Dams are structures used to control, block or divert the flow of a river or any other water body. Based on structure, dams are classified as Gravity Dams, Arch Dams, Buttress Dams, and Embankment Dams. In this article, we will discuss what is a Gravity Dam. Also, we will look at some famous Gravity Dams from around the world.
What is a Gravity Dam?
Gravity Dams are designed and constructed in such a way that the weight of the dam structure is able to resist external forces. The external forces acting on the dam are the pressure of the water and the uplift pressure. The water pressure acts horizontally towards the downstream side. The uplift pressure acts upwards from the foundation.
Uplift pressure is a vertical pressure acting on a structure from beneath when the foundation is below the surrounding water level. This pressure is applied by the water that seeps or flows below the foundation.
Gravity Dams are built with either concrete or masonry. However, nowadays mostly concrete is used. These dams require solid rock foundations. The initial cost of building is generally very high. However, these dams are known to last for years with relatively low maintenance. Some Gravity Dams have an arch-like structure, such dams are called Arch-Gravity Dams and have the qualities of both an Arch dam and a Gravity dam e.g. Hoover dam in the United States built on the Colorado River is an Arch-Gravity Dam. Now that you know what is a Gravity Dam. Let’s discuss some famous ones.
Some famous Gravity Dams
The Grande Dixence Dam
The Grande Dixence Dam in Hérémence, Switzerland is the tallest Gravity Dam in the world. Made from concrete, it has a height of 285 meters. The dam became operational in 1961. The installed capacity of the dam is 2,069 MW.
Hoover Dam in the United States is an Arch-Gravity Dam built on the Colorado River. With a height of 221.4 meters, the Hoover dam produces 2,080 MW of output.
Sardar Sarovar Dam
The Sardar Sarovar Dam in Gujarat, India is a recently constructed concrete Gravity Dam. It is built on the Narmada river and has a height of 163 meters. With a length of over 1.2 kilometers, it is one of the biggest dam structures in the world in terms of the amount of concrete used. The installed capacity of the dam is 1,450 MW.