Complete and translate the following sentences
1. The simplest bridge is a beam or girder structure. A beam stretches from one side of a gap to the other side and rests directly on the ground or (опоры). The length of a beam bridge depends on the (собственный вес) of the beam and the live load from the traffic it carries. Longer (балочные мосты) are constructed by joining a number of beams in (секции).
2. A (консольный мост) is a variation of the simple beam bridge. It consists of three parts: the outer beams, the cantilevers, and the (центральная балка). A cantilever, firmly anchored at one end, is a very (прочная конструкция).
3. (Фермы) can increase the strength of a cantilever bridge (or any bridge). A truss is a structure that consists of a number of joined (треугольники). It adds strength to the bridge elements with relatively little additional weight due to its open structure that allows the wind to blow through it.
4. As a rule, railway bridges according to their (расчетная схема) are beam structures. (Сквозная ферма) (fig. 3.2h) consists of separate elements for reducing the (собственный вес) and can resist wind loads.
5. (Криволинейные) elements in an arch bridge are its main supporting structure. The (пята свода) of the arch bridge are sunk deep into the (грунт) or bedrock, and are able to (выдерживать) very large forces.
6. The (проезжая часть моста) of an arch bridge can be placed on top, beneath or within the arch. If the roadway is above the arch, it is (прикрепляется) to the arch by vertical posts (ribs and columns). Ropes or cables (suspenders) support the roadway from the arch when it is below the arch. If the roadway is somewhere within the arch it is attached to it by some (сочетание) of the two.
7. (Разводные мосты) are built over waterways in large cities to allow the vessels with big displacement tonnage to pass. Their height exceeds the size of (подмостовой габарит) even for the first class rivers.
8. A (поворотный мост) has a large, heavy pier that supports a rotating central span. A (однокрылый раскрывающийся мост) can raise its roadway at one end. A (подъёмный мост) splits in two sections in the middle. Each half of the span can rise in the opposite direction. A vertical-lift bridge raises the central portion of the bridge straight up by means of (стальные тросы).
9. (Городские мосты) involve the structures built in cities and towns for (автомобили, трамваи и пешеходы).
10. (Рамные мосты) are used as overpasses or trestle bridges because of their small pier width. They provide the most economical use of (строительные материалы).
11. (Комбинированные мосты) are used in cities because of their architectural merits. Besides, these structures can realise record spans from 500 to 1,991 m as (висячие и вантовые мосты) which also belong to this bridge type.
12. (Наплавные мосты) differ from other bridge types by supports made out of pontoons and barges, which do not rest on the ground. These bridges are short-term structures (fig. 3.3d).
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