Problem $3(25$ points$)$

Design the given reinforced concrete cross$-$section to withstand an ultimate moment of $460kNm.$

$f_a=25\frac{N}{m}{m}^2$

$f_i=500\frac{N}{m}{m}^2$

$d=600mm$

$b=250mm$

$d^{\text{'}}=110mm$