Coarse grained soil is sub$-$divided in to

a$)$ Gravel and clay,

c$)$ Sand and silt.

b$)$ Gravel and sand

d$)$ Silt and clay

The vertical stress at a point within soil mass at a depth $z$ is

a$){}_2=+z$

c$){}_2=\frac{}{z}.$

b$){}_2=-z$

d$){}_2=z$