 0.28 0.29
SLENDERNESS RATIOS : 7.89 4.20
ADDITION MOMENTS (Maddz and Maddy) : 0.00 0.00
TOTAL DESIGN MOMENTS : 45.17 9.41
REQD. STEEL AREA : 26.99 Sq.mm.
REQD. CONCRETE AREA: 1213.61 Sq.mm.
MAIN REINFORCEMENT : Provide 4 - 12 dia. (0.17%, 452.40 Sq.mm.)
(Equally Distributed)
TIE REINFORCEMENT : Provide 8 mm dia. rectangular ties @ 140 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KNS-MET)
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Puz : 25.50 Muz1 : 45.22 Muy1 : 51.48
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