Name Pont du Gard means literally bridge of the Gard (river). The Gard River, which has given its name to the Gard departement, does not actually exist under this name. The river, formed by many tributaries, several of which are called Gardon, is itself called Gardon until its end.
Built on three levels, the Pont is 49 m high, and the longest level is 275 m (300 yards) long.
Lower level: 6 arches, 142 m long, 6 m thick, 22 m high
Middle level: 11 arches, 242 m long, 4 m thick, 20 m high
Upper level: 35 arches, 275 m long, 3 m thick, 7 m high
On its first level, it carries a road and at the top of the third level, a water conduit, which is 1.8 metres (6 ft) high and 1.2 meters (4 ft) wide and has a gradient of 0.4 percent.
It has long been thought that the Pont du Gard was built by Augustus' son-in-law and aide, Marcus Vipsanius Agrippa, around the year 19 BC. Newer excavations, however, suggest the construction may have taken place in the middle of the first century A.D, consequently, opinion is now somewhat divided on the matter. Designed to carry the water across the small Gardon river valley, it was part of a nearly 50 km (31 mi) aqueduct that brought water from the Fontaines d'Eure springs near Uzès to the Castellum in the Roman city of Nemausus (Nîmes).The full aqueduct had a gradient of 34 cm/km (1/3000), descending only 17 m vertically in its entire length and delivering 20,000 cubic meters (5 million gallons) of water daily. It was constructed entirely without the use of mortar. The aqueduct's stones – some of which weigh up to 6 tons – were precisely cut to fit perfectly together eliminating the need for mortar. The masonry was lifted into place by block and tackle with a massive human-powered treadmill providing the power for the winch. A complex scaffold was erected to support the aqueduct as it was being built. The face of the aqueduct still bears the mark of its construction, in the form of protruding scaffolding supports and ridges on the piers which supported the semicircular wooden frames on which the arches were constructed. It is believed to have taken about three years to build, employing between 800 and 1,000 workers.
|Главная страница сайта «Мосты»||-||http://bestbridge.net/index.php|