It consists of inclined cover and buttress. The pier supports the cover plate, and the water pressure is transferred from the cover plate to the pier and then from the pier to the foundation. Pier dam is one of the most economical and reliable dam types. Compared with gravity dam, it has the advantages of small volume, low cost and strong adaptability to foundation.

According to the form of cover plate, buttress dam can be divided into three types: flat cover plate is called flat dam; The arched roof is called a multi-arch dam; A dam whose cover is thickened at the upstream end of the pier is called a big head dam.

Dams are usually concrete or reinforced concrete structures. Compared with gravity dams, buttress dams have the following characteristics: the upstream cover plate is often inclined, and the weight of water on the cover plate helps to stabilize the dam; The pier and dam members are thin and the internal stress is uniform, which can give full play to the strength of the material; The lateral stiffness of the pier is small, so the working condition of the pier should be checked when designing. The requirements of buttress dam on foundation conditions are higher than those of gravity dam.

Extended data

Dams include earth dams, rockfill dams and earth-rock mixed dams. , also collectively referred to as local material dam. It has the advantages of local materials, saving cement and low requirements for dam site foundation conditions. Generally, an earth dam consists of dam body, impervious body, drainage body and slope protection.

① Dam body: the main component of the dam. Under the action of water pressure and self-weight, the dam body mainly relies on its own weight to maintain stability.

② Impervious body: Its main function is to reduce the amount of water seepage from upstream to downstream, generally including core wall, inclined wall and bedding.

③ Drainage body: Its main function is to take away the seepage from upstream to downstream and enhance the stability of downstream slope protection.

④ Slope protection: to prevent the dam from being damaged by waves, ice, temperature changes and rainwater runoff.