ROAD DESIGN, STRUCTURE, CONSTRUCTION

1. How many stages of road building do you know? What are they? Read the text and give the title.

СRoad needs are closely associated with the relative location of centres of population, commerce, industry, and transportation. Traffic between two centres is approximately proportional to their populations and inversely proportional to the distance between them. Estimating traffic on a route thus requires a prediction of future population growth and economic activity, an estimation of their effects on land use and travel needs, and acknowledge of any potential transport alternatives. The key variables defining road needs are the traffic volumes, tonnages, and speeds to be expected throughout the road's life.

2. Match the words to make word combinations. Check your answers in the text above. Make up your own sentences with those word combinations which were matched improperly.

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6. What are the main considerations in road planning? Mark the correct word boundaries to read the text. What is its main idea?

Sheffieldcitycouncilofficershaverecommendedchangestothelayoutofb radfieldroadinhillsborough.themeasuresarebeingsuggestedbecauseofthe highnumberofpeoplewhohavebeenknockeddowntryingtocrosstheroad.thepr oposalswillbediscussedatthecouncil'splanningandhighwaysmeetinglater.tw entytwopedestrianshavebeenhurtinthepastfiveyears, sixofthosewereseriouslyinjured.thecouncilsaidtheissuewasmanypeoplewere

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crossingtheroadawayfromthepedestriancrossings.aspartoftheimprovements,

railswouldbeputalongtheroadtostoppeoplecrossingwheretheyshouldnot.ifap proved,workonthe£150,000schemewouldstartbytheendofjanuary. http://news.bbc.co.uk/2/hi/uk_news/england/south_yorkshire/7188886.stm

С7. Read about USA and Canada road planning and answer the questions:

1. Who is responsible for constructing and maintaining roads in USA and Canada?

и2. What is the Hayden-Cartwright Act? 3. What does FHWA stand for?

4. What do engineers do to plan roadway improvements?

бRoad planning and administration

In the United States, the state governments are responsible for constructing and maintaining interstate highways, U.S. highways, and state highways. Local governments – counties, cities, and townships – are generally responsible for theАrest of the road system. In Canada, the provincial governments share the obligation for road planning and construction with local cities and municipalities. Many groups, including road users, business owners, the general public, and environmental groups, have interests and concerns in regard to road construction.ДThe various government agencies involved attempt to balance these concerns when planning a road system.

In the first quarter of the 20th century, roads in the United States and Canada were often little more than dirt paths. These primitive roads were impassable after heavy rains, and automobiles would become stranded in thick mud. At the time, highway agencies concentratedИon little more than paving existing rural roads. A more organized program of planning in the United States began in earnest in 1934, when the U.S. Congress passed the Hayden-Cartwright Act. This act provided federal aid for state highway departments to plan in-depth studies. By 1940 most states were examining such factors as road conditions, volume and nature of highway traffic, highway lifespans, and future highway needs. Later highway acts expanded funding to include considerations of state policies and state, regional, and local issues.

Today, federal funding and planning guidelines in the United States are administered by the Federal Highway Administration (FHWA) of the

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U.S. Department of Transportation. The FHWA distributes funds according to formulas established by Congress and sets general policies for design, construction, operations, and maintenance. The agency does not, however, provide any of these functions. Its basic goal is to provide for a safe and consistent national system of highways. The state departments of

Сtransportation or local governments actually plan, construct, and maintain the highway systems.

Local highway agencies include those operated by counties, cities, and townships. Cities operate primarily with local funds, typically under a mayor or city manager. A city’s public works department may be responsible for most road functions, or there may be separate departments for design, construction, and maintenance. Counties and townships, as well as

иIn Canada, the majority of roads are constructed and funded by individual provincesбand cities, with the federal government playing a minor role. Provincial and municipal governments responded to increases in motor vehicle use during the early part of the 20th century by expanding and improving the road network already in existence. At the time, individual cities were responsibleАfor road construction and maintenance. As automobile and truck use expanded, the provincial governments began to establish highway departments and allocate funds for highway construction.

small towns and villages, typically have less complex systems.

The Canadian federal government does not play as large a role in highway planning and funding as does the U.S. government. However, in the late 1980s the Canadian federal government instituted the National

Canadian portion of the Alaska Highway.Д

Highway System, a network of over 24,000 km (15,000 mi) of roads connecting major cities and ports. The federal government also supports high-

ways located on federal property, such as national parks, and maintains the И

In planning roadway improvements, engineers collect data about current roadway use and planned new uses of roads, as well as other information, such as planned construction or nearby development. They also

examine the land and decide where bridges or viaducts may be needed to carry the roadway over obstacles like rivers or other roads. Engineers then use computers to simulate or model new roadway designs. Depending on available funding, projects are planned for construction based on the priorities of the highway department and of the state, provincial, or local government in charge.

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8. Find 25 words from the text (across, down). Read out the sentences with the words found.

A B C D E F G H I J K L M N O P Q R S T

1 I M P R O V E M E N T S B C O M P L E X С2 P U K Y X M W R S Q O H Q Y Y P F I I X 3 B C O N S T R U C T I O N K E L B F K O 4 U Y N H H T U F C G W U P K X P G E W A 5 L B B H C O N S I D E R A T I O N S K D

и6 W E L L D D M N O F G R X P S J G P L M 7 L C T J R Y F B S M P D L A T E O A G I 8 C O N S T R U C T I N G A U E B X N X N 9 бK M S U T T N I A F Z D O W N E R S Y I 10 M E Y S V R D T T S F V N H C C F J A S 11 J X S T U T E D E P A R T M E N T S W T 12 M F P A O K D K S K V O V O T X X X H R 13 A J O GАK M N U N K N L W S X C D A T A 14 I N G E N V I R O N M E N T A L C L H T 15 N U A Y Y M Z D R H G O O Q J N R R E I 16 T R A N S P O R T A T I O N W B I E K O 17 A Q C Y L C U I M B V S D N W A Y A C N 18 I R M U N I C I P A L I T I E S E D B E 19 N U L K I U V X Z X Y N U J H E G Y O O

9. Read and study the followingДwords. Make up 3 sentences, using these words:

adjacent – прилегающий, смежный; соседний to alert – привести в состояние готовности amply – достаточно, много

20 S R C O N C E N T R A T E D B D L I J T И

bisect – разрезать, делить пополам blighted – здесь: тесный, скученный to employ – применять, использовать to exert – оказывать давление, влияние

to jam – загромождать, создавать пробку

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preliminary – предварительный proximity – близость, соседство ramp – наклонный въезд, съезд

reconnaissance – разведка, расследование substantial – значительный

Сsurvey – обследование, изыскание

10. Use the words given in brackets in the proper tense.

1. As the number of cars (to increase), this through traffic (to cause)

increasing congestion. 2. Today, most major city streets (to jam) at peak periodsиand many (to crowd) for several hours per day. 3. Today, new ar-

teries in urban areas (to locate) generally clear of the existing streets. 4. Spaces as great as several ordinary city blocks (to require) where the design speed of the freeway is high. 5. In some instances no preliminary survey (to require).

передв женбе на автомо иле промышленная зона цель, место назначения скоростная магистраль

11. Find the English equivalents in the text below.

полоса движения зона отдыха и развлечений

вертеть(ся), поворачивать(ся) единообразный, одинаковый фиксированный, неизменный землемерная съемка, разведка осмотр, исследование пересечение в разных уровнях крупномасштабный фотограмметрический метод

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12. Find the odd word in each sentence.

1. To relieve congestion widening major arteries is being necessary. 2. By the proper combination of major important radial and circum-

ferential routes, growth can be made to conform to a logical, reasonable Сpattern.

3. Where several new facilities into the heart of a city are planned, it may be advantageous to locate situation them encircling the business district.

4. Often the best solution is to change the flow of the adjacent city ruralиstreets.

5. Here it is such often desirable to swing entirely clear of the community.

13. Readбthe text and divide it into several paragraphs, supplying each with a heading.

Highway location and surveys in urban areas

Vehicular travel inАthe typical city is heaviest along radial routes to and from the business and industrial areas. Volumes increase with proximity to the central areas. In some cases movements can be substantial in other directions also. Generally this travel is over ordinary city streets on which there are business and commercial developments.ДThrough the years, as the number of cars has increased, this through traffic combined with vehicles having local destinations has caused increasing congestion. Today, most major city streets are jammed at peak periods, and many are badly crowded for several hours per day. To relieve congestion widening major arteries is necessary. Where possible, modern practice removesИthrough traffic from the streets to free-flowing, high-capacity freeways or expressways. Today, then, new arteries in urban areas are generally located clear of the existing streets, although they usually follow parallel courses.

Freeway and expressway locations should be related to the master plan for city development, for these arteries will exert marked influence on all aspects of a city’s growth. By the proper combination of major radial and circumferential routes, growth can be made to conform to a logical, reasonable pattern.

Locations for freeways need not pass directly through the central business area of a large city; in fact, for them to do so is often prohibitively

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expensive. If the routes pass close by, vehicles destined to the central area can traverse the short remaining distance on the streets. Favourable freeway routes often can be found in the blighted districts close to the areas of high property values. Where several new facilities into the heart of a city

are planned, it may be advantageous to locate them so that they are partial- Сly or entirely encircle the business district.

The locations for offand on-ramps connecting freeways with downtown city streets often present serious difficulties. One of them is the extreme cost. Another and more compelling argument is that such close spac-

ingиof connections impairs the free-flowing and accident-free characteristics of the freeway. (The clear distance preceding each connection should

be great enough that drivers can be alerted and given time for appropriate action. Spaces as great as several ordinary city blocks are required where the design speedбof the freeway is high.) Often the best solution is to change the flow on the adjacent city streets to one-way and to provide connections to appropriate pairs of them. Where large volumes must be carried by single ramps, good practice calls for an added lane on the freeway sole-

ly for these vehicles.

ramps. Grade separationАfor cross streets can be provided without disrupting established development in adjoining blocks. Space remains for developing parks and recreational areas.ДThen, the existing streets along the boundaries serve local traffic and provide full access to fronting housing. Unfortunately, rights of way of sufficient wide often cannot be taken (par-

The ideal right-of-way width for a depressed urban freeway is a full city block. This provides amply for all future needs and for onand off-

tially because funds are not available) and in some cases, rights of way for freeways and expressways have been gained by widening the alleys which bisect the main blocks or by taking a half blockИincluding one street and

one alley. Alley frontage is of much lower value than street frontage, which makes the over-all cost of such rights of way less.

The location of arterial highways bypassing small communities presents quite a different problem. Here it is often desirable to swing entirely clear of the community rather than to pass between a segment of residential area and the business district.

Procedures of location and surveys on urban projects are much less uniform and fixed. For example, in many instances such data as property location, street improvement may be complete and accurate enough that no preliminary survey is required.

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Paired aerial photographs often are the primary reconnaissance tool for urban location. Examination will suggest alignment that avoids highly developed areas of high right-of-way costs. Often preliminary studies for grade separation structures and interchanges can also be made from them. Thus, with little field work, the most desirable locations can be selected for

Сfurther examination on the ground. Then, seldom is an urban survey made in a location free from conflict with motor vehicles on the existing streets, which occasions many delays and is at times actually dangerous to the personnel involved. Many of these problems can be minimized by employing large-scale vertical serial photographs and maps made from the photographs by photogrammetric methods.

text: Д

15. Replace the underlined words with the equivalents from the

Road location, township area, in some instances, industrial zone, the course of jam, heavily crowded streets, to decrease congestion, to locate mainly in … , to have considerable influence on … ,to fit to a pattern, location of connections, the proper action, the best decision, the main recon-

16. Look through the text about highway design for 2 minutes and pick out the word connected with your speciality.

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17. Read the text again and write short sentences that summarize the content of each paragraph.

Highway design

In order to fully understand the design stage, a few standard terms Сmust be defined. A traffic lane is the portion of pavement allocated to a single line of vehicles; it is indicated on the pavement by painted longitudinal lines or embedded markers. The shoulder is a strip of pavement outside an outer lane; it is provided for emergency use by traffic and to protect the pavement edges from traffic damage. A set of adjoining lanes and shouldersиis called a roadway or carriageway, while the pavement, shoulders, and bordering roadside up to adjacent property lines are known as the

right-of-way.

Highway design is the art of anticipating the needs of the cars and trucks that willбbe using the roadway, and of taking care of these needs when preparing plans for construction. Highway design includes choosing the best width for the road; selecting the degree of curves and steepness of hills; preserving trees, plants, and other natural features in the vicinity; ensuring safe and efficientАtraffic flow; and designing the finished highway to blend with the natural landscape as much as possible.

In designing a highway, engineers must take into account the area it will serve – industrial, rural, agricultural, or residential. From this information they estimate the type andДnumber of vehicles that will use the completed road. Then they design a pavement that can carry this type of traffic for approximately 20 years without cracking or developing potholes. Design standards for major highways in the United States and in many other countries are prepared by the American Association of State Highway

and Transportation Officials in Washington, D.C.И Most major modern roads are crowned – that is, they are higher in the

middle than at the edges. This crown allows water to run off the roads so that it does not accumulate into large puddles and wash away the pavement surface. The water drains from the pavement to the edges of the road, where the water is carried away by catch basins into ditches or culverts – wide pipes laid under the pavement. These drains and ditches not only catch water that runs off the pavement, but, in areas where the road has been cut through higher ground, they also prevent water from reaching the roadway from surrounding hills and side slopes.

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The number of lanes to be built on a highway depends on the number of cars and trucks that will use the road. Country roads that do not carry a large number of vehicles generally have two lanes and a total width of 7 meters. Arterial highways may have four lanes in areas where vehicles enter or exit.

Limitedor controlled-access highways can be entered or exited only СибАДИat special interchanges, generally on ramps that allow entering traffic to merge smoothly with traffic already on the highway. Limited-access highways range from four lanes in width to six or eight lanes, and in some cases even more. The New Jersey Turnpike, which carries more than 160 million vehicles a year, is twelve lanes wide near New York City. In some cases the highway may be built on bridges or embankments that pass over the crossroads (elevated highways) or underneath the crossroads (depressed highways). Such highways are known as grade-separated high-

ways.

Many roads today are designed for stage construction. If the road is serving a new business or residential area where traffic is light, planners design it with a thinner, less expensive pavement. Then, as more people and businesses move in and the number of cars and trucks on the road increases, engineers can place additional layers of asphalt or concrete over the original pavement to support the heavier traffic.

In major highways, a median strip – usually a wide, grassy area, sometimes with a barrier or fence – divides the traffic going in either direction. Where there is enough land available on either side of the traffic lanes, modern highways are built with wide shoulders and off-road areas. Thus, disabled vehicles and cars that skid or lose control have room to stop safely. Light posts and signs can be set back far enough from the traffic lanes to avoid posing a hazard to traffic, and the wide shoulder area provides a natural barrier to lessen the amount of air and noise pollution that reaches homes and businesses.

Check your answers (Ex. 8 p. 58)

administration (t4-v), already (r13-v), based (p16-v), become (b5-v), complex (n1-h), concentrated (c20-h), considerations (e5-h), constructing (a8-h), construction (b3-h), data (q13-h), environmental (d14-h), existence (o3-v), funded (g7-v), improvements (a1-h), late (m7-h), lifespans (r1-v), maintains (a12-v), most (n11-v), municipalities (c18-h), owners (m9-h), role (l11-v), departments (c11-h), states (i7-v), transportation (a16-h), well (a6-h)

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18. Study the list of paragraph headings and match them with the summary sentences you have written.

Verbs:

--

--

--

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22. Try to describe highways using the words from your mind

map.

3. In the text (Highway design) find the synonyms to the words in the box.

Do you know any other synonyms to the given words?

и25. Write a short article for a students’ book about highway design (about 120–180 words). Do not forget to draw pictures.

24. Work in pairs. Ask each other questions about highway de-

sign and answer them.

alignment –бвыравнивание; трасса, разбивка cross section – поперечное сечение, разрез

26. Study the following words:

27. Translate the sentences containing the words to be remembered into Russian:

1. Good appearance is also intimately integrated in almost every element of highway design. 2. Highways with long tangents, possibly inspired

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by the railroads, have proved more dangerous to traffic than a curving alignment. 3. The flattening of grades is generally desirable near intersections or wherever a driver will be encouraged to look away from the pavement.4. The design of the cross section of drainage ways has changed radically in keeping with other streamline cross sections in highway design.

С5. The width of shoulders and drainage ways may become standardized, but the slope of cuts and fills should be specially designed to meet the controlling conditions of the site.

28. Arrange the words with the same meaning.

For example: urban, city.

Plan, urban, vehicle, city, slope, design, grade, automobile, hollow, maintenance, cut, fill, upkeep, embankment.

2. Railroadбengineers built long tangents and flattened grades.

3. The design of a highway includes, as a rule, two main principles – safety and efficiency.

4. The design of a highway provides also the economy of construction and maintenance of a road. Д

30. Guess the meaning of the following words, basing on their phonetic and graphic similarity with the Russian words:

Phases, automobile, masses, methods, period,Иprinciples, engineering, tangents, natural, maximum, efficiency, logically, economy, location.

31. Find in the text sentences in Present Indefinite, Past Indefinite and Present Perfect. Point out their functions in the text.

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32. Have methods of designing highways changed a lot? Read the text and check your answer.

Development of highway design

The last fifty years in the history of highways have seen the effect of Сthe automobile on many phases of highway design. It is probable that the increase of population, changes in the distribution of the masses of people in line with the trend of dispersed urban development, and the accompanying growth and changes on motor vehicles will cause far greater changes in

the manner and methods of designing highways.

During that early period, highway design was influenced by certain principles of railroad engineering. Long tangents and flattened grades were

34. Read and study the following words:

centre line – ось полотна дороги circular curve – круговая кривая

curve (curvature) – кривая, изгиб (кривизна) grade line – продольный уклон

horizontal alignment – горизонтальная проекция horse-drawn transport – гужевой транспорт junction – соединение, стык

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reverse curve – обратная кривая runoff – отгон виража

skidding – боковое скольжение, занос автомобиля superelevation – подъем виража

thrust – боковое давление, удар, толчок Сvertical alignment – проектная линия на продольном профиле дороги

35. Find sentences with modal verbs and infinitives of purpose used to express requirements for the alignment in the texts about alignment.

и36. What dependence is denoted in the text Horizontal Alignment with the aid of adjectives in comparative degree?

37. Findбwords with the opposite meaning in the texts.

Danger, potential, reduce, sharp, compound, gradually.

38.Match English phrases with their translations.

A. Standpoint of safety and convenience; excessive grades; riding quali-

ties; to be adequately marked; to fit the topography; at summits of steep grades; to be rounded off with a vertical curve.А

39. Read the texts and answer the questions after them.

Horizontal Alignment

The position of the road in the horizontal plane is termed its horizontal alignment. The centre line is used to fix the alignment. There are always certain control points through or near which a road must pass. Between these points the ideal alignment is straight. Such direct alignment is not always possible, due to prohibitive cost of construction, excessive grades or other topographic features.

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The normal alignment is, therefore, one which consists of series of tangents (direct lines) connected by curves. The problem is to establish a line that is as direct or short as possible and is reasonable in cost of construction, maintenance and operation. A large amount of curvature indicates a considerable departure from a direct line and hence added cost of

Сconstruction and operation. But curvature on highways is of most importance from the standpoint of safety and convenience rather than cost.

Curvature must have an obvious reason for its presence. The curve only unites the two tangents; but there must be some obvious reason for the

change of direction.

иThe safety of traffic is less not only because of the motor car stability decrease but because of the sight distance decrease as well if the curve is located in a cut, in a forest or in a built-up area particularly in the night time when the head-lights are directed nor along the curve but along a tan-

The curvature reduces the road quality because the stability of the motor-car and the safety of traffic on the curves become less. While moving on the curve the motor-car undergoes the centrifugal force which re-

sults in skidding and side thrust. The comfort of driving also decreases.

the superelevation is zero at the beginning of theИspiral and increases directly with the distance, as does the degree of curvature, and attains its full amount at the circular curve. In this way the superelevation and curvature are at all times in accord, which results in good appearance and good riding qualities.

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Circular curves.

A simple curve is the arc of a circle connecting two tangents. The radius of a circular curve is determined according to the traffic speed, the cross-section, the quality of the pavement.

The circular curve must conform to the topography or to traffic Сneeds.

In days of horse-drawn traffic radii were generally quite short. The higher speeds of motor traffic demanded flatter radius curves with the result that the radius for the right-angled turns has been gradually increasing.

Local conditions must necessitate shorter radii in which case the curvesиbecome points of potential, if not actual, congestion and danger. They should, therefore, be adequately marked and made as safe as possible.

A compound curve is a continuous curve in one direction composed of two or moreбsimple curves placed end to end with a common tangent at the junction. A reverse curve adds to the steering difficulties especially if sharp. If the curves are superelevated, the superelevation must change side and this cannot be suddenly.

АVertical Alignment

The position of a highway in the vertical plane is given by its grade line. The grade line is analogous to the centre line in horizontal alignment and, like it, is made up of tangents connected by curves. The tangents are termed straight grades while the curvesДare known as vertical curves.

Direct grade lines of any considerable length are rarely obtainable, because they are very likely to require prohibitive cuts and fills. Consequently, the indirect grade line which dips into valleys and climbs over ridges is the normal one.

So the vertical curves should be used freely andИalways of ample length. To ensure the smoothness of traffic the minimum length is rarely less than 20 m. The length should be chosen which fits the topography the best. Where two straight grades connect, the grade line is rounded off with

a vertical curve, which is exactly analogous to the horizontal curve. Since the intersection angle is always small and gravity constantly holds the vehicle to the roadway, the effect of centrifugal force is imperceptible and the application of vertical curves is less complicated than horizontal curves.

At summits of steep grades the length of the curve may depend on the necessary sight distance. The present tendency is towards the curves with greater radius.

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The grade line with long easy vertical curves which fit the topography are much more pleasing in appearance as well as safer and more con-

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42. You are going to read the text about highway structure. Do you know anything about it? Read the text and divide it into several paragraphs supplying each with a title. First watch a short video about designing a road https://www.youtube.com/watch?v=oKgWk-U4eMI and write out all the terms concerning the road structure.

С Highway Structure

To support heavy vehicles moving at high speeds, a modern road is made up of several layers (pic. 17). Each layer helps the layers above it support the weight and pressure of moving traffic. Roads that carry more traffic at higher speeds,иlike highways, are built to stronger standards than roads that carry less traffic, such as rural collector roads. The number of layers in a road often depends on the intended use of the road, but generally roads have three distinct layers. From bottom to top, the layers are the roadbed (subgrade), the base course (subbase),бand the wearing course (pavement).

А Д

Pic. 17 И

Flexible and rigid pavements each contain several different layers of materials. The layers below combine to support the traffic moving along on the surface layer, which is known as the wearing course. Asphalt makes up the wearing course of flexible pavement and is often found on residential streets in cities. Rigid pavement made of concrete is more durable and is a popular choice for highway construction.

The roadbed is the very bottom layer of a road. Natural soil is the most common roadbed material. The roadbed is shaped to make a smooth, level

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surface that will support the layers built over it. Engineers use bulldozers and other construction equipment to distribute soil evenly along the roadbed. If a road is planned through an area where the natural landscape is uneven, soil can be removed or filled in as needed to obtain a level surface.

When vertical pressure is exerted locally on the pavement it sends, and Сhence produces additional pressure on the subgrade. The ability of the subgrade to resist deformation under this pressure depends on its stiffness, and this is measured by the “modulus of subgrade reaction”. The modulus of subgrade reaction, now universally known by the symbol “k”, is the number of pound per square inch of subgrade reaction per inch of slab deflection.иIt is expressed as pounds per square inch per inch (lb per sq. in per in.) or pounds per cubic inch (lb per cu in.). When a pavement slab is laid directly on the subgrade, the phenomenon knows as “mud pumping” is very apt to occur. It thus is important that a granular nonpumping subbase be used whenбthe subgrade is of the type that will be damaged by mud

pumping.

The base course rests directly on top of the roadbed and is often made up of compacted gravel. If the roadbed material itself is suitable, it may be treated, or stabilized, andАused as the base. Soil can be stabilized by adding or mixing materials such as calcium chloride, bituminous material, lime, or portland cement to the soil. For very inexpensive, light-traffic roads, stabilized soil alone can suffice as the finished road surface. Drainpipes are usually installed within the base courseДto control rain and moisture drainage. Without adequate drainage, roads may buckle or collapse as water swells the ground underneath. Some roads include a second base layer, called the top course, for extra support.

Thus, the purposes of the subbase are to prevent mud pumping, reduce frost damage, control moisture in subgrade soilsИhaving high volume change, and improve the constancy and effectiveness of pavement support.

A road’s top layer, which directly supports moving vehicles, is called the wearing course. It is made of a solid layer of pavement and is designed to be smooth and to withstand erosion from traffic and weather. Two main types of pavements are used – bituminous, or flexible, pavement and concrete, or rigid, pavement. Bituminous pavement is cheaper and easier to construct, but it requires more maintenance. Concrete pavement lasts for a very long time with minimal upkeep but is much more expensive and timeconsuming to build.

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43. Read the definition of the following words and try to find the Russian equivalent. It would be fine if you memorize these words.

44. Look through the text and find the words the first letters of which form the word given. You may do it in groups.

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46. State the forms of the Passive Voice in the following sentences:

1. The subgrade is the underlying soil portion of the pavement structure which has been prepared to grade for the support either of the pavement is constructed.

С2. When vertical pressure is exerted locally on the pavement it bends. 3. The ability of subgrade to resist deformation under this pressure depends on its stiffness, and this is measured by the “modulus of subgrade

reaction”.

4. It is expressed as pounds per square inch per inch. и5. When a pavement slab is laid directly on the subgrade, the phenomenon known as “mud pumping” is very apt to occur.

6. It is important that a granular no pumping subbase be used when the subgrade is of the type that will be damaged by mud pumping.

47. Findбand state the functions of Participle Forms in the following sentences:

1.Rigid pavement distribute loads to the foundation, e.g., portland- cement-concrete pavement and bituminous, brick, or stoned lock pavement supported on a portland-cement-concrete base.

2.The modulus of subgrade reaction, now universally known by the symbol “k”, is the number of pounds per square inch of subgrade reaction per inch of slab deflection.

3.When a pavement slab is laid directly on the subgrade, the phenomenon known as “mud pumping” is very apt to occur.

4.The subbase is a layer of selected granular material placed on the subgrade for the pavement.АД

48. Substitute the synonymic words from the text for the underlined words in the following sentences:

И

1.The pavement, subgrade and subbase are the main gradients of a highway.

2.The pavement may be of two types: rigid and flexible.

3.The subgrade is the low gradient of the pavement structure.

4.The aim of the subbase is to reduce frost damage, improve drain-

age, etc.

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49. Discuss the following questions with your partner.

The typical Roman road (pic. 18) was bold in conception and construction. Where possible, it was built in a straight line from one sighting point to the next, regardless of obstacles, and was carried over marshes, lakes, ravines, and mountains. In its highest stage of development, it was constructed by excavating parallel trenches about 40 feet (1219,2 cm) apart to provide longitudinal drainage – a hallmark of Roman road engineering. The foundation was then raised about three feet above ground level, employing material taken from the drains and from the adjacent cleared

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ground. As the importance of the road increased, this embankment was progressively covered with a light bedding of sand or mortar on which four main courses were constructed:

1. The statumen layer 10 to 24 inches (250 to 600 millimetres) thick, composed of stones at least 2 inches (5 cm) in size;

С2. The rudus, a 9-inch-thick (22,5 cm) layer of concrete made from stones under 2 inches in size;

3. The nucleus layer, about 12 inches (30 cm) thick, using concrete made from small gravel and coarse sand;

4. For very important roads, the summum dorsum, a wearing surface

иThe total thickness thus varied from 3 to 6 feet (91,44 to 182,88 cm). The width of the Appian Way in its ultimate development was 35 feet (1066,8 cm). The two-way, heavily crowned central carriageway was 15 feet (457,2 cm) wide. On each side it was flanked by curbs 2 feet (60,96 cm) wide and 18 inches (548,64 cm) high and paralleled by one-way side lanes 7 feet (213,36 cm) wide. This massive Roman road section, adopted

of large stone slabs at least 6 inches (15 cm) deep.

about 300 BC,бset the standard of practice for the next 2,000 years.

a) the main gradients of a highway structure; b) the types of the pavements;

51. Tell of: А

c) the characteristics of the subgrade;Д d) the structure and the functions of the subbase.

52. Work in groups of 4. Read one of the paragraphs and underline the key words (In one group students have to read different passages). What is the main idea of your excerpt?ИRender the text to your partners.

Pavement (part I)

Road traffic is carried by the pavement, which in engineering terms is a horizontal structure supported by in situ natural material. In order to design this structure, existing records must be examined and subsurface explorations conducted. The engineering properties of the local rock and soil are established, particularly with respect to strength, stiffness, durability, susceptibility to moisture, and propensity to shrink and swell over time.

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The relevant properties are determined either by field tests (typically by measuring deflection under a loaded plate or the penetration of a rod), by empirical estimates based on the soil type, or by laboratory measurements. The material is tested in its weakest expected condition, usually at its highest probable moisture content. Probable performance under traffic is then

Сdetermined. Soils unsuitable for the final pavement are identified for removal, suitable replacement materials are earmarked, the maximum slopes of embankments and cuttings are established, the degree of compaction to be achieved during construction is determined, and drainage needs are specified.

иIn a typical rural pavement, the top layer of the pavement is the wearing course. Made of compacted stone, asphalt, or concrete, the wearing course directly supports the vehicle, provides a surface of sufficient smoothness and traction, and protects the base course and natural formation fromбexcessive amounts of water. The basecourse provides the required supplement to the strength, stiffness, and durability of the natural formation. Its thickness ranges from 4 inches (10 centimetres) for very light traffic and a good natural formation to more than 40 inches (100 centimetres) for heavy trafficАand a poor natural formation. The subbase is a protective layer and temporary working platform sometimes placed between the base course and the natural formation.

Pavements are called either flexible or rigid, according to their relative flexural stiffness. Flexible pavements (see figure, left) have base courses of broken stone pieces either compactedДinto place in the style of McAdam or glued together with bitumen to form asphalt. In order to maintain workability, the stones are usually less than 1.5 inches in size and often less than 1 inch. Initially the bitumen must be heated to temperatures of 300° – 400° F (150° – 200° C) in order to make it fluid enough to mix with the stone. At the road site a paving machine places the hot mixИin layers about twice the thickness of the stone size. The layers are then thoroughly rolled before the mix cools and solidifies. In order to avoid the expense of heating, increasing use has been made of bitumen emulsions or cutbacks, in which the bitumen binder is either treated with an emulsifier or thinned with a lighter petroleum fraction that evaporates after rolling. These treatments allow asphalts to be mixed and placed at ambient temperatures.

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Student B

Pavement (part II)

The surface course of a flexible pavement protects the underlying base

course from traffic and water while also providing adequate tire friction, generating minimal noise in urban areas, and giving suitable light reflec-

Сcourses for light to moderate traffic volumes or to rehabilitate existing asphalt surfaces. It is relatively cheap, effective, and impermeable and lasts aboutи10 years. Its main disadvantage is its high noise generation. Maintenance usually involves further spray coating with a surface dressing of bitumen. Asphalt surfacing is used with higher traffic volumes or in urban areas. Surfacing asphalt commonly contains smaller and more wearresistant stonesбthan the base course and employs relatively more bitumen. It is better able to resist horizontal forces and produces less noise than a

tance for night-time driving. Such surfaces are provided either by a bitumi-

nous film coated with stone (called a spray-and-chip seal) or by a thin asphalt layer. The spray-and-chip seal is used over McAdam-style base

spray-and-chip seal.

Rigid pavements are made of portland cement concrete. The concrete slab ranges in thicknessАfrom 6 to 14 inches. It is laid by a paving machine,

often on a supporting layer that prevents the pressure caused by traffic from pumping water and natural formation material to the surface through joints and cracks. Concrete shrinks as it hardens, and this shrinkage is resisted by friction from the underlying layer, causing cracks to appear in the

concrete. Cracking is usually controlled by adding steel reinforcement in order to enhance the tensile strength of the pavement and ensure that any cracking is fine and uniformly distributed. Transverse joints are sometimes

base course, it can be “stabilized” with relativelyИsmall quantities of lime, portland cement, pozzolana, or bitumen. The strength and stiffness of the mix are increased by the surface reactivity of the additive, which also reduces the material's permeability and hence its susceptibility to water. Special machines distribute the stabilizer into the upper 8 to 20 inches of soil.

In deciding whether to use a flexible, rigid, or stabilized pavement, engineers take into account lifetime cost, riding characteristics, traffic disruptions due to maintenance, ease and cost of repair, and the effect of climatic

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conditions. Often there is little to choose between rigid and flexible pavements.

The properties of the base course material are usually determined by laboratory tests, although field tests are sometimes conducted to check that the construction process has achieved the designer's intent. Designers typi-

Сcally consider the possibility of structural failure resulting from a single overload and also from damage accumulating under the passage of many routine loads. Both of these types of failure are almost entirely caused by trucks.

иStudent C

Bituminous Pavement

Bituminous pavements are made with by-products of petroleum, such as asphalt. Weather and seasonal changes can cause roadways and the earth below themбto rise or fall slightly. As these natural shifts occur, bituminous pavements allow the road surface to bend or flex slightly without breaking.

Bituminous material softens when heated and can be prepared and applied in a wide range of concentrations. Thin layers of bituminous material are sometimes appliedАwith a pressure sprayer to the base course or the top course. The bituminous material seeps into the crushed rock and penetrates the tiny spaces between the compacted rocks, binding the aggregate together. To provide traction for moving traffic, a thin layer of aggregate may then be spread over the bituminousДmaterial and compacted.

Asphalt, a thick bituminous material, can be used directly as a pavement. Asphalt can be applied in thin overlays less than 2 cm (0.75 in) deep or in layers several centimeters deep, depending on the type of surface and its purpose. Asphalt is commonly mixed with aggregates for added strength and traction. The asphalt and aggregatesИare usually mixed and heated at a central location. The material is then transported to the construction site, where it is spread directly over the base course or top course and compacted. Asphalt surfaces are fairly easy to construct and repair.

Concrete Pavement

Concrete, or rigid, pavements are made from a mix of portland cement and aggregate. Concrete pavements have a long life and require little maintenance. Concrete is generally laid as a single thick layer directly over a base course. For heavily traveled roads, concrete layers can range in thickness from 20 to 36 cm (8 to 14 in). Concrete is usually laid in long

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carrying layer – несущий слой chopped stone – колотый камень cobble – булыжник

cohesion – сцепление distortion – деформация

Сdurability – прочность

inlaid pavement – мозаиковая мостовая rolling stock – подвижной состав

rut – колея

slag – шлак

to sag – пров сать, прог баться singleиout – выделять

subgrade ground – грунт полотна

wear of the middle part of the pavement?

55. Read the text and check your answers.

Road Surfaces

Road surface (pavement) is a special strengthening of the carriage way of the road with the aim of creating hard and most possibly comfortable surface of rolling for the wheels of the rolling stock.

The main qualities required of the road pavement are the pavement durability and the surface smoothness. Durability of the entire construction of the highway pavement is necessary for the sake of avoiding its sagging or breaking under the wheel pressure.

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The upper layer must be durable in order to avoid the damage by the wheels and the formation of local distortion and ruts. At present rather considerable number of types of road pavements are used in road construction.

The pavement is the principal element of the road as it is directly subjected to the traffic.

СIt is on the qualities of pavement that the comfort of running depends. Durability and smoothness of some types of pavements may be not constant dur-

ing a long period of time. The higher the type of the pavement is the less its durability depends upon the geophysical factors and the less the durability of this pavement changes during the year.

иTo provide for all the year round traffic along the road there is a tendency to build the pavements durability of which is more or less constant during the year and does not decrease in wet seasons. While considering the scheme of the pavement consisting of more than one layer it is usual to single out the wearing surface, the carrying layer, the foundation and subgrade ground. The wearing surface receives the direct action of wheels and is subjected to the vertical impacts and loads as well as horizontal ones. The wearing surface must be

hard but not бbrittle. It must possess good resistance to grinding action.

The wearing surfaceАmust ensure the smoothness of the pavement. Usually the wearing surface is made of mixture of stone materials and organic binder.

The carrying layer undergoes vertical forces from the wheels of the rolling stock. Such layers are made durable and bound.

They may be made of the rolledДlayer of broken stone and gravel and besides this, they may be made of the same materials treated with organic binding materials. Subbase undergoes the vertical forces from the carrying layer in the weakened state, the impacts of the wheels being considerably amortized by the above lying carrying lауеr and distributed by it over the large area.

The foundation layer material feels only compression.ИThe foundation is made of sand layer, gravel layer and broken stone layer of soft rock. The road- bed-ground feels vertical pressure from the pavement. Constant durability or the least possible change of the durability independently of the season of the year is demanded of it. The construction of the subgrade and pavement must be done in such a way as not to permit the ground moistening beneath the lower limit of plasticity.

It is usual to divide all the types of pavements in the following way: 1) rigid pavements, resisting bending (cement and concrete), 2) flexible pavements which do not resist bending or which resist it but little.

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There are some intermediate types of pavements between hard and soft ones. Road pavements may be classified according to the following features:

1) durability and constancy of qualities;

2) degree of using the local materials;

3) pavement layer structure.

СAccording to the standard of technical classification of highways road pavements are divided into 4 groups as to the technical and economical indications:

1) improved capital types: asphalt and concrete, cement and concrete and inlaid pavements;

2) improved pavements of lightened type: black broken stone pavements, black gravel pavements, brick surfaces;

3) intermediate types: black earth roads, broken stone pavements, slag pavements, pavements of chopped stone and cobbles;

For the sake of the traffic safetyДand comfort the cross-section of the roadway surface is desired to approach horizontal lines as much as possible. Nevertheless, for the transversal drainage the sufficient cross-section of the pavement surface is necessary.

The (outline) form of a roadway and its cross-section must satisfy both requirements. The firmness of the vehicle on the sloping (inclined) roadway surface depends upon the cross-section value, condition of the pavement surface and traffic speed. On the pavement with the considerable cross-section vehicles tend to occupy the middle of the pavement where thus the traffic concentrates. This promotes wear of the middle part of the pavement.

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Watch a short video https://www.youtube.com/watch?v=mxOn5evRZEY. Why is compaction very important? Describe this process.

56. Look through the text and find –ing forms used for describ- Сing different processes concerning highway pavement.

57. Find the synonyms to the following words in the text. Influence, plan, deformation, mark out, driving, whole, frail, tread, below.

58.Find the antonyms to the words below (they are in the text). Slow, firm, underneath, lower, dry, increase, unpleasant.

59.Form the words denoting different qualities of the pavement. List the suffixes used for it.би

Enumerate the layers from the bottom to the top in the right order.

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61. Word construction. Translate the following words keeping in mind their suffixes and prefixes.

Durable, durably, durability, duration, during.

Consider, considered, considering, considerable, considerably, considera- Сtion, considerate.

Resist, resisted, resisting, resistance, resistant, resistive, resister, resistible, resistor, resistibility, resistivity.

Press, pressed, presser, pressing, pression, pressure.

62. Complete the sentences, using the text.

63. Read the text to find answers to the following questions:

1.What factors decrease surfacing thickness?

2.How do you understand the term wear?

3.Why is the determination of the possible wear in the course of the time important? Д

Road Surfacing WearИ

When the road is in service there takes place the influencing of different factors upon the road surfacing and this causes the surfacing getting gradually thinner. The first factor causing the decrease of surfacing thickness is the influence of traffic, and the second factor is the influence of atmosphere.

The loss of the material of the road surface while in service and the decrease of its thickness is termed wear. The surface wear is uneven on the surface area.

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The weakest sections which had different defects in the process of constructing or repairing are the most quickly worn out. As a result of the unevenness of the wear there appear some roughness and potholes on the road. The most even wear is observed with the black surfaces.

The determination of the possible wear in the course of time is rather important for the proper organization of the exploitation of the road because such determination gives the possibility to fix: 1) the amount of work and the quantity of materials necessary for ordinary repairs; 2) the terms of the average and capital repairs, which may appear necessary for restoring

the evenness of the surfacing.

wearвание– знос

3) покрыт е дорожной одежды

wear out – знаш ваться, истираться

64. Translateбthese words depending on their part of speech.

Which of them were used in the text?

66. Translate the following words keeping in mind their suffixes and prefixes.

Differ, different, difference, differentia, differential.

Possible, possibility, impossible, possibly.

Quantity, quantify, quantifiable, quantification, quantifying.

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67. Read the text and answer the questions:

1. What is road revetment?

2. What is the common width of road revetment?

3. What kinds of road revetment are used?

4. How can constructive layers in a road revetment be divided?

Сwidth of the carriage way is called road revetment. It serves to strengthen theиcarriage way and to give it the stability against the traffic influence and the influence of climate factors, smoothness and other properties necessary for the motor-car traffic. In some cases the revetment may be made upon the whole width of the subgrade, i.e. it covers also the road sides completely or partially.

Principles of the road revetment designing

One or more constructive layers of durable material, made on the

Road revetment may be made of different kinds. For the roads outside the town sickle-shaped, trough and half trough profiles of the road revet-

ment are mostly used.

б The advantages ofАthe trough profile are:

1) possibility to use road-revetment of any thickness;

2) the availability of the side walls of the trough makes the construct-

ing of the road revetment of the unbound materials easier;

3) rational utilizing of material of the road revetment according to the width.

The defects of such profile are:

1) the necessity of draining the water which can penetrate into the trough if the revetment is permeable;

Principal Constructive Layers of Road Revetment.ИThere are two groups of constructive layers in a road revetment – surfacing and artificial foundation.

The surfacing may consist of one or more layers sometimes of material of different character and durability.

The layers are directly subjected to traffic and must defend all the construction from the influence of climate factors and from penetrating water first of all. In the consequence with this any surfacing must have

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smooth, but not slippery, dustless and impervious surface, stable enough to resist the influence of the load in any period of time.

carriage way – проезжая часть revetment – одежда (дорожная)

Сroad side – обочина, боковая полоса sickle-shaped – серповидный subgrade – земляное полотно trough profile – корытный профиль permeable – водопрон цаемый

и68. Word construction. Translate the following words keeping in mind their suffixes and prefixes.

Strong,бstrongly, strength, strengthen, strengthened, strengthening. Construct, constructive, construction, constructor, constructing, constructible, reconstruction.

Permeate, permeating, permeation, permeable, permeability.

69. What constituentsАdoes this compound word consist of? Give other examples of compound words, using these and other roots.

sickle-shaped

70. Look through the text andДfind the words formed from these ones. What parts of speech do derivative words belong to?

Wide, stable, smooth, easy, dust, complete, partial, bind, pervious, slip.

71. Read the text and define its main idea.И

Designing Road Revetments

Road revetment is the most extensive element of the motor highway. With the perfected motor highways it forms 75% of the whole cost, whereas the cost of the subgrade seldom exceeds 15 – 16%.

As it is impossible and irrational to construct the high class road revetments in all cases, it is necessary to use the stage principle on a large scale i.e. to improve the revetment gradually taking into consideration its importance for the national economy and the growing amount of transportation.

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Choosing the type of surface and construction of the road revetment for the new road as for the reconstructed one it is necessary to realize what period of time they are designed for and what measures for preserving the surface in a good state will be necessary. Irrespective of the chosen type of surface and revetment construction it is necessary to remember that the du-

Сrability of surface and economy of road revetment construction depend upon the following factors:

1) durability and stability of road revetment foundation;

2) technical characteristics of the utilized materials;

3) provision of necessary machinery and means of transport; и4) the kind of work organization;

5) correctness of the technological process of the work performance; 6) the careful control of the qualities of the applied materials and

ready-made constructions, maintaining the technological progress.

The durabilityбof the foundation which to some extent predetermines the further surface work, depends upon the proper estimating of the soils, hydrological and temperature conditions of the subgrade, the proper designing and constructing of the foundation.

Proper placing theАgrounds in the subgrade body and their proper consolidating are of the special importance. Not less important is the ensuring of the surface water drainage and ground water drainage, and one must take into account the redistribution of moisture which occurs as a result of influence of temperature difference.Д

For the road construction requiring the large amount of the transportation work, it is necessary to utilize local materials on a large scale. Nevertheless, it is very important to use the materials sufficient for the chosen type of construction and on the contrary it is necessary to choose types of surfacing and to design constructions, taking Иinto account the specific properties of the materials, projected for the utilization. That is why the problem of providing the construction with the road building materials is to be put to one of the first places while building the road revetment.

There appears the necessity of creating the industry of road building materials: mainly the broken stone, different mineral material mixed with organic binders (black, cold asphalt, mastic etc.) and binders themselves - mineral binders (cement, lime) and organic binders (bitumen, tar, emulsion

of tar).

The quality and economy of the work greatly depend upon the proper selection of mechanisms and upon the proper organization of work.

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The great problems standing before the motor highway constructors will appear unfeasible without mechanization of all the processes requiring much labour expenditure.

But equipping the roadbuilding with the necessary perfected machinery is not sufficient if the latter is not rationally utilized, or if there is no co-ordination in the efficiency of different mechanisms. It will not give the desirable effect if there is no systematic daily control of the utilized materials, ready-made constructions and without the exact following of the fixed technological process.

74. Word construction. Translate the following words keeping in mind their suffixes and prefixes.

Provide, provided, provision, provident.

Necessity, necessary, necessarily, necessitate.

Utilize, utilization, utilizable, utilizer, utilized, utilizing.

Quality, qualitative, qualify, qualification, qualified.

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75. Complete the following sentences, using the information from the text:

1. Choosing the type of surface and construction of the road revetment for the new road as for the reconstructed one it is necessary to realize … .

2. The durability of the foundation to some extent … .

3. Proper placing the grounds in the subgrade body and their proper consolidating are … .

Road Surfaces in the USA and Canada

There are concrete highways in parts of the US, especially the Interstates. Canadian highways are asphalt/blacktop/tar/whatever you want to

call it. Reason is that concrete expands and contracts to such a degree that it'd self-destruct during a Canadian Дwinter.

The joins between the slabs of concrete often cause a rhythmic thump

as you drive which does the tyres and suspension no good at all.

The vast majority of roads in the USA and Canada are paved. Howev-

er, there are some unpaved minor roads.

Most car rental companies include clauses in their rental agreements

prohibiting the use of their vehicles on unpaved roads.

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77. Watch the lecture (61 minutes) on measuring pavement quality https://www.youtube.com/watch?v=kH5RhtsaVnI. Make notes. Identify the road quality criteria using the ideas from the video and inspect some Omsk road surfaces. Make a report and discuss it with

78. Read the words below and try to memorize them (be sure you

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79. Look at the pictures (pic. 23, 24). Do you have any ideas what is happening there? Try to make as many suppositions as possible.

the roadway or adjacent property. In areas whereИland use is changing from agricultural to residential or commercial, peak flows will increase notably as the surrounding area is covered with roofs and paving.

Safety requires that water be rapidly removed from the pavement surface. In urban areas, the water runs into shallow gutters and thence into the inlets of underground drains. In rural areas, surface water flows beyond the shoulders to longitudinal drainage ditches, which have flat side slopes to

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enable vehicles leaving the pavement to recover without serious incident. Cut-off surface drains are used to prevent water from flowing without restriction down the slopes of cuttings and embankments.

Vertical drainage layers, formed from single-sized aggregate or special sheets called geofabrics and geomembranes, are used to prevent groundwa- Сter from seeping laterally into the pavement structure. In addition, a horizontal drainage layer is often inserted between base course and natural ground in order to remove water from the pavement structure and stop upward capillary movement of any natural groundwater. Underground drains can also be used to lower the groundwater level by both preventing water

entry and removing water that does enter the pavement structure.

81. Give Russian equivalents to the following words without a dictionary. Use the words in the sentences and let your groupmates

Design; designedly; designee; designer; designing; designed.

Water; watered; waterer; watering; wateriness; waterless; watery; unwater. Layer; lay; layered; layering; laying; unlay; inlay.

84. Complete the sentences using information from the text.

1.Drainage systems can be …

2.Drainage involves handling …

3.The drainage system must be able to …

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4.Safety requires that …

5.Vertical drainage layers are used to …

6.A horizontal drainage layer is used to …

scotchlite – светоотражательный материал sight distance – расстоян е видимости

The sight distance is the maximum distance at which two vehicles are mutually visible, or it is possible to say sight distance is the minimum distance in meters, at which the driver must see the road or the obstacle on the road in front of himself. The sight distance is the function of the traffic

The safetyбdemands that the sight distance be ample for the vehicles to clear each other at theАmaximum road speeds and could stop if necessary. For ensuring the necessary sight distance the curvature should be as flat as possible. Experience dictates a minimum sight distance 50 – 300 m depending on the traffic speed and on the conditions of traffic. To secure this sight distance at night with the help of the headlights it is necessary to have the curves of the sufficient radii. It was proved that to obtain the minimum

speed.

sight distance of 100 m the radii of curves must be no less than 1.500 m.

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86. Translate the following words keeping in mind their suffixes and prefixes. Define their part of speech. Make up some wordcombinations using these words.

Vision, visible, visibly, visibility, visionally, visional, invisible, prevision.

СSuffice, sufficient, sufficiency, sufficiently, insufficient. Safe, safely, safety, unsafe, unsafeness, save, saving, saver.

87. Find four different modal verbs used in the text. What is theirиmeaning? Use them in your own sentences.

88. Fill in the correct preposition from the list below, then choose

any three items and make sentences.

бIn, at, on, than, for, in, on, by, for.

… the road; … the maximum speed; … front of sb/sth; depending … the traffic speed; less … 1.500 m; to be ample … the vehicles; located … the cut; to improve … Аinstalling sth; an obstacle … good visibility.

89. Read these words and find them in the text below. Make your

own sentence using 5 words from the list.

addition – добавка

adjoining land – прилегающая полоса земли curb – бордюр

normal – перпендикулярный outline – контур, очертание, схема plane – плоскость

roadway – проезжая часть дороги riding surface – ездовая поверхность

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road bed – дорожное полотно

road side – обочина, боковая полоса side track – разъезд

subgrade – земляное полотно surface – поверхность, покрытие

Сtraffic – уличное движение

traffic capacity of the lane – пропускная способность полосы traffic density – нтенс вность движения

traffic lane – полоса дв жения

иRoadway

The roadway is the name given to a part of a subgrade surface directly

subjected to the traffic of vehicles. The roadway surface may be also called the riding surface. The roadway is directly joined to by the two roadsides.

from the roadsidesбby the curbs.

The roadway may be composed of natural ground, of the ground improved

(strengthened) by different additions and forces or of a layer of different,

mostly rock, materials, making the pavement. The roadway is separated А

If there is no pavement, the roadway forms one monolithic structure with the roadsides.

The roadway together with the roadsides forms a road bed. The road

bed is limited by the slopes on both sides. The lines separating the roadsides from the slopes are called the edges of the road bed. Beyond the limits of the roadway side drainage ditches may be situated. The side ditches are separated from the adjoining land by the outer edges of the ditches.

plane normal to its centre line. WhileДdesigning the roadway it is first of all necessary to determine the width of the roadway, the kind of a road surface and its outline.

The cross-section of a highway is the intersection of its surface by a

The width of a roadway depends upon the number of traffic lanes and the width of each of them.

И

The roadway consists of two traffic lanes and, serving two-way traffic, is mostly used on the motor highways. Each of the two traffic lanes is destined for the traffic in one direction only. The number of traffic lanes in its turn depends on traffic density.

Traffic density is a number of vehicles passing a definite section of the highway during a given unit of time. Maximum quantity of transport vehicles passing through one traffic lane of a roadway during a given unit of

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time (hour) is known to be a traffic capacity of the lane. Traffic capacity depends upon the rate and regime of traffic, type and condition of surfacing. Considering the destined designed traffic speed and the supposed maximum density per hour it is possible to design the number of necessary traffic lanes. The necessity often appears to have some traffic lanes in one di-

Сrection when the traffic includes not only motor-lorries but cars with high speeds peculiar for them as well. In case one traffic lane serves the traffic in both directions the meeting and passing of the vehicles may be exercised by moving the vehicles out to a road side with one wheel, the speed being decreased by this. With one traffic-lane roadway and narrow road bed the sideиtracks are necessary.

The side tracks are made in the form of widening the roadside, road bed and the roadway. On the roadway having two traffic lanes with intensive traffic passing is exercised with some difficulties too. The high-speed motor-car hasбto exercise passing very often and thus its trajectory becomes very winding. That is why the designing of fouror six-traffic-lane roadways is necessary with intensive traffic and with different rate traffic flow. The four-traffic-lane-roadway ensures the comfort and traffic safety for high-speed motor-Аcars with more slowly moving motor-lorries available on the neighboring lane. There being no passing allows developing high speed and economizes fuel. The width of the traffic lane depends upon the dimensions of vehicles and their speed. The continuous developing

1.What is a roadway? Д

2.What materials may a roadway be composedИof?

3.What does the width of a roadway depend on?

4.How is it possible to design the number of necessary traffic lanes?

5.When does the necessity appear to have some traffic lanes in one direction?

6.How wide is a traffic lane becoming nowadays?

91.What is the name of an element/line separating:

-the roadway from the roadsides;

-the roadsides from the slopes;

-the side ditches from the adjoining land?

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92. Match the words with the more and less general meanings:

Vehicle, material, width, rock, part, motor-lorry, hour, car, time, wheel, structure, dimension.

93. Find in the text words with a similar meaning:

Riding surface, type, traffic density, side, quantity.

Side ditches

Side ditches are constructed along the sides of the road bed in the cuts and small fills. In the cuts the side ditches serve the purpose of collecting and removing the water falling from the road bed and from the slopes. In the fills the side ditches also remove water from the road bed and while constructing the road the earth from the ditches is used for making the fills.

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The depth and the area of the cross-section of the ditch are determined depending on the amount of the water to be removed. With the little pervious soils by which the water is absorbed weakly the side ditches must be deeper than with the sandy loam soils absorbing considerable part of water.

Besides this side ditches may also drain the ground water partly if the Сwater level is high and the bottom of the side ditch is placed below the water level. The depth of the side ditch considerably depends on the soil type

of the road bed and at the same time the depth of the side ditch is considerably influenced by the width of the road bed since upon this depends the amount of water entering the ditch.

1:и1.5 and the width of the bottom of 0.4 – 0.5 m is considered to be normal.

The depth of the side ditch is measured from the edge of the subgrade

to the bottom of the side ditch.

The form of the cross-section of the side ditch depends on ground and

hydrological conditions. The trapezoidal ditch with the inner slope of

surface waterбflow, with the ground water level near to the surface and in the impervious grounds.А

The trapezoidal ditches are made in the localities with the intensive

The availability of the side ditches reduces the safety of the motor-car traffic essentially. The automobile got into a deep side ditch even at a low speed is wrecked. The usefulness of deep ditches in all the cases of subgrade structure is rather doubtful.

For the safety of motor-traffic the side ditch should be shallow and the slope into it must be comparatively flat with the simultaneous reducing of

A.Along the sides of the road bed; the simultaneousИreducing of the depth; in the cuts and small fills; from the edge of the subgrade; the depth of the side ditch; to drain the ground water; the form of the cross-section.

B.Дренировать грунтовую воду, в выемках и небольших насыпях, одновременное уменьшение глубины, параллельно краям дорожного полотна, глубина кювета, форма поперечного профиля, от границы земляного полотна.

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98. Answer the questions.

1. What purpose do the side ditches serve in the fills? In the cuts? 2. Where are the trapezoidal ditches made?

Intersections

Intersections reduce the capacities of the roads involved. Crossing traffic interferes with the free movement on either; road. On roads of the same dimensions the maximum capacity of the intersection for crossing traffic is theoretically equal to that of either road. Cross movements cannot be made at the same rate as direct movement, therefore the capacity of each road is less than 50 per cent, probably never more than 45 per cent, of

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Disjunctive Strips

On the trunk highways designed for the traffic with high speeds and on the roads with dense traffic it is necessary to take special measures for the safe meeting and passing of the motor-cars. The making of disjunctive strips is one of the essential measures taken with the purpose.

СThe principal purpose of this disjunction is not to allow any occasional moving of the motor-car out to the traffic lane of the opposite direction. The width of the disjunctive strip is destined from 1 to 5 m. For the designed speed of 120 km per hour the width of such a strip must be 3.0-3.5 m.

и106. Find the Past Participles in the text and state their syntactic function.

107. Find the antonyms to the following words in the text. Feeder (highway),бlight, common, dangerous, optional, direct.

108. Word construction. Translate the following words keeping in mind their suffixes andАprefixes. Define their part of speech.

Dense, densely, denseness, density, densify, densifier, densification. Junction, juncture, disjunctive, disjunctively, disjunction.

Oppose, opposing, opposed, opposite,Дopposition, oppositely.

109. Read the text and answer the questions after it.

Roadsides

The roadsides serve the following purposes:

1)to be the side stop for the pavement to avoid moving pavement material aside under the action of traffic;

2)to be safety lane between the pavement and the edge of the road bed to prevent the break downs at the time of the occasional moving of the automobile out of the pavement;

3)to be the place for the forced stop of the rolling stock in case of disrepair;

4)to be the place for the temporary disposition of materials for repairing the pavement;

5)to be the lane for the footpaths and bicycle-paths when the traffic is not dense; И

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6) to be the reserve strip for widening the pavement when improving the type of the highway and for the circuit when repairing the road.

The normal width of the roadside is the width of 2.0-2.5 m. It is allowed to reduce the width of the roadside to 1.0 m or even to 0.5 m in the

highlands.

Сmethods (by paving, by stabilization with binding materials etc.).

The roadsides must let the water running from the surface of the roadway freely pass to the slope of the road cross-section. For this purpose the surface of the roadsides is made 2% steeper than the cross-section of the

pavement i.e. practically 4 or 5%.

To avoid deformation the road-sides may be strengthened by different

113. Fill in the correct prepositions from the list below, then choose any three items and make sentences.

1) … the action of something; 2) … the time of something; 3) the moving … the automobile; 4) … case of something; 5) to be the place … something; 6) to be strengthened … something.

By, at, of, under, in, for.

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114. Read the text to find the answer to the given question. Where are footpaths usually made?

Footpaths and sidewalks

It is necessary to make footpaths or sidewalks on the sections of the highways running through the inhabited locality, workmen's settlements, summer resorts on the suburban sections of the roads with more or less pedestrian traffic density otherwise pedestrians will use the roadway which will result in some inconveniences and accidents.

Which of them were used in the text?

б 116. Translate Аthese words depending on their part of speech.

A use – to use; a result – to result; a strip – to strip; the earth - to earth.

Make up your own word-combinations and sentences with these words.

Borrow Pit

Reserve or borrow pit is a regular shaped excavation of the ground from which the ground has been used for making the fill.

If possible, the borrow pit is laid in the immediate nearness to the fill into which the ground from the borrow pit is placed.

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Borrow pits may be laid either from one side of the road or from both sides. The depth and the area of the borrow pits are determined dependently on the amount of the ground required for making the fill with the consideration of the securing of the drainage. In the flat country it is advisable to have the depth of the reserve not more than 1 m.

СThe borrow pits must have the regular outline in the plan and in the profile ensuring the water flow.

Where is the borrow pit usually laid?

и119. Translate the related Verbs and Nouns. What words were used in the text?

To fill – a fill, to reserve – a reserve, to plan – a plan, to flow – a flow, to profile – a profile, to shape – a shape, to ground – the ground.

120. In the text find the nouns derived from these words. Name

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122. Read the text to answer the question: What are the reasons of planting trees along the roads?

Planting trees along the roads

The planting of trees is an inalienable part of a road. СThe design of the road must contain the design of trees planting with

the placing of the trees along the right-of-way and with the choice of the tree species.

Planting of trees is divided into 3 groups according to the purposes they serve:

и1) planting of trees for protection from snow and sand;

2) planting of trees for decoration;

3) camouflaging planting of trees.

The planting of trees along the right-of-way must limit neither the

tion. What бpart of speech do they belong to?

traffic itself nor the operations necessary for the traffic service.

123. Find the -ing forms in the text and state their syntactic func-

124. Translate theАfollowing words keeping in mind their suffixes and prefixes. Define their part of speech.

125. Find in the text above aДsentence with the construction “neither … nor …” and translate it. Make your own sentence, using this construction.

Divide, divided, undivided, dividend, dividing, divider, divisible, division, divisional.

Protect, protected, protecting, protection, protective, unprotect, unprotected.

Contain, contained, container, content, contents. И

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126. Read the following text to find the answer to the question: What facilities are usually located on the right-of-way?

ings and special tracks, planting of trees, spoil banks and reserves are located. The necessary width of the right-of-way is destined by the design.

On the right-of-way it is possible to locate a number of constructions having nothing to do directly with the road and belonging to the other or-

127. Translate the following words. What part of speech do they belong to?

Locate, located, locating, location, locator, dislocate,Иdislocation, relocate. Wide, widely, widen, widened, widening, width.

Direct, director, directness, directly, direction, directional, directive, undirected.

128. Find in the text equivalent English phrases to the following

Определяется проектом; требуемая ширина; линии связи; подземные трубопроводы; не относящийся непосредственно (к чему-то).

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129. In each line find a word with the opposite meaning to the first word.

1. Tape

-the act or process of recording on magnetic tape;

-a long thin strip, made of cotton, linen, etc., used for binding, fastening, etc.

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2. Light

-anything that illuminates, such as a lamp or candle;

-not heavy; weighing relatively little

- to fight using swords or foils;

- a structure that serves to enclose some area, usually made of posts of timber, concrete, or metal connected by wire, netting, rails, or boards.

132. In each line find the word which is translated at the beginning of a line.

133.What modal verbs are used in the text? Make your own sentences with them and other modal verbs.

134.Try to memorize the words. Close your book and write as many words from the box as you can.Д

135. What operations are shown in the pictures (pic. 30–35)? Match the following verbs with the pictures below: to place; to install; to spray; to compact; to clear; to pave. In what word combinations can the given verbs be used?

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136. Scan the text Road Construction and arrange the phrases in the appropriate order:

– clearing, earthmoving, shaping, and compacting the natural formation;

– constructing bridges and culverts; С– installing underground drainage;

– manufacturing asphalt and concrete;

– placing and compacting the pavement layers;

– producing and handling the road-making aggregate.

137. Match the words to make word combinations used in the text. Then find these word combinations in the text and check your an-

Д Road ConstructionИ

After the road has been approved and financing found, surveyors define its three-dimensional location on the ground. Forming of the in-situ material to its required shape and installation of the underground drainage system can then begin. Imported pavement material is placed on the natural formation and may have water added; rollers are then used to compact the material to the required density. If possible, some traffic is permitted to operate over the completed earthwork in order to detect weak spots.

In countries where labour is inexpensive and less skilled, traditional manual methods of road construction are still commonplace. However, the developed world relies heavily on purpose-built construction plant. This

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can be divided into equipment for six major construction purposes: clearing, earthmoving, shaping, and compacting the natural formation; installing underground drainage; producing and handling the road-making aggregate; manufacturing asphalt and concrete; placing and compacting the pavement layers; and constructing bridges and culverts.

СFor clearing vegetation and undesirable materials from the roadway, the bulldozer is often employed. The construction of rock cuts is commonly done with shovels, draglines, and mobile drills. Shaping the formation and moving earth from cuttings to embankments is accomplished with bulldozers, graders, hauling scrapers, elevating graders, loaders, and large dumpиtrucks. The material is placed in layers, brought to the proper moisture content, and compacted to the required density. Compaction is accomplished with tamping, sheepsfoot, grid, steel-wheeled, vibrating, and pneumatic-tired rollers. Backhoes, back actors, and trenchers are used for drainage work.б

In order to avoid high haulage costs, the materials used for base course construction are preferably located near the construction site; it is economically impossible to use expensive materials for long lengths of road construction. The excavationАprocess is the same as for rock cuts, although rippers may be used for obtaining lower-grade material. Crushers, screens, and washers produce stone of the right size, shape, and cleanliness.

The placement of paving material increasingly involves a paving machine for distributing the aggregate,Дasphalt, or concrete uniformly and to the required thickness, shape, and width (typically, one or two traffic lanes). The paving machine can slipform the edges of the course, thus avoiding the need for fixed side-forms. As it progresses down the road, it applies some preliminary compaction and also screeds and finishes the pavement surface. In modern machines, level controlИis by laser sighting.

In producing a spray-and-chip seal surface (or a bituminous surface treatment), a porous existing surface is covered with a film of hot, fluid bitumen that is sprayed in sufficient quantity to fill voids, cracks, and crevices without leaving excess bitumen on the surface. The surface is then sprayed with a more viscous hot bitumen, which is immediately covered with a layer of uniform-size stone chips spread from a dump truck. The roadway is then rolled to seat the stone in the sticky bitumen, and excess stone is later cleared by a rotary broom.

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139. Look at the pictures (pic. 36,a – 36,h).Which one is:

Pic. 36 (the beginning)

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141. Work in pairs.АTalk about road construction. Remember to ask about construction purposes and machinery used.

142. Read the text and giveДtitle to each paragraph. It will be your plan of the text.

Watch the video https://www.youtube.com/watch?v=ox0mP SrAFw and describe the road building process. Imagine you are a journalist.

Construction of Highways in cold regions

Design of highways in cold regions should be preceded by field investigations which are of the same general character and scope as required in nonfrost regions, but which are carried somewhat farther. In addition to the usually data on topography, hydrology, etc., special information is needed on the climatic factors of temperature and precipitation, on the frost characterization of soil and construction materials, and on ground-moisture condition.

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Frost effects and the occurrence of low temperatures very seriously affect the scheduling of construction operations in cold regions. In both seasonalfrost and permafrost areas, effective highway construction is usually limited to the period during which air temperatures are at or about freezing, though welldrained granular materials and hot-mix bituminous surfacing are occasionally

Сequipment. In permafrost areas, cuts in untrained frozen materials are commonly made by first removing trained materials, excavation may be carried down to the elevation required. Thaw in fine-grained frozen soils may be as much as 6 in. per day following exposure. Frozen materials may also be

placed in below-freezing temperatures for emergency purposes.

Construction is also limited by the spring “mud time”, during which the

surface of the fine-grained solids may be practically impossible for constriction

Permafrost – perennially frozen ground.

Annual frost zone – the top layer of ground subject to annual freezing

Non-frost-susceptible materials – cohesionless materials such as crushed rock, gravel, sand, slag, and cinders in which significant ice segregation does not occur.

143. Read and study the following words:

to proceed – происходить, действовать

field investigations – исследования местности

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non-frost region – район незамерзания precipitation – осадки (метеор.)

emergency – крайний случай, критическое положение, авария undrained materials – водонепроницаемый материал

thawed material – талый, оттаявший материал thaw – таяние

exposure – метеорологическая сводка to cope with – справиться, совладать

liquefied material – материал в жидком состоянии

вздувание

144. Stateбthe Tense of verbs in Passive Voice in the following sentences:

1. Design of highwayАin cold regions should be preceded by field investigation. 2. Field investigation in cold regions must be carried farther then in nonfrost regions. 3. In cold regions to the usual data topography, hydrology, etc. special information is needed on the climatic factors of temperature. 4. In seasonal frost andДpermafrost areas highway construction is limited to the period during which air at or above freezing. 5. Welldrained granular materials and hot-mix bituminous surfacing are occasionally placed in below-freezing temperatures for emergency purposes. 6. Constructions of highways is also limited by the spring “mud time”. 7. Frozen materials may also be thawed by use of coldИ-water.

145. State the -ing forms, their functions and translate into Russian.

1. Frost effect and the occurrence of low temperatures very seriously affect the scheduling of construction operations in cold regions. 2. Effective highway construction is usually limited to the period during which air temperatures are at or above freezing, though well-drained granular materials and hot-mix bituminous surfacing are occasionally placed in bellow- freezing temperatures. 3. In permafrost areas, cuts in undrained frozen materials are commonly made by first removing thawed materials. 4. Care

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must be taken to avoid permitting too great a depth of fine-grained soil. 5. Establishment of grades when the ground is freezing or thawing is difficult in areas of frost-susceptible materials. 6. In permafrost regions this problem extends through the summer thawing season. 7. In borderline permafrost areas, where freezing does not reach the permafrost surface until late

Сin the winter, the pavement may be continuously rising and falling throughout the year. 8. Annual frost zone is the top layer of ground subject to annual freezing and thawing. 9. Frost heave is the raising of a surface due to the formation of ice in the underling soil. 10. When the requisite moisture and freezing condition are present frost-susceptible soils are formed.и

146. Answer the question to the text.

1. Doesбthe design of a highway in cold regions need any investigation? 2. What investigation are required? 3. What are the peculiarities of cold regions highway engineering? 4. What is the main difficulty in highway construction in cold regions? 5. What is the period of construction operation in cold regions?А6. What are the ways of handling of thawed materials? 7. What are the characteristics of soil in frost permafrost areas?

147. Read and retell.

Considering the frost action inДdesign is much need. Frost action to highways and airfield pavement results in the following damaging effects:

1. Seasonal frost heave and settlement

2. Surface roughness

3. Loss of compaction И

4. Deterioration of the pavement surfacing

5. Loss of strength during that

6. Degradation through melting of permafrost

7. Restriction of subsurface drainage

148. Watch a piece of lecture on UK highway roads (University of Leeds) https://www.youtube.com/watch?v=MW4jJ46A15w. Be ready to tell the same material in Russian.

149. Give the short summary of the text “Construction of Highways in cold regions”.

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