Problem $2$: $(70$ Points$)$

You are required to design the beams B$-1$ and G$-2$ during the construction stage. Which means during casting of concrete. The only loads to be considered are construction loads and the weight of the fresh concrete, which are given below.

Refer to the following floor framing plan shown in the below figure and the assumptions:

Steel is Grade S$355$

This is a one storey structure.

In the east$-$west direction lateral load resisting system consists of concentrically braced frames. All beam$-$column connections are pinned connections in this direction.

Column length is $4m.$

In the south$-$north direction all the beam$-$column connections of the frames in Axis$-0$ and Axis$-2$ are pin connections.

In the south$-$north direction all the beam$-$column connections of the frame in Axis$-1$ are moment connections. Lateral loads in the south$-$north direction are resisted only by the frame in Axis$-1.$

Construction loads are $0\mathrm{.}5k\frac{N}{m^2}($includes self$-$weight of beams$)$

Weight of fresh unhardened concrete is $2500k\frac{g}{m^3}.$

Consider only these two loads and multiply them by $1\mathrm{.}2$ to use as design loads. No other load combinations will be used. You will design beams during the construction stage.

Although this is a one storey structure, consider the framing plan shown as a floor in any multi$-$storey building. Do not consider it as a roof floor.

Determine the following:

a$.$ Design beam B$-1$ for the construction phase with the given loads above. Assume the unbraced length of these beams as $9m.(30$ Points$)$

b$.$ Design girder G$-2$ for the construction phase with the given loads above. Assume these girders are braced at the beam$-$girder connections. $(30$ Points$)$

$2$