Example $3$

$22$

The foundation in the figure below is to be $3$ m wide, $4$ m long, and $0\mathrm{.}5$ m thick. The sum of the column loads is to be $1$ MN with $e_L$ is $0\mathrm{.}2$ m and $e_B$ is $0\mathrm{.}15$ m $.$ Determine the differential bearing pressure. $D_f=3\mathrm{.}5m,D_w=2\mathrm{.}5m,{}_{\text{c}\text{o}\text{n}\text{c}}=24k\frac{N}{m^3},=16k\frac{N}{m^3},$ and ${}_{\text{s}\text{a}\text{t}}=19k\frac{N}{m^3}.$