QUESTION $1$

A $6$ m tall retaining wall shown below is to be backfilled with non$-$cohesive soil that has the following prope

Soil Layer $1$

Layer thickness $=1$m

Moist unit weight $=16$kN$//$m$3$

Internal friction angle $=30$ degrees

Soil Layer $2$

Layer thickness $=3$m

Moist unit weight $=17$kN$//$m$3$

Internal friction angle $=35$ degrees

Soil Layer $3$

Layer thickness $=2$m

Saturated unit weight $=21$kN$//$m$3$

Internal friction angle $=28$ degrees

The groundwater table is $4$ m down from the top of the backfill, at the Layer $2$ and $3$ interface as shown.

Plot or create a complete table showing the total lateral earth pressure acting on the wall as a function