9.4 Find the Russian equivalents for the following English terms
Double-leaf bascule bridge, downstream, flood barrier, hydraulic pump, steam, surge tides, to sway, to put into operation, tower
Part III
9.5 Read the text about the most astonishing British bridges and tell about them
In 1779, Abraham Darby wrote a new page in the world’s bridge engineering history by building the first cast-iron bridge to span the Severn at Coalbrookdale in Great Britain. Designed by Thomas Pritchard, the bridge, constructed of cast-iron pieces, imitated stone construction with nearly semicircular 30-metre arch span (fig. 8.1a; 9.4a). Cast-iron plates covered each of its five thin cast-iron arch ribs. Despite the arch is slightly humped, the bridge is still used today but not for vehicles. It is now a British national monument.
Figure 9.4 Bridges of Great Britain
a – the earliest cast iron bridge across the Severn River; b – the Britannia Bridge;
c – the Tower Bridge
The upcoming of railways during the 19th century resulted in new bridge forms strong enough to resist the dynamic loads of trains. The most significant of these early railway bridges was the Britannia Bridge by Robert Stephenson across the Menai Strait. He supported a pair of completely enclosed iron tubes of rectangular section by a pier in the centre of span. He was the first to employ the hollow box girder, which gave the deck the extra stiffness of a truss. The workers delievered the iron tubes afloat, and then a capstan and hydraulic power lifted them. The lengths of spans are 140 m and each abutment span is 71 m long (fig. 9.4b). The bridge builders completed the structure in 1850.
There were towers for chains on the bridge. The towers were originally to carry the wrought iron boxes through which the trains ran. Now they are useless because there are no cables on the bridge. In 1960’s the structure was severely damaged by fire, and during the repairs the tubes disappiered completely. Steel arches support modern concrete deck. At present, the bridge carries railway and motor traffic (fig. 9.6a).
Exercises
9.6 Find the Russian equivalents for the following English terms
Capstan, enclosed iron tubes of rectangular section, hollow box girder, hydraulic power, semicircular arch, vehicle, wrought-iron box
9.7 Complete and translate the following text
There are two unique bridges (перекрывающие) the Firth of Forth in Scotland – the Forth Rail Bridge (fig. 9.5a, 9.6b) and the Forth Motorway Bridge. The Forth Rail Bridge was (спроектирован) and (построен) by engineer Benjamin Baker in 1891. He joined three giant (411-m) (консоли) (projecting members supported at only one end) together with two suspended spans of 107 m each, making a total of 518 m of (подмостовой габарит) over either arm of the firth. The steel structure rises 103 m above the masonry (опоры). The length of the middle span is the second in the world amongst non-suspended structures. The Forth Rail Bridge has no decorative elements, but it is a work of art, that towers above the sea into the sky. The great bridge has the (решётчатые связи жёсткости), that provide a visually dense interior. It provokes wonder and admiration to people from around the world, because viewed from different angles it takes on quite a different appearance.
Figure 9.5 Diadgram of Firth-of-Forth Bridges (схемы Фортских мостов)
a – Beam-cantilever Trusses (балочно-консольные фермы);
b – Suspension structure (висячий мост)
The neighbouring (автодорожный трехпролетный висячий мост) across the Firth of Forth was built in 1964. It carries two (полоса движения), a bikeway and a sidewalk in each direction.
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a - The modern Britannia Bridge (1980) |
b - The Firth-of-Forth Railway Bridge |
Figure 9.6 Famous Bridges in Great Britain
The main span is 1,006 m long, and ranks the bridge among the top ten structures with super long spans. Its (боковые пролеты) are 408 m long, and its (пилоны) are 154 m high. The cable diameter is 0.6 m and contains 37 (прядь) consisting of 314 wires in each strand. The total number of (высокопрочные проволоки) in the cable is 11,618. The diameter of each wire is 4.8 mm. The bridge, light and delicate in its design, seems a suspended in air structure.