An average dam is a wall of solid material built across a river to impede the flow of lake hence saving liquid in the lake which will develop upstream of this dam as water consistently move from the lake upstream associated with dam.
The key intent behind most dams is always to produce a permanent reservoir of liquid for use at another time. The dam must be watertight (ie impermeable or impervious to water) making sure that liquid doesn't leak out of the dam and escape downstream. An essential element of a dam is therefore the "impermeable membrane", ie the watertight an element of the dam that stops liquid leaking on. As we shall see later, it is really not needed your whole dam wall be watertight. The normal earth or rock on which the dam is created (ie the dam basis) should be watertight as must the river area in which the storage reservoir kinds. If these all-natural areas (dam foundation and storage space) aren't watertight then water could leak out of the reservoir even though the dam itself is watertight.
Including being watertight a dam must be steady ie the dam wall need enough strength to firstly, stay forever under unique weight particularly when at the least the main dam wall surface is saturated with water and next, resist water pressure within the pond upstream associated with the dam. This liquid stress exerts a force on dam wall maintaining press it downstream. The higher the dam, the greater the depth of liquid stored behind the dam plus the better water stress on the dam wall. The dam additionally needs to have sufficient energy to withstand other causes to which it might be exposed from time to time eg trembling from earthquakes. The danger that earthquakes pose to dams differs widely with respect to the area worldwide where the dam is found.
A dam should have somehow of releasing liquid in controlled amounts because it's required ie an outlet device of some type. Depending on the purpose of the dam water can be released into a pipeline to produce a city with liquid, or into a hydro-electric energy station to build electrical energy or even the liquid may simply be circulated to the river sleep downstream of the dam and allowed to move obviously along the river, ultimately to be pumped aside and utilized for irrigation of crops further downstream. The outlet valve needs to be connected via a pipe or tunnel to some kind of intake framework in which the water is attracted from the storage space reservoir.
As soon as the lake which the dam has-been built floods a really big level of flooding liquid will flow in to the storage space reservoir. Frequently that is extremely, truly more water than can be circulated through the outlet valve. A dam must have some means whereby these big volumes of flood water can move all over dam without producing harm to the dam itself; ie a spillway which, generally, is an open slice station large enough to carry the flood liquid all over dam. In the event that dam is built of tangible the spillway may form the main dam wall itself. But in the event that dam is built of planet and/or rock fill (ie earth and broken stone) the spillway needs to be a separate framework because flooding seas can't be allowed to move outrageous of a fill (or embankment) dam which would be quickly cleaned away because of the flood liquid if this was to take place.
A sizable dam project may include many types of construction aside from creating the dam wall itself eg tunnelling for diversion or outlet works; roadway building to displace roadways overloaded by the reservoir; quarrying to get rock fill along with other building materials; excavation of open slices the spillway, accessibility roads and roadway deviations.