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UNIT 1: HISTORY OF ROAD BUILDING
Стр 1 из 12Следующая ⇒
Данное учебное пособие предназначено для студентов 1 курса автодорожного факультета технических ВУЗов.
Целью учебного пособия является развитие и совершенствование умений и навыков устной речи в деловой и общепрофессиональной коммуникации, формирование профессионально ориентированной лингвистической компетентности студентов.
Деление на главы осуществляется в соответствии с тематикой. Учебное пособие состоит из четырех тематических глав. Первая глава посвящена строительству автомобильных дорог, вторая – организации и безопасности дорожного движения, третья – строительству автодорожных мостов и тоннелей, четвертая глава раскрывает особенности использования строительных и дорожных машин. Каждая тематическая глава включает в себя соответствующие разделы (Units), посвященные таким проблемам как: «История строительства дорог», «Основные элементы дороги», «Этапы строительства автодороги», «Типы дорожного покрытия», «Дорожные развязки», «Дорожные знаки», «Дорожная разметка», «Типы мостов», «Этапы строительства мостов», «Методы строительства тоннелей», «Строительная техника для расчистки территории, отведенной под строительство автодороги», «Строительная техника для формирования дорожного покрытия» и т.д.
Данное учебное пособие направлено на развитие разных видов речевой деятельности: чтения, диалогической и монологической речи, навыков письменного и устного перевода.
Каждый раздел (Unit) включает тексты для ознакомительного, изучающего и просмотрового чтения, которые содержат актуальную информацию из аутентичных источников. Тексты сопровождаются подробным словарем, а также значительным количеством иллюстраций, что привлекает внимание студентов и облегчает понимание представленного им материала.
Разделы также включают в себя лексические упражнения, направленные на расширение словарного запаса по специальности. Предусмотрены задания для индивидуальной, парной и групповой работы, в которых студенты создают и участвуют в коммуникативных ситуациях профессиональной направленности, что способствует уменьшению языкового барьера при реальном общении с носителями языка. Таким образом, каждый текст сопровождается упражнениями, имеющими коммуникативную направленность и позволяющими активизировать приобретенные навыки в речи.
Представленные задания помогут студентам научиться вести беседы на темы вышеуказанных сфер деятельности на английском языке, тем самым формируя общее представление об области дорожного строительства. Таким образом, изучив представленные в учебном пособии материалы, студенты смогут на базовом уровне участвовать в процессе коммуникации на профессиональные темы.
Каждый раздел содержит контрольные задания (Final Tasks), направленные на контроль усвоения пройденного материала.
Учебное пособие может быть использовано как для работы в аудитории, так и для самостоятельной работы.
UNIT 1: HISTORY OF ROAD BUILDING
Read the words and learn them by heart.
1. to tend – стремиться, иметь тенденцию к чему-либо
2. to take for granted – принимать как само собой разумеющееся
3. vast – огромный
4. extensive – большой, протяженный
5. well-maintained – в хорошем состоянии
6. grumbling – ворчание
7. pothole – выбоина, рытвина, яма
8. traffic jam – затор в уличном движении, «пробка»
9. to pave – мостить
10. paved road – мощеная дорога
11. site – территория, площадка, строительная площадка
12. route – маршрут, путь
13. market outlet – рынок сбыта, торговая точка
14. to carry – нести, перевозить
15. to stretch – тянуться, простираться
16. to consume – потреблять
17. supplies – припасы, провиант
18. equipment – оборудование
19. engineer corps – инженерные войска
20. pontoon bridge – понтонный мост
21. to level – выравнивать
22. track – тропа, курс
23. cart – телега, повозка
24. siege engine – осадное орудие
25. stone – камень
Read the text, translate it and compare your ideas in ex.1 with the facts.
Roads. How it all started.
A road built in Egypt by the Pharaoh Cheops around 2500 BC is believed to be the earliest paved road on record – a construction road 1,000 yards long and 60 feet wide that led to the site of the Great Pyramid.
The various trade routes, of course, developed where goods were transported from their source to a market outlet and were often named after the goods which travelled upon them. For example, the Silk Route stretched 8,000 miles from China, across Asia, and then through Spain to the Atlantic Ocean. However, carrying bulky goods with slow animals over rough, unpaved roads was a time consuming and expensive. As a general rule, the price of the goods doubled for every 100 miles they had to travel.
Some other ancient roads were established by rulers and their armies. The Old Testament contains references to ancient roads like the King’s Highway, dating back to 2000 BC. This was a major route from Damascus in Palestine, and ran south to the Gulf of Aqaba, through Syria to Mesopotamia, and finally on to Egypt. Later it was renamed Trajan’s Road by the Romans, and was used in the eleventh and twelfth centuries by the Crusaders.
Later another imperial road, the Royal Road, was being built by the Persians from the Persian Gulf to the Aegean Sea, a distance of 1,775 miles. Around 800 BC, Carthage, on the northern coast of Africa, began to use stones for paving roads. Although they may not have been the first to pave their roads with stones, they were among the earliest, and some people believe that the Romans imitated Carthaginian techniques.
As they say, the rest is history – a history that most of us have experienced and just about any drive we take today provides concrete evidence of the outcome. Ironically, even at its height, American modern interstate highway system totals only about 42,500 miles (as of 1991). Granted, this figure does not include surface streets or other roads.
But 2,000 years ago the Romans, without the help of all our engineering technology or road-building machinery, constructed 53,000 miles of roads, much of which is still in use today.
I can’t help but wonder if our roads will be as impressive to historians 2,000 years from now.
The zone which is marked to lay the road is called the road zone or right-of-way. The higher is the technical classification of the road, the wider is the right-of-way for its construction. The road zone includes such parts of a road as a carriageway, road shoulders, inner and outer slopes, and other parts.
The road surface strip within the limits of which motor vehicles run is called a carriageway. Usually it is reinforced by means of natural or artificial stone aggregates. These stone aggregates form the pavement.
The strips of the ground which adjoin the carriageway are called the road shoulders. The shoulders render lateral support to the pavement. In future the pavement will always be made of solid materials within the limits of the carriageway.
To lay the carriageway at the required level above the ground surface a formation or roadbed is constructed. It is constructed in the form of embankments or cuttings with side ditches for drainage and the diversion of water.
The formation includes borrow pits – shallow excavations from which the soil was used for filling the embankments. It also includes spoil banks. Spoil banks are heaps of excessive soil remaining after the excavation of cuttings.
The carriageway and shoulders are separated from the neighbouring land by slopes. The cuttings and side ditches have inner and outer slopes. The junction of the surface of the shoulders and the embankment slope is called the edge of the roadbed. The distance between the edges is called the width of the roadbed.
Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова,Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.72
Pavement Structural Layers
To ensure all-year-round operation of vehicles traffic on a road, the carriageway is covered with a pavement. The pavement is laid on the surface of the roadbed. It can have rigid or semi-rigid structure. The pavement resists traffic stresses and climatic factors.
The stresses induced in the pavement by motor vehicle wheels attenuate with the depth. This enables the pavement to be designed in the form of a multilayer structure. The pavement consists of the following layers: the surfacing, the pavement base, the sub-base and the subgrade.
2. Below the surfacing base coat is the pavement base, a strong bearing layer of stony material or stone with a binding matrix. This layer is designed to distribute the individual wheel-loads. The pavement base is not subjected to the direct action of automobile wheels.
3. The sub-base is a layer of earth or stone materials, resistant to moisture, inserted when necessary between the pavement base and the roadbed. The sub-base is made of gravel, slag, soil treated with binding agents, sand, etc. Subbase is often the main load-bearing layer of the pavement. The primary functions of the sub-base are to provide structural support and improve drainage. The quality of subbase is very important for the useful life of the road.
4. The subgrade is the native material underneath a pavement. It comprises the thoroughly compacted upper layers of the roadbed upon which the layers of the pavement are laid. It is also called formation level.
Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова,Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.72-73
For collecting water from the roadbed side ditches, flumes, interceptor ditches and drain channeling can be used. Present road construction provides side ditches parallel with the roadway. A side ditch is intended to collect the water discharged by the crown. It also collects the water from the roadside. Water from the adjoining land must be collected by the side ditch too. The side ditch discharges into a natural outlet at the first opportunity.
Side ditches in cuttings and next to embankments may be excavated to a depth of up to 0.6 m. These ditches are for the collection of water flowing off the road surface and from adjoining land during rainfall or snow thawing. The side ditch may contribute to the drainage of the subgrade because of the evaporation of moisture from the side ditch inner slopes. However, the major use of the side ditch is to permit the rapid discharge of water. When this water discharge is not ensured and ponding occurs, the side ditch becomes a source from which water may penetrate back under the road, resulting in saturation of the subgrade.
Source: Английский язык. Контрольные задания. / Л.В. Лукина, Л.Н. Крячко, О.Ф. Нестерова, Н.В.Сидорова. Воронеж: Воронеж. гос. арх.-строит. ун.-т., 2009 – C.73-74
UNIT 3: TYPES OF PAVEMENT
Circle the odd word.
Asphalt (specifically, asphalt concrete) has been widely used since the 1920s. Most asphalt surfaces are laid on a gravel base, which is generally at least as thick as the asphalt layer, although some asphalt surfaces are laid directly on the native subgrade.
An asphalt concrete surface will generally be constructed for high volume primary highways having an average annual daily traffic load greater than 1200 vehicles per day. Advantages of asphalt roadways include relatively low noise, relatively low cost compared with other paving methods, and perceived ease of repair. Disadvantages include less durability than other paving methods, less tensile strength than concrete, the tendency to become slick and soft in hot weather and a certain amount of hydrocarbon pollution to soil and groundwater.
Concrete surfaces (specifically, PCC) are usually used on roads with heavy traffic of heavy vehicles and created using a concrete mix of Portland cement, coarse aggregate, sand and water. In virtually all modern mixes there will also be various admixtures added to increase workability, reduce the required amount of water, mitigate harmful chemical reactions and for other beneficial purposes. In many cases there will also be Portland cement substitutes added, such as fly ash. This can reduce the cost of the concrete and improve its physical properties.
Concrete surfaces are divided into three common types: jointed plain (JPCP), jointed reinforced (JRCP) and continuously reinforced (CRCP). Each of the jointing system types is used to control crack development.
Jointed reinforced concrete pavements control cracks by dividing the pavement up into individual slabs separated by contraction joints. However, these slabs are much longer than JPCP slabs, so JRCP uses reinforcing steel within each slab to control within-slab cracking. Today very few of agencies use this design, because it is not recommended as both of the other types offer better performance and are easier to repair.
Continuously reinforced concrete pavements use reinforcing steel rather than contraction joints for crack control. Cracks are held tightly together by the underlying reinforcing steel. A number of agencies have made decisions to use continuously reinforced designs in their heavy urban traffic corridors.
One of the major advantages of concrete pavements is that they are typically stronger and more durable than asphalt roadways. They can also provide a durable skid-resistant surface. A notable disadvantage is that it can typically have a higher initial cost, as well as can be more time consuming to construct. This cost can typically be offset through the long life cycle of the pavement.
Composite surface combines Portland cement concrete and asphalt. They are usually used to rehabilitate existing roadways rather than in new construction.
The ease of application of BST is one reason for its popularity, but another is its flexibility, which is important when roadways are laid down over unstable terrain that thaws and softens in the spring.
Pavers generally have the form of pre-cast concrete blocks, are often used for aesthetic purposes. Pavers are rarely used in areas with high-speed vehicle traffic.
Circle the odd word.
Step I: Planning
A road project begins with evaluating the transportation system, taking into account statewide priorities, including strategic plans for the state’s transportation system. Department of Transportation collects and maintains information about our roads, including road and bridge conditions, traffic volumes, crash statistics.
Using this data, transportation planners, engineers, environmentalists, landscape architects, soil scientists and others identify trends that determine what and how to build.
A survey of the area is step two. Recently, Global Positioning Systems, laser surveys, and other technology have sped up the process and improved accuracy. Many factors influence designs, including location, terrain and soil properties, drainage capabilities, traffic volume, the ratio of cars to trucks and buses, possible future development in the area, effects on the environment or nearby residents.
Step III. Earthwork
Earthwork is one of the most important elements in road construction because it establishes a stable foundation. The aim of the earthworks phase of the construction is to position the subgrade underlying the pavement layers in the right location and at the correct level and to provide drainage.
The earthwork is often the largest task in the road building process and therefore careful planning and organization are essential. Speed and efficiency depend very much upon the quantity and types of earthmoving plant available.
Step IV. Pavement Construction
A formula that includes all these factors tells engineers to use either asphalt (bituminous) or concrete pavement.
Asphalt uses bitumen, a petroleum product, to glue together sand and crushed rock. This mixture is heated to approximately 300 degrees at the asphalt plant. At the construction site, workers spread and compact the hot mixture onto the roadbed.
Concrete uses cement and water as the glue between sand and crushed rock. Workers place concrete into steel molds called forms. A finishing machine vibrates and trims it to the necessary height. To prevent cracks, workers cut joints between the concrete slabs.
At each joint, wire baskets and steel dowels connect the slabs. These allow the slabs to expand and contract as the temperature changes. The slabs can slide from side to side along the dowels, but not up and down.
Step V. Open to traffic
With the new surface in place, quality testing is conducted. Testers use seismology equipment to measure vibrations of the new pavement. If there is too much vibration, the contractor must grind the pavement to ensure a smooth surface. The final steps are:
· another drainage test;
· applying the permanent pavement markings.
UNIT 1: TRAFFIC SIGNS
In the Middle Ages, multidirectional signs at intersections became common, giving directions to cities and towns.
New generations of traffic signs based on electronic displays can also change their text (or, in some countries, symbols) to provide for “intelligent control” linked to automated traffic sensors.
A. Danger warning signs
B. Priority signs
C. Prohibitory or restrictive signs
D. Mandatory signs
E. Special regulation signs
G. Direction, position, or indication signs
H. Additional panels
Distances on traffic signs generally follow the measurement system in use by the country. Most US road signs use miles or feet, although the Federal Department of Transportation has developed metric standards for all signs. The United Kingdom signs also display distances in miles. Elsewhere, metric distances are in very wide use, though not universal.
Where signs use a language, the recognized languages of the area is normally used. Signs in most of the US, Canada, Australia, and New Zealand are in English. Quebec uses French, while, in Montreal and some other Canadian provinces use both English and French, a territory of the US, Mexico, and Spain use Spanish. Within a few miles of the US–Mexico border, road signs are often in English and Spanish in places like San Diego.
Circle the odd word.
UNIT 2: TRAFFIC CONTROL
It is obvious that in existing urban areas much of the congestion is due to narrow streets and junctions which are incapable of taking peak-hour traffic. The solutions of this problem are costly. They include adequate roundabouts and street widening and the segregation of traffic by means of flyover roads, underpasses, bridges and pedestrian subways.
Much of the congestion in urban areas is due to traffic which has no business in the area but is only passing through.
Signposting is, of course, a directional control and a very effective one. In fact it is important for all signs and symbols used on the roads to be seen well in advance by drivers approaching at normal speed. Directional control cannot increase the capacity of the highway system but it can avoid local congestion.
One-way traffic is a special kind of directional control which is very effective in maintaining the traffic flow in congested areas.
A major cause of congestion in towns is the interruption to the free flow of traffic by cross traffic at junctions. But if the need for traffic streams to cross each other can be avoided then the movement of vehicles will be much easier. This easier movement of traffic can often be achieved by making traffic move in one direction only along certain streets and by prohibiting incoming vehicles from side streets from crossing the main stream. The streets may be either one-way or two-way according to local conditions of traffic or width of carriageway, and traffic at the junctions can be guided by constructing suitably-shaped islands. Besides, one-way traffic can also be introduced where the carriageway width is inadequate for two opposing lines of traffic.
The two main objections to street intersections are that they are a cause of accidents and that they interrupt the flow of traffic. The best thing to do with intersections is to get rid of them. If that is not possible they may be improved and made safer but they will always remain a source of danger and delay.
Many accidents are caused because traffic streams of different types, or traffic streams travelling in different directions are using the same carriageway, and these accidents can be avoided either by reservations between traffic lanes, or by vertical (or “grade”) separation.
In many cities in America and in Europe segregation of traffic is achieved by means of flyovers or underpasses; at some junctions there are even three different levels. Each has its advantages and disadvantages according to the circumstances. Flyover structures are not always aesthetically pleasing while an underpass may be more expensive to construct. The separation of fast and slow traffic from the heavier and faster traffic is most desirable not only in the interests of freedom of traffic movement, but also of safety. This ideal is not easy to achieve.
Urban traffic control will be of benefit to the general public in the district concerned and will result in greater comfort for road users of all classes, as well as bringing economic advantages to the community as a whole.
Source: Пособие по английскому языку для студентов II-III курсов строительных вузов / М.: Высш. школа, 1978. – C.27-29
UNIT 3: ROAD SAFETY
Road traffic safety refers to methods and measures for reducing the risk of a person using the road network being killed or seriously injured. The users of a road include pedestrians, cyclists, motorists, their passengers, and passengers of on-road public transport, mainly buses and trams. Best-practice road safety strategies focus upon the prevention of serious injury and death crashes in spite of human fallibility. Safe road design is now about providing a road environment which ensures vehicle speeds will be within the human tolerances for serious injury and death wherever conflict points exist.
Major highways are designed for safer high-speed operation and generally have lower levels of injury per vehicle km than other roads.
Safety features include:
· Limited access from properties and local roads.
· Grade separated junctions
· Median dividers between opposite-direction traffic to reduce likelihood of head-on collisions
· Removing roadside obstacles.
Modern safety barriers are designed to absorb impact energy and minimize the risk to the occupants of cars, and bystanders. For example some road fixtures such as road signs and fire hydrants are designed to collapse on impact. Highway authorities have also removed trees in the vicinity of roads; while the idea of “dangerous trees” has attracted a certain amount of skepticism, unforgiving objects such as trees can cause severe damage and injury to any road users.
Road surface markings
Road surface marking is a kind of device or material used on a road surface in order to convey official information. They can also be applied to mark parking spaces or areas for other uses.
Road surface markings can be mechanical, non-mechanical, or temporary.
Mechanical devices may be raised into the road surface. They are either reflective or non-reflective. Most are permanent; some are movable.
Cat’s eyes equip most major routes in the British Isles. They consist of four reflective lenses mounted in durable white rubber housing, two facing fore and two facing aft. The lenses are available in a variety of different colours, mainly white, yellow, orange, green, red and blue.
A rumble strip is usually either applied in the direction of travel along an edge- or centerline to alert drivers when they drift from their lane, or in a series across the direction of travel to warn drivers of a stop ahead or nearby danger spot. In favorable circumstances rumble strips are effective (and cost-effective) at reducing accidents due to inattention.
Paint is generally used to mark traffic lanes, spaces in parking lots or special purpose spaces for disabled parking. Colors for these applications vary by locality. Paint is usually applied right after the road has been paved. The road is marked commonly by a truck called a “striper”. These trucks contain hundreds of gallons of paint stored in huge drums. The markings are controlled manually or automatically by the controller.
Thermoplastic is one of the most common types of road marking. The main advantages of thermoplastic are durability and retro-reflectivity. Most thermoplastic is produced in white and yellow colours.
Pylons are sometimes used to separate HOV lanes from regular traffic lanes.
Circle the odd word.
History of bridges
The first bridges were made by nature itself – as simple as a log fallen across a stream or stones in the river. The first bridges made by humans were probably spans of cut wooden logs or eventually stones, using a simple support and crossbeam arrangement. Some early Americans used trees or bamboo poles to cross small wells to get from one place to another. A common form of sticks, logs, and deciduous branches together involved the use of long fibres woven together to form a rope used for binding and holding together the materials used in early bridges.
The greatest bridge builders of antiquity were the ancient Romans. The Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs. Some stand today. An example is the Alcántara Bridge, built over the river Tagus, in Spain. The Romans also used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, and volcanic rock. Brick and mortar bridges were built after the Roman era, as the technology for cement was lost then later rediscovered.
Although large Chinese bridges of wooden construction existed at the time of the Warring States (476-221 BC), the oldest surviving stone bridge in China is the Zhaozhou Bridge, built from 595 to 605 AD.
Rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes Mountains of South America, just prior to European colonization in the 16th century.
With the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron did not have the tensile strength to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of Gustave Eiffel.
In 1927 welding pioneer Stefan Bryła designed the first welded road bridge in the world.
UNIT 2: TYPES OF BRIDGES
The four main factors are used in describing a bridge. By combining these terms one may give a general description of most bridge types:
· span (simple, continuous, cantilever),
· material (stone, concrete, metal, etc.),
· placement of the travel surface in relation to the structure (deck, pony, through),
· form (beam, arch, truss, etc.).
The three basic types of spans are shown below. Any of these spans may be constructed using beams, girders or trusses. Arch bridges are either simple or continuous. A cantilever bridge may also include a suspended span.
Examples of the three common travel surface configurations are shown in the truss type drawings below. In a deck configuration, traffic travels on top of the main structure; in a pony configuration, traffic travels between parallel superstructures which are not cross-braced at the top; in a through configuration, traffic travels through the superstructure (usually a truss) which is cross-braced above and below the traffic.
Simple deck beam bridges are usually metal or reinforced concrete. Other beam and girder types are constructed of metal. The end section of the two deck configuration shows the cross-bracing commonly used between beams. The pony end section shows knee braces which prevent deflection where the girders and deck meet.
Many modern bridges use new designs developed using computer stress analysis. The rigid frame type has superstructure and substructure which are integrated. Commonly, the legs and deck are a single piece which is riveted to other sections.
Arch bridge is one of the most popular types of bridges, which came into use over 3000 years ago and remained in height of popularity until industrial revolution and invention of advanced materials enabled architect to create other modern bridge designs. However, even today arch bridges remain in use, and with the help of modern materials arches can be build on much larger scales.
The basic principle of arch bridge is its curved design. Abutments carry the load of the bridge and are responsible for holding the arch in the unmoving position.
Arch configuration is another method of classification. Examples of tied arch,trussed arch and spandrel-braced arches are shown. A tied arch is commonly constructed using curved girder sections. A trussed arch has a curved through truss rising above the deck. A spandrel-braced arch carries the deck on top of the arch.
Arch bridges rely on vertical members to convey the load carried by the arch.
Trusses work much like beams: they carry a combination of compression and tension forces. The main difference is that trusses are less heavy than beams. Beams use extra material in some areas; these areas don’t use the full strength available to them. Engineers and builders can determine which portions of beams can be removed. The resulting truss concentrates the forces into many smaller members and eliminates the under-stressed areas of beams.
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