Three types of gravity dams, arch dams and buttress dams

The gravity dam mainly relies on its own weight. The dam axis is generally a straight line, and there are transverse joints perpendicular to the dam axis direction to divide the dam body into several sections, and the cross section is triangular.

1) According to the height of the dam body, it is divided into high dam, medium dam and low dam. A dam with a height greater than 70m is called a high dam, a dam with a height less than 30m is called a low dam, and a dam in between is called a medium dam.

(2) According to dam construction materials, they are divided into concrete gravity dams and mortar masonry gravity dams. Most important gravity dams and high dams are made of concrete, while medium and low dams can be built with mortar blocks and stones.

3) According to water release conditions, they are divided into overflow gravity dams and non-overflow gravity dams.

4) According to the structure of the dam body, it is divided into solid gravity dam, open-belt gravity dam and wide-slit gravity dam.

(5) According to the construction method, it is divided into poured concrete gravity dam and roller compacted concrete gravity dam.

The wave-proof wall should leave expansion joints at the transverse joints of the dam body and set up water stops. The wall height can be 1.2m. Railings should be installed on the downstream side of the dam crest.

The width of the dam crest of the non-overflow dam section should not be less than 3.0m. The road surface on the top of the dam should have a transverse slope and drainage facilities, and the transverse slope should be appropriately increased in severe cold areas.

The top of the overflow dam should be equipped with working bridges and traffic bridges on the top of the dam in accordance with the requirements for gates, hoisting and closing equipment layout, operation and maintenance, traffic and observation. The bridge on the top of the dam can adopt a prefabricated reinforced concrete structure or a prestressed reinforced concrete structure, and there should be sufficient clearance under the bridge.

When the top of the dam is used as a highway, the sidewalks on both sides of the road should be 30cm higher than the road surface on the top of the dam.