Exercise 3. Read and translate text A. Text A. Suspension structures (i)

Text A. SUSPENSION STRUCTURES (I)

Technologically primitive societies use lines and ropes for suspension bridges. Beginning in the early nineteen century, suspension bridges began to be built of iron chains, and then bundled steel wire cables. The classic example of the modern suspension bridge is the Brooklyn Bridge, begun by John Augustus Roebling in 1867 and finished by his son, George Washington Roebling in 1883. In this bridge steel wire was used in the cables for the first time. It has remained the model for suspension bridges since its construction.

Only since 1955 has the principle of cables in tension been used extensively for buildings. A tension structure is especially efficient, since the entire cable is in tension, whereas most other structural forms have mixed stresses (as in a simple beam which is in compression along the top and in tension along the bottom). A suspended cable is an ideal structural form, for it is entirely in tension. In fact, if it were possible to freeze that form and invert it, the result would be a parabolic arch virtually entirely in compression. Such arches and vault forms derived from them, were used by the Spanish architect Antoni Gaudi last century in Barcelona, Spain.

Eero Saarinen also used suspension in a number of buildings. Saarinen put up a reinforced concrete parabolic arch the length of the rink, suspending cables from that arch down to curved walls on either side of the rink. A wooden roof deck was then laid on the cables, Saarinen enlarged on this idea in his Dulles Airport Terminal, outside Washington, D.C., 1958-62. Here two rows were created of outward-leaning columns, curving over at the top to carry beams running the length of the terminal. Between these two parallel beams, cables were suspended. Concrete slabs were placed on the cables to create the roof deck. This may not seem a lightweight structure, but the dead weight of the roof deck was necessary to keep the roof from fluttering in the wind.

Exercise 4. Translate the words:

deck, iron, bottom, parabolic, rope, chain, cable, model, tension, compression, vault, rink, column, top, length, beam, suspend, slab, row, wall, freeze, entirely, invert, result, side, carry, remain, construction.

Exercise 5. Choose the right translation from A to B:

A: iron, steel, deck, vault, derive, tension, chain, compression, cable, rope, top, bottom, length, side, row, beam, suspend, slab, weight.

B: длина, железо, ряд, подвешивать, плита, вес, сталь, свод, цепь, настил, заимствовать, растяжение, сжатие, трос, балка, кабель, нижняя часть, верхняя часть, сторона.

Exercise 6. Are these meanings correct or incorrect? Correct the mistakes:

flutter – вибрация

dead weight – мертвый вес

top – верхняя часть

deck – палуба

bottom – нижняя часть

live weight – временный вес

chain – цепь

tension – сжатие

parabolic – параболический

cable – кабель

derive – заимствовать

freeze – замораживать

wire – трос

arch – арка

Exercise 7. Translate the following word combinations:

dead weight, live weight, modern suspension bridge, steel wire cable, suspended cable, ideal structural form, reinforced concrete, parabolic arch, wooden roof deck, concrete slab, lightweight structure, mixed stresses.

Exercise 8. Guess the meaning of the following words:

steel, cable, model, efficient, result, arch, idea, terminal, parallel, parabolic, form, classic, primitive, column, principle, vertical, dilemma, crane, architect, central, material, diameter, section.