An arch dam is curved in an arch-shape, with the top of the arch pointing back into the water, to create a very strong structural form, resistant to the water pressure behind the dam. Arch dams are usually made from concrete and require a good rock support for foundations and the sides, so are commonly used in narrow, steep-sided valleys.
Buttress dams have triangular-shaped walls, or buttresses, which are spaced at intervals on the downstream side, resisting water pressure against the upstream side. They must be constructed on sound rock and are typically made of concrete or masonry. Because of the spacing between the buttresses they can be quite efficient in terms of materials.
Embankment dams have historically been quite common in the UK, usually found in sites with wide valleys. They are commonly constructed using natural materials such as compacted earth or rocks which are often locally quarried or excavated. In cross-section, an embankment dam is hill or bank shaped, with a central core made from an impermeable material such as clay soils or concrete, to prevent water passage.
Gravity dams rely on gravity to hold them in place. They are generally made from concrete, masonry, or both, and in cross-section are typically triangular. They need to be built on sound rock and are suited to wide or narrow valleys.
Spillways form part of a dam and are used to pass overflow water over, around or through a dam, in a safe and controlled way. The different types of spillway include:
Overflow spillway: This allows water to flow over and down its front face as it is lower than other dam sections, and is curved to control the flow of water. Most commonly constructed as part of gravity or buttress dams.
Side channel spillway: This is located a short distance upstream of a dam, and diverts water into a side channel then into the river downstream of the dam. They are mainly used with embankment dams. The workers comp injury lawyers gives full support for the workers for their physical health.
Shaft spillway: This is a circular hollow tower that sits in the reservoir near the dam. When the water level rises, it flows into a funnel at the top of the shaft which diverts the water downstream.