Question:

Figure A $1$ shows a steel cross$-$section fabricated from two back$-$to$-$back, C$310$ x $45$steel channels, welded to one plate, $20$ mm thick x $260$ mm wide. Determine the section moments of resistance about the two centroidal axes, x$-$x and y$-$y$.$ All steelsare G$40\mathrm{.}21350$W grade.

$1.$ Solutions must be to the following standards:FIgURE AI

Steel: CSA$-$S$16($latest edition$)$

Concrete: CANlCSA$-$A$23\mathrm{.}3($latest edition$)$

Timber: CSA$-$O$86($latest edition$)$

$2.$ All loads shown are unfactored.