(Solved): The figure below shows a 1.0m thick raft and the column loads acting on this raft. Calculate ...

The figure below shows a $1.0\mathrm{m}$ thick raft and the column loads acting on this raft. Calculate the maximum and minimum stresses under the raft (by specifying at which point or points they occur) taking into account the weight of the raft. Use unit weight of concrete as $24\mathrm{kN}/{\mathrm{m}}^3$. In the figure: $\begin{array}{l}a=3mb=7mc=2md=3m\\ V_1=1289\mathrm{kN}{V}_2=863\mathrm{kN}{V}_3=2011\mathrm{kN}{V}_4=1544\mathrm{kN}\end{array}$ $\mathrm{q}=\frac{?\mathrm{V}}{\mathrm{Alan}}\pm \frac{M_{xx}}{I_{xx}}\mathrm{y}\pm \frac{M_{yy}}{I_{yy}}\mathrm{x}$