Q$1.$ Consider the plan layout of a three$-$story office building shown in Figure $1.$ The solid black walls $($in plan$)$ are load$-$bearing and support the suspended slabs and loads from above. It is assumed that the roof and floor slabs are of continuous in$-$situ reinforced concrete construction. The load bearing walls comprise standard clay bricks, are double skin masonry $($collar jointed$),$ and align from ground floor to roof. The blue dashed walls $($in plan$)$ are non load$-$bearing partition walls.

c$)$ Calculate the design load $($in $k\frac{N}{m})$ acting on the slab given the following information.

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Live load supported by slab $=3k\frac{N}{m^2}$

Normal density concrete $($Unit weight $=24k\frac{N}{m^3})$

Slab thickness $=175mm$

Load combinations: $(1\mathrm{.}2D_n+1\mathrm{.}6L_n)$ and $(1\mathrm{.}5D_n)$

Find a satisfactory brick strength and mortar class for the wall defined Wall $A,$ given that it must support design load of $150k\frac{N}{m}.$ Make the following assumptions in your design calculations:

Assume a clay brick wall thickness $($t$)$ of $215mm.$

The design load of $150k\frac{N}{m}$ includes all dead and live loads and has already been factored, i$.$e$.,$ no load calculations are required in this question.

Assume that the eccentricity of the design load, at the top of the wall, $e_x=\frac{t}{10}.$

Assume normal construction and manufacturing controls.

Assume a wall height of $2\mathrm{.}6m$ and enhanced end resistance $($so $h_{ef}=0\mathrm{.}75h)$

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b$)$ On the same sketch, indicate the portion of wall that supports the highest concentration of load.

$[3]$