$2-3$ A width of $2\mathrm{.}0$ m strip foundation, as shown in Figure $2-43,$ the foundation buried depth of $2\mathrm{.}0$ m $,$

the vertical load on the central axis of the foundation $F=400k\frac{N}{m},M=10kN.m.$ The soil layer in the depth

of foundation is divided into two layers: the thickness of the upper layer is $1\mathrm{.}0$ m $,$ the weight is $18\mathrm{.}0k\frac{N}{m}$;

The thickness of the subsoil is $1\mathrm{.}0$ m and the weight is $18\mathrm{.}5k\frac{N}{m}3.$ Find: $(1)$ the additional pressure

distribution of the substrate; $(2)$ Additional stress at a depth of $4$ m below the midpoint of the basement.

$2-432-3$