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Учебное пособие. Английский язык в профессии.docx
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Unit 1. Bridges Classification.

Vocabulary.

mention - упоминать

in a wide sense - в широком смысле

provide a crossing over - обеспечить возможность пересечения

be classified - классифицироваться

function - функция

reinforced concrete - железобетон

сable-stayed - вантовый

include - включать

flexible - гнущийся

rigid - негнущийся

service life - срок службы

It has already been mentioned that bridges in a wide sense of this term mean constructional works comprising a superstruc­ture and a substructure. In a narrow sense this term means a structure built to provide a crossing over a river.

In technical literature bridges are classified according to their indications as follows:

Indication №1—by the main road function.

1. Railway bridges.

2. Motorway bridges.

3. Foot-bridges (Pedestrian bridges).

4. City bridges.

5. Pipe lines.

6. Metro-bridges.

7. Combined systems or road-cum-rail bridges (carrying various means of transport).

Indication №2 - by the superstructure material.

2.1. Timber bridges (wooden bridges).

2.2. Stone bridges (masonry bridges).

2.3. Reinforced concrete bridges.

2.4. Metal bridges.

2.5. Steel reinforced concrete bridges (composite bridges).

2.6. Suspension bridges.

2.7. Cable-stayed bridges.

The suspension and cable-stayed bridges include the structures with the flexible stayed ropes as the main carrying element. Curvilinear ropes are used for suspension bridges and rectilinear ropes are used for cable-stayed structures. The ropes are made of metal wire strands and that is why suspension and cable-stayed structures can be regarded as variants of metal bridges.

Indication № 3 – by a structural model.

1.

Beam bridges. (Spans of rectangular shape rest on supports).

2.

Arch bridges. (A curvilinear structure produces a horizontal thrust through skewbacks to the supports).

3.

Frame-type bridges. (Spans and supports are all indivisible rigid structure).

4.

Cantilever bridges. (These structures include cantilever arms, i.e. elements built out of their supports).

5.

Combined systems. (They consist of several simple structures – beam + arch).

Indication № 4 – by the position of the bridge floor.

1.

Deck bridges.

2.

Through bridges.

3.

Half-through bridges.

Indication № 5 – by the overall bridge length.

1.

Short bridges (up to 25 m long).

2.

Medium bridges (from 25 to 100 m long).

3.

Long bridges (more than 100 m long).

Indication № 6 – by the number of spans.

1.

Single-span bridges.

2.

Double-span bridges.

3.

Three-span bridges.

4.

Multi-span bridges.

Indication № 7 – by the service life.

1.

Permanent bridges. (Service life is 80-100 years.)

2.

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

3.

Short-term bridges. (They are built for the period from two – three days to one year.)

In addition to the mentioned bridge types there are drawbridges (movable bridges), floating (raft) bridges and the ferrying.

Answer the questions:

  1. How bridges are classified in technical literature?

  2. What are the advantages and disadvantages of beam bridges?

  3. What are the advantages and disadvantages of truss bridges?

  4. What are the advantages and disadvantages of cable-stayed bridges?

  5. What materials are most commonly used and why?

Exercises:

1) Find the equivalents:

трубопровод

совмещенный мост (для автомобильного и ж/д транспорта)

железобетонный

вантовый мост

балочный мост

рамный мост

балочно-консольный мост

комбинированный мост с ездой посередине

мост с ездой понизу

сквозная ферма с ездой понизу

разводной; подъемный мост