A gravity dam is being designed as shown below and has the following design

characteristics: B$=50$ m$,$ H$=80$ m$,$ d$=20$ m$,$ Gs$=2\mathrm{.}7,$ n$=0\mathrm{.}4.$ Check if the safety factor FS is

greater than $2.$ If it is not, find what porosity should the soil have $($by compaction$)$ and what

depth $($d$)$ should the sheet pile have under the dam in order to achieve FS$>2.(40$ points$)$ A gravity dam is being designed as shown below and has the following design

characteristics: $B=50m,H=80m,d=20m,Gs=2\mathrm{.}7,n=0\mathrm{.}4.$ Check if the safety factor $FS$ is

greater than $2.$ If it is not, find what porosity should the soil have $($by compaction$)$ and what

depth $($d$)$ should the sheet pile have under the dam in order to achieve FS$>2.$