Apportion a strap footing to support two columns, shown in Figure below, spaced at a distance of $6\mathrm{.}0$ m center$-$to$-$center. Column A is $400$ mm x $400$ mm and carries a dead load of $500$ kN and Live load of $300$ kN $.$ Column B is also $400mm400mm$ in cross$-$section and carries a dead load of $700$ kN and a live load of $500$ kN ; Net allowable bearing capacity of $150$ kPa $.$ Discuss design criteria need to be considered in designing strap