A buttress dam or hollow dam is a

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of

buttresses A buttress is an architectural structure built against or projecting from a wall which serves to support or reinforce the wall. Buttresses are fairly common on more ancient (typically Gothic) buildings, as a means of providing support to act a ...

or supports. The dam wall may be straight or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the ground. Water pushes against the dam, but the buttresses are inflexible and prevent the dam from falling over. Buttress or hollow gravity dams were originally built to retain water for irrigation or mining in areas of scarce or expensive resources but cheap labour. A buttress dam is a good choice in wide valleys where solid rock is rare. As designs have become more sophisticated, the virtues and weaknesses of buttress dams have become apparent. The Romans were the first to use buttresses to increase the stability of a dam wall. Buttress dams of slab concrete construction became popular in the United States in the early 20th Century with the patented process of Norwegian-American civil engineer Nils F. Ambursen. Barrage de Roselend 2.jpg, Buttresses and an arch of the Roselend Dam in France 昔からある谷の土砂堰 - panoramio.jpg, Buttreresses check dam in Japan

Construction

Buttressed dams are so-called 'permitted dams'. They consist of piers of triangular cross-section with a free space between the piers and a sloping wall on the water side. The loads from the horizontal water head are transmitted underground through the wall and the columns. The load on the ground is relatively high due to the small footprint, which is why column foundations require a sufficiently load-bearing foundation. Depending on the shape of the pillars and the slab or vault water wall, a distinction is made between:{{Cite web, title=Types of Dam, url=https://britishdams.org/about-dams/dam-information/types-of-dam/, accessdate=2022-11-28, work=britishdams.org * Pier dam * Holpfeilerstauer * Pillar slab dam * Pillar vaulted dam

Notes

External links

Buttress dams Table of contents
Dams by type . Concrete buildings and structures Masonry dams