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30-609: Crystal Dam is a 323-foot-tall (98 m), double-curvature, concrete, thin arch dam located 6 miles downstream from Morrow Point Dam on the Gunnison River in Colorado , United States. Crystal Dam is the newest of the three dams in Curecanti National Recreation Area ; construction on the dam was finished in 1976. The dam impounds Crystal Reservoir . Crystal Dam and Reservoir are part of

60-460: A contract for the diversion tunnel was awarded in 1972, which was holed through the same year. The construction contract for the dam itself was awarded to the J.F. Shea Company in June 1973. Cofferdam work continued into 1974, encountering problems with leakage though the upstream cofferdam; 24-inch (61 cm) wells were drilled below the cofferdam to intercept water. In the meantime, the dam foundation

90-484: A radius of 35 m (115 ft). Their second dam was built around 1350 and is called the Kurit Dam . After 4 m (13 ft) was added to the dam in 1850, it became 64 m (210 ft) tall and remained the tallest dam in the world until the early 20th century. The Kurit Dam was of masonry design and built in a very narrow canyon. The canyon was so narrow that its crest length is only 44% of its height. The dam

120-617: Is double-curved in both its horizontal and vertical planes may be called a dome dam . Arch dams with more than one contiguous arch or plane are described as multiple-arch dams . Early examples include the Roman Esparragalejo Dam with later examples such as the Daniel-Johnson Dam (1968) and Itaipu Dam (1982). However, as a result of the failure of the Gleno Dam shortly after it was constructed in 1923,

150-502: Is 214 meters (702 ft) high and 1,314 meters (4,311 ft) long across its crest. It was completed in 1968 and put in service in 1970. Pensacola Dam was one of the last multiple arch types built in the United States. Its NRHP application states that this was because three dams of this type failed: (1) Gem Lake Dam, St. Francis Dam (California), Lake Hodges Dam (California). None of these failures were inherently caused by

180-403: Is made of concrete and placed in a V-shaped valley. The foundation or abutments for an arch dam must be very stable and proportionate to the concrete. There are two basic designs for an arch dam: constant-radius dams , which have constant radius of curvature, and variable-radius dams , which have both upstream and downstream curves that systematically decrease in radius below the crest. A dam that

210-557: Is still erect, even though part of its lower downstream face fell off. The Tibi Dam in Tibi , Spain was a post-medieval arch dam built between 1579 and 1594 and the first in Europe since the Romans. The dam was 42.7 metres (140 ft) high and 65 metres (213 ft) long. This arch dam rests on the mountains sides. In the early 20th century, the world's first variable-radius arch dam

240-516: Is uncertain, but may rather point to a common gravity dam . The construction and design of the dam was related by the East Roman historian Procopius around 560 AD in his treatise on the architectural achievements of the Justinian I era ( De Aedificiis II.3). His report is notable for its clear understanding of arch action and the distribution of water pressure in arch dams; it provides

270-579: The Glanum Dam in France . Field work on the ground by the German scholar Günther Garbrecht in the late 1980s has raised some doubts whether Procopius's account are to be interpreted as referring to an arch dam. Garbrecht was able to identify a dam site near the ancient city-walls whose characteristics were consistent with Procopius' precise description – with the exception of the crescent-shaped contour of

300-588: The 143-meter double-curved Morrow Point Dam in Colorado, completed in 1968. By the late 20th century, arch dam design reached a relative uniformity in design around the world. Currently, the tallest arch dam in the world is the 305 metres (1,001 ft) Jingpin-I Dam in China , which was completed in 2013. The longest multiple arch with buttress dam in the world is the Daniel-Johnson Dam in Quebec , Canada . It

330-693: The Bureau of Reclamation's Wayne N. Aspinall Unit of the Colorado River Storage Project , which retains the waters of the Gunnison River and its tributaries for agricultural and municipal use in the American Southwest. The dam's primary purpose is hydroelectric power generation. Crystal Dam, like the higher Morrow Point Dam farther upstream, is a thin-shell arch dam, primarily planned to generate hydroelectric power. Unlike its upstream companions, excess water spills over

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360-602: The Colorado River Storage Project to be completed. Crystal Dam's design and construction lagged behind Morrow Point and Blue Mesa dams. Construction started in 1964 on a materials borrow pit, with construction at the damsite beginning in 1965 for an access road and exploratory drilling. Work then stopped for five years. Initially planned as an earth-fill dam, the design was changed to a double-curvature, thin-shell concrete arch dam. After an initial bidding process in which all bid were rejected as too high,

390-479: The Dara Dam would have resisted the water pressure by its sheer weight , not any arch action. Garbrecht surmises that the irregular shape of the dam may have led Procopius to a poetical allusion to the crescent-shaped firmament . By his own admission, however, his observations in situ fell short of a systematic hydrological and topographical field survey which he urged in view of the continuing deterioration of

420-434: The Romans in 300 AD. It was 5.7 metres (19 ft) high and 52 m long (171 ft), with a radius of 19 m (62 ft). The curved ends of the dam met with two winged walls that were later supported by two buttresses. The dam also contained two water outlets to drive mills downstream. The Dara Dam was another arch dam built by the Romans in which the historian Procopius would write of its design: "This barrier

450-564: The Vallon de Baume Dam, was built by the Romans in France and it dates back to the 1st century BC. The dam was about 12 metres (39 ft) high and 18 metres (59 ft) in length. Its radius was about 14 m (46 ft), and it consisted of two masonry walls. The Romans built it to supply nearby Glanum with water. The Monte Novo Dam in Portugal was another early arch dam built by

480-458: The construction of new multiple arch dams has become less popular. Contraction joints are normally placed every 20 m in the arch dam and are later filled with grout after the control cools and cures. Dara Dam The Dara Dam was a Roman arch dam at Dara in Mesopotamia (modern-day Turkey ), a rare pre-modern example of this dam type. The modern identification of its site

510-415: The dam has a clear span of 60 ft (18 m) and each buttress is 24 ft (7.3 m) wide. Arch dam designs would continue to test new limits and designs such as the double- and multiple-curve. Alfred Stucky and the U.S. Bureau of Reclamation developed a method of weight and stress distribution in the 1960s, and arch dam construction in the United States would see its last surge then with dams like

540-400: The dam. The discovered structure, a ca. 4 m wide and 5 m high masonry wall with a Roman concrete core, had an estimated crest length of 180–190 m; its middle section was completely destroyed on a length of 60–70 m. Although it cannot be ruled out that the dam once followed a slightly curved course in the gap, the extant flanking walls rather indicate a polygonal ground plan. In this case,

570-467: The diversion tunnel on April 12. The powerplant was not completed until 1978, the victim of a fire in the contractor's warehouse that destroyed many electrical components intended for the plant. Because of Crystal Dam's then-new design, and as a result of the failure of the contemporary Teton Dam in 1976, Crystal Dam was inspected in 1978 by divers to verify the integrity of the structure. Arch dam In general, arch dams are classified based on

600-401: The earliest description of such types of dam as opposed to the gravity dam , the standard design throughout antiquity and beyond. Procopius makes two essential points clear: first, the dam had a curved plan in order to withstand the water pressure, and did not follow a more or less curved line just because this was where the most solid bedrock was found, and secondly, the thrust of the water

630-401: The multiple arch design. The design of an arch dam is a very complex process. It starts with an initial dam layout, that is continually improved until the design objectives are achieved within the design criteria. The main loads for which an arch dam is designed are: Other miscellaneous loads that affect a dam include: ice and silt loads, and uplift pressure. Most often, the arch dam

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660-401: The ratio of the base thickness to the structural height (b/h) as: Arch dams classified with respect to their structural height are: The development of arch dams throughout history began with the Romans in the 1st century BC and after several designs and techniques were developed, relative uniformity was achieved in the 20th century. The first known arch dam, the Glanum Dam , also known as

690-459: The state of Oklahoma in 1940, was considered the longest multiple arch dam in the United States. Designed by W. R. Holway , it has 51 arches. and a maximum height of 150 ft (46 m) above the river bed. The total length of the dam and its sections is 6,565 ft (2,001 m) while the multiple-arch section is 4,284 ft (1,306 m) long and its combination with the spillway sections measure 5,145 ft (1,568 m). Each arch in

720-583: The top of the dam through a notched-out, ungated spillway that can create a 227-foot (69 m) waterfall in times of overflow. Under normal conditions the river flows through an 11.5 feet (3.5 m) diameter penstock to the 28 MW turbine. The dam is deep within the Black Canyon of the Gunnison in pre-Cambrian metamorphic rock. Crystal Dam was the last of the three dams in the Aspinall Unit of

750-401: The two cliffs, that the water of the river could not possibly get by that point, even if it should come down very violently...This barrier was not built in a straight line, but was bent into the shape of a crescent, so that the curve, by lying against the current of the river, might be able to offer still more resistance to the force of the stream. Another ancient dam working by arch action was

780-614: The world, in particular by the U.S. Bureau of Reclamation . In 1920, the Swiss engineer and dam designer Alfred Stucky developed new calculation methods for arch dams, introducing the concept of elasticity during the construction of the Montsalvens arch dam in Switzerland, thereby improving the dam profile in the vertical direction by using a parabolic arch shape instead of a circular arch shape. Pensacola Dam , completed in

810-629: Was built on the Salmon Creek near Juneau , Alaska . The Salmon Creek Dam's upstream face bulged upstream, which relieved pressure on the stronger, curved lower arches near the abutments. The dam also had a larger toe, which off-set pressure on the upstream heel of the dam, which now curved more downstream. The technology and economical benefits of the Salmon Creek Dam allowed for larger and taller dam designs. The dam was, therefore, revolutionary, and similar designs were soon adopted around

840-558: Was excavated, with first concrete placement in June. Excavation and concrete work for the powerplant started the same year. Concrete work stopped in November, and resumed in April 1975. Work was behind schedule; the dam was supposed to be completed by December 1975. Concrete work resumed in April 1976, with final completion of the dam structure on August 30, 1976. Filling operations in the reservoir began on March 14, 1977, permanently blocking

870-460: Was not built in a straight line, but was bent into the shape of a crescent, so that the curve, by lying against the current of the river, might be able to offer still more resistance to the force of the stream." The Mongols also built arch dams in modern-day Iran. Their earliest was the Kebar Dam built around 1300, which was 26 m (85 ft) high and 55 m (180 ft) long, and had

900-439: Was not contained by the sheer weight of the structure (as in gravity dams), but transferred by the abutments to the wing walls of the gorge through the curvature of the lying arch . Procopius writes: At a place about forty feet removed from the outer fortifications of the city, between the two cliffs between which the river runs, he constructed a barrier of proper thickness and height. The ends of this he so mortised into each of

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