Situation $7.$ A $400$ mm diameter RC column is to be reinforced with $\frac{O}{10}mm$ circular ties. Steel strength $f_y=415$MPa and concrete strength $f_{c^{\text{'}}}=21$ MPa $.$Use $2010/2015$ NSCP$.$

$37.$ The column is reinforced with $6-\frac{O}{20}mm$ vertical bars, Determine its maximum nominal axial strength, $P_{n,\text{m}\text{a}\text{x}}.$

A$.2,542kN$

C$.1,907$ kN

B$.2,393$ kN

D$.1,555kN$

$38.$ The column is reinforced with $6-\frac{O}{20}mm$ vertical bars. If for a certain load eccentricity, the computed nominal axial strength of the column is $2,600kN,$ which of the following most nearly gives the design axial strength of the column?

A$.1,690$ kN

C$.1,907kN$

B$.1,950kN$

D$.1,555kN$

$39.$ If the required minimum vertical steel ratio is $2\%,$ which of the following most nearly gives the minimum required number of $\frac{O}{20}mm$ vertical bars?

A$.6$

C$.10$

B$.8$

D$.12$