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X > 25, hence column is slender In N-S direction

The slenderness in the E-W direction will be found to be approximately the same.

The structure is braced and non-sway (by inspection), hence the Model Column Method may be used with the column designed as an isolated column.

X „ = 25(2 - e 7e ,) = 50 in both E-W and N-S directions crit o1 o2'

Slenderness ratios in both directions are less than X , hence it is only necessary to ensure that the column can withstand an end moment of at least

Eqn 4.64

This exceeds the first order moments.

bhf ck

bh2f. 3003 x 32

Hence

Use 4T20 (1260 mm2)

Note:

In the design by Higgins and Rogers, the slenderness ratio exceeds the equivalent of Acrit but the design moment is still Nhl20. EC2 requires less reinforcement due to the smaller design load and the assumption of a smaller cover ratio. If the same cover ratio is used in the Higgins and Rogers design, 4T20 are sufficient in both cases.

2.6.5 External column 2.6.5.1 Loading and moments at various levels

These are summarized in Table 2.6.

Table 2.6 Loading and moments for external column
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