$($a$)$ What is the basic difference between a cantilever retaining wall and a gravity retaining wall. $(2\%)$

$($b$)$ Check the overturning and sliding stabilities of the gravity wall given $($masonry$).$

$($c$)$ Check the overturning and sliding stabilities of the cantilever wall given $($reinforced concrete$).$

$($d$)$ State which one is more feasible as far as safety and economy are concerned. $($Assume the unit costs of masonry wall is $50$ pounds $\frac{?}{m^3},RC$ is $34$ pounds $\frac{?}{m^3}$ concrete $+10\%$ of the volume to be reinforcement of unit cost $1000$ pounds$/$ton$)$

Base soil:

$=20k\frac{N}{m^3}$

${}^{\text{'}}=35$

$c=30$kPa

c$-$ suma

Figure $1.$ Gravity Wall and RC Cantilever Wall$($a$)$ What is the basic difference between a cantilever retaining wall and a gravity retaining wall. $(2\%)$

$($b$)$ Check the overturning and sliding stabilities of the gravity wall given $($masonry$).$

$($c$)$ Check the overturning and sliding stabilities of the cantilever wall given $($reinforced concrete$).$

$($d$)$ State which one is more feasible as far as safety and economy are concerned. $($Assume the unit costs of masonry wall is $50$ pounds $\frac{?}{m^3},RC$ is $34$ pounds $\frac{?}{m^3}$ concrete $+10\%$ of the volume to be reinforcement of unit cost $1000$ pounds$/$ton$)$

Base soil:

$=20k\frac{N}{m^3}$

${}^{\text{'}}=35$

$c=30$kPa

c$-$ suma

Figure $1.$ Gravity Wall and RC Cantilever Wall