Question $2$: $(30$ marks$)$

In the case of lateral earth pressures:

a$)$ Describe the difference between the development of active and passive pressures

$(10$ marks$)$

b$)$ For the soil profile shown in Fig Q$2.$ The soil contained has a bulk density of $1975K\frac{g}{m^3}$ with $\frac{O}{?}=29$ and $C=0$kPa. Assuming active conditions exist draw the stress profile that would develop and calculate the thrust and position of the thrust that would develop against the wall.

$(10$ marks$)$

c$)$ The soil in Fig Q$2$ is re$-$examined and the soil properties are found to be different to those assumed in part b$).$ The new properties are $\frac{O}{?}=25,C=22$kPa and $=19\mathrm{.}8k\frac{N}{m^3}.$ Calculate the difference in magnitude, position and thrust to the soil outline in part b$).$

Fig. Q$2$