Example $3$

Gravity dam section shown in the figure below for the following loading conditions:

Normal uplift pressure with gallery drain working

Silt deposit up to $30m$ height. Assume the fetch length $(F)=35km$ and the wind speed $(V)=22k\frac{m}{h}$

No ice pressure

Unit weight of concrete $=24K\frac{N}{m^3},$ and for water $)=(10K\frac{N}{m^3}$

The unit weight of silty water $=14K\frac{N}{m^3}$ and submerged weight of silt $=9K\frac{N}{m^3}$

Coefficient of friction $=0\mathrm{.}65$ and the angle of internal friction of the soil as $=25.$

Allowable stress in concrete may be taken as $2500K\frac{N}{m^2}$