Problem # One $(50$ points$)$

For $x=27$ inches, determine the nominal axial strength $(P_n)$ and the nominal moment strength $(M_n)$ for the column section shown below. Draw the stain and stress distribution diagrams. Please note that the bending is about the strong axis.

Material Properties:

Concrete $f_c^{\text{'}}=4,500$ psi

Concrete Ultimate Strain $=0\mathrm{.}003$

Normal weight concrete

Steel $f_y=60,000$ psi

$E_s=29,000$Ksi

Section Properties:

Main Bars $12$ # $11$

Stirrups # $4$ @ $6"$

Max. Size Aggregate $={0\mathrm{.}75}^{\text{'}\text{'}}$

Concrete cover to center of main bars $={3\mathrm{.}0}^{\text{'}\text{'}}$