Hydrostatic Pressure on Gravity Dam

Q. A concrete gravity dam has 40 m height of water on its upstream side and 3 m water on its downstream side. If the level of water on the upstream side is increased by 1 m, the hydrostatic force acting on the dam will_____

1. increase by 9.8 kN/m
2. decrease by 9.8 kN/m
3. increase by 4.9 kN/m
4. decrease by 19.6 kN/m

Q. Net hydrostatic force acting on a gravity dam is F. If the coefficient of friction at the base of the dam is doubled, the new hydrostatic force on the dam will be?

1. 4F
2. 2F
3. F
4. 0.5F

Q. The top width and the bottom width at river thalweg level of a concrete gravity dam are 6 m and 24 m respectively. The vertical section of the dam at the thalweg alignment is 38 m above the thalweg. The upstream face is vertical and the depth of water on the upstream side is 36 m. The moment of hydrostatic force about the toe at the level is

1. 77760 kN-m
2. 25292 kN-m
3. 6480 kN-m
4. 51840 kN-m