毕业设计中英翻译.pdf

The road highway The road is one kind of linear construction used for travel It is made of the roadbed the road surface the bridge the culvert and the tunnel In addition it also has the crossing of lines the protective project and the traffic engineering and the route facility The roadbed is the base of road surface road shoulder side slope side ditch foundations It is stone material structure which is designed according to route s plane position The roadbed as the base of travel must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding The road surface is the surface of road It is single or complex structure built with mixture The road surface require being smooth having enough intensity good stability and anti slippery function The quality of road surface directly affects the safe comfort and the traffic The route marking is one kind of traffic safety facility painted by oil paint or made by the concrete and tiles on high level less high type surface Its function is coordinating the sign to make the effective control to the transportation directing the vehicles skip road travel serving unimpeded and the safe purpose Our country s road route marking has the lane median line the traffic lane boundary the curb line the parking line the conduction current belt the pedestrian crossing line the four corners center circle the parking azimuth line The route marking has the continual solid line the broken line and the arrow indicator and its color uses the white or the yellow The arch of bridge is the structure which strides over rivers mountain valley and channel It is made generally by steel rod concrete and stone The tunnel is the cave which connects both sides of the road The technique of this construction is very complex the cost of the projects is higher than common road However it reduces the driving distance between two places enhances the grade of the technical in building the road and guarantees the cars can drive fast and safely thus reduces the cost of transportation The protective project is to protect and consolidate the roadbed in order that it can guarantee the intensity and the stability of the road thus maintains the automobile to pass through safely In order to guarantee that safe operation of the highway transportation besides the highway engineering and the vehicles performance it must have some traffic signal route marking each kind of director and demonstrate facility The highway marking uses certain mark and draw symbol simple words and number then installs in the suitable place to indicate the front road s condition or the accident condition including the informational sign the warning signal the prohibitory sign the road sign and so on The road which Join city village and industry mainly are used for the automobile and has certain technical standard and the facility path can be called the highway The highway in Chinese is the modern view but it was not existed in old day It gets the name from the meaning of being used for the public traffic Where are the human there are the road It is a truth However the road is not the highway If we PDF 文件使用 pdfFactory Pro 试用版本创建 talk the history about the road the earliest highway is that built by the old Egyptians for making the pyramid Next is the street which built by the Babylon people about 4000 years ago All these are much earlier than our country About 500 B C the Persian Empire road has linked up East and West and connected the road to China It is the earliest and longest Silk Road 2500 years ago it might be the greatest road The ancient Rome Empire s road was once celebrated it took Rome as the center all around built 29 roads Therefore it came out one common saying every road leads to Rome The road s construction is the process to enhance technique and renew the building materials The earliest is the old road it is easy to build but it is also to destroy If there is too much water or cars it will be uneven and even be destroyed The macadam road appeared in the Europe which outbalanced the earliest mud road Then the brick road appeared which was earlier than China It was one great breach that we molded bitumen on the macadam road From ancient times to the present China has courier station and courier road while the first more advance road was the one that from Long Zhou in Gang Xi to Zhen Nan Guan in 1906 The difference between Road and path The path is the project for each kind of vehicles and people to pass through According to its function we can divide it into the urban road the road the factories and mines path the forest road and county road The classification of road First according to administrative rank it includes national highway province road county road and the special road Generally the national highway and province road are named main line the county road is named branch line The national road is the main line and has political and economy significance including the important national defense road and the road collecting our capital with other provinces autonomous regions and municipalities It is also the road links the economy center seaport hinge factory and important strategic place The highway striding over different provinces are built protected and managed by the special organizations which are approved by the ministry of communications The provincial road is the main line built protected managed by the road manage department It is full of political and economic sense to the whole province The single way four levels of roads can adapt below each day and night medium duty truck volume of traffic 200 The county route is refers to has county wide county level city politics the econom icsignificance connects in the county and the county the main township town the prin cipal commodities production and the collection and distribution center road as well as does not belong to the federal highway provincial road s county border the road The coun ty route by the county the city road Department responsible for the work is responsible to construct the maintenance and the management The township road refers to mainly the road which for the township town the villa geeconomy the culture the administration serves as well as does not belong to above t hecounty route between road s township and the township and the township PDF 文件使用 pdfFactory Pro 试用版本创建 and the exte rior contact road Township is responsible by the people s government to construct the m aintenance and the management The special purpose road is refers to feeds specially or mainly supplies the factories andmines the forest region the farm the oil field the tourist area the military importantplace and so on and the external relations road The special purpose road is responsibleby the special purpose unit to construct the maintenance and the management May also entrust the local road department to construct the maintenance and the management Second according to the use duty the function and adapts the volume of traffic division According to our country present Highway engineering Technical standard the roadaccording to the use duty the function and the adaptation volume of tra fficdivides into highway arterial road second class road tertiary highway four level of road five ranks 1st the highway to feed specially the automobile and should control the difference c ompletely respectively toward the dividing strip on roads travel the multiple highway The four traffic lane highways ought to be able to adapt each kind of automobile reduce passenger vehicle s year mean diurnal volume of traffic 25000 55000 The six traffic lane highways ought to be able to adapt each kind of automobile reduce passenger vehicle s year mean diurnal volume of traffic 45000 80000 The eight traffic lane highways ought to be able to adapt each kind of automobile r educe passenger vehicle s year mean diurnal volume of traffic 60000 100000 2nd the arterial road to supply the automobile and may according to need to control the difference respectively toward the dividing strip on roads travel the multiple highway The four traffic lane arterial roads ought to be able to adapt each kind of automobil reduce passenger vehicle s year mean diurnal volume of traffic 15000 30000 The six traffic lane arterial roads ought to be able to adapt each kind of automobile reduce passenger vehicle s year mean diurnal volume of traffic 25000 55000 3rd the second class road to supply the automobile travel the two lane highway Can adapt each day and nights 3000 7500 medium duty truck volume of traffic generally 4rd tertiary highways to mainly supply the automobile travel the two lane highway Can adapt each day and nights 1000 4000 medium duty truck volume of traffic generally The 5 four levels of roads to mainly supply the automobile travel the two lane or the single lane highway The two lane four levels of roads can adapt below each day and night medium duty truck volume of traffic 1500 PDF 文件使用 pdfFactory Pro 试用版本创建 Highway engineering includes Highway planning location design and maintenance Before the design and construction of a new highway or highway improvement can be undertaken there mint be general planing and consideration of financing As part of general planning it is decided what the traffic need of the rea will be for a considerable period generally 20 years and what construction will meet those needs To assess traffic needs the highway engineer collects and analyzes information about the physical features of existing facilities the volume distribution and character of present traffic and the changes to be expected in these factor The highway engineer must determine the most suitable location layout and capacity of the new route and structures Frequently a preliminary line or location and several alternate routes are studied The detailed design is normally begun only when the preferred location has been chosen In selecting the best route careful consideration is given to the traffic requirements terrain to be traversed value of land needed for the right of way and estimated cost of construction for the various plans The photogrammetric method which makes use of aerial photographs is used extensively to indicate the character of the terrain on large projects where it is most economical On small project Financing considerations determine whether the project can be carried out t t one time or whether construction must be in stages with each stage initiated as funds become available In deciding the best method of financing the work the engineer makes an analysis of whom it will benefit Important highways and streets benefit in varying degrees three groups users owners of adjacent property and the general public Users of improved highways benefit from decreased cost of transportation greater travel comfort increased safety and saving of time They also obtain recreational and educational benefits Owners of abutting or adjacent property may benefit from better access increased property value more effective police and fire protection improved street parking greater pedestrian traffic safety and the use of the street right of way for the location of public utilities such as water lines and sewers Evaluation of various benefits from highway construction is often difficult but is a most important phase of highway engineering Some benefits can be measured with accuracy but the evaluation of others is more speculative As a result numerous methods arc used to finance construction and much engineering work may he involved in selecting the best procedure Environmental evaluation The environmental impact of constructing highways has received increased attention and importance Many projects have been delayed and numerous others canceled because ot environmental problems The environmental study or report covers many factors including noise generation air pollution disturbance of areas traversed destruction of existing housing and possible alternate routes Highway engineers must also assist in the acquisition of right of way needed for new highway facilities Acquisition of the land required for construction of expressway lending into the central business areas of cities has proved extremely difficult i the public is demanding that traffic engineers work closely with city PDF 文件使用 pdfFactory Pro 试用版本创建 planners architects sociologists and all groups interested in beautification and improvement of cities to assure that expressways extendinx through metropolitan areas be built only after coordinated evaluation of all major questions including the following 1 Is sufficient attention being paid to beautification of the expressway itself 2 Would a change in location preserve major natural beauties of the city 3 Could a depressed design he logically substituted for those sections where an elevated expressway is proposed 4 Can the general design he improved to reduce the noise created by large volumes of traffic 5 Are some sections of the city being isolated by the proposed location Detailed design Detailed design of a highway project includes preparation of drawings or blueprints to be used for construction These plans show for example the location the dimensions of such elements as roudway width the finaj profile for he road the location and type of drainage facilities and the quantities of work involved including earthwork and surfacing In planning the grading operations the design engineer considers the type of material to be encountered in excavating or in cutting away the high points along the project and how the rnaterial removed can best be utilised for fill or for constructing embankments across low areas elsewhere on the project For this the engineer must analyze the gradation and physical properties of the soil determine how the embankments can best be compacted and calculate the volume of earthwork to be done Electronic calculating procedures are now sometimes used for the last step Electronic equipment has also speeded up many other highway engineering calculations Powerful and highly mobile earth moving machines have been developed TO permit rapid and economical operations Selection of the type and thickness of roudway surfacing to be constructed is an important part of design The type chosen depends upon the maximum loads to be accommodated the frequency of these loads and other factors For some mures traffic volume may be so low that no surfacing is economically justified and natural soil serves as the roadway As traffic increases a surfacing of sandy cluy crushed slag crushed stone caliche crushed oyster shells or a combination of these may be applied If gravel is used it usually contains sufficient clay and fine material to help stabilize the surfacing Gravel surfaces may be further stubilized by application of calcium chloride which also aids in controlling dust Another surfacing is composed of Portland cement and water mixed iuto the upper few inches of the suhgrade and compacted with rollers This procedure forms A soil cement base that can be surfaced with bituminous materials Roadways ro carry large volumes of heavy vehicles must be carefully designed and made of considerable thickness Much of highway engineering is devoted to the planing and construction of facilities to drain the highway or street and lo carry streams across the highway right of way Removal of surface water from the road or street is known a surface druiuage It is accomplished by constructing the road so that it has a crown and by sloping the shoulders and adjacent areas so as to control the flow of water either toward existing PDF 文件使用 pdfFactory Pro 试用版本创建 natural drainage such as open ditches or into a storm drainage system of calehbasins and underground pipes If a storm drainage system is used as it would be with city streets the design engineer must give consideration to the rntal area draining onto the street the maximum rate of runoff expected the duration of the design storm the amount of ponding allowable at each carchbasin and the proposed spacing of the catchbasins along the street From this information the desired capacity of the individual eatehbaxin and the size of the underground piping network urc calculated In designing facilities to carry streams under the highway the engineer must determine the area to be drained the maximum probable precipitation over the drainage basin the highest expected runoff rare and then using hit information must calculate the required capacity of llit drainage structure Generally designs are made adequate to accommodate not only the largest flow ever recorded for that location but the greatest discharge that might be expected under the most adverse conditions for a given number of years Factor considered in calculating the expected flow through a culvert opening include size length and shape of the opening roughness of the walls shape of the entrance and downstream end of the conduit maximum allowable height of water at the entrance and water level at the outlet Much engineering und construction work has been done to provide rest stops along major expressway routest especially the national system of interstate highways These facilities must be carefully located to permit easy and safe exit and return access to the highway Many units have been built scenic locations in forested areas to permit picnic grounds and walkways through the forest These rest areas are especially beneficial to tho e drivers traveling long distances with few stops The control and reduction of noise along busy routes especially expressways has become an important part of highway engineering In many communities high walls have been huilt along either side of the expressway Such walls can he costly to construct hut can prove very beneficial barriers can reduce overall noise levels by over 50 Construction operations Although much engineering and planing must be done preliminary to it the actual construction is no