A gravity dam is to be designed as a high dam if it’s height h is as follows:
where fc = permissible comp, stress, μ, W and Ss have their usual meaning
In modern practice the free board normally provided for gravity dam is
Fine board is provided in gravity dam is normally 3/2 hw or 4-5% of the dam material.
Consider the following statements :
Phreatic line in an earth dam is
1. elliptical in shape
2. an equipotential line
3. the top-most flow line with zero water pressure
4. approximately a parabola
Which of these Statements are correct?
The down stream slope of an earthen dam is critical when
The safe base width B of an elementary gravity dam profile using stability or sliding criteria is given by
h = height of dam;
C = uplift pressure coefficient.
Others have usual meaning
When a reservoir is full, the maximum compressive stress in gravity-dam occurs
An earthquake acceleration of 0.1 g acting vertically downward causes in a gravity dam
Effective unit weight is given by,
so when αv = 0.1 g (downward)
effective unit weight
Net effective weight of Dam
What is the height of wave which is likely to be generated by a wind of 80 km/hr in a reservoir having a fetch of 50 km?
Waves are generated on the surface of reservoir by the blowing winds, which causes a pressure towards the downstream side. Wave pressure depends upon the wave, height. Wave height in metres may be given by the equation.
where V is wind velocity in km/hr and F is fetch in km.