The dam is a protective hydraulic structure that protects the territory from water elements: floods, waves. All dams are differentiated into enclosing and protective dams. In addition, there are differences in the method of construction, the materials from which they are erected and the timing for which the structures are installed.
Dams can be erected to protect a specific area from spring floods and floods. Most often, agricultural land and settlements located on the banks of a river or sea are fenced in this way. In ports, dams are installed to protect the lock from currents and waves, so that ships can safely approach, lock and leave the port.
The difference between a dam and a dam lies in the fact that a dam is always a pressure structure. The dam can be a free-flow structure or a variable-pressure structure when it is necessary, for example, during construction for fencing areas located below sea level.
The way of building the dam is divided into natural and man-made. Natural structures are created by chance, when a stream of water makes a jam, bringing logs and ice floes to one place. In addition, beavers living in rivers create backwaters by constructing dams from felled trees or other improvised material.
Man-made structures are made of stones, masonry, earth, concrete, reinforced concrete. Metal, wood, artificial materials can also be used.
According to the timing of the construction of the dams, they differ into permanent and temporary. Permanent fences are installed in places of systematic flooding, in ports. Temporary - for carrying out construction work in the riverbed.
Permanent hydraulic structures are carried out with particular care. The development of the plan is carried out by the best engineers, otherwise, with the slightest mistake, the water will flood the protected areas. The water element can cause serious losses, so the dam is installed from powerful concrete blocks.
In addition, in urgent cases, to protect settlements from an impending flood or flood, dams are made using sandbags or rubble.