A raft foundation will be designed for a structure as shown in Figure $1.$ Geotechnical site investigation program was carried out and the soil was found to be as shown in Figure $2.$

You are assigned to design:

$1)$ Rraft $($mat$)$ foundation for the structure with bearing capacity factor of safety, F$.$S$-2\mathrm{.}5.$ Use your knowledge skills, procedures, and codes to do the work. You need to design for:

$-$ Raft foundation thickness, T

$-$ Steel reinforcement

$-$ Reinforcement development length

$2)$ Basement retaining wall $($Dimensions & Reinforcement$)$

All Dimensions are in $mm$

Columns dimensions

$C1$: $400mm400mm$

$C2$: $300mm400mm$

$1.$ Loads $(Unfactored)$:

$C1$: $DL=790kN$

$LL=510kN$

$C2$: $DL=580kN$

$LL=345kN$

$2.-$ Material Properties

Concrete: $f{c}^{\text{'}}=4000$~$=28$MPa

Steel: grade $60$:$fy=60$ksi~$=420$MPa

$3.-$ Factor of Safety for bearing

capacity failure, F$.$S $=2\mathrm{.}0$

Allowable settlement, $s_{\text{a}\text{l}\text{l}}=20mm$