QUESTION $1$

$[28$ MARKS$]$

A concrete base with a depth of $475mm$ will be built at ground level. The base has a preliminary length of $2500mm$ and the width of $Bmm$ and is designed to support a cantered square column measuring $350mm350mm.$ The base will be subjected to the following nominal loads:

Dead Load: $375kN$ vertical downwards, $30kNm$ moment

Live Load: $300kN$ vertical downwards, $20kNm$ moment

NOTE: all dimensions are in millimeters

The allowable working pressure on the ground cannot exceed $180$kPa. The recommended materials are grade $\frac{25}{26}$ concrete and high$-$tensile steel with a minimum cover thickness of $50mm.$

$1\mathrm{.}1.$ Determine the required base width $(Bm)$ to ensure the pressure under the base is within the allowable working pressure.

$1\mathrm{.}2.$ Determine the design moments for the base in both directions.