公路边坡支护中英文对照外文翻译文献

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煤矿软岩巷道支护强度优化外文文献翻译、中英文翻译

英文原文The optimal support intensity for coal mine roadway tunnelsin soft rocksC. Wang*Mining Engineering Program, Western Australian School of Mines, PMB 22, KalgoorlieWA6430, Australia1. IntroductionThe essence of underground roadway support is to provide the surrounding rocks of an underground roadway with assistance to help them achieve stress and strain equilibrium and ultimately stability of deformation.The approaches to this goal are either to reinforce the rock mass by rock bolting or injection(internal rock stabilization) or to provide the surrounding rocks with a support resistance with a magnitude being described as the support intensity (external rock stabilization).When an underground roadway is located in soft rocks which are too soft to be reinforced by bolting and/or unsuitable for rock injection because of restraints imposed by either the rock mass impermeability or rock mass deterioration when water is encountered, external rock support, such as steel sets, therefore becomes the only option for the stability control of the roadway. Under this circumstance, the support intensity means a support force acting per unit surface area of the surrounding rocks of the roadway. In soft rock engineering practice, the design of a support pattern for a roadway in underground coal mining is normally based on rules of thumb. In most cases, heavy support measures are adopted to secure a successful roadway.Fig. 1(a) demonstrates the excellent condition of a sub-level roadway within soft rocks at an underground coal mine in north China, where an excessive capital cost was applied for the achievement of roadway stability. In some cases, such as a service roadway driven in soft rocks at the same mine (Fig. 1(b)), insufficient support intensity was specified as a result of a lack of relevant experience and design codes. Consequently, failure of the roadway stability was inevitable and an extra cost was incurred when the subsequent roadway repair or rehabilitation was undertaken.The critical issue in both cases lies in the determination of an optimal support intensity which is the function of the geometry and dimension of a roadway and its geotechnicalconditions including rock mass properties, stress conditions and hydrological status.Physical modelling using simulated materials based on the theory of similarity provides a direct perceptional methodology for mining geomechanics study [1-6].Using simulated materials of the same composition to construct a roadway and its soft surrounding rocks, applying a certain magnitude of simulated support intensity to the surface of a roadway under simulated stress conditions, the three-dimensional physical modelling method depicted in this Note emonstrates a quantitative solution for strategic design of roadway support concerned with soft rocks. A relation between the support intensity and deformation of the surrounding rocks of a roadway has been established after a series of simulation tests had been conducted. A discussion on the optimal support intensity for a roadway in soft rocks is also given.Fig. 1. Examples of successful and unsuccessful support of underground roadways within soft rocks: (a) Good condition of a sublevel roadway, (b) Unsuccessful support of a service roadway.2. Features of the three-dimensional physical modellingA physical modelling study of the interaction between support intensity and roadway deformation was carried out using the three dimension physical modelling system (see Fig.2) at the Central Laboratory of Rock Mechanics and Ground Control, China University of Mining and Technology. Features of this system are described in the following sub-sections.Fig. 2.Three-dimensional loaded physical modelling system at the Central Laboratory of Rock Mechanics and Ground Control, China University of Mining and Technology.2.1. Size of the physical modelThe effective size of a physical model is 1000 mm wide, 1000 mm high and 200 mm thick.2.2. Three dimensional active loading capabilitySix flatjacks are used to apply loads to the six sides of the physical model in the form of a rectangular prism. Each flatjack was designed to cover the full area of one of the six sides and be capable of applying a pressure of up to 10 MPa on to the surface of the simulated rock mass. This means that the flatjacks are capable of applying an active load of up to 1000 tonnes and 200 tonnes simultaneously on the front and back facets, the top andbottom, and the two side facets of a model, respectively.2.3. Long-term continuous loading capabilityA high-pressure, nitrogen-operated, hydraulic pressure stabilising unit was employed to maintain a consistent magnitude of load applied to the model so that the physical modelling test is able to last continuously for weeks, months or even years without interruption. This feature ensures that the study of the long-term rheological behaviour of soft rocks can be carried out.3. Physical modelling testsPhysical modelling of an underground roadway/ tunnel within soft rocks with a hydrostatic stress condition was carried out. The same simulated materials were repeatedly used six times to construct six physical models. Each roadway model was provided with adifferent magnitude of support intensity.3.1. Geotechnical conditions for the prototype and the modelling scaleA specified underground roadway within soft rocks was assumed to be the prototype for the modelling study. Detailed geotechnical conditions of the roadway and its surrounding rocks are:circular roadway with a diameter (D) of 4.5 m and cross-sectional area of 16 m2;UCS (Rc ) of the surrounding rock was 20 MPa;bulk density of the surrounding rock was 2500 kg/m3;depth of the roadway location was 500 m below surface;rock mass stress (s0 ) was 12.5 MPa in all directions;support intensity(pa) to be applied to the roadway was 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 MPa, respectively.The geotechnical modelling scale (Cl ) determined was 1 : 25. The bulk density (gm )of the simulated rock mass materials was 1600 kg/m3.Therefore, all the related simulation constants are:similarity constant for bulk density: Cg ¼ 1600/2500=0.64;similarity constant for strength: Cs ¼ ClCg ¼ 0:256;similarity constant for load: CF ¼ CgC1 ¼ 4:096 10ÿ5 ;similarity constant for time: Ct ¼ C l:5 ¼ 0:2:Geotechnical conditions of the simulated rock massand roadway were derived from those of the prototype rock mass as presented below: strength of the simulated rock mass: Rm=RcCs=0.512;diameter of the simulated roadway: Dm=DCl=180 mm;load intensity on the facets of the model: pm=s0Cs=0.32 MPa;Simulated support intensity: pam=paCs=0.00256, 0.00516, 0.00768, 0.01024, 0.0128and 0.01536 MPa; respectively.3.2. Realization of support intensity in physical modellingDue to the restraints of the small dimensions of the model roadway on the simulation of support structure, the support pattern and structure were unable to be simulated. Instead, an equivalent support intensity was simulated and applied to the surface of the surrounding rock of the model roadway. A Static Water Support and Deformation Measurement System (SWSDMS) was designed specially. Fig. 3 illustrates the SWSDMS being installed in the model roadway. The mechanism of SWSDMS is to use 4 separate water capsules to apply a support intensity to the surface of the roadway roof, two side walls and floor. Four rubber tubes, each of which was linked to a water capsule and filled with water, were used to generate a water pressure at the capsule/rock interface and measure it through the water level reading.A certain constant simulated support intensity was achieved by applying a certain height of static water pressure. A change to support intensity could be made by changing the water height in the rubber tube. The volume change of each of the four water capsules was measured at the due time by collectingand weighing the water overflow. The volume of water coming from each of the four water capsules was used to calculate the radial deformation of roadway surrounding rock, i.e., roof subsidence, wall-to-wall closure and floor heave. The proposed simulated supportintensities, i.e., Pam ¼ 0:00256, 0.00516, 0.00768, 0.01024, 0.0128 and 0.01536 MPa, were achieved by adjusting the static water level to 256, 516, 768, 1024, 1280 and 1536 mm high, respectively.Fig. 3. Static Water Support and Deformation Measurement System (SWSDMS) being accommodated in a roadway model in the real 3-D loaded physical modellingsystem.3.3. Construction of physical modelThe compositions and properties of materials to be used for the construction of physical models were studied prior to the physical model construction. Given the significant rheological deformation of roadways excavated in soft rock, sand and paraffin wax were chosen for the simulated soft rock. The properties of a series of sand/paraffin wax mixtures were studied in laboratory and are presented in Table 1.Table 1 Compositions and properties of sand/paraffin wax mixturesAccording to the geotechnical conditions of the prototype rock mass and the model scale, a mixture of sand/paraffin wax of 100 : 3 was selected to construct the rock massmodel. The procedures involved in the model construction include cold mixing of the sandand paraffin wax, oven heating the sand/wax mixture and constructing the physical modelusing the hot sand/wax mixture.3.4. Process of physical modellingThe real process of an underground roadway excavation, support installation and deformation of the surrounding rocks with time was simulated in the laboratory physical modelling. After the model had cooled down, prestressing the model, excavation of the roadway under pressure, installation of the SWSDMS device and measurement of the roadway deformation were carried out step by step. The whole process of modelling was strictly conducted according to the time similarity constant. Each physical modelling step lasted for 10-25 days in the laboratory, which were equivalent to a real time period of 50-125 days approximately.4. Relations between support intensity and roadway deformationComparable results of the six physical modelling tests conducted with the identical materials and geotechnical conditions revealed the significance of the support intensity inunderground roadway/tunnel support.4.1. Effect of support intensity on the deformation characteristics of a roadwayThe deformation characteristics of an identical roadway with different support intensityis graphically presented in Fig. 4(a) and (b). It can be seen that the influence of supportintensity on the deformation characteristics is significant. With a support intensity of 0.1MPa, the roadway experienced a large eformation for a period of 118 days after theroadway excavation and the provision of support intensity. During this period, an average of828 mm deformation was accumulated. Following this period, the wall-to-wall closure androof-to-floor convergence stayed steady at a level of 4.4 mm/day. By contrast, when a support intensity of 0.6 MPa was provided to the identical roadway, its post-excavation deformation merely lasted for 36 days with an accumulative closure/convergence of 40 mm, followed by a rheological deformation of 0.08 mm/day, which was continuously reducing withFig. 4. Deformation of roadway with a series of support intensities:(a) Deformation of roadway with time, (b) Deformation rate of roadway with time.time. The comparison shows that the deformation magnitude of the latter was only 4.8% that of the former.A negative exponential relation between the deformation rate and support intensity can also be deduced from the curve of deformation rate vs. support intensity presented in Fig. 5 and be mathematically expressed as: v ¼ 0:023pa2:4 :where v is the rheological deformation rate of the surrounding rock of a roadway in mm/day, pa is the support intensity in MPa provided to the surrounding rock.Fig.5 Relations between rheological deformation rate and support intensity of aroadway in soft rocks.4.2. Optimal support intensity for a roadway in soft rocksRequirements on the control of roadway deformation depend on the usage and service life of the roadway. It is known that a zero deformation rate is impossible practically to target in supporting a roadway in soft rocks. A wise approach is to exercise a designprinciple that the roadway deformation is allowed to take place to a degree within an acceptable limit. Physical modelling results indicated that an increase of support intensity from 0.1 to 0.5 MPa can markedly reduce the deformation rate of the surrounding rocks. A further increase of support intensity from 0.5 to 0.6 MPa, however, did not bring about as much reduction of deformation rate as that created by the support intensity increase of from 0.1 to 0.2 MPa or from 0.3 to 0.4 MPa. This means that a reasonable range of support intensity exists and an increase of support intensity can be rewarded with a significant reduction of roadway deformation if the actual support intensity is within this range.Further increases of support intensity can only cause less reduction of roadway deformation. Therefore, if both technical and economical considerations are taken into account, a support intensity of from 0.3 to 0.5 MPa would be appropriate for most temporary tunnels such as roadways in underground coal mining. With this support intensity, the rheological deformation rate of the surrounding rocks can be controlled within a range of from 0.1 to 0.4 mm/day, with which an ordinary temporary roadway can be maintained safely for years to one decade.5. ConclusionsThe three-dimensional physical modelling method provides a ‘co nceptual approach to quantitative design’of roadway support associated with soft rocks. With lack of knowledge of the constitutive relations, especially for the rheological mechanisms, in rock engineering practice, the modelling results could serve as a foundation on which a scientific design of underground roadway/tunnel support is developed, particularly when a large amount of rock mass deformation is concerned.The experimental study conducted with a series of support intensities revealed that a reasonable support intensity exists. Its value depends on the geotechnical and geometric conditions of the underground roadway/tunnel concerned and the requirements applied by the roadway/tunnel safe use specifications and the roadway/tunnel service life span. The results indicate that a support intensity of 0.3 to 0.5 MPa can securely control the closure rate for the conditions tested within a magnitude of 0.1 to 0.4 mm/day for a medium size underground roadway/tunnel driven in soft rocks of around 20 MPa at a depth of about 500 m below surface.References[1] Internal Research Report. Study on the technology of large deformation control for roadways within soft rocks. China University of Mining and Technology, 1995 [in Chinese].[2] Wang C. Study on the supporting mechanism and technology for roadways in soft rocks. PhD thesis, China University of Mining and Technology, 1995 [in Chinese].[3] Internal reference (1993). Properties of simulated materials for physical geomechanical modelling. The Central Laboratory of Rock Mechanics and Ground Control, China University of Mining and Technology [in Chinese].[4] Lin Y. Simulated materials and simulation for physical modelling. Publishing House of China Metallurgy Industry, Beijing, China, 1986 [in Chinese].[5] Duro ve J, Hatala J, Maras M, Hroncova E. Support’s design based on physical modelling. Proceedings of the International Conference of Geotechnical Engineering of Hard Soils } Soft Rocks. Rotterdam: Balkema, 1993.[6] Singh R, Singh TN. Investigation into the behaviour of a support system and roof strata during sub-level caving of a thick coal seam. Int J Geotech Geol. Engng. 1999;17:21-35.中文译文煤矿软岩巷道支护强度优化C. Wang采矿工程专业，西澳矿业学校，港口及航运局22卡尔古利W A6430，澳大利亚1引言地下巷道支护的实质是给巷道围岩提供支撑以实现应力应变平衡，并最终使变形稳定。

公路通行能力外文翻译文献

公路通行能力外文翻译文献(文档含中英文对照即英文原文和中文翻译)Highway Capacity And Levels of Service Capacity DefinedA generalized definition of capacity is: The capacity of any element of the highway system is the maximum number of vehicles which has a reasonable expectation of passing over that section (in either one or both directions) during a given time period under prevailing roadway and trafficconditions. A sampling of capacities for modern highway elements is as follows:Capacity in PassengerFacilityCars Freeways and expressways away from ramps and2000 weaving sections, per lane per hourTwo-Lane highways, total in both directions, per2000hourThree-lane highways, total in each direction, per2000hourTwelve-foot lane at signalized intersection, per hour1800of green signal time(no interference and idealprogression)In treating capacity，TRB Circular 212 divides freeways into components: basic freeway segments and those in the zone of influence of weaving areas and ramp junctions. Capacities of expressways，multilane highways，and two- and three-lane facilities also have the two components: basic and those in the zone of influence of intersections. Each of these is treated separately below.Speed-Volume-Capacity Relationships for BasicFreeway and Multilane Highway SegmentsA knowledge of the relationships among speed，volume，and capacity is basic to understanding the place of capacity in highway design and operation. Figurel3.1，which gives such a relationship for a single freeway or expressway lane, is used for illustrative purposes.If a lone vehicle travels along a traffic lane，the driver is free to proceed at the design speed. This situation is represented at the beginning of the appropriate curve at the upper left of Fig. 13.1. But as the number of vehicles in the lane increases, the driver's freedom to select speed is restricted. This restriction brings a progressive reduction in speed. For example，many observations have shown that，for a highway designed for 70 mph (113km/h)，when volume reaches 1900 passenger cars per hour，traffic is slowed to about 43 mph (69km/h). If volume increases further, the relatively stable normal-flow condition usually found at lower volumes is subject to breakdown. This zone of instability is shown by the shaded area on the right side of Fig. 13. 1. One possible consequence is that traffic flow will stabilize at about 2000 vehicles per hour at a velocity of 30 to 40 mph (48 to 64km/h) as shown by the curved solid line on Fig. 13. 1. Often，however , the quality of flow deteriorates and a substantial drop in velocity occurs; in extreme cases vehicles may come to a full stop. In this case the volume of flow quickly decreases as traffic proceeds under a condition known as …forced flow.‟ V olumes under forced flow are shown by the dashed curve at the bottom of Fig. 13. 1. Reading from that curve，it can be seenthat if the speed falls to 20 mph (32km/h)，the rate of flow will drop to 1700 vehicles per hour; at 10 mph （16km/h) the flow rate is only 1000;and,of course，if vehicles stop，the rate of flow is 0. The result of this reduction in flow rate is that following vehicles all must slow or stop，and the rate of flow falls to the levels shown. Even in those cases where the congestion lasts but a few seconds, additional vehicles are affected after the congestion at the original location has disappeared. A …shock wave’develops which moves along the traffic lane in the direction opposite to that of vehicle travel. Such waves have been observed several miles from the scene of the original point of congestion，with vehicles slowing or stopping and then resuming speed for no apparent reason whatsoever.Effects of the imposition of speed limits of 60, 50, and 40 mph are suggested by the dotted lines on Fig. 13. 1. A 55-mph (88km/h) curve could also be drawn midway between the 60 and 50 mph dotted curves to reflect the effects of the federally imposed 55-mph limit, but this is conjectural since the level of enforcement varies so widely.Vehicle spacing，or its reciprocal, traffic density, probably have the greatest effect on capacity since it generates the driver's feeling of freedom or constraint more than any other factor. Studies of drivers as they follow other vehicles indicate that the time required to reach a potential collision point，rather than vehicle separation，seems to control behavior. However，this time varies widely among drivers and situations. Field observations have recordedheadways (time between vehicles) ranging from 0. 5 to 2 sec, with an average of about 1. 5s.Thus，the calculated capacity of a traffic lane based on this 1. 5 s average, regardless of speed，will be 2400 vehicles per hour. But even under the best of conditions, occasional gaps in the traffic stream can be expected，so that such high flows are not common. Rather, as noted，they are nearer to 2000 passenger cars per hour.The ‘Level of Service’ ConceptAs indicated in the discussion of the relationships of speed, volume or density, and vehicle spacing, operating speed goes down and driver restrictions become greater as traffic volume increase. …Level of service‟ is commonly accepted as a measure of the restrictive effects of increased volume. Each segment of roadway can be rated at an appropriate level，A to F inclusive，to reflect its condition at the given demand or service volume. Level A represents almost ideal conditions; Level E is at capacity; Level F indicates forced flow.The two best measures for level of service for uninterrupted flow conditions are operating or travel speed and the radio of volume to capacity达到最大限度的广播，called the v/c ratio. For two- and three-lane roads sight distance is also important.Abbreviated descriptions of operating conditions for the various levels of service are as follows:Level A—Free flow; speed controlled by driver's desire，speed limits, orphysical roadway conditions.Level B—Stable flow; operating speeds beginning to be restricted; little or no restrictions on maneuverability from other vehicles.Level C—Stable flow; speeds and maneuverability more closely restricted.Level D—Approaches unstable flow; tolerable speeds can be maintained but temporary restrictions to flow cause substantial drops in speed. Little freedom to maneuver，comfort and convenience low.Level E—V olumes near capacity; speed typically in neighborhood of 30 mph (48km/h); flow unstable; stoppages of momentary duration. Ability to maneuver severely limited.Level F—Forced flow，low-operating speeds，volumes below capacity; queues formed.A third measure of level of service suggested in TRB Circular 212 is traffic density. This is，for a traffic lane，the average number of vehicles occupying a mile (1. 6km) of lane at a given instant. To illustrate，if the average speed is 50 mph，a vehicle is in a given mile for 72 s. If the lane carrying 800 vehicles per hour，average density is then 16 vehicles per mile ;spacing is 330 ft (100m)，center to center. The advantage of the density approach is that the various levels of service can be measured or portrayed in photographs.From: Clarkson H. Oglesby and R. Gary Hicks “Highwayengineering”, 1982公路通行能力和服务水平通行能力的定义道路通行能力的广义定义是：在繁忙的道路和交通条件下公路系统任何元素的通行能力是对在指定的时间通过一断面（一个或两个方向）的最大数量的车辆有一个合理的预期。

交通工程公路建设中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)英文原文：The Basics of a Good RoadWe have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads are still in service.If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:（1）Get water away from the road（2）Build on a firm foundation（3）Use the best materials（4）Compact all layers properly（5）Design for traffic loads and volumes（6）Design for maintenance（7）Pave only when ready（8）Build from the bottom up（9）Protect your investment（10）Keep good records1．Get water away from the roadWe can’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any layer of a road’sstructure can weaken that layer, leading to failure.In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moisture problems.To prevent these problems remember that water:• flows downhill• needs to flow someplace• is a problem if it is not flowingEffective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1⁄4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crown should be 1⁄2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drainthe road surface.Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.2．Build on a firm foundationA road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.3．Use the best materialsWith all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ballbearings, moving under loads.Angular particles are more stable than rounded particles.Asphalt and concrete pavement materials must be of the highest quality, designed for the conditions, obtained from established firms, and tested to ensure it meets specifications. 4．Compact all layersIn general, the more densely a material is compacted, the stronger it is. Compaction alsoshrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Goodcompaction of asphalt pavement lengthens its life.5．Design for traffic loads and volumesDesign for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road will carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for traffic loadings through a road’s life.6．Design for maintenanceWithout maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:• adequate ditches that can be cleaned regularly• culverts that are marked for easy locating in the spring• enough space for snow after it is plowed off the road• proper cross slopes for safety, maintenance and to avoid snow drifts• roadsi des that are planted or treated to prevent erosion• roadsides that can be mowed safelyA rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.Mark culverts with a post so they can be located easily.7．Pave only when readyIt is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.Don’t assume that laying down asphalt will fix a gravel road that is failing. Before you pave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.8．Ê Build from the bottom upThis commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.9．Ê Protect your investmentThe road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and iceDrainage —clean and repair ditches and culverts; remove all excess materialRoadside —cut brush, trim trees and roadside plantings, control erosionTraffic service —clean and repair or replace signsDesign roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.10．Keep good recordsYour maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.Good record keeping starts with an inventory of the system. It should include the history andsurface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions, shoulders, signs, and such structures as retaining walls and guardrails.Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.ResourcesThe Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presents the Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASER Manual (32 pp). These booklets contain extensive photos and descriptions of road surfacesto help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.Roadware, a computer program which stores and reports pavement condition information. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to provide five-year cost budgets and roadway repair/reconstruction priority lists.Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.Geotextiles in Road Construction/Maintenance andErosion Control, No. 16. Definitions and common applications of geotextiles on roadways and for erosion control.T.I.C. workshops are offered at locations around the state.Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpful articles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.译文：一个良好的公路的基础长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。

道路路桥工程中英文对照外文翻译文献

道路路桥工程中英文对照外文翻译文献Asphalt Mixtures: ns。

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and Principles1.nsXXX industry。

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while the sub-base and base courses provide nal support for the pavement。

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the use of XXX.The n of flexible pavement can be subdivided into high and low types。

英文文献及翻译

Geotextile reinforced by soft soil1. IntroductionGeotextile known, it has high tensile strength, durability, corrosion resistance, texture, flexibility, combined with good sand, to form reinforced composite foundation, effectively increase the shear strength , tensile properties, and enhance the integrity and continuity of soil. Strengthening mechanism for the early 60's in the 20th century, Henri Vidal on the use of triaxial tests found a small amount of fiber in the sand, the soil shear strength can improve the image of more than 4 times in recent years, China's rock Laboratory workers also proved in the reinforced sand can effectively improve the soil's bearing capacity, reduce the vertical ground settlement, effectively overcome the poor soil and continuity of overall poor performance. As with the above properties of reinforced soil and the characteristics of its low price, so the project has broad application prospects.2.1 Project OverviewThe proposed retaining wall using rubble retaining wall of gravity, the wall is 6 meters high, the bearing capacity of foundation soil required to 250kPa, while the basement geology from the top down as follows: ①clay to a thickness of 0.7 to 2 meters saturated, soft plastic; ② muddy soil, about 22 - 24 meters thick, saturated, mainly plastic flow, local soft plastic; ③ sand layer to a thickness of 5 to 10 meters, containing silty soil and organic matter, saturated, slightly wet; ④ gravel layer, the thickness of the uneven distribution points, about 0 to 2.2 meters, slightly dense; ⑤ weathered sandstone. Including clay and silty soil bearing capacity is 70kPa, obviously do foundation reinforcement.2.2 Enhanced Treatment of reinforced foundation cushion Reinforcement replacement method can be used for sand and gravel used forsoil treatment, but due to loose bedding, based on past experience, witha gravel mat to treat a large settlement of the foundation always exist, even the characteristics of poor, often resulting in cracks in the superstructure, differential settlement of the image, this works for6-meter-high rubble retaining walls, height and large, and because the walls are 3 meters high wall, if there is differential settlement of retaining walls, cracks, will result in more serious consequences and thus should be used on the cushion reinforcement through economic and technical analysis, decide on the sand and gravel stratum were reinforced hardening. Reinforcement treatment method: first the design elevation and the basement excavation to 200mm thick layer of gravel bedding, and then capped with a layer of geotextile, and then in the thick sand and gravel on the 200, after leveling with the yellow sand using roller compaction; second with loaded bags of sand and gravel laying of geotextile, the gap filled with slag, geotextile bags capped 100 thick gravel, roller compaction. Its on repeat laying geotextile → → compacted gravel, until the design thickness of the cushion, the bridge is 1 m thick cushion, a total of 4 layers of geotextile, two bags of sand.This method works fast, simple machine, investment, after years of use, that reinforce good effect, building and construction units are satisfied.3 ExperienceTo achieve the reinforced soil reinforcement effect, must be reinforced earth construction technology, construction strict quality control: 1, geotextile should increase the initial pre-stress, and its end should be a reliable anchor to play the tensile strength of geotextile, anchoring more firmly, more capacity to improve, the foundation of the stress distribution more uniform, geotextile side Ministry of fixed length by laying end to ensure the fold, the folded end wrapped sand to increase its bond strength to ensure that the use will not be pulled out duringthe period.Second, the construction process have a significant effect on the reinforcement effect, the construction should be as soon as possible so that geotextile in tension, tensile strength geotextile can be played only when the deformation, so do not allow construction of geotextile crease occurs, the earth Fabric tension leveling as much as possible. Geotextile in order to have enough by the early Dutch strain, according to the following procedure works: ① laying geotextile; ② leveled the tension at both ends; both ends of the folded package gravel and sand filling at both ends; ③ center fill sand; ④ 2 higher end of sand; ⑤ Finally, the center of sand filling. Click here to enable the construction method of forming corrugated geotextile being stretched as soon as possible, to play a role in the early loaded.Third, the construction of geotextile-reinforced cushion should the level of shop using geotextile geotextile and laying of gravel bags cushion the turn to play bag cushion integrated turn out good, flexural rigidity, and dispersion of good and peace bedding layer of the overall continuity of good advantages.4 ConclusionGeotextile reinforced by soft soil is an effective, economical, safe, reliable, simple method, but the literature describes only qualitative, experience more components, yet the lack of rigorous The theoretical formula, reliable test data to be adequate, these are yet to be theoretical workers and the general engineering and technical personnel continue to explore.土工织物加筋垫层加固软土地基1. 引言土工织物又称土工聚合物，它具有高抗拉强度，耐久性、耐腐蚀性，质地柔韧，能与砂土很好地结合，组合成加筋土复合地基，有效地提高土的抗剪强度、抗拉性能，增强土体的整体性和连续性。

道路与桥梁工程中英文对照外文翻译文献

中英文对照外文翻译(文档含英文原文和中文翻译)Bridge research in EuropeA brief outline is given of the development of the European Union, together withthe research platform in Europe. The special case of post-tensioned bridges in the UK is discussed. In order to illustrate the type of European research being undertaken, an example is given from the University of Edinburgh portfolio: relating to the identification of voids in post-tensioned concrete bridges using digital impulse radar.IntroductionThe challenge in any research arena is to harness the findings of different research groups to identify a coherent mass of data, which enables research and practice to be better focused. A particular challenge exists with respect to Europe where language barriers are inevitably very significant. The European Community was formed in the 1960s based upon a political will within continental Europe to avoid the European civil wars, which developed into World War 2 from 1939 to 1945. The strong political motivation formed the original community of which Britain was not a member. Many of the continental countries saw Britain’s interest as being purelyeconomic. The 1970s saw Britain joining what was then the European Economic Community (EEC) and the 1990s has seen the widening of the community to a European Union, EU, with certain political goals together with the objective of a common European currency.Notwithstanding these financial and political developments, civil engineering and bridge engineering in particular have found great difficulty in forming any kind of common thread. Indeed the educational systems for University training are quite different between Britain and the European continental countries. The formation of the EU funding schemes —e.g. Socrates, Brite Euram and other programs have helped significantly. The Socrates scheme is based upon the exchange of students between Universities in different member states. The Brite Euram scheme has involved technical research grants given to consortia of academics and industrial partners within a number of the states—— a Brite Euram bid would normally be led by partners within a number of the statesan industrialist.In terms of dissemination of knowledge, two quite different strands appear to have emerged. The UK and the USA have concentrated primarily upon disseminating basic research in refereed journal publications: ASCE, ICE and other journals. Whereas the continental Europeans have frequently disseminated basic research at conferences where the circulation of the proceedings is restricted.Additionally, language barriers have proved to be very difficult to break down. In countries where English is a strong second language there has been enthusiastic participation in international conferences based within continental Europe —e.g. Germany, Italy, Belgium, The Netherlands and Switzerland. However, countries where English is not a strong second language have been hesitant participants }—e.g. France.European researchExamples of research relating to bridges in Europe can be divided into three types of structure:Masonry arch bridgesBritain has the largest stock of masonry arch bridges. In certain regions of the UK up to 60% of the road bridges are historic stone masonry arch bridges originally constructed for horse drawn traffic. This is less common in other parts of Europe as many of these bridges were destroyed during World War 2.Concrete bridgesA large stock of concrete bridges was constructed during the 1950s, 1960s and 1970s. At the time, these structures were seen as maintenance free. Europe also has a large number of post-tensioned concrete bridges with steel tendon ducts preventing radar inspection. This is a particular problem in France and the UK.Steel bridgesSteel bridges went out of fashion in the UK due to their need for maintenance as perceived in the 1960s and 1970s. However, they have been used for long span and rail bridges, and they are now returning to fashion for motorway widening schemes in the UK.Research activity in EuropeIt gives an indication certain areas of expertise and work being undertaken in Europe, but is by no means exhaustive.In order to illustrate the type of European research being undertaken, an example is given from the University of Edinburgh portfolio. The example relates to the identification of voids in post-tensioned concrete bridges, using digital impulse radar.Post-tensioned concrete rail bridge analysisOve Arup and Partners carried out an inspection and assessment of the superstructure of a 160 m long post-tensioned, segmental railway bridge in Manchester to determine its load-carrying capacity prior to a transfer of ownership, for use in the Metrolink light rail system..Particular attention was paid to the integrity of its post-tensioned steel elements.Physical inspection, non-destructive radar testing and other exploratory methods were used to investigate for possible weaknesses in the bridge.Since the sudden collapse of Ynys-y-Gwas Bridge in Wales, UK in 1985, there has been concern about the long-term integrity of segmental, post-tensioned concrete bridges which may b e prone to ‘brittle’ failure without warning. The corrosion protection of the post-tensioned steel cables, where they pass through joints between the segments, has been identified as a major factor affecting the long-term durability and consequent strength of this type of bridge. The identification of voids in grouted tendon ducts at vulnerable positions is recognized as an important step in the detection of such corrosion.Description of bridgeGeneral arrangementBesses o’ th’ Barn Bridge is a 160 m long, three span, segmental, post-tensionedconcrete railway bridge built in 1969. The main span of 90 m crosses over both the M62 motorway and A665 Bury to Prestwick Road. Minimum headroom is 5.18 m from the A665 and the M62 is cleared by approx 12.5 m.The superstructure consists of a central hollow trapezoidal concrete box section 6.7 m high and 4 m wide. The majority of the south and central spans are constructed using 1.27 m long pre-cast concrete trapezoidal box units, post-tensioned together. This box section supports the in site concrete transverse cantilever slabs at bottom flange level, which carry the rail tracks and ballast.The center and south span sections are of post-tensioned construction. These post-tensioned sections have five types of pre-stressing:1. Longitudinal tendons in grouted ducts within the top and bottom flanges.2. Longitudinal internal draped tendons located alongside the webs. These are deflected at internal diaphragm positions and are encased in in site concrete.3. Longitudinal macalloy bars in the transverse cantilever slabs in the central span .4. Vertical macalloy bars in the 229 mm wide webs to enhance shear capacity.5. Transverse macalloy bars through the bottom flange to support the transverse cantilever slabs.Segmental constructionThe pre-cast segmental system of construction used for the south and center span sections was an alternative method proposed by the contractor. Current thinkingire suggests that such a form of construction can lead to ‘brittle’ failure of the ententire structure without warning due to corrosion of tendons across a construction joint，The original design concept had been for in site concrete construction.Inspection and assessmentInspectionInspection work was undertaken in a number of phases and was linked with the testing required for the structure. The initial inspections recorded a number of visible problems including:Defective waterproofing on the exposed surface of the top flange.Water trapped in the internal space of the hollow box with depths up to 300 mm.Various drainage problems at joints and abutments.Longitudinal cracking of the exposed soffit of the central span.Longitudinal cracking on sides of the top flange of the pre-stressed sections.Widespread sapling on some in site concrete surfaces with exposed rusting reinforcement.AssessmentThe subject of an earlier paper, the objectives of the assessment were:Estimate the present load-carrying capacity.Identify any structural deficiencies in the original design.Determine reasons for existing problems identified by the inspection.Conclusion to the inspection and assessmentFollowing the inspection and the analytical assessment one major element of doubt still existed. This concerned the condition of the embedded pre-stressing wires, strands, cables or bars. For the purpose of structural analysis these elements、had been assumed to be sound. However, due to the very high forces involved,、a risk to the structure, caused by corrosion to these primary elements, was identified.The initial recommendations which completed the first phase of the assessment were:1. Carry out detailed material testing to determine the condition of hidden structural elements, in particularthe grouted post-tensioned steel cables.2. Conduct concrete durability tests.3. Undertake repairs to defective waterproofing and surface defects in concrete.Testing proceduresNon-destructi v e radar testingDuring the first phase investigation at a joint between pre-cast deck segments the observation of a void in a post-tensioned cable duct gave rise to serious concern about corrosion and the integrity of the pre-stress. However, the extent of this problem was extremely difficult to determine. The bridge contains 93 joints with an average of 24 cables passing through each joint, i.e. there were approx. 2200 positions where investigations could be carried out. A typical section through such a joint is that the 24 draped tendons within the spine did not give rise to concern because these were protected by in site concrete poured without joints after the cables had been stressed.As it was clearly impractical to consider physically exposing all tendon/joint intersections, radar was used to investigate a large numbers of tendons and hence locate duct voids within a modest timescale. It was fortunate that the corrugated steel ducts around the tendons were discontinuous through the joints which allowed theradar to detect the tendons and voids. The problem, however, was still highly complex due to the high density of other steel elements which could interfere with the radar signals and the fact that the area of interest was at most 102 mm wide and embedded between 150 mm and 800 mm deep in thick concrete slabs.Trial radar investigations.Three companies were invited to visit the bridge and conduct a trial investigation. One company decided not to proceed. The remaining two were given 2 weeks to mobilize, test and report. Their results were then compared with physical explorations.To make the comparisons, observation holes were drilled vertically downwards into the ducts at a selection of 10 locations which included several where voids were predicted and several where the ducts were predicted to be fully grouted. A 25-mm diameter hole was required in order to facilitate use of the chosen horoscope. The results from the University of Edinburgh yielded an accuracy of around 60%.Main radar sur v ey, horoscope verification of v oids.Having completed a radar survey of the total structure, a baroscopic was then used to investigate all predicted voids and in more than 60% of cases this gave a clear confirmation of the radar findings. In several other cases some evidence of honeycombing in the in site stitch concrete above the duct was found.When viewing voids through the baroscopic, however, it proved impossible to determine their actual size or how far they extended along the tendon ducts although they only appeared to occupy less than the top 25% of the duct diameter. Most of these voids, in fact, were smaller than the diameter of the flexible baroscopic being used (approximately 9 mm) and were seen between the horizontal top surface of the grout and the curved upper limit of the duct. In a very few cases the tops of the pre-stressing strands were visible above the grout but no sign of any trapped water was seen. It was not possible, using the baroscopic, to see whether those cables were corroded.Digital radar testingThe test method involved exciting the joints using radio frequency radar antenna: 1 GHz, 900 MHz and 500 MHz. The highest frequency gives the highest resolution but has shallow depth penetration in the concrete. The lowest frequency gives the greatest depth penetration but yields lower resolution.The data collected on the radar sweeps were recorded on a GSSI SIR System 10.This system involves radar pulsing and recording. The data from the antenna is transformed from an analogue signal to a digital signal using a 16-bit analogue digital converter giving a very high resolution for subsequent data processing. The data is displayed on site on a high-resolution color monitor. Following visual inspection it isthen stored digitally on a 2.3-gigabyte tape for subsequent analysis and signal processing. The tape first of all records a ‘header’ noting the digital radar settings together with the trace number prior to recording the actual data. When the data is played back, one is able to clearly identify all the relevant settings —making for accurate and reliable data reproduction.At particular locations along the traces, the trace was marked using a marker switch on the recording unit or the antenna.All the digital records were subsequently downloaded at the University’s NDT laboratory on to a micro-computer.（The raw data prior to processing consumed 35 megabytes of digital data.） Post-processing was undertaken using sophisticated signal processing software. Techniques available for the analysis include changing the color transform and changing the scales from linear to a skewed distribution in order to highlight、突出certain features. Also, the color transforms could be changed to highlight phase changes. In addition to these color transform facilities, sophisticated horizontal and vertical filtering procedures are available. Using a large screen monitor it is possible to display in split screens the raw data and the transformed processed data. Thus one is able to get an accurate indication of the processing which has taken place. The computer screen displays the time domain calibrations of the reflected signals on the vertical axis.A further facility of the software was the ability to display the individual radar pulses as time domain wiggle plots. This was a particularly valuable feature when looking at individual records in the vicinity of the tendons.Interpretation of findingsA full analysis of findings is given elsewhere, Essentially the digitized radar plots were transformed to color line scans and where double phase shifts were identified in the joints, then voiding was diagnosed.Conclusions1. An outline of the bridge research platform in Europe is given.2. The use of impulse radar has contributed considerably to the level of confidence in the assessment of the Besses o’ th’ Barn Rail Bridge.3. The radar investigations revealed extensive voiding within the post-tensioned cable ducts. However, no sign of corrosion on the stressing wires had been foundexcept for the very first investigation.欧洲桥梁研究欧洲联盟共同的研究平台诞生于欧洲联盟。

公路工程建设中英文对照外文翻译文献

公路工程建设中英文对照外文翻译文献(文档含英文原文和中文翻译)Asphalt Mixtures-Applications, Theory andPrinciples1 . ApplicationsAsphalt materials find wide usage in the construction industry. The use of asphalt as a cementing agent in pavements is the most common of its applications, however, and the one that will be considered here.Asphalt products are used to produce flexible pavements for highways and airports. The term “flexible” is used to distinguish these pavements from those made with Portland cement, which are classified as rigid pavements, that is, having beam strength. This distinction is important because it provides they key to the design approach which must be used for successful flexible pavement structures.The flexible pavement classification may be further broken down into high and low types, the type usually depending on whether a solid or liquid asphalt product isused. The low types of pavement are made with the cutback, or emulsion, liquid products and are very widely used throughout this country. Descriptive terminology has been developed in various sections of the country to the extent that one pavement type may have several names. However, the general process followed in construction is similar for most low-type pavements and can be described as one in which the aggregate and the asphalt product are usually applied to the roadbed separately and there mixed or allowed to mix, forming the pavement.The high type of asphalt pavements is made with asphalt cements of some selected penetration grade.Fig. ·1 A modern asphalt concrete highway. Shoulder striping is used as a safely feature.Fig. ·2 Asphalt concrete at the San Francisco International Airport.They are used when high wheel loads and high volumes of traffic occur and are, therefore, often designed for a particular installation.2 . Theory of asphalt concrete mix designHigh types of flexible pavement are constructed by combining an asphalt cement, often in the penetration grade of 85 to 100, with aggregates that are usually divided into three groups, based on size. The three groups are coarse aggregates, fine aggregates, and mineral filler. These will be discussed in detail in later chapter.Each of the constituent parts mentioned has a particular function in the asphalt mixture, and mix proportioning or design is the process of ensuring that no function is neglected. Before these individual functions are examined, however, the criteria for pavement success and failure should be considered so that design objectives can be established.A successful flexible pavement must have several particular properties. First, it must be stable, that is to resistant to permanent displacement under load. Deformation of an asphalt pavement can occur in three ways, two unsatisfactory and one desirable. Plastic deformation of a pavement failure and which is to be avoided if possible. Compressive deformation of the pavement results in a dimensional change in the pavement, and with this change come a loss of resiliency and usually a degree of roughness. This deformation is less serious than the one just described, but it, too, leads to pavement failure. The desirable type of deformation is an elastic one, which actually is beneficial to flexible pavements and is necessary to their long life.The pavement should be durable and should offer protection to the subgrade. Asphalt cement is not impervious to the effects of weathering, and so the design must minimize weather susceptibility. A durable pavement that does not crack or ravel will probably also protect the roadbed. It must be remembered that flexible pavements transmit loads to the subgrade without significant bridging action, and so a dry firm base is absolutely essential.Rapidly moving vehicles depend on the tire-pavement friction factor for control and safety. The texture of the pavement surfaces must be such that an adequate skid resistance is developed or unsafe conditions result. The design procedure should be used to select the asphalt material and aggregates combination which provides a skid resistant roadway.Design procedures which yield paving mixtures embodying all these properties are not available. Sound pavements are constructed where materials and methods are selected by using time-tested tests and specifications and engineering judgments along with a so-called design method.The final requirement for any pavement is one of economy. Economy, again, cannot be measured directly, since true economy only begins with construction cost and is not fully determinable until the full useful life of the pavement has been recorded. If, however, the requirements for a stable, durable, and safe pavement are met with a reasonable safety factor, then the best interests of economy have probably been served as well.With these requirements in mind, the functions of the constituent parts can be examined with consideration give to how each part contributes to now-established objectives or requirements. The functions of the aggregates is to carry the load imposed on the pavement, and this is accomplished by frictional resistance and interlocking between the individual pieces of aggregates. The carrying capacity of the asphalt pavement is, then, related to the surface texture (particularly that of the fine aggregate) and the density, or “compactness,”, of the aggregates. Surfac e texture varies with different aggregates, and while a rough surface texture is desired, this may not be available in some localities. Dense mixtures are obtained by using aggregates that are either naturally or artificially “well graded”. This means that the fine aggregate serves to fill the voids in the coarser aggregates. In addition to affecting density and therefore strength characteristics, the grading also influences workability. When an excess of coarse aggregate is used, the mix becomes harsh and hard to work. When an excess of mineral filler is used, the mixes become gummy and difficult to manage.The asphalt cement in the flexible pavement is used to bind the aggregate particles together and to waterproof the pavements. Obtaining the proper asphalt content is extremely important and bears a significant influence on all the items marking a successful pavement. A chief objective of all the design methods which have been developed is to arrive at the best asphalt content for a particular combination of aggregates.3 . Mix design principlesCertain fundamental principles underlie the design procedures that have been developed. Before these procedures can be properly studied or applied, some consideration of these principles is necessary.Asphalt pavements are composed of aggregates, asphalt cement, and voids. Considering the aggregate alone, all the space between particles is void space. The volume of aggregate voids depends on grading and can vary widely. When the asphalt cement is added, a portion of these aggregate voids is filled and a final air-void volume is retained. The retention of this air-void volume is very important to thecharacteristics of the mixture. The term air-void volume is used, since these voids are weightless and are usually expressed as a percentage of the total volume of the compacted mixture.An asphalt pavement carries the applied load by particle friction and interlock. If the particles are pushed apart for any reason , then the pavement stability is destroyed. This factor indicates that certainly no more asphalt should be added than the aggregate voids can readily hold. However ,asphalt cement is susceptible to volume change and the pavement is subject to further compaction under use. If the pavement has no air voids when placed, or if it loses them under traffic, then the expanding asphalt will overflow in a condition known as bleeding. The loss of asphalt cement through bleeding weakens the pavement and also reduces surface friction, making the roadway hazardous.Fig. ·3 Cross section of an asphalt concrete pavement showing the aggregate frameworkbound together by asphalt cement.The need for a minimum air-void volume (usually 2 or 3 per cent ) has been established. In addition, a maximum air-void volume of 5 to 7 per cent should not be exceed. An excess of air voids promotes raveling of the pavement and also permits water to enter and speed up the deteriorating processes. Also, in the presence of excess air the asphalt cement hardens and ages with an accompanying loss of durability and resiliency.The air-void volume of the mix is determined by the degree of compaction as well as by the asphalt content. For a given asphalt content, a lightly compacted mixwill have a large voids volume and a lower density and a greater strength will result. In the laboratory, the compaction is controlled by using a specified hammer and regulating the number of blows and the energy per blow. In the field, the compaction and the air voids are more difficult to control and tests must be made no specimens taken from the compacted pavement to cheek on the degree of compaction being obtained. Traffic further compact the pavement, and allowance must be made for this in the design. A systematic checking of the pavement over an extended period is needed to given factual information for a particular mix. A change in density of several per cent is not unusual, however.Asphalt content has been discussed in connection with various facets of the ix design problem. It is a very important factor in the mix design and has a bearing an all the characteristics ld a successful pavement: stability, skid resistance, durability, and economy. As has been mentioned, the various design procedures are intended to provide a means for selecting the asphalt content . These tests will be considered in detail in a future chapter ,but the relationship between asphalt content and the measurable properties of stability, unit weight, and air voids will be discussed here.Fig.4 Variations in stability, unit weight, and air-void content with asphalt cement content.If the gradation and type of aggregate, the degree of compaction, and the type of asphalt cement are controlled, then the strength varies in a predictable manner. The strength will increase up to some optimum asphalt content and then decrease with further additions. The pattern of strength variation will be different when the other mix factors are changed, and so only a typical pattern can be predicted prior to actualtesting.Unit weight varies in the same manner as strength when all other variable are controlled. It will reach some peak value at an asphalt content near that determined from the strength curve and then fall off with further additions.As already mentioned, the air-void volume will vary with asphalt content. However, the manner of variation is different in that increased asphalt content will decrease air-void volume to some minimum value which is approached asymptotically. With still greater additions of asphalt material the particles of aggregate are only pushed apart and no change occurs in air-void volume.In summary, certain principles involving aggregate gradation, air-void volume, asphalt content, and compaction mist be understood before proceeding to actual mix design. The proper design based on these principles will result in sound pavements. If these principles are overlooked, the pavement may fail by one or more of the recognized modes of failure: shoving, rutting, corrugating, becoming slick when the max is too ‘rich’; raveling, cracking,having low durability when the mix is too‘lean’.It should be again emphasized that the strength of flexible is, more accurately, a stability and does not indicate any ability to bridge weak points in the subgrade by beam strength. No asphalt mixture can be successful unless it rests on top of a properly designed and constructed base structure. This fact, that the surface is no better than the base, must be continually in the minds of those concerned with any aspect of flexible pavement work.[1] International Journal of Pavement Research and Technology, 2014, V ol.7 (2), pp.83-92[2] Neville Adam .Concrete Technology-An Essential Element of Structural Design[M].Concrete International，1998.[3] Hewlett Peter C，et al. Lea，s Chemistry of Cement and Concrete[M]. 4thed.Butter-worth-Heinemann，London，1998.[4] M Karasahin . Anisotropic Characteristics of Granular Material . Proceedings of the Fifith Inter-national Symposium on Unbound Aggregates in Roads，2000:139-142 .[5]Sean Davit .Irish Experience in the Use of Unbound Aggregates in Roads1970-2000 .Un-bound Aggregates in Roads Construction，2000.[6]Moore W M，Milberger L J .Evaluation of the TTI Gyratory Compactor .Texas Transportation Institute Report No .99-3 .译文：沥青混合料的应用、理论和原则1、应用沥青材料如今在建筑行业广泛使用。

沥青路面的养护发展外文文献翻译、中英文翻译、外文翻译

附录The Development of the Conservation of AsphaltPavementAsphalt pavement in the use of the process, constantly subject to the role of repeated traffic loads, climate impact and asphalt pavement materials, physical and chemical changes, over time, will have a pit, crack, swarming spore, subsidence, while eating, Ma surface , peeling and loose a variety of damage, if not repaired, the damage will be expanded rapidly and affect the normal passage of vehicles, and may lead to a greater degree of damage. Asphalt Pavement Maintenance vehicle is dedicated to timely repair the damage part of the special vehicles. Shown as an ordinary car Asphalt Pavement Maintenance.1 Classification and functionAccording to the nature of road paving materials, road vehicles can be divided into a comprehensive conservation Asphalt Pavement Maintenance trucks and cement trucks Pavement Maintenance two categories, this book introduces the Asphalt Pavement Maintenance Truck. Asphalt Pavement Maintenance vehicles is divided into trailers by the way traffic and two types of self-propelled.Towed Asphalt Pavement Maintenance vehicles are a variety of equipment and devices will be installed on the trailer chassis, the general use of self-powered engine output range of devices and equipment, from a car or tractor to the construction of sections of the conservation work carried out.Self-Asphalt Pavement Maintenance vehicles are a variety of equipment and devices will be installed on the vehicle chassis or exclusive as the self-end, removed from the chassis host two types of motivation and self-engines. At present, the production of integrated conservation of the asphalt is the most self-propelled vehicles of.Based on the technical level of the road, the quality and quantity of the different selection of different types of Asphalt Pavement Maintenance vehicles. High-gradehighway mileage in the asphalt pavement of more than 300km for the use of large-scale conservation of self-propelled vehicles; medium-sized self-propelled vehicle for the conservation of 200-300km of high-grade asphalt pavement minor repairs, maintenance; 200km below the asphalt pavement for the use of high-grade self-small conservation of vehicles. Daily Maintenance of Asphalt Pavement in general for the use of small self-propelled or towed vehicle conservation.Asphalt Pavement Maintenance for road vehicles in addition to day-to-day tasks of conservation, but also other facilities can be used for highway maintenance, traffic engineering facilities, such as spraying and cleaning, snow removal, cleaning the road surface, cut away weeds, spraying, planting and trimming trees.2 multi-purpose road vehicles at home and abroad overview of conservation and development trends2.1 Overview abroadAsphalt Pavement Maintenance Machinery abroad have been a hundred years the history of high-grade highway for minor repairs of the asphalt pavement of the integrated conservation of mechanical operations have 60-a 70-year history. Them according to the functions and operations can be divided into the following.(1)With infrared heating function Pavement Maintenance car models for the United States on behalf of Thermal Power Corporation (Thermal PowerCo.) King of the road. Its most prominent feature of the old material can be recycled in situ, thereby bring about considerable savings in asphalt mixture, in favor of environmental protection and conservation of energy. At the same time, as a result of mixture with the original road is a natural joints combination of old and new roads close, you can extend the life of the new road. The model applicable to shallow holes, cracks, cracks and other damage to the handling of the asphalt pavement. The vehicle is equipped with hot-mix boxes, asphalt tanks and sprinkler systems, and infrared propane gas heater, compaction tools, waste tanks.(2)Mixture with hot boxes and broken pavement compaction tool Pavement Maintenance car model is the United States on behalf of Akzo Nobel company TP4-based integrated conservation vehicles. The more the number of vehicles in foreign countries, usually with the following equipment: 7t heat insulation material boxes, spiral out of feeder, asphalt spraying device, and vibration-ho ram broken. The models applied to patch small pit operation.(3)Jet car repair on behalf of the conservation model is the official music of the high road repair company cars, the largest high-pressure injection is characterized by the adoption of the ways in which a different charge of the emulsified asphalt and aggregate to be mixed and sprayed into the pits to deal with in to achieve the purpose of maintenance and repair of the road the car can be opened to traffic immediately. The model applies to a smaller stream of pits of repair work.(4)Comprehensive conservation repair work on behalf of car models produced LeeBoy the United States 1200-S-type of asphalt pavement repair vehicle integrated. It has a miller, spraying asphalt, paving and other features, equipped with a milling machine, paving equipment, asphalt me, hydraulic sprinkler system and asphalt-ho. The model applies to a small area of repair operations.2.2 Overview of domesticWith highway construction in China's rapid development, in particular, the traffic mileage of highway continues to increase, the domestic machinery of the road more and more emphasis on conservation. The 20th century, some of the 80's started a lot of companies have developed products to market. On the integrated conservation of vehicles, the domestic current owners have developed the following types of conservation.(1)TP4-based Pavement Maintenance car full hydraulic control, with storage, crushing, compaction equipment and other road maintenance equipment Yung Road, Maung. It is the introduction of the United States in Xi’an building auromatically • Akzo Nobel technology, enterprise development by the domestic products.(2)Regeneration asphalt mixture characterized by the conservation of cars expected to regeneration with the old, old asphalt can generally through the addition of some new materials and renewable sources of new agents is expected to achieve the old shop, with a broken, regeneration, compaction equipment and other attachments. However, this equipment can not be used for high-grade renewable materials for road maintenance, the use of occasions by a lot of restrictions.(3)Heating wall with regeneration in situ conservation of vehicles on the road to soften it, harrow, Tim the new material, first-class one-stop operating pressure, energy saving, environmental protection. Both drive electric drive, there are hydraulic driven. Because development time is too short, the reliability of the product there are stilllarge deficiencies. In addition, because the device can only use the new asphalt mixture, there is also a conservation site is not expected to work without problems. 2.3 Asphalt Pavement Maintenance of our direction of development of carConservation equipment available in the planned economy era developed. With highway construction in China's rapid development. China's existing mechanisms for road maintenance is no longer suited to this situation, the state departments are to develop new policy and regulatory road maintenance to adapt to this change, it is foreseeable that this policy applies to the new norms of conservation equipment market will be favored .附录沥青路面的养护发展沥青路面在使用过程中，不断承受行车载荷的反复作用、气候的影响和沥青路面材料的物理化学变化，随着时间的推移，将产生坑槽、裂缝、涌包、沉陷、啃边、麻面、脱皮和松散等各种损坏，如不及时修补，这些损坏将迅速扩大，影响车辆的正常通行，并可能造成更大程度的损害。

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中英文对照外文翻译文献(文档含英文原文和中文翻译)公路边坡常见支护方法目前，我国山区高速公路建设迅猛发展。

在高等级公路的修建中，出现大量的深挖路堑与高填路堤边坡，其防护问题非常突出。

为了满足安全可靠和经济合理双重目标，对高边坡病害特征的深入分析和对其治理工程方案的慎重选择显得十分重要。

公路边坡沿公路分布的范围广，对自然环境的破坏范围大，如果在防护的同时，能够注意保护环境和创造环境，采用适当的绿化防护方法来进行，则会使公路具有安全、舒适、美观、与环境相协调等特点，也将会产生可观的经济效益、社会效益和生态效益。

边坡设计应遵循“安全绿色、水土保持、恢复自然、环保之路”的设计原则。

对公路边坡进行防护，必须考虑以下问题：①边坡稳定：保护路基边坡表面免受雨水冲刷，减缓温差与温度变化的影响，防止和延缓软岩土表面的风化、破碎、剥蚀演变过程，从而保护路基的整体稳定性。

②环境保护：使工程对环境的扰乱程度减少到最小，并谋求人工构造物与自然环境相协调。

③综合效应：综合防光，防眩，防烟，诱导司机视线，改善景观等目的进行边坡绿化防护，充分发挥防护工程的综合效益。

1、工程防护1.1 抹面与捶面1.1.1适用条件：①对各种易于风化的软岩层（如泥质砂岩、页岩、千枚岩、泥质板岩等）边坡，当岩层风化不甚严重时；②所防护的边坡，本身必须是稳定的，但其坡面形状、陡度及平顺性不受限制；③所防护的边坡，必须是干燥、无地下水的岩质边坡。

1.1.2构造要求：①抹面厚度一般为5～7cm，捶面厚度为10～15cm，一般为等厚截面。

②抹面与捶面工程的周边与未防护坡面衔接处，应严格封闭。

如在其边坡顶部做截水沟，沟底与沟边也要做抹面或捶面防护。

③大面积抹面或捶面时，每隔5～10m应设伸缩缝。

1.2 灌浆与勾缝灌浆适用于石质坚硬、不易风化、岩层内部节理发育，但裂缝宽度较小的岩质路堑边坡。

勾缝适用于石质较坚硬、不易风化、张开节理不甚发育，且节理缝较大较深的岩石路堑边坡上。

1.3水泥土护坡1.3.1适用条件：①适用于粉土、粉砂、粉质粘土、粘土等填方边坡。

②易受洪水浸淹的路基填方边坡。

③可用于盐渍土地区。

1.3.2构造要求：水泥土护坡厚度一般为10～20cm.水泥掺量一般为8％～15％，具体掺量施工时根据现场试验确定。

1.4 护面墙1.4.1适用条件：①多用于易风化的云母岩、绿泥片岩、千枚岩及其它风化严重的软质岩层和较破碎的岩石地段，以防止继续风化；②所防护的边坡本身必须是稳固的；③护面墙有实体护面墙、孔窗式护面墙、拱式护面墙和肋式护面墙。

实体护面墙适用于一般土质及碎石边坡；空窗式护面墙用于边坡缓于1：0.75，孔窗内可采用捶面（坡面干燥时）或干砌片石；拱式护面墙用于边坡下部岩层较完整，而需要防护上部边坡者或通过个别软弱地段时，边坡岩层较完整且坡度较陡时采用肋式护面墙。

1.4.2构造要求：1.实体护面墙①厚度视墙高而定，一般采用0.4～0.6m，底宽一般等于顶宽加H/10～H/20；单级护墙的高度一般不超过15m，多级护墙的总高度一般不超过30m.②沿墙身长度每隔10m设置一道2cm的伸缩缝，缝内用沥青麻筋填塞。

在泄水孔后用碎石和砂做成反滤层，以排除墙后排水。

③修筑护面墙前，对所有的边坡清除风化层至新鲜岩层，对风化迅速的岩质（如云母岩、绿泥片岩等）边坡，清挖出新鲜岩面后，应立即修筑护面墙。

④顶部应用原土夯填，以免水流冲刷。

2.孔窗式护面墙孔窗式护面墙的窗孔通常为半圆拱形，高2.5～3.5m，宽2～3m，半径1～1.5m.其基础、厚度、伸缩缝等与实体护面墙相同，窗孔内视具体情况，采用干砌片石、植草或捶面。

3.拱式护面墙拱跨较小时（2～3m），拱圈可采用10#水泥砂浆砌片石，拱高视边坡下面完整岩层高度而定，拱跨较大时，可采用砼拱圈。

1.5 喷浆或喷射混凝土防护1.5.1适用条件：①适用于岩性较差、强度较底、易风化或坚硬岩层风化破碎、节理发育、其表层风化剥落的岩质边坡；②当岩质边坡因风化剥落和节理切割而导致大面积碎落，以及局部小型坍塌、落石时，可采用局部加固处理后，进行大面积喷浆（喷射混凝土）。

③对于上部岩层风化破碎下部岩层坚硬完整的高大路堑边坡；④不能承受山体压力，边坡须是稳定的。

1.5.2构造要求：①喷浆厚度不宜小于1.5～2cm，喷射混凝土的厚度以3～5cm为宜。

②为防止坡面水的冲刷，沿喷浆（喷射混凝土）坡面顶缘外侧设置一条小型截水沟。

③浆体两侧凿槽嵌入岩层内。

1.6 喷锚防护1.6.1适用条件：凡易于喷浆（喷射混凝土）防护的岩质边坡，当岩层风化破碎严重、节理发育，在破碎岩层较厚的情况下，如果继续风化，将导致坠石或小型崩塌，从而影响整个边坡的稳定性。

它具有较高的强度，较好的抗裂性能，能使坡面内一定深度内的破碎岩层得以加强，并能承受少量的破碎体所产生的侧压力。

1.6.2构造要求：①为防止坡面水的冲刷，沿喷浆（喷射混凝土）坡面顶缘外侧设置一条小型截水沟。

②锚固深度视边坡岩层的破碎程度及破碎层的厚度而定，用1：3的水泥沙浆固结。

③喷浆厚度不小于3cm，喷射混凝土的厚度不小于5cm.④锚杆的类型有树脂锚杆、全长砂浆锚杆、塑料锚杆、水泥锚杆和缝管锚杆。

⑤提高锚杆承载力的措施主要有延长锚固段长度、二次压浆、采用端头扩大或多段扩大头锚杆、重复高压灌浆和改变锚杆传力特征的剪力或压力型锚杆。

其中二次压浆和重复高压灌浆比较实用有效。

1.7 土钉墙土钉墙是一种较新式的结构物，它主要由“钉”（即锚杆）、混凝土面板（挂网喷射混凝土）、锚板组成。

1.7.1作用机理通过规则排列的锚杆（“钉”）、面板、锚板将边坡一定范围内的土体进行原位加固，形成一种复合结构式的墙——土钉墙，墙后土压力由土钉墙承担。

1.7.2适用条件主要适用于风化破碎较严重的岩石边坡，也可用于粉土、砾石和砂土边坡。

承受土压力一般，其最大优点是从上往下逐层开挖土石方并及时对边坡进行封闭加固，能有效减少边坡因开挖临空而带来的英里释放，使边坡保持原来的稳定结构，避免坍塌。

1.7.3构造要求：①施工程序为：成孔－清孔－置筋－注浆－喷射第一层细石混凝土－装挂钢丝网－喷射第二层细石混凝土；②第一层细石混凝土厚7～10cm，第二层细石混凝土厚8cm.1.8 预应力锚索梁预应力锚索梁是最近几年发展起来的一种新型加固措施。

结构分为锚索和锚梁两部分。

1.8.1作用机理把破碎松散岩层组合连接成整体，并锚固在地层深部稳固的岩体上，通过施加预应力，使锚索长度范围内的软弱岩体（层）挤压密实，提高岩层层面间的正压力和摩阻力，阻止开裂松散岩体位移，从而达到加固边坡的目的。

这种方法的最大特点是：可保持既有坡面状态下深入坡体内部进行大范围加固；预先主动对边坡松散岩层施加正压力，起到挤密锁固作用；同时，锚索孔高压注浆，浆液充填裂隙和孔隙，又可提高破碎岩体的强度和整体性；结构简单、工期短、造价低廉。

1.8.2适用条件裂隙和断层发育、防缓边坡工作量巨大的高陡边坡。

1.8.3构造要求：①锚梁：锚梁为钢筋混凝土梁，采用C30混凝土浇注，它不仅为预应力锚索提供反力装置，而且也对边坡岩土有着框箍和压紧作用。

②锚梁的施工顺序为：防线挖槽—绑扎钢筋—支模—浇注混凝土。

③锚梁与锚索交叉部位预留塑料套管，便于锚索从中间穿过；在锚头部位预埋承压钢板，并与锚梁浇注成整体。

④预应力锚索施工程序为：放点钻孔—编制钢绞线—注浆—张拉锁定。

⑤可与喷射混凝土或框格护坡相结合。

2、植物防护2.1 种草2.1.1适用条件边坡稳定、坡面冲刷轻微的路堤或路堑边坡，一般要求边坡坡度不陡于1：1，边坡坡面水径流速度不超过0.6m/s，长期浸水边坡不适用。

2.1.2种植方式根据施工方法不同，有以下几种方式：①种子撒播法：适用于边坡土质较软，厚度在25mm以下的沙性土，23mm以下的粘性土，以及边坡缓于1：1的情况。

②喷播法：适用于砾间有砂的砾质土，或厚度在25mm以下的砂质土，厚度在23mm以下的粘性土、亚粘土土坡，或当厚度在25mm以上的硬质土时，在常降暴雨地区，则与铺席工程并用。

③客土喷播法：客土喷播技术是一种改善边坡植生环境，促进植物生长，从而在普通条件下无法绿化或绿化效果差的边坡上实现立体绿化、恢复自然植被的新技术。

客土喷播法具有广泛的适应性，土质或岩质边坡都适用。

④点穴、挖沟法方法：点穴法是在边坡上用钻具挖掘直径5～8cm、深10～15cm的洞，每平方米约8～12个，将固体肥料等防入，用土、砂等将洞埋住后，再种种子。

挖沟法是在边坡大致按水平间隔50cm左右，挖掘10～15cm深的沟，放入肥料后，撒播种子。

适用于：公路两侧的绿化用地立地条件较差的情况，如硬质土或花岗岩风化砂土挖方边坡。

2.2 铺草皮2.2.1适用条件各种土质边坡，特别是坡面冲刷比较严重、边坡较陡（可达60°），径流速度达0.6m/s 时。

2.2.2铺草皮的方式平铺、水平叠铺、垂直坡面或与坡面成一半破脚的倾斜叠置，以及采用片石等铺砌成方格或拱形边框、方格内铺草皮等。

2.3 植树适用于：各种土质边坡和风化极严重的岩石边坡，边坡坡度不陡于1：1.5，在路基边坡和漫水河滩上种植植物，对于加固路基与防护河岸收到良好的效果。

可以降低水流速，种在河滩上可促使泥沙淤积，防止水流直接冲刷路堤。

植树最好与植草相结合。

高等级公路边坡上严禁种乔木。

3、柔性支护3.1 三维植被网三维植被网又称防侵蚀网，以热塑树脂为原料。

结构分为上下两层，上层为一个经双面拉伸的高模量基础层，强度足以防止植被网的变形，并能有效防止水土流失，下层是一层弹性的、规则的、凹凸不平的网包组成。

3.1.1作用机理：三维植被网是由多层塑料凹凸网和高强度平网复合而成的立体网结构。

面层外观凹凸不平。

材质疏松柔韧，留有90%以上的空间可填充土壤及沙粒，将草籽及表层土壤牢牢护在立体网中间。

3.1.2特点① 固土效果极好。

实验证明：在草皮形成之前，当坡度为45度时，三维植被网的固土阻滞率高达97.5%.即使坡面角达到90°时，三维植被网仍可保留阻滞住60%的土壤。

② 抗冲刷能力强。

三维网垫及植物根系可起到浅层加筋的作用，这种复合体系具有及强的抗冲刷能力，能够达到有效防护边坡的目的。

③ 网垫原材料采用聚乙烯，无毒且化学性质稳定可靠，埋在地下寿命可达50年以上，即使暴露在阳光下寿命也长达10多年。

④ 草种采用混合草种，生长成坪快；抗逆性强、耐贫瘠、耐粗放式管理等。

3.1.3适用条件设计稳定的土质和岩质边坡，特别是土质贫瘠的边坡和土石混填的边坡可以起到固土防冲并改善植草质量的良好效果。

3.2 钢绳网主动防护通过锚杆和支撑绳以固定方式将钢绳网盖在坡面上。

作用机理为通过固定在锚杆或支撑绳上并施以一定预张拉的钢绳网，以及在用作风化剥落、溜塌或坍落防护中抑制细小颗粒、洒落或土体流失时铺以金属网或土工格栅，对整个边坡形成连续支撑。