Read the text and make up a bridgework glossary in Russian.

A bridge is a raised structure made of wood, stone, brick, concrete, iron, or steel, linking two opposite sides without disturbing or making contact with the roadway, body of water, obstacle or depressionbeneath it. Bridges vary in construction according to the gap they span and the loads they resist. So bridges are designed, firstly, to carry their own permanent weight, or dead load; secondly, to carry traffic, or live loads; and finally, to resist natural forces such as wind or earthquakes. A cantilever bridge is ideal for heavy loads, although an arch bridge is preferable where terrain prevents erection of piers. A suspension bridge may span distances of up to 1 km. Bridges are classified according to the following criteria:

Criterion № 1. (the primary function of the bridge roadway)

1.1. Railway bridges.

1.2. Motorway bridges.

1.3. Footbridges.

1.4. Town bridges.

1.5. Pipe lines.

1.6. Metro bridges.

1.7. Combination or road-cum-rail bridges (for different means of transport).

Criterion № 2. (the superstructure material):

2.1. Timber (wooden) bridges.

2.2. Masonry bridges.

2.3. Reinforced-concrete bridges.

2.4. Metal bridges.

2.5. Steel reinforced-concrete bridges (composite bridges).

2.6. Suspension bridges (fig. 3.1a).

2.7. Cable-stayed bridges (fig. 3.1b).

The four primary materials used for bridges have been wood, stone, iron and concrete. Of these, iron has had the greatest effect on modern bridges. Steel is made from iron, and steel is used to make reinforced and prestressed concrete. Modern bridges are almost exclusively built with steel, reinforced concrete, and prestressed concrete. Suspension and cable-stayed bridges suspend the structures using flexible ropes or cables as the main supporting element. Curved cables are used for suspension bridges (fig. 3.1a), and nearly straight diagonal cables carry the main span in cable-stayed structures (fig. 3.1b). The cables comprise metal wire strands and that is why suspension and cable-stayed structures can be regarded as variants of metal bridges.

Criterion № 3. (the design model or structural design):

3.1 Beam bridges (fig. 3.1c) (a freely-supported slab or girder construction resting on piers).

3.2 Arch bridges (fig. 3.1d) (a curved structure producing a horizontal thrust through skewbacks to piers).

3.3 Frame-type bridges (fig. 3.1e) (a rigid frame structure with the horizontal deck slab made monolithic with the vertical abutment walls).

3.4 Cantilever bridges (fig. 3.1f) (a structure with projecting cantilever arms).

3.5 Combined systems (fig. 3.1f) (several simple structures: beam and arch).

Criterion № 4. (the position of the bridge floor):

4.1 Deck bridges (fig. 3.1c, e and d).

4.2 Through bridges (fig. 3.1h).

4.3 Half-through bridges (fig. 3.1g).

Criterion № 5. (the total bridge span):

5.1 Short bridges (up to 25 m long).

5.2 Medium size bridges (from 25 to 100 m long).

5.3 Long bridges (more than 100 m long).

Criterion № 6. (the number of spans):

6.1 Single-span bridges.

6.2 Double-span bridges.

6.3 Three-span bridges.

6.4 Multi-span bridges.

Criterion № 7. (Bridge service life):

7.1 Permanent bridges (Service life is 80 – 100 years).

7.2 Temporary bridges (Service life is about 10 – 15 years).

7.3 Short-term bridges (They are built for two/three days up to one year).

Further to the aforementioned bridge types there are movable bridges (drawbridges, leaf bridges, opening bridges, pivot bridges) (fig. 3.1i), floating bridges (raft bridges) (fig. 3.1j) and ferries. The drawbridge, or bascule, is the best known; it may be single or double-leaf. For exceptionally long spans, the pivot, or swing bridge, which turns on a table, is suitable, but it limits navigation. In practice, the basic forms are often combined. The principle factors determining bridge choice are: span, location and site conditions, availability of materials and labour, maintenance, loading conditions, appearance and cost.

Exercises:

Find the Russian equivalents for the following English terms:

A railway bridge, a pipeline, a timber bridge, a reinforced concrete bridge, a suspension bridge, a steel reinforced concrete bridge, curved ropes, an arch bridge, combined systems, a deck bridge.

Find the English equivalents to the following Russian terms:

Пешеходный мост, совмещенный мост, каменный мост, металлический мост, вантовый мост, гибкий кабель, балочный мост, мост с ездой понизу, капитальный мост, разводной мост, паромная переправа.

Complete and translate the following sentences:

1. (Городские мосты) involve the structures built in cities and towns for (автомобили, трамваи и пешеходы).

2. As a rule, railway bridges according to their (расчетная схема) are beam structures, which are considered the most reliable under operation. (Сквозная ферма) (fig. 3.1h) consists of separate elements for reducing the (собственный вес) and can resist wind velocity.

3. The carriages of (арочные мосты) transmit the vertical loads and horizontal thrust to the piers.

4. (Рамные мосты) are used as overpass or trestle bridges because of their small pier width. They provide the most economical use of (строительные материалы).

5. (Комбинированные мосты) are used in cities because of their architectural merits. Besides, these structures can realise record spans from 500 to 1, 410 m as (висячие и вантовые мосты) which also belong to this bridge type.

6. (Разводные мосты) are constructed in large cities over (водная преграда) for vessels with big displacement tonnage. Their height exceeds the size of (подмостовой габарит) even for first class rivers.

7. (Временные мосты) have as a rule timber piers and steel spans.

8. (Наплавные мосты) differ from other bridge types by supports made of pontoons and barges, which do not rest on the ground. These bridges are used as short-term structures.

Describe different bridge structures according to their structural design using the terminology below:

Beam bridges, arch bridges, drawbridges, cable-stayed bridges, combined bridges, suspension bridges, and permanent bridges

Answer the questions:

Unit 4

MOSCOW BRIDGES