For Nos. $9$ to $12$: The retaining wall supports a horizontal backfill with a surchargo load of $12K\frac{N}{m^2}.$

Soil Properties of backfill:

Unit weight of backfill soil $=18K\frac{N}{m^3}$; Angle of internal friction $=28$; Cohesion $=10$KPa

Soil Properties at the toe:

Unit weight of soil at toe $=19\mathrm{.}5K\frac{N}{m^3}.$ Angle of internal friction $=30$; Cohesion $=$ zero

Concrete Retaining Wall properties:

Unit weight of concrete $=23\mathrm{.}6K\frac{N}{m^3}$; Coefficient of base friction $=0\mathrm{.}25$

Determine:

$9.$ the total Rankine's active force per unit length of the retaining wall.

a$.)54\mathrm{.}82$ kN

b$.)63\mathrm{.}43$ kN

c$.)48\mathrm{.}74$ KN

d$.)92\mathrm{.}51$ KN

$10.$ Rankine's passive force per unit length at the toe of the retaining wall.

a$.)7\mathrm{.}92$ KN

b$.)60\mathrm{.}76$ KN

c$.)56\mathrm{.}09$ KN

d$.)65\mathrm{.}81$ KN

$11.$ Factor of safety against sliding considering the passive earth pressure at the toe.

a$.)1\mathrm{.}93$

b$.)1\mathrm{.}25$

c$.)3\mathrm{.}15$

d$.)1\mathrm{.}75$

$12.$ Factor of safety against overturning considering the passive earth pressure at the toe.

a$.)2\mathrm{.}24$

b$.)3\mathrm{.}51$

c$.)1\mathrm{.}83$

d$.)4\mathrm{.}24$