Dams & Bridges

ITAIPU DAM

The Itaipu Dam is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The name "Itaipu" was taken from an isle that existed near the construction site. In theGuaraní language, Itaipu means "the sounding stone".

The dam is the largest operating hydroelectric facility in terms of annual energy generation, generating 94.7 TWh in 2008 and 91.6 TWh in 2009, while the annual energy generation of the Three Gorges Dam was 80.8 TWh in 2008 and 79.4 TWh in 2009. The dam's 14,000 MW installed capacity is second to the Three Gorges Dam's 22,500 MW, though. It is a binational undertaking run by Brazil and Paraguay at the Paraná River on the border section between the two countries, 15 km (9.3 mi) north of the Friendship Bridge. The project ranges from Foz do Iguaçu, in Brazil, and Ciudad del Este in Paraguay, in the south to Guaíra and Salto del Guairáin the north. The installed generation capacity of the plant is 14 GW, with 20 generating units providing 700 MW each with a hydraulic design head of 118 m. In 2008 the plant generated a record 94.68 TWh, supplying 90% of the electricity consumed by Paraguay and 19% of that consumed by Brazil.

Of the twenty generator units currently installed, ten generate at 50 Hz for Paraguay and ten generate at 60 Hz for Brazil. Since the output capacity of the Paraguayan generators far exceeds the load in Paraguay, most of their production is exported directly to the Brazilian side, from where two 600 kV HVDC lines, each approximately 800 km long, carry the majority of the energy to the São Paulo/Rio de Janeiro region where the terminal equipment converts the power to 60 Hz.

Construction

• The course of the seventh biggest river in the world was shifted, as were 50 million tons of earth and rock.
• The amount of concrete used to build the Itaipu Power Plant would be enough to build 210 football stadiums the size of the Estádio do Maracanã.
• The iron and steel used would allow for the construction of 380 Eiffel Towers.
• The volume of excavation of earth and rock in Itaipu is 8.5 times greater than that of the Channel Tunnel and the volume of concrete is 15 times greater.
• Around forty thousand people worked in the construction.
• Itaipu is one of the most expensive objects ever built.

Generating station and dam

• The total length of the dam is 7235 m. The crest elevation is 225 m. Itaipu is actually four dams joined together — from the far left, an earth fill dam, a rock fill dam, a concrete buttress main dam, and a concrete wing dam to the right.
• The spillway has a length of 483 m.
• The maximum flow of Itaipu's fourteen segmented spillways is 62.2 thousand cubic metres per second, into three skislope formed canals. It is equivalent to 40 times the average flow of the nearby natural Iguaçu Falls.
• The flow of two generators (700 m³·s⁻¹ each) is roughly equivalent to the average flow of the Iguaçu Falls (1500 m³·s⁻¹).
• If Brazil were to use Thermal Power Generation to produce the electric power of Itaipu, 434,000 barrels (69,000 m³) of petroleum would have to be burned every day.
• The dam is 196 metres high, equivalent to a 65-story building.
• Though it is the seventh largest reservoir in size in Brazil, the Itaipu's reservoir has the best relation between electricity production and flooded area. For the 14,000 MW installed power, 1350 square kilometres were flooded. The reservoirs for the hydroelectric power plants of Sobradinho Dam, Tucuruí Dam, Porto Primavera Dam, Balbina Dam, Serra da Mesa Dam and Furnas Dam are all larger than the one for Itaipu, but have a smaller installed generating capacity. The one with the largest hydroelectric production, Tucuruí, has an installed capacity of 8,000 MW, while flooding 2,430 km² (938 sq mi) of land.
• Electricity is 55% cheaper when made by the Itiapu Dam than the other types of power plants in the area.

GORDAN DAM

The Gordon Dam (also known as Gordon River Dam), is a double curvature arch dam on the Gordon River in Tasmania, Australia. The dam has a length of 192 m (630 ft), and a height of 140 m (459 ft),making it the tallest dam in Tasmania and the fifth-tallest in Australia.

Water from the dam drops 183 m (600 ft) underground into its power station, where three turbines of 144 MW generates up to 432 MW of power, covering about 13% of the electricity demand of Tasmania.The first two turbines were commissioned in 1978, before the third was commissioned a decade later in 1988.

The power station is fuelled by water from Lake Gordon. Water from Lake Pedder is also drawn into Lake Gordon through the McPartlans Pass Canal at42°50′51″S 146°11′45″E.

Akashi Kaikyo Bridge

The bridge has three spans. The central span is 1,991 m (6,532 ft),and the two other sections are each 960 m (3,150 ft). The bridge is 3,911 m (12,831 ft) long overall. The two towers were originally 1,990 m (6,529 ft) apart, but the Great on January 17, 1995, moved the towers so much (only the towers had been erected at the time) that the span had to be increased by 1 m (3.3 ft).

The bridge was designed with a two hinged stiffening girder system, allowing the structure to withstand winds of 286 kilometers per hour (178 mph), earthquakes measuring to 8.5 on the Richter scale, and harsh sea currents. The bridge also contains pendulums that are designed to operate at the resonance frequency of the bridge to dampen forces. The two main supporting towers rise 282.8 m (928 ft) above sea level, and the bridge can expand because of heat by up to 2 m (7 ft) over the course of a day. Each anchorage required 350,000 tones (340,000 long tons; 390,000 short tons) of concrete. The steel cables have 300,000 kilometers (190,000 mi) of wire: each cable is 112 centimeters (44 in) in diameter and contains 36,830 strands of wire.

The Akashi-Kaikyo Bridge has a total of 1,737 illumination lights: 1,084 for the main cables, 116 for the main towers, 405 for the girders and 132 for the anchorages. On the main cables three high light discharged tubes are mounted in the colors red, green and blue. The RGB model and computer technology make for a variety of combinations. Currently, 28 patterns are used for occasions as national or regional holidays, memorial days or festivities.