Which one of the following, in a gravity dam, is the major resisting force?

Concept:

Gravity dam:

A gravity dam has been defined as a structure which is designed in such a way that its own weight resists the external forces. So the main stabilizing force for a gravity dam is self-weight of dam. This type of a structure is most durable and solid, and requires very little maintenance.

Such a dam may be constructed of masonry or concrete. However, concrete gravity dams are preferred these days and mostly constructed. They can be constructed with ease on any dam site, where there exists a natural foundation strong enough to bear the enormous weight of the dam.

It uses the weight of the material to resist the horizontal pressure of the water that is pushing it. Gravity dams are independent of any other section of the dam.

• Based on their structural height, the gravity dams are classified as low and high dams.
• For the gravity dam, the height of the dam is obtained from the equation,  \(h = \frac{f}{{w(\rho + 1)}}\) 

Note:

From the above equation obtained height is the maximum possible height of the dam when uplift is neglected. 

• If the value of h is exceeded then the dam is called a high gravity dam.
• If the height of the dam is less than the given equation height, That dam is known as a low gravity dam.

Additional Information 

Other definitions of a low and high gravity dam are:

• If the structural height of a gravity dam is up to 100 feet it is known as a low gravity dam.
• If the structural height is greater than 300 feet it is known as high gravity dam.