a$)$ Draw soil three$-$phase diagram $(Vs=1)$

b$)$ Using the three$-$phase soil model to show that:

$e=\frac{WGs+AV}{1-AV}$

$=\frac{G_s{}_w-}{-S_r{}_w}$

$=(1+W)\frac{G_s{}_w}{}-1$

c$)$ Would the derivations for part b change if you use Vs $=2?$

d$)$ Using algebra or the three$-$phase diagram, show that:

$e=\frac{G_{s}w}{S_r}$