What Is a Hydropower Dam?

Dam, a Chinese vocabulary, with the pinyin dà bà, refers to dikes that intercept rivers to block water, dams for reservoirs, rivers, and so on. Generally, a reservoir dam is mainly composed of a main dam, a secondary dam, a gravity dam, a normal spillway, a very spillway, a newly added spillway, a Lingzheng culvert and a power station.

[dà bà]

Dam <; name>

(Phonetic. From the soil, domineering. Original meaning: dyke)

Barrage to intercept the river. Dam [dam]

Its river runs from Xiba to

Dams can be divided into two categories, concrete dams and earth-rock dams. The type of dam is selected based on the comprehensive comparison of the natural conditions, construction materials, construction site, diversion, construction period, and cost of the dam site.

Role: Flood prevention, power generation

Concrete dam

There are three types of gravity dams, arch dams and buttress dams.

Gravity dam

Gravity dam: rely on the friction between the dam body's own weight and the foundation to withstand the thrust of water to maintain stability.

The advantages of gravity dams are simple structure, easy construction, and good durability. It is suitable for high dam construction on rock foundations, and it is convenient to set up drainage structures. However, the gravity dam is large and the amount of cement is large, and the material strength cannot be fully utilized.

Arch dam: It is a space shell structure, which is arched in the plane and protrudes upstream. The horizontal load applied by the arch is used to transfer the axial pressure to the bedrock on both sides of the bank. The dam is stable. Arch dams have high overload capacity. Arch dams have higher requirements on the foundation and rocks on both sides of the bank, and they are more difficult to construct than gravity dams. The dam site of the narrow river valley with hard and complete rock foundations on both banks is particularly suitable for the construction of arch dams. Generally, the ratio (T / H) of the dam bottom thickness T to the maximum dam height H (T / H) is less than 0.1; it is called a thin arch dam; If the T / H value is larger, the effect of the arch is very small, that is, it is closer to the gravity dam.

buttress dam: It consists of inclined cover and buttress. The support pier supports the cover surface, and the water pressure is transmitted from the cover surface to the support pier, and then from the support pier to the foundation. The branch pier dam is one of the most economical and reliable dam types. Compared with the gravity dam, it has the advantages of small size, low cost, and strong ability to adapt to the foundation. According to the form of the cover surface, the branch pier dam can be mainly divided into three types: the flat surface is called a flat dam; the cover surface is arched called a double arch dam; the cover surface is formed by the thickened upstream end of the pier. For the big head dam. Buttress dams are generally concrete or reinforced concrete structures. Compared with gravity dams, branch pier dams have the following characteristics: the upstream cover surface is often inclined, and the water weight on the cover surface can help stabilize the dam body; the branch pier dam has a thin component and uniform internal stress, which can give full play to the strength of the material; The lateral stiffness of the pier is relatively small, and the working conditions of the supporting piers during lateral earthquakes should be checked during design. The requirements for the foundation conditions of the supporting piers are higher than those of gravity dams.

Earth-rock dam ^[1]

Including earth dams, rockfill dams, earth-rock mixed dams, etc., also collectively referred to as local material dams. It has the advantages of taking materials locally, saving cement, and lower requirements for the foundation conditions of the dam site. Generally, the local material dam is composed of dam body, anti-seepage body, drainage body and slope protection.

Dam body: The main component of the dam. Under the effect of water pressure and dead weight, the dam body is mainly maintained by the dam body weight to maintain stability.

Impervious body: The main function is to reduce the amount of infiltrating water from upstream to downstream. Generally there are core walls, inclined walls, and coverings.

Drainage body: The main function is to drain the seepage water from the upstream to the downstream, and enhance the stability of the downstream slope protection.

Slope protection: to prevent damage to the dam by waves, ice, temperature changes and rainwater runoff.