Question $8.($Earth Pressures: $10$ Marks$)$

A $5-$m high vertical wall supports a cohesive backfill with horizontal surface as shown in Figure $4.$ The

properties of the backfill are as follows $($i$)$ Upper $3m$ depth: ${}_d=17k\frac{N}{m^3},c^{\text{'}}=10$kPa and ${}^{\text{'}}=20$;

$($ii$)$ Lower $2m$ depth: ${}_{\text{s}\text{a}\text{t}}=19k\frac{N}{m^3},c^{\text{'}}=10$kPa, and ${}^{\text{'}}=20.$ The free water level stands behind the

wall at a depth of $3m$ from the natural ground surface. Draw the earth pressure distribution diagram.

Figure $4$