Girder and Cantilever Bridges

A bridge is a structure carrying a roadway or a railway across rivers, valleys or other roads and railways, leaving a passage below. Bridges are classified as girder bridges, cantilever bridges, suspension bridges and also as mixed type bridges.

The plank across the stream is the simplest form of a bridge. Obviously the widest stream that can be bridged by such a method is one which is less than the length of the longest tree trunk that can be brought to the site. Such a bridge is called a girder bridge.

Modern bridge truss is derived from the tree-trunk bridge. Since the river was too wide for a single tree-trunk span the difficulty could be overcome by driving piles into the middle of the river and laying tree trunks on them.

But if the water was too deep for pile driving, other methods were available. Large brackets would be erected on each bank, jutting out over the water, and planks were laid from bracket to bracket. The deck of the bridge in the brackets had to be firmly anchored into the banks of the river, otherwise the load passed on to the overhanging part the bracket would tilt and fall into the water. This bracket construction is called a cantilever bridge.

РИСУНОК 1

Single Span Beam Bridge

РИСУНОК 2

Multi-Span Beam Bridge

РИСУНОК 3

Cantilever Bridge

EXERCISES

I. Find all the international words in the text.

II. Read and translate into Russian the following pairs of words:

leave – live

side – site

deck – desk

single – signal

too – two

pile – pier

since – science

III. Match the equivalents:

1. leave 1. преодолевать

2. passage 2. консоль

3. classify 3. настил

4. girder 4. арка

5. arch 5. подвеска

6. suspension 6. ещё

7. cantilever 7. забивка свай

8. deck 8. классифицировать

9. truss 9. проход

10. as far back as 10. балка

11. determine 11. больше не

12. call 12. закреплять

13. no longer 13. определять

14. pile driving 14. оставлять

15. anchor 15. называть

16. overcome 16. ферма

IV. Match the Synonyms:

1. single 1. secure

2. bridge 2. beam

3. girder 3. one

4. erect 4. securely

5. firmly 5. build

6. anchor 6. cross

V. Form the degrees of comparison:

Simple, little, modern, difficult, beautiful, short, long.

VI. Translate attributive groups:

Beam bridge, side span, pile bridge, modern bridge truss, tree trunk span, modern steel bridge, suspension span bridge, mixed type bridge.

VII. Translate the sentences paying attention to the word “one”:

1. Girders of the Hammersmith Bridge had to be placed above the deck, one on either side of the bridge. 2. One should be careful working in the caisson. 3. One never knows the author of the first bridge. 4. This article is easier than the previous one.

VIII. Pay attention to the translation of the word “since”:

1. так как

since 2. когда

3. с

1. Pile driving has been used since prehistoric times. 2. Since cantilever form offered great rigidity longer and stronger bridges became available. 3. Since the invention of iron and steel it became possible to erect large truss bridges.

IX. Pay attention to the underlined words:

1. There are many types of bridges. 2. Large water space can be bridged by beautiful structures. 3. The Neva is spanned by many bridges. 4. The Troitsky Bridge has several spans.

X. Translate the sentences into Russian, paying attention to “would” and “should”:

1. Large brackets would be erected on each bank. 2. One should remember that early bridge-builders knew nothing of trusses.

XI. Complete the following sentences according to the text:

1. Bridge is a structure… 2. Bridges are classified according to… 3. The simplest form of a bridge is… 4. If the water was too deep… 5. The deck of the bridge in the brackets…

XII. Give the definition to:

1. a bridge

2. a girder bridge

3. a cantilever bridge

XIII. Read the text without a dictionary: