روزانه تعداد زیادی از هموطنان عزیزمان به دنبال مقاله انگلیسی با موضوع ات مختلف هستند. این مقالات انگلیسی می توانند به عنوان تحقیق برای دانشگاه یا ترجمه بکار برده شوند.
در این پست یک مقاله انگلیسی درباره سد سازی که یکی از دروس رشته مهندسی عمران میباشد ورده شده است. این مقاله به زبان انگلیسی بدون ترجمه فارسی میباشد که امید واریم مورد استفاده عزیزان قرار گیرد.
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are often used in conjunction with dams to provide generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations.
ادامه مقاله پروژه سد سازی
The word dam can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities.
Most early dam building took place in Mesopotamia and the Middle East. Dams were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers, and could be quite unpredictable.
The earliest known dam is the Jawa Dam in Jordan, 100 km northeast of the capital Amman. This gravity dam featured a 4.5 m high and 1 m wide stone wall, supported by a 50 m wide earth rampart. The structure is dated to 3000 BC. The Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, located about 25 kilometers south of Cairo, was 102 m long at its base and 87 m wide. The structure was built around 2800 or 2600 B.C. as a diversion dam for flood control, but was destroyed by heavy rain during construction or shortly afterwards.
Roman dam construction was characterized by "the Romans' ability to plan and organize engineering construction on a grand scale". Roman planners introduced the then novel concept of large reservoir dams which could secure a permanent water supply for urban settlements also over the dry season. Their pioneering use of water-proof hydraulic mortar and particularly Roman concrete allowed for much larger dam structures than previously built, such as the Lake Homs Dam, possibly the largest water barrier to date, and the Harbaqa Dam, both in Roman Syria. The highest Roman dam was the Subiaco Dam near Rome; its record height of 50 m remained unsurpassed until its accidental destruction in 1305.
Roman engineers made routine use of ancient standard designs like embankment dams and masonry gravity dams. Apart from that, they displayed a high degree of inventiveness, introducing most of the other basic dam designs which had been unknown until then. These include arch-gravity dams, arch dams, buttress dams and multiple arch buttress dams, all of which were known and employed by the 2nd century AD (see List of Roman dams). Roman workforces also were the first to built dam bridges, such as the Bridge of Valerian in Iran.
Eflatun Pınar is a Hittite dam and spring temple near Konya, Turkey. It's thought to the time of the Hittite empire between the 15th and 13 century BC.
The Kallanai is a massive dam of unhewn stone, over 300 meters long, 4.5 meters high and 20 meters (60 ft) wide, across the main stream of the Kaveri river in Tamil Nadu, South India. The basic structure dates to the 1st century AD. and is considered one of the oldest water-diversion or water-regulator structures in the world, which is still in use. The purpose of the dam was to divert the waters of the Kaveri across the fertile Delta region for irrigation via canals.
Du Jiang Yan is the oldest surviving irrigation system in China that included a dam that directed waterflow. It was finished in 251 B.C. A large earthen dam, made by the Prime Minister of Chu (state), Sunshu Ao, flooded a valley in modern-day northern Anhui province that created an enormous irrigation reservoir (62 miles in circumference), a reservoir that is still present today.
مقاله انگلیسی درباره سد سازی (تحقیق و پروژه دانشجویی)
In Iran, bridge dams such as the Band-e Kaisar were used to provide hydropower through water wheels, which often powered water-raising mechanisms. One of the first was the Roman-built dam bridge in Dezful, which could raise 50 cubits of water for the water supply to all houses in the town. Also diversion dams were known. Milling dams were introduced which the Muslim engineers called the Pul-i-Bulaiti. The first was built at Shustar on the River Karun, Iran, and many of these were later built in other parts of the Islamic world. Water was conducted from the back of the dam through a large pipe to drive a water wheel and watermill. In the 10th century, Al-Muqaddasi described several dams in Persia. He reported that one in Ahwaz was more than 3,000 feet long, and that and it had many water-wheels raising the water into aqueducts through which it flowed into reservoirs of the city. Another one, the Band-i-Amir dam, provided irrigation for 300 villages.
In the Netherlands, a low-lying country, dams were often applied to block rivers in order to regulate the water level and to prevent the sea from entering the marsh lands. Such dams often marked the beginning of a town or city because it was easy to cross the river at such a place, and often gave rise to the respective place's names in Dutch. For instance the Dutch capital Amsterdam (old name Amstelredam) started with a dam through the river Amstel in the late 12th century, and Rotterdam started with a dam through the river Rotte, a minor tributary of the Nieuwe Maas. The central square of Amsterdam, covering the original place of the 800 year old dam, still carries the name Dam Square or simply the Dam.
The age of hydropower and large dams emerged following the development of the turbine. French engineer Benoît Fourneyron perfected the first water turbine in 1832. The era of mega-dam building was initiated after Hoover Dam was completed on the Colorado River in 1936. By 1997, there were an estimated 800,000 dams worldwide, some 40,000 of them over fifteen meters high.
Types of dams
Dams can be formed by human agency, natural causes, or even by the intervention of wildlife such as beavers. Man-made dams are typically classified according to their size (height), intended purpose or structure.
International standards (including International Commission on Large Dams, ICOLD) define large dams as higher than 15 meters and major dams as over 150 meters in height. The Report of the World Commission on Dams also includes in the large category, dams, such as Barrages, which are between 5 and 15 meters high with a reservoir capacity of more than 3 million cubic meters.
The tallest dam in the world is the 300-meter-high Nurek Dam in Tajikistan.
Intended purposes include providing water for irrigation to a town or city water supply, improving navigation, creating a reservoir of water to supply industrial uses, generating hydroelectric power, creating recreation areas or habitat for fish and wildlife, retaining wet season flow to minimise downstream flood risk and containing effluent from industrial sites such as mines or factories. Some dams can also serve as pedestrian or vehicular bridges across the river as well. When used in conjunction with intermittent power sources such as wind or solar, the reservoir can serve as pumped water storage to facilitate base load dampening in the power grid. Few dams serve all of these purposes but some multi-purpose dams serve more than one.
A saddle dam is an auxiliary dam constructed to confine the reservoir created by a primary dam either to permit a higher water elevation and storage or to limit the extent of a reservoir for increased efficiency. An auxiliary dam is constructed in a low spot or saddle through which the reservoir would otherwise escape. On occasion, a reservoir is contained by a similar structure called a dike to prevent inundation of nearby land. Dikes are commonly used for reclamation of arable land from a shallow lake. This is similar to a levee, which is a wall or embankment built along a river or stream to protect adjacent land from flooding.