2020-04-07
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1. Why is steel the best material for long span bridge building?
2. What property allows steel to deform before it breaks?
3. What material is preferable for cables in suspension and cable bridges?
4. What structures made of steel are used in beam and girder bridges nowadays?
5. Is timber used for basic structures in long span bridges?
6. How can smart materials be used in bridge building?
III. Match English words and Russian equivalents:
| 1) yield strength | a) прочность на сжатие |
| 2) compressive strength | b) сжатие |
| 3) tension strength | с) растяжение. |
| 4) tension | d) прочность на растяжение, |
| 5) compression | e) изгиб |
| 6) buckling | f) коробление |
| 7) bending | g) вязкость |
| 8) ductility | h) предел текучести. |
IV. Connect words on the left to the words on the right to make possible phrases using the text: ex.: temperature changes
temperature deposits
compressive changes
memory crystals
liquid bridge
vertical strength
beam stiffeners
dirt materials
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V. Complete the sentences with the words from ex. III.
1. A special merit of steel is its ________ due to which it deforms considerably before it breaks.
2. Concrete better works on _________.
3. ___________of reinforced concrete is better than concrete.
4. Plate girder construction now prevails, in which large thin steel plates must be stiffened against _________.
5. When we speak about steel and its properties ____________is used as the first term in standard quality terms.
VI. Are these statements True or False?
1. Smart materials are called so because they react to changes in their environment.
2. Now timber is used essentially for permanent structures.
3. So plate girder construction now prevails, in which large thin concrete plates must be stiffened against buckling.
4. The high strengths of steel allow small cross-sections of beams or girders and therefore a low live load of the structure.
5. Normal building steel has high compressive and tensile strengths.
VII. Use the following plan to present structures made from different materials. For example: The type of material is reinforced concrete.
1. type of material reinforced concrete
2. the time of appearance, 19th century
3. dead load of constructions significant, heavy
4. forces the material resists compression, tension
5. examples of constructions made from it Novo-Kalinkin bridge
6. maximum span of the bridges from this material 200-280 m
SECTION II. PRESENTING DESIGN TECHNOLOGIES
Unit 3 SURVEY AND DATA FOR THE BRIDGE DESIGN
I. Read and translate the following collocations:
Longitudinal section, cross-section, railway section; environmental conditions, soil conditions, economic conditions, weather conditions, local conditions; desired alignment, vertical alignment; bridge width, lane width, walkway width; superstructure length, span length, route length, highway length; pedestrian bridge, pedestrian crossing.
II. Find the opposites of the words.
1) primitive a) mountainous
2) substantial b) sophisticated
3) flat c) insignificant
4) skilled d) rare
5) frequent e) global
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6) high f) low
7) local g) inexperienced
III. Read, translate the text and answer the questions.
HOW A BRIDGE IS DESIGNED
A substantial amount of data is needed at the beginning of the design work for a bridge:
a) A plan of the site showing all obstacles to be bridged such as rivers, streets, roads or railroads, the contour lines of valleys and the desired alignment of the new traffic route.
b) Longitudinal section of the ground along the axis of the planned bridge with the conditions for clearances or required flood widths.
c) Desired vertical alignment of the new route.
d) Required width of the bridge, width of lanes, median, walkways, safety rails etc.
e) Soil conditions for foundations, results of borings with a report on the geological situation and soil mechanics data. The degree of difficulty of the foundation work has a considerable influence on the choice of the structural system and on the economical span length.
f) Local conditions like accessibility for the transport of equipment, materials and structural elements. Which materials are available and economical in that part of the country? Is there water or electric power at hand? Can a high standard of technology be used or must the bridge be built with primitive methods and a small number of skilled workers?
g) Weather and environmental conditions, floods, high and low tide levels, periods of drought, range of temperatures, duration of frost periods.
h) Topography of the environment - open land, flat or mountainous land, scenic country, town with small old houses or city with high rise buildings. The scale of the environment has an influence on the design.
i) Environmental requirements regarding aesthetic quality. Bridges in towns that affect the urban environment and that are frequently seen at close range - especially pedestrian bridges - need more delicate shaping and treatment than bridges in open country. Sometimes protection of pedestrians against spray and noise is needed. Noise protection is often necessary for houses close to the bridges.
The designer should answer a lot of questions before building a bridge.
IV. Answer the questions.
1. What problems can be faced by designers before construction?
2. What are the bridge design stages?
3. What specialists are busy from the very beginning to the end of the bridge construction?
4. What is the difference between town and open country bridges?
5. Can you name some bridge building organizations in St. Petersburg?
