桥梁设计外文翻译--超轻大跨度桥
桥梁外文翻译
Prestressed Concrete bridgesPrestressed concrete has been used extensively in U.S. bridge construction since its first introduction from Europe in the late 1940s. Literally thousands of highway bridges of both precast, prestressed concrete and cast-in-place post-tensioned concrete have been constructed in the United States. Railroad bridges utilizing prestressed concrete have become common as well. The use and evolution of prestressed concrete bridges is expected to continue in the years ahead.Short-span BridgeShort-span Bridge, as shown in Fig.18for the purposes of this discussion, will be assumed to have a maximum span of 45ft (13.7m). It should be understood that this is an arbitrary figure, and there is no definite line of demarcation between short, moderate, and long spans in highly bridges. Short-span bridges are most efficiently made of precast prestressed-concrete hollow slabs, I-beams, solid slabs or cast-place solid slabs, and the T-beams of relativily generous proportions.Precast solid slabs are most economical when used on very short spans. The slabs can be made in any convenient width, but widths of 3 or 4ft(0.9 to 1.2m ) have been common. Keys frequently are cast in the longitudinal sides of the precast units. After the slabs have been erected and joints between the slabs have been filled with concrete, the keys transfer live load shear forces between the adjacent slabs.Precast hollow slabs used in short-span bridge may have round or square void. They too are generally made in units 3 to 4 ft (0.9 to 1.2m) wide with thicknesses from 18 to 27 inch 9 (45.7 to 68.8cm). Precast hollow slabs can be made in any convenient width and depth, and frequently are used in bridges having spans from 20 to 50 ft (6.1 to 15.2cm). Longitudinal shear keys are used in the joints between adjacent hollow slabs in the same way as with solid slabs, but the use of a leveling course of some type normally is required as a means of obtaining an acceptable appearance and levelness.Transverse reinforcement normally is provided in precast concrete bridge superstructures for the purpose of tying the structure together in the transverse direction. Well-designed ties ensure that the individual longitudinal members forming the superstructure will act as a unit under the effects of the live load. In slab bridge construction, transverse ties most frequently consist of threaded steel bars placedthrough small holes formed transversely through the member during fabrication. Nuts frequently are used as fasteners at each end of the bars. In some instances, the transverse ties consist of post tensioned tendons placed, stressed, and grouted after the slabs have been erected. The transverse tie usually extends from one side of the bridge to the other.The shear forces imposed on the stringers in short-span bridges frequently are too large to be resisted by the concrete alone. Hence, shear reinforcement normally is required. The amount of shear reinforcement required may be relatively large if the webs of the stringers are relatively thin.Concrete diaphragms, reinforced with post-tensioned reinforcement or nonprestressed reinforcement, normally are provided transversely at ends and at intermediate locations along the span in stringer-type bridges. The diaphragms ensure the lateral-distribution of the live loads to the various stringers from displacing or rotating significantly with respect to the adjacent stringers.No generalities will be made here about the relative cost of each of the above types of construction; construction costs are a function of many variables which prohibit meaningful generalizations. However, it should be noted that the stringer type of construction requires a considerably greater construction depth that is requires a considerably greater construction depth that is required for solid, hollow, or channel slab bridge superstructure. Stringer construction does not require a separate wearing surface, as do the precast slab types of construction, unless precast slabs are used to span between the stringers in lieu of the more commonly used cast-in-place reinforced concrete deck. Strings construction frequently requires smaller quantities of superstructure materials than do slab bridges (unless the spans are very short). The construction time needed to complete a bridge after the precast members have beenerected is greater with stringer framing than with the slab type of framing.Bridge of moderate spanAgain for the purposes of this discussion only, moderate spans for bridges of prestressed concrete are defined as being from 45 to 80ft (13.7 to 24.4m). Prestressed concrete bridges in this spans range generally can be divided into two types; stringer-type bridges and slab-type bridges and slab-type bridges. The majority of the precast prestressed concrete bridges constructed in the United States have been stringer bridges using I-shaped stringers, but a large number of precast prestressedconcrete bridges have been constructed with precast hollow-box girders (sometimes also called stringer). Cast-in-place post-tensioned concrete has been used extensively in the construction of hollow-box girder bridges-a form of construction that can be considered to be a slab bridge.Stringer bridges, which employ a composite, cast-in-place deck slab, have been used in virtually all parts of the United States. These stringers normally are used at spacing of about 5 to 6 ft (1.5 to 1.8m). The cast-in-place deck is generally form 6.0 to 8.0 inch (15.2 to 20.3 cm) in thickness. This type of framing is very much the same as that used on composite stringer construction for short-span bridges.Diaphragm details in moderate-span bridges are generally similar to those of the short spans, with the exception that two or three interior diaphragms sometime are used, rather than just one at mid span as in the short-span bridge.As in the case of short-span bridges, the minimum depth of construction in bridges of moderate span is obtained by using slab construction, which may be either solid-or hollow-box in cross section. Average construction depths are required when stringers with large flanges are used in composite construction, and large construction depths are required when stringers with small bottom flanges are used. Composite construction may be developed through the use of cast-in-place concrete decks or with precast construction may be developed through the use of cast-in-place concrete decks or with precast concrete decks. Lower quantities of materials normally are required with composite construction, and dead weight of the materials normally is less for stringer construction than for slab construction.Long-Span BridgesPrestressed concrete bridges having spans of the order of 100 ft are of the same general types of construction as structures having moderate span lengths, with the single exception that solid slabs are not used for long spans. The stringer spacings are frequently greater (with stringers at 7 to 9 ft) as the span lengths of bridges increase. Because of dead weight consideration, precast hollow-box construction generally is employed for spans of this length only when the depth of construction must be minimized. Cast-in-place post-tensioned hollow-box bridges with simple and continues spans frequently are used for spans on the order of 100 ft and longer.Simple, precast, prestressed stringer construction would be economical in the United States in spans up to 300 ft under some condition. However, only limited use has been made of this type of construction on spans greater than 100 ft. For very longsimple spans, the advantage of precasting frequently is nullified by the difficulties involved in handing, transporting, and erecting the girders, which may have depths as great as 10 ft and weight over 200 tons. The exceptions to this occur on large projects where all of the spans are over water of sufficient depth and character that precast beams can be handled with floating equipment, when custom girder launchers can be used, and when segmental construction techniques can be used.The use of cast-in-place, post-tensioned, box-girder bridges has been extensive. Although structures of these types occasionally are used for spans less than 100 ft, they more often are used for spans in excess of 100ft and have been used in structures having spans in excess of 300ft. Structure efficient in flexure, especially for continues bridges, the box girder is torsionally stiff and hence an excellent type of structure for use on bridges that have horizontal curvature. Some governmental agencies use this form of construction almost exclusively in urban areas where appearance from the side, is considered important.Segmental BridgesBridges that are constructed in pieces of one various connected together in some way, frequently are referred to as segmental bridges. The segments may be cast-in-place or precast, elongated units, such as portions of stringers or girders, or relatively short units that are as wide as the completed bridge superstructure.The Esbly Bridge in France is an example of one of the earliest precast concrete segmental bridges. This bridge is one of five bridges that were made with the same dimensions and utilized the same steel molds for casting the concrete units. All of the bridges span the River Marne, and because of the required navigational clearances and the low grades on the roads approaching the bridge, the depth of construction at the center of each span was restricted. The bridges were formed of precast elements, 6ft long, and were made in elaborate molds by first casting and steam-curing the top and bottom flanges in which the ends of the web reinforcement were embedded. The flanges were then jacked apart, and held apart by the web forms resulted in the prestressing of the webs. The 6-ft-long elements were temporarily post-tensioned in the factory into units approximately 40ft long. The 40ft units were transported to the bridge site, raised into place, and post-tensioned together longitudinally, after which the temporary post tensioned was removed. Each span consists of six ribs or beams that were post tensioned together transversely after they were erected. Hence, the beams are triaxially prestressed. The completed Esbly Bridge consists of a very flat,two hinged, prestressed concrete arch with a span of 243 ft and a depth at midspan of about 3ft.Cast-in-place prestressed concrete segmental construction, in which relatively short, full-width sections of a bridge superstructure are constructed, cantilevered from both sides of a pier, originated in Germany shortly after World War 2. This procedure sometimes is referred to as balanced cantilever construction. The well-known, late German engineer U.Finterwalder is credited with being originator of the technique. The basic construction sequence used in this method is illustrated in Fig.18.2 which shows that segments, erected one after another on each side of a pier, form cantilevered spans. The construction sequence normally progresses from pier to pier, from one end of the bridge to the other, with the ends of adjacent cantilevered being joined together to continuous deck. The individual segments frequently are made in lengths of 12 to 16 ft in cycles of four to seven days. The method has been used in the United States for bridges having spans as long as 750ft.The segmental construction technique also has been used with precast segments. The technique originated in France and has been used in the construction of bridges having spans in excess of 300ft. the eminent French engineer Jean Muller is credited with originating precast segment bridge construction using match cast segments. The precast segment may be erected in balanced cantilever, similar to the method described above for cast-in-place segment bridges construction in cantilever, or by using span-by-span technique. Precast segments have been made in precasting plants located on the construction site as well as off site. The segments frequently are stored for a period of weeks or months before being moved to the bridge site and erected- a factor having favorable effects on concrete strength, shrink-age, and creep. Construction of precast segmental bridge superstructures normally progresses at a rapid rate once the erection progress begins. The erection of precast concrete segments normally does not commence, however, until such time as a large number of segments have been precast and stockpiled because the erection normally can progress at a faster rate than the production of the segments.Bridge DesignThe design of bridges requires the collection of extensive date and from this the selection of possible options. From such a review the choice is narrowed down to a shortlist of potential bridge design. A sensible work plan should be devised for the marshaling and deployment of information throughout the project from conception tocompletion to completion. Such a checklist will vary from project to project but a typical example might be drawn up on the following lines.Selection of Bridge TypeThe chief factors in deciding whether a bridge will be built as girder, cantilever, truss, arch, suspension, or some other type are: (1) location ;for example, across a river ; (2) purposes; for example, a bridge for carrying motor vehicles; (3) span length;(4) strength of available materials; (5) cost ; (6) beauty and harmony with the location.Each type of bridge is most effective and economical only within a certain range of span lengths, as shown in the following table:Selection of MaterialThe bridge designer can select from a number of modern high-strength materials, including concrete, steel, and a wide variety of corrosion-resistant alloy steels.For the Verrazano-narrows bridge, for example, the designer used at least seven different kinds of alloy steel, one of which has a yield strength of 50000 pounds per square inch (psi) (3515 kgs/sq cm) and does not need to be painted because an oxide coating forms on its surface and inhibits corrosion. The designer also can select steel wires for suspension cables that have tensile strengths up to 250 000 psi (14 577 kgs/sq cm).Concrete with compressive strength as high as 8 000 psi (562.5 kgs/sq cm) can now be produced for use in bridges, and it can be given high durability against chipping and weathering by the addition of special chemical and control of the hardening process. Concrete that has been prestressed and reinforced with steel wires has a tensile strength of 250 000 psi (17 577kgs/sq cm).Other useful materials for bridges include aluminum alloys and wood. Modern structural aluminum alloys have yield strengths exceeding 40 000 psi (2 812 kgs/spcm). Laminated strips of wood glued together can be made into beams with strengths twice that of natural timbers; glue-laminated southern pine, for example, can bear working stresses approaching 3 000 psi (210.9 kgs/sq cm).Analysis of ForcesA bridge must resist a complex combination of tension, compression, bending, shear, and torsion forces. In addition, the structure must provide a safety factor as insurance against failure. The calculation of the precise nature of the individual stresses and strains in the structure, called analysis, is perhaps the most technically complex aspect of bridge building. The goal of analysis is to determine all of the forces that may act on each structural member.The forces that act on bridge structure member are produced by two kinds of loads-static and dynamic. The static load-the dead weight of bridge structure itself-is usually the greatest load. The dynamic or live load has components, including vehicles carried by the bridge, wind forces, and accumulation of ice and snow.Although the total weight of the vehicles moving over a bridge at any time is generally a small fraction of the static and dynamic load, it presents special problems to the bridge designer because of the vibration and impact stresses created by moving vehicles. For example, the sever impacts caused by irregularities of vehicle motion or bumps in the roadway may momentarily double the effect of the live load on the bridge.Wind exerts forces on a bridge both directly by striking the bridge structure and indirectly by striking vehicles that are crossing the bridge. If the wind induces aeronautic vibration, as in the case of the Tacoma Narrows Bridge, its effect may be greatly amplified. Because of this danger, the bridge designer makes provisions for the strongest winds that may occur at the bridge location. Other forces that may act on the bridge, such as stresses created by earthquake tremors must also be provided for.Special attention must often be given to the design of bridge piers, since heavy loads may be imposed on them by currents, waves, and floating ice and debris. Occasionally a pier may even be hit by a passing ship.Electronic computers are playing an everincreasing role in assisting bridge designers in the analysis of forces. The use of precise model testing particularly for studying the dynamic behavior of bridges, also helps designers. A scaled-down model of the bridge is constructed, and various gauges to measure strains, acceleration, and deforestation are placed on the model. The model bridge is then subjected to variousscaled-down loads or dynamic conditions to find out what will happen. Wind tunnel tests may also be made to ensure that nothing like the Tacoma Narrows Bridge failure can occur. With modern technological aids, there is much less chance of bridge failure than in the past.预应力混凝土桥19世纪40年代后期，预应力混凝土首次引入美国，很快便广泛应用于桥梁结构中。
桥梁英语词汇
下部结构 substructure桥墩 pier 墩身 pier body墩帽 pier cap, pier coping台帽 abutment cap, abutment coping盖梁 bent cap又称“帽梁”。
重力式[桥]墩 gravity pier实体[桥]墩 solid pier空心[桥]墩 hollow pier柱式[桥]墩 column pier, shaft pier单柱式[桥]墩 single-columned pier, single shaft pier 双柱式[桥]墩 two-columned pier, two shaft pier排架桩墩 pile-bent pier丫形[桥]墩 Y-shaped pier柔性墩 flexible pier制动墩 braking pier, abutment pier单向推力墩 single direction thrusted pier抗撞墩 anti-collision pier锚墩 anchor pier辅助墩 auxiliary pier破冰体 ice apron防震挡块 anti-knock block, restrain block桥台 abutment台身 abutment body前墙 front wall又称“胸墙”。
翼墙 wing wall又称“耳墙”。
U形桥台 U-abutment八字形桥台 flare wing-walled abutment一字形桥台 head wall abutmentT形桥台 T-abutment箱形桥台 box type abutment拱形桥台 arched abutment重力式桥台 gravity abutment埋置式桥台 buried abutment扶壁式桥台 counterfort abutment, buttressed abutment 衡重式桥台 weight-balanced abutment锚碇板式桥台 anchored bulkhead abutment支撑式桥台 supported type abutment又称“轻型桥台”。
桥梁工程毕业设计外文翻译(箱梁)
西南交通大学本科毕业设计(论文）外文资料翻译年级:学号：姓名：专业:指导老师:2013年 6 月外文资料原文：13Box girders13.1 GeneralThe box girder is the most flexible bridge deck form。
It can cover a range of spans from25 m up to the largest non—suspended concrete decks built, of the order of 300 m。
Single box girders may also carry decks up to 30 m wide。
For the longer span beams, beyond about 50 m，they are practically the only feasible deck section. For the shorter spans they are in competition with most of the other deck types discussed in this book.The advantages of the box form are principally its high structural efficiency （5.4），which minimises the prestress force required to resist a given bending moment，and its great torsional strength with the capacity this gives to re—centre eccentric live loads，minimising the prestress required to carry them。
The box form lends itself to many of the highly productive methods of bridge construction that have been progressively refined over the last 50 years，such as precast segmental construction with or without epoxy resin in the joints，balanced cantilever erection either cast in—situ or coupled with precast segmental construction, and incremental launching （Chapter 15)。
道路桥梁专业 中英文对照---毕业设计论文 外文文献翻译
附录一英文翻译原文AUTOMATIC DEFLECTION AND TEMPERATURE MONITORING OFA BALANCED CANTILEVER CONCRETE BRIDGEby Olivier BURDET, Ph.D.Swiss Federal Institute of Technology, Lausanne, SwitzerlandInstitute of Reinforced and Prestressed Concrete SUMMARYThere is a need for reliable monitoring systems to follow the evolution of the behavior of structures over time.Deflections and rotations are values that reflect the overall structure behavior. This paper presents an innovative approach to the measurement of long-term deformations of bridges by use of inclinometers. High precision electronic inclinometers can be used to follow effectively long-term rotations without disruption of the traffic. In addition to their accuracy, these instruments have proven to be sufficiently stable over time and reliable for field conditions. The Mentue bridges are twin 565 m long box-girder post-tensioned concrete highway bridges under construction in Switzerland. The bridges are built by the balanced cantilever method over a deep valley. The piers are 100 m high and the main span is 150 m. A centralized data acquisition system was installed in one bridge during its construction in 1997. Every minute, the system records the rotation and temperature at a number of measuring points. The simultaneous measurement of rotations and concrete temperature at several locations gives a clear idea of the movements induced by thermal conditions. The system will be used in combination with a hydrostatic leveling setup to follow the long-term behavior of the bridge. Preliminary results show that the system performs reliably and that the accuracy of the sensors is excellent.Comparison of the evolution of rotations and temperature indicate that the structure responds to changes in air temperature rather quickly.1.BACKGROUNDAll over the world, the number of structures in service keeps increasing. With the development of traffic and the increased dependence on reliable transportation, it is becoming more and more necessary to foresee and anticipate the deterioration of structures. In particular,for structures that are part of major transportation systems, rehabilitation works need to be carefully planned in order to minimize disruptions of traffic. Automatic monitoring of structures is thus rapidly developing.Long-term monitoring of bridges is an important part of this overall effort to attempt to minimize both the impact and the cost of maintenance and rehabilitation work of major structures. By knowing the rate of deterioration of a given structure, the engineer is able to anticipate and adequately define the timing of required interventions. Conversely, interventions can be delayed until the condition of the structure requires them, without reducing the overall safety of the structure.The paper presents an innovative approach to the measurement of long-term bridge deformations. The use of high precision inclinometers permits an effective, accurate and unobtrusive following of the long-term rotations. The measurements can be performed under traffic conditions. Simultaneous measurement of the temperature at several locations gives a clear idea of the movements induced by thermal conditions and those induced by creep and shrinkage. The system presented is operational since August 1997 in the Mentue bridge, currently under construction in Switzerland. The structure has a main span of 150 m and piers 100 m high.2. LONG-TERM MONITORING OF BRIDGESAs part of its research and service activities within the Swiss Federal Institute of Technology in Lausanne (EPFL), IBAP - Reinforced and Prestressed Concrete has been involved in the monitoring of long-time deformations of bridges and other structures for over twenty-five years [1, 2, 3, 4]. In the past, IBAP has developed a system for the measurement of long-term deformations using hydrostatic leveling [5, 6]. This system has been in successful service in ten bridges in Switzerland for approximately ten years [5,7]. The system is robust, reliable and sufficiently accurate, but it requires human intervention for each measurement, and is not well suited for automatic data acquisition. One additional disadvantage of this system is that it is only easily applicable to box girder bridges with an accessible box.Occasional continuous measurements over periods of 24 hours have shown that the amplitude of daily movements is significant, usually amounting to several millimeters over a couple of hours. This is exemplified in figure 1, where measurements of the twin Lutrive bridges, taken over a period of several years before and after they were strengthened by post-tensioning, areshown along with measurements performed over a period of 24 hours. The scatter observed in the data is primarily caused by thermal effects on the bridges. In the case of these box-girder bridges built by the balanced cantilever method, with a main span of 143.5 m, the amplitude of deformations on a sunny day is of the same order of magnitude than the long term deformation over several years.Instantaneous measurements, as those made by hydrostatic leveling, are not necessarily representative of the mean position of the bridge. This occurs because the position of the bridge at the time of the measurement is influenced by the temperature history over the past several hours and days. Even if every care was taken to perform the measurements early in the morning and at the same period every year, it took a relatively long time before it was realized that the retrofit performed on the Lutrive bridges in 1988 by additional post-tensioning [3, 7,11] had not had the same effect on both of them.Figure 1: Long-term deflections of the Lutrive bridges, compared to deflections measured in a 24-hour period Automatic data acquisition, allowing frequent measurements to be performed at an acceptable cost, is thus highly desirable. A study of possible solutions including laser-based leveling, fiber optics sensors and GPS-positioning was performed, with the conclusion that, provided that their long-term stability can be demonstrated, current types of electronic inclinometers are suitable for automatic measurements of rotations in existing bridges [8].3. MENTUE BRIDGESThe Mentue bridges are twin box-girder bridges that will carry the future A1 motorway from Lausanne to Bern. Each bridge, similar in design, has an overall length of approximately 565 m, and a width of 13.46 m, designed to carry two lanes of traffic and an emergency lane. The bridges cross a deep valley with steep sides (fig. 2). The balanced cantilever design results from a bridge competition. The 100 m high concrete piers were built using climbing formwork, after which the construction of the balanced cantilever started (fig. 3).4. INCLINOMETERSStarting in 1995, IBAP initiated a research project with the goal of investigating the feasibility of a measurement system using inclinometers. Preliminary results indicated that inclinometers offer several advantages for the automatic monitoring of structures. Table 1 summarizes the main properties of the inclinometers selected for this study.One interesting property of measuring a structure’s rotations, is that, for a given ratio of maximum deflection to span length, the maximum rotation is essentially independent from its static system [8]. Since maximal allowable values of about 1/1,000 for long-term deflections under permanent loads are generally accepted values worldwide, developments made for box-girder bridges with long spans, as is the case for this research, are applicable to other bridges, for instance bridges with shorter spans and other types of cross-sections. This is significant because of the need to monitor smaller spans which constitute the majority of all bridges.The selected inclinometers are of type Wyler Zerotronic ±1°[9]. Their accuracy is 1 microradian (μrad), which corresponds to a rotation of one millimeter per kilometer, a very small value. For an intermediate span of a continuous beam with a constant depth, a mid-span deflection of 1/20,000 would induce a maximum rotation of about 150 μrad, or 0.15 milliradians (mrad).One potential problem with electronic instruments is that their measurements may drift overtime. To quantify and control this problem, a mechanical device was designed allowing the inclinometers to be precisely rotated of 180° in an horizontal plane (fig. 4). The drift of each inclinometer can be very simply obtained by comparing the values obtained in the initial and rotated position with previously obtained values. So far, it has been observed that the type of inclinometer used in this project is not very sensitive to drifting.5. INSTRUMENTATION OF THE MENTUE BRIDGESBecause a number of bridges built by the balanced cantilever method have shown an unsatisfactory behavior in service [2, 7,10], it was decided to carefully monitor the evolution of the deformations of the Mentue bridges. These bridges were designed taking into consideration recent recommendations for the choice of the amount of posttensioning [7,10,13]. Monitoring starting during the construction in 1997 and will be pursued after the bridges are opened to traffic in 2001. Deflection monitoring includes topographic leveling by the highway authorities, an hydrostatic leveling system over the entire length of both bridges and a network of inclinometers in the main span of the North bridge. Data collection iscoordinated by the engineer of record, to facilitate comparison of measured values. The information gained from these observations will be used to further enhance the design criteria for that type of bridge, especially with regard to the amount of post-tensioning [7, 10, 11, 12, 13].The automatic monitoring system is driven by a data acquisition program that gathers and stores the data. This system is able to control various types of sensors simultaneously, at the present time inclinometers and thermal sensors. The computer program driving all the instrumentation offers a flexible framework, allowing the later addition of new sensors or data acquisition systems. The use of the development environment LabView [14] allowed to leverage the large user base in the field of laboratory instrumentation and data analysis. The data acquisition system runs on a rather modest computer, with an Intel 486/66 Mhz processor, 16 MB of memory and a 500 MB hard disk, running Windows NT. All sensor data are gathered once per minute and stored in compressed form on the hard disk. The system is located in the box-girder on top of pier 3 (fig. 5). It can withstand severe weather conditions and will restart itself automatically after a power outage, which happened frequently during construction.6. SENSORSFigure 5(a) shows the location of the inclinometers in the main span of the North bridge. The sensors are placed at the axis of the supports (①an d⑤), at 1/4 and 3/4 (③an d④) of the span and at 1/8 of the span for②. In the cross section, the sensors are located on the North web, at a height corresponding to the center of gravity of the section (fig.5a). The sensors are all connected by a single RS-485 cable to the central data acquisition system located in the vicinity of inclinometer ①. Monitoring of the bridge started already during its construction. Inclinometers①,②and③were installed before the span was completed. The resulting measurement were difficult to interpret, however, because of the wide variations of angles induced by the various stages of this particular method of construction.The deflected shape will be determined by integrating the measured rotations along the length of the bridge (fig.5b). Although this integration is in principle straightforward, it has been shown [8, 16] that the type of loading and possible measurement errors need to be carefully taken into account.Thermal sensors were embedded in concrete so that temperature effects could be taken into account for the adjustment of the geometry of the formwork for subsequent casts. Figure 6 shows the layout of thermal sensors in the main span. The measurement sections are located at the same sections than the inclinometers (fig. 5). All sensors were placed in the formwork before concreting and were operational as soon as the formwork was removed, which was required for the needs of the construction. In each section, seven of the nine thermal sensor (indicated in solid black in fig. 6) are now automatically measured by the central data acquisition system.7. RESULTSFigure 7 shows the results of inclinometry measurements performed from the end ofSeptember to the third week of November 1997. All inclinometers performed well during that period. Occasional interruptions of measurement, as observed for example in early October are due to interruption of power to the system during construction operations. The overall symmetry of results from inclinometers seem to indicate that the instruments drift is not significant for that time period. The maximum amplitude of bridge deflection during the observed period, estimated on the basis of the inclinometers results, is around 40 mm. More accurate values will be computed when the method of determination ofdeflections will have been further calibrated with other measurements. Several periods of increase, respectively decrease, of deflections over several days can be observed in the graph. This further illustrates the need for continuous deformation monitoring to account for such effects. The measurement period was .busy. in terms of construction, and included the following operations: the final concrete pours in that span, horizontal jacking of the bridge to compensate some pier eccentricities, as well as the stressing of the continuity post-tensioning, and the de-tensioning of the guy cables (fig. 3). As a consequence, the interpretation of these measurements is quite difficult. It is expected that further measurements, made after the completion of the bridge, will be simpler to interpret.Figure 8 shows a detail of the measurements made in November, while figure.9 shows temperature measurements at the top and bottom of the section at mid-span made during that same period. It is clear that the measured deflections correspond to changes in the temperature. The temperature at the bottom of the section follows closely variations of the air temperature(measured in the shade near the north web of the girder). On the other hand, the temperature at the top of the cross section is less subject to rapid variations. This may be due to the high elevation of the bridge above ground, and also to the fact that, during the measuring period, there was little direct sunshine on the deck. The temperature gradient between top and bottom of the cross section has a direct relationship with short-term variations. It does not, however, appear to be related to the general tendency to decrease in rotations observed in fig. 8.8. FUTURE DEVELOPMENTSFuture developments will include algorithms to reconstruct deflections from measured rotations. To enhance the accuracy of the reconstruction of deflections, a 3D finite element model of the entire structure is in preparation [15]. This model will be used to identify the influence on rotations of various phenomena, such as creep of the piers and girder, differential settlements, horizontal and vertical temperature gradients or traffic loads.Much work will be devoted to the interpretation of the data gathered in the Mentue bridge. The final part of the research project work will focus on two aspects: understanding the very complex behavior of the structure, and determining the most important parameters, to allow a simple and effective monitoring of the bridges deflections.Finally, the research report will propose guidelines for determination of deflections from measured rotations and practical recommendations for the implementation of measurement systems using inclinometers. It is expected that within the coming year new sites will be equipped with inclinometers. Experiences made by using inclinometers to measure deflections during loading tests [16, 17] have shown that the method is very flexible and competitive with other high-tech methods.As an extension to the current research project, an innovative system for the measurement of bridge joint movement is being developed. This system integrates easily with the existing monitoring system, because it also uses inclinometers, although from a slightly different type.9. CONCLUSIONSAn innovative measurement system for deformations of structures using high precision inclinometers has been developed. This system combines a high accuracy with a relatively simple implementation. Preliminary results are very encouraging and indicate that the use of inclinometers to monitor bridge deformations is a feasible and offers advantages. The system is reliable, does not obstruct construction work or traffic and is very easily installed. Simultaneous temperature measurements have confirmed the importance of temperature variations on the behavior of structural concrete bridges.10. REFERENCES[1] ANDREY D., Maintenance des ouvrages d’art: méthodologie de surveillance, PhD Dissertation Nr 679, EPFL, Lausanne, Switzerland, 1987.[2] BURDET O., Load Testing and Monitoring of Swiss Bridges, CEB Information Bulletin Nr 219, Safety and Performance Concepts, Lausanne, Switzerland, 1993.[3] BURDET O., Critères pour le choix de la quantitéde précontrainte découlant de l.observation de ponts existants, CUST-COS 96, Clermont-Ferrand, France, 1996.[4] HASSAN M., BURDET O., FAVRE R., Combination of Ultrasonic Measurements and Load Tests in Bridge Evaluation, 5th International Conference on Structural Faults and Repair, Edinburgh, Scotland, UK, 1993.[5] FAVRE R., CHARIF H., MARKEY I., Observation à long terme de la déformation des ponts, Mandat de Recherche de l’OFR 86/88, Final Report, EPFL, Lausanne, Switzerland, 1990.[6] FAVRE R., MARKEY I., Long-term Monitoring of Bridge Deformation, NATO Research Workshop, Bridge Evaluation, Repair and Rehabilitation, NATO ASI series E: vol. 187, pp. 85-100, Baltimore, USA, 1990.[7] FAVRE R., BURDET O. et al., Enseignements tirés d’essais de charge et d’observations à long terme pour l’évaluation des ponts et le choix de la précontrainte, OFR Report, 83/90, Zürich, Switzerland, 1995.[8] DAVERIO R., Mesures des déformations des ponts par un système d’inclinométrie,Rapport de maîtrise EPFL-IBAP, Lausanne, Switzerland, 1995.[9] WYLER AG., Technical specifications for Zerotronic Inclinometers, Winterthur, Switzerland, 1996.[10] FAVRE R., MARKEY I., Generalization of the Load Balancing Method, 12th FIP Congress, Prestressed Concrete in Switzerland, pp. 32-37, Washington, USA, 1994.[11] FAVRE R., BURDET O., CHARIF H., Critères pour le choix d’une précontrainte: application au cas d’un renforcement, "Colloque International Gestion des Ouvrages d’Art: Quelle Stratégie pour Maintenir et Adapter le Patrimoine, pp. 197-208, Paris, France, 1994. [12] FAVRE R., BURDET O., Wahl einer geeigneten Vorspannung, Beton- und Stahlbetonbau, Beton- und Stahlbetonbau, 92/3, 67, Germany, 1997.[13] FAVRE R., BURDET O., Choix d’une quantité appropriée de précontrain te, SIA D0 129, Zürich, Switzerland, 1996.[14] NATIONAL INSTRUMENTS, LabView User.s Manual, Austin, USA, 1996.[15] BOUBERGUIG A., ROSSIER S., FAVRE R. et al, Calcul non linéaire du béton arméet précontraint, Revue Français du Génie Civil, vol. 1 n° 3, Hermes, Paris, France, 1997. [16] FEST E., Système de mesure par inclinométrie: développement d’un algorithme de calcul des flèches, Mémoire de maîtrise de DEA, Lausanne / Paris, Switzerland / France, 1997.[17] PERREGAUX N. et al., Vertical Displacement of Bridges using the SOFO System: a Fiber Optic Monitoring Method for Structures, 12th ASCE Engineering Mechanics Conference, San Diego, USA, to be published,1998.译文平衡悬臂施工混凝土桥挠度和温度的自动监测作者Olivier BURDET博士瑞士联邦理工学院，洛桑，瑞士钢筋和预应力混凝土研究所概要：我们想要跟踪结构行为随时间的演化，需要一种可靠的监测系统。
(完整版)桥梁毕业设计外文翻译
外文资料The Tenth East Asia-Pacific Conference on Structural Engineering and ConstructionAugust 3-5, 2006, Bangkok, ThailandStructural Rehabilitation of Concrete Bridges with CFRPComposites-Practical Details and ApplicationsRiyad S. ABOUTAHA1, and Nuttawat CHUTARAT2 ABSTRACT: Many old existing bridges are still active in the various highway transportation networks, carrying heavier and faster trucks, in all kinds of environments. Water, salt, and wind have caused damage to these old bridges, and scarcity of maintenance funds has aggravated their conditions. One attempt to restore the original condition; and to extend the service life of concrete bridges is by the use of carbon fiber reinforced polymer (CFRP) composites. There appear to be very limited guides on repair of deteriorated concrete bridges with CFRP composites. In this paper, guidelines for nondestructive evaluation (NDE), nondestructive testing (NDT), and rehabilitation of deteriorated concrete bridges with CFRP composites are presented. The effect of detailing on ductility and behavior of CFRP strengthened concrete bridges are also discussed and presented.KEYWORDS: Concrete deterioration, corrosion of steel, bridge rehabilitation, CFRP composites.1 IntroductionThere are several destructive external environmental factors that limit the service life of bridges. These factors include but not limited to chemical attacks, corrosion of reinforcing steel bars, carbonation of concrete, and chemical reaction of aggregate. If bridges were not well maintained, these factors may lead to a structural deficiency, which reduces the margin of safety, and may result in structural failure. In order to rehabilitate and/or strengthen deteriorated existing bridges, thorough evaluation should be conducted. The purpose of the evaluation is to assess the actual condition of any existing bridge, and generally to examine the remaining strength and load carry capacity of the bridge.1 Associate Professor, Syracuse University, U.S.A.2 Lecturer, Sripatum University, Thailand.One attempt to restore the original condition, and to extend the service life of concrete bridges is by the use of carbon fiber reinforced polymer (CFRP) composites.In North America, Europe and Japan, CFRP has been extensively investigated and applied. Several design guides have been developed for strengthening of concrete bridges with CFRP composites. However, there appear to be very limited guides on repair of deteriorated concrete bridges with CFRP composites. This paper presents guidelines for repair of deteriorated concrete bridges, along with proper detailing. Evaluation, nondestructive testing, and rehabilitation of deteriorated concrete bridges with CFRP composites are presented. Successful application of CFRP composites requires good detailing as the forces developed in the CFRP sheets are transferred by bond at the concrete-CFRP interface. The effect of detailing on ductility and behavior of CFRP strengthened concrete bridges will also be discussed and presented.2 Deteriorated Concrete BridgesDurability of bridges is of major concern. Increasing number of bridges are experiencing significant amounts of deterioration prior to reaching their design service life. This premature deterioration considered a problem in terms of the structural integrity and safety of the bridge. In addition, deterioration of a bridge has a considerable magnitude of costs associated with it. In many cases, the root of a deterioration problem is caused by corrosion of steel reinforcement in concrete structures. Concrete normally acts to provide a high degree of protection against corrosion of the embedded reinforcement. However, corrosion will result in those cases that typically experience poor concrete quality, inadequate design or construction, and harsh environmental conditions. If not treated a durability problem, e.g. corrosion, may turn into a strength problem leading to a structural deficiency, as shown in Figure1.Figure1 Corrosion of the steel bars is leading to a structural deficiency3 Non-destructive Testing of Deteriorated Concrete Bridge PiersIn order to design a successful retrofit system, the condition of the existing bridge should be thoroughly evaluated. Evaluation of existing bridge elements or systems involves review of the asbuilt drawings, as well as accurate estimate of the condition of the existing bridge, as shown in Figure2. Depending on the purpose of evaluation, non-destructive tests may involve estimation of strength, salt contents, corrosion rates, alkalinity in concrete, etc.Figure2 Visible concrete distress marked on an elevation of a concrete bridge pier Although most of the non-destructive tests do not cause any damage to existing bridges, some NDT may cause minor local damage (e.g. drilled holes & coring) that should be repaired right after the NDT. These tests are also referred to as partial destructive tests but fall under non-destructive testing.In order to select the most appropriate non-destructive test for a particular case, thepurpose of the test should be identified. In general, there are three types of NDT to investigate: (1) strength, (2) other structural properties, and (3) quality and durability. The strength methods may include; compressive test (e.g. core test/rebound hammer/ ultrasonic pulse velocity), surface hardness test (e.g. rebound hammer), penetration test (e.g. Windsor probe), and pullout test (anchor test).Other structural test methods may include; concrete cover thickness (cover-meter), locating rebars (rebar locator), rebar size (some rebar locators/rebar data scan), concrete moisture (acquameter/moisture meter), cracking (visual test/impact echo/ultrasonic pulse velocity), delamination (hammer test/ ultrasonic pulse velocity/impact echo), flaws and internal cracking (ultrasonic pulse velocity/impact echo), dynamic modulus of elasticity (ultrasonic pulse velocity), Possion’s ratio (ultrasonic pulse velocity), thickness of concrete slab or wall (ultrasonic pulse velocity), CFRP debonding (hammer test/infrared thermographic technique), and stain on concrete surface (visual inspection).Quality and durability test methods may include; rebar corrosion rate –field test, chloride profile field test, rebar corrosion analysis, rebar resistivity test, alkali-silica reactivity field test, concrete alkalinity test (carbonation field test), concrete permeability (field test for permeability).4 Non-destructive Evaluation of Deteriorated Concrete Bridge PiersThe process of evaluating the structural condition of an existing concrete bridge consists of collecting information, e.g. drawings and construction & inspection records, analyzing NDT data, and structural analysis of the bridge. The evaluation process can be summarized as follows: (1) Planning for the assessment, (2) Preliminary assessment, which involves examination of available documents, site inspection, materials assessment, and preliminary analysis, (3) Preliminary evaluation, this involves: examination phase, and judgmental phase, and finally (4) the cost-impact study.If the information is insufficient to conduct evaluation to a specific required level, then a detailed evaluation may be conducted following similar steps for the above-mentioned preliminary assessment, but in-depth assessment. Successful analytical evaluation of an existing deteriorated concrete bridge should consider the actual condition of the bridge and level of deterioration of various elements. Factors, e.g. actual concrete strength, level of damage/deterioration, actual size of corroded rebars, loss of bond between steel and concrete, etc. should be modeled into a detailed analysis. If such detailed analysis is difficult to accomplish within a reasonable period of time, thenevaluation by field load testing of the actual bridge in question may be required.5 Bridge Rehabilitation with CFRP CompositesApplication of CFRP composite materials is becoming increasingly attractive to extend the service life of existing concrete bridges. The technology of strengthening existing bridges with externally bonded CFRP composites was developed primarily in Japan (FRP sheets), and Europe (laminates). The use of these materials for strengthening existing concrete bridges started in the 1980s, first as a substitute to bonded steel plates, and then as a substitute for steel jackets for seismic retrofit of bridge columns. CFRP Composite materials are composed of fiber reinforcement bonded together with a resin matrix. The fibers provide the composite with its unique structural properties. The resin matrix supports the fibers, protect them, and transfer the applied load to the fibers through shearing stresses. Most of the commercially available CFRP systems in the construction market consist of uniaxial fibers embedded in a resin matrix, typically epoxy. Carbon fibers have limited ultimate strain, which may limit the deformability of strengthened members. However, under traffic loads, local debonding between FRP sheets and concrete substrate would allow for acceptable level of global deformations before failure.CFRP composites could be used to increase the flexural and shear strength of bridge girders including pier cap beams, as shown in Figure3. In order to increase the ductility of CFRP strengthened concrete girders, the longitudinal CFRP composite sheets used for flexural strengthening should be anchored with transverse/diagonal CFRP anchors to prevent premature delamination of the longitudinal sheets due to localized debonding at the concrete surface-CFRP sheet interface. In order to prevent stress concentration and premature fracture of the CFRP sheets at the corners of concrete members, the corners should be rounded at 50mm (2.0 inch) radius, as shown in Figure3.Deterioration of concrete bridge members due to corrosion of steel bars usually leads in loss of steel section and delamination of concrete cover. As a result, such deterioration may lead to structural deficiency that requires immediate attention. Figure4 shows rehabilitation of structurally deficient concrete bridge pier using CFRP composites.Figure3 Flexural and shear strengthening of concrete bridge pier with FRP compositesFigure4 Rehabilitation of deteriorated concrete bridge pier with CFRP composites6 Summary and ConclusionsEvaluation, non-destructive testing and rehabilitation of deteriorated concrete bridges were presented. Deterioration of concrete bridge components due to corrosion may lead to structural deficiencies, e.g. flexural and/or shear failures. Application of CFRP composite materials is becoming increasingly attractive solution to extend the service life of existing concrete bridges. CFRP composites could be utilized for flexural and shear strengthening, as well as for restoration of deteriorated concrete bridge components. The CFRP composite sheets should be well detailed to prevent stress concentration and premature fracture or delamination. For successful rehabilitation of concrete bridges in corrosive environments, a corrosion protection system should be used along with the CFRP system.第十届东亚太结构工程设计与施工会议2006年8月3-5号，曼谷，泰国碳纤维复合材料修复混凝土桥梁结构的详述及应用Riyad S. ABOUTAHA1, and Nuttawat CHUTARAT2摘要：在各式各样的公路交通网络中，许多现有的古老桥梁，在各种恶劣的环境下，如更重的荷载和更快的车辆等条件下，依然在被使用着。
土木工程桥梁方向毕业设计外文及翻译
土木工程桥梁方向毕业设计外文及翻译(总13页)--本页仅作为文档封面，使用时请直接删除即可----内页可以根据需求调整合适字体及大小--学生姓名：学号：班级:专业：土木工程（桥梁方向）指导教师：2010 年 3 月What is traffic engineeringTraffic engineering is still a relatively new discipline within the overall bounds of civil engineering. it has nevertheless already been partially planning. the disciplines are not synonymous though. transportation planning is concerned with the planning, functional design, operation and management of facilities for any mode of transportation in order to provide for the safe, rapid, comfortable, convenient, economical and enviromenally-comparible movement of people and goods. within that broad scope, traffic engineering deals with those functions in respect of roads, road networks, terminal points , about lands and their relationships with other modes of transportation.Those definitions, based on the 1976 ones of the of transportation engineers are complete than, the British instituting of civil engineering which deals with traffic planning and design of roads, of frontage development and of parking facilities and with the control of traffic to provide safe, convenient and economical movement of vehicles and pedestrians.The definitions of the disicipline are becoming clearer: the methodology is developing continuously and becoming increasingly scientific. the early rule-of-thumb techniques are disappearing.Traffic problemThe discipline is young: the problem is large and still growing. in 1920 the total number of motor vehicles, licensed in great Britain was,650, year later the comparable figure was 14,950,000-a growth factor of 23 times. in recent years the rate of growth has slackened somewhat, but it is still considerable: 1955 6,466,0001960 9,439,0001965 12,938,0001970 14,950,0001974 17,247,000In order to see the problem in every day terms ,consider high street. anywhere. assuming that present trends continue, it is expected that within the next fifteen years of so the traffic on this road will increase by around forty to fifty persent. if this increased volume of traffic were to be accommodated at the same standard as today, the road might need to be widened by a similar forty to fifty percent-perhaps extra lane of traffic for the pedestrian to cross. In man cases, to accommodate the foreseeable future demand would destroy the character of the whole urban environment, and is clearly unacceptable.the traffic problem is of world-wide concern, but different countries are obviously at different stages in the traffic escalation-with America in the lead, while a county has few roads and a relatively low problem, as soon as the country is opened up by a road system, the standard of living and the demand for motor transport both rise, gathering momentum rapidly. eventually-and the stage at which this happens is open to considerable debate-the demand for cars, buses and lorries become satiated. the stage is known as saturation level.For comparison ,car ownership figures in different countries in 1970 were:India cars/personIsrael personJapan cars/personIreland cars/personNetherlands cars/personGreat Britain cars/personWest Germany cars/personAustralia cars/personUSA cars/personBut the growth in vehicle ownership is only part of the overall traffic problem. obviously,if a country has unlimited roads of extreme width, the traffic problem would not rise. no country in the world could meet this requirement: apart from anything else, it would not make economic for each vehicle using the roads. This figure is decreasing steadily.Three possible solutionsThe basic problem of traffic is therefore simple-an ever-increasing number of vehicles seeking to use too little roade space. the solution to the problem-is else a not-too-difficult choice from three possiblilities:build, sufficient roads of sufficient size to cope with the demand.Restrict the demand for roads by restricting the numbers of licensed vehicles.A compromise between (a) and (b) build some extra roads, using the and the existing road network to their full potential, and at the same time apply some restraint measures, limiting, the increase in demand as far as possible.With no visible end to the demand yet in sight, and 216 with modern road-making costs ranging around ￡1 million per kilometer cost of building roads in Britain to cope with an unrestricted demand would be far too great. added to this, such clossal use of space in a crowed island cannot be, seriously considered. in Los Angeles, a city built around the parking space for, the automobile. our citie are already largely built-and no one would consider ruining their character by pulling them down and rebuilding around the car, thus the first possible soluting is rule out.Even today,in an age of at least semi-affluence in most of the Western World, the car is still to some extent a status symbol, a symbol of family wants to own one, and takes steps saving or borrowing-to get one. as incomes and standards rise thesecond car becomes the target. any move to restrict the acquisition of the private car would be most unpopular-and politically unlikely.For many purpose the flexibility of the private car-conceptually affording door-to-door personal transport is ideal, and its use can be accommodate. for the mass, movement of people along specific corridors within a limited period of .. particularly the journey to work it may be less easily accommodated. other transport mode may be more efficient. some sort of compromise solution is the inevitable answer to the basic traffic problem .it is in the execution of the compromise solution that, traffic engineering comes into its own. traffic engineering ensures that any new facilities are not over-deigned and are correctly located to meet the demand. it ensures that the existing facilities are fully used, in the most efficient manner. the fulfillment of these duties may entail the selective throttling of demand: making the use of the car less attractive in the peak periods in order that the limited road space can be more efficiently used by public transport.Such restraint measures will often be accompanied by improvements in the public transport services, to accommodate the extra demand for them.Prestressed Concrete BridgesPrestressed concrete has been used extensively in . bridge construction since its first Introduction from Europe in the late 1940s. Literally thousands of highway bridges of both precast, prestressed concrete and cast-in-place post-tensioned concrete has been constructed in the United States. Railroad bridges utilizing prastressed concrete have become common as well. The use and evolution of prastressed concrete bridges is expected to continue in the years ahead.Short-span BridgesShort-span bridges will be assumed to have a maximum of 45 ft .It should be understood that this is an arbitrary figure, and there is no definite line of demarcation between short, moderate, and long spans in highway bridges. Short-span bridges are most efficiently made of precast ,prestressed-concrete hollow slabs, I-beams, solid slabs or cast-place solid slabs. and T-beams of relatively generous proportions.Precast solid slabs are most economical when used on very short spans. The slabs can be made in any convenient width,but widths of 3 or 4 ft to have been frequently are cast in the longitudinal sides of the precast units. After the slabs have been erected and the joints between the slabs have been filled with concrete, the keys transfer live load shear forces between the adjacent slabs.Precast hollow slabs used in short-span bridges may have round or square voids. They too are generally made in units 3 to 4 ft to m) wide with thicknesses from 18 to 27 in to . Precast hollow slabs can be made in any convenient width and depth, and frequently are used in bridges having spans from 20 to 50 ft to . Longitudinal shear keys are used in the joints between adjacent hollow slabs in the same way as with solid slabs. Hollow slabs may or may not be used with a composite, cast-in-place concrete topping an accecptable appearance and levelness.Transverse reinforcement normally is provided in precast concrete bridge superstructures for the purpose of tying the structure together in the transverse direction. Well-designed ties ensure that the individual longitudinal members forming the superstructure will act as a unit under the effects of the live load. In slab bridge construction, transverse ties most frequently consist of threaded steel bars placed through small holes formed transversely through the member during fabrication. Nuts frequently are used as fasteners at each end of the bars. In some instances, the transverse ties consist of post tensionedtendons placed, stressed, and grouted after the slabs have been erected. The transverse tie usually extends from one side of the bridge to the other.The shear forces imposed on the stringers in short-span bridges frequently are too large to be resisted by the concrete alone. Hence, shear reinforcement normally is required. The amount of shear reinforcement required may be relatively large if the webs of the stringers are relatively thin.Concrete diaphragms, reinforced with post-tensioned reinforcement or nonprestressed reinforcement, normally are provided transversely at the ends and at intermediate locations along the span in stringer-type bridges. The disaphragms ensure the lateral-distribution of the live load to the various stringers and prevent individual stringers from displacing or rotating significantly with respect to the adjacent stringers.No generalities will be made here about the relative cost of each of the above types of construction; construction costs are a function of many variables which prohibit meaningful generalizations. However, it should be noted that the stringer type of construction requires a considerably greater construction depth that is required for solid, hollow, or channel slab bridge superstructures. Stringer construction does not require a separate wearing surface, as do the precast slab types of construction, unless precast slabs are used to span between the stringers in lieu of the more commonly used cast-in-place reinforced concrete deck. Stringer construction frequently requires smaller quantities of superstructure materials than do slab bridges (unless the spans are very short). The construction time needed to complete a bridge after the precast members have been erected is greater with stringer framing than with the slab type of framing.Bridges Of Moderate SpanAgain for the purpose of this discussion only, moderate spans for bridges of prestressed concrete are defined as beingfrom 45 to 80 ft to . Prestressed concrete bridges in this span range generally can be divided into two types: stringer-type bridges and slab-type bridges. The majority of the precast prestressed concrete bridges constructed in the United States have been stringer bridges using I-shaped stringers, but a large number of precast prestressed concrete bridges have been constructed with precast hollow-box girders (sometimes also called stringers). Cast-in-place post-tensioned concrete has been used extensively in the construction of hollow-box girder bridges-a form of construction that can be considered to be a slab bridge.Stringer bridges, which employ a composite, cast-in-place deck slab, have been used in virtually all parts of the United States. These stringers normally are used at spacing s of about 5 to 6 ft to . The cast-in-place deck is generally from to in to in thickness. This type of framing is very much the same as that used on composite-stringer construction for short-span bridges.Diaphram details in moderate-span bridges are generally similar to those of the short spans, with the exception that two or three interior diaphragms sometime are used, rather than just one at midspan as in the short-span bridge.As in the case of short-span bridges, the minimum depth of construction in bridges of moderate span is obtained by using slab construction, which may be either solid – or hollow – box in cross section. Average construction depths are requires when stringers with large flanges are used in composite construction, and large construction depths are required when stringers with small bottom flanges are used. Composite construction may be developed through the use of cast-in-place concrete decks or with precast concrete decks. Lower quantities of materials normally are required with composite construction , and the dead weight of the superstructure normally is less for stringer construction than for slab construction.Long-Span BridgesPrestressed concrete bridges having spans of the order of 100ft are of the same general types of construction as structures having moderate span lengths, with the single exception that solid slabs are not used for long spans. The stringer spacings are frequently greater (with stringers at 7 to 9 ft) as the span lengths of bridges increase. Because of dead weight considerations, precast hollow-box construction generally is employed for spans of this length only when the depth of construction must be minimized. Cast-in-place post-tensioned hollow-box bridges with simple and continuous spans frequently are used for spans on the order of 100 ft and longer.Simple, precast, prestressed stringer construction would be economical in the United States in the spans up to 300 ft under some conditions. However, only limited use has been made of this type of construction on spans greater than 100 ft. For very long simple spans, the advantage of precasting frequently is nullified by the difficulties involved in handling, transporting, and erecing the girders, which may have depths as great as 10 ft and weigh over 200 tons. The exceptions to this occur on large projects where all of the spans are over water of sufficient depth and character that precast beams can be handled with floating equipment, when custom girder launchers can be used, and when segmental construction techniques can be used.The use of cast-in-place , post-tensioned, box-girder bridges has been extensive. Although structures of these types occasionally are used for spans less than 100ft, they more often are used for spans in excess of 100 ft and have been used in structuresHaving spans in excess of 300 ft. Structurally efficient in flexure, especially for continuous bridges, the box girder is torsionally stiff and hence an excellent type of structure for use on bridges that have horizontal curvature. Some governmental agencies use this form of construction almost exclusively in urban areas where appearance from underneath the superstructure,as well as from the side, is considered important.交通工程介绍什么是交通工程交通工程仍然是在土木工程的总的界限内的一种相对新的训练。
桥梁设计的历史 汉英互译
The history of bridge designModern bridges, the focus of this article, began with the introduction of industrially produced iron. They have evolved over the past 200 years as engineers have come to understand better the new possibilities inherent first in cast iron, then in wrought iron and structural steel, and finally in reinforced and prestressed concrete. These materials have led to bridge designs that have broken completely with the designs in wood or stone that characterized bridges before the Industrial Revolution.本文介绍的重点-现代桥梁,开始于工业用铁的引入。
过去200年的发展史，首先使工程师来更好地发掘了铸铁的内在潜力，然后是锻铁、钢结构,最后是钢筋和预应力混凝土。
这些材料的使用使现在桥梁的设计完全打破了工业革命之前用石头或木头建筑桥梁的传统。
Industrial strength has been an important factor in the evolution of bridges. Great Britain, the leading industrialized country of the early 19th century, built the most significant bridges of that time. Likewise, innovations arose in the United States from the late 19th century through the mid-20th century and in Japan and Germany in subsequent decades. Switzerland, with its highly industrialized society, has also been a fertile ground for advances in bridge building.工业实力是桥梁发展的一个重要因素。
桥梁毕业设计外文原文及翻译
外文文献翻译BRIDGE ENGINEERING AND AESTHETICSEvolvement of bridge Engineering,brief reviewAmong the early documented reviews of construction materials and structure types are the books of Marcus Vitruvios Pollio in the first century B.C.The basic principles of statics were developed by the Greeks , and were exemplified in works and applications by Leonardo da Vinci,Cardeno,and Galileo.In the fifteenth and sixteenth century, engineers seemed to be unaware of this record , and relied solely on experience and tradition for building bridges and aqueducts .The state of the art changed rapidly toward the end of the seventeenth century when Leibnitz, Newton, and Bernoulli introduced mathematical formulations. Published works by Lahire (1695)and Belidor (1792) about the theoretical analysis of structures provided the basis in the field of mechanics of materials .Kuzmanovic(1977) focuses on stone and wood as the first bridge-building materials. Iron was introduced during the transitional period from wood to steel .According to recent records , concrete was used in France as early as 1840 for a bridge 39 feet (12 m) long to span the Garoyne Canal at Grisoles, but reinforced concrete was not introduced in bridge construction until the beginning of this century . Prestressed concrete was first used in 1927.Stone bridges of the arch type (integrated superstructure and substructure) were constructed in Rome and other European cities in the middle ages . These arches were half-circular , with flat arches beginning to dominate bridge work during the Renaissance period. This concept was markedly improved at the end of the eighteenth century and found structurally adequate to accommodate future railroad loads . In terms of analysis and use of materials , stone bridges have not changed much ,but the theoretical treatment was improved by introducing the pressure-line concept in the early 1670s(Lahire, 1695) . The arch theory was documented in model tests where typical failure modes were considered (Frezier,1739).Culmann(1851) introduced the elastic center method for fixed-end arches, and showed that three redundant parameters can be found by the use of three equations of coMPatibility.Wooden trusses were used in bridges during the sixteenth century when Palladio built triangular frames for bridge spans 10 feet long . This effort also focused on the three basic principles og bridge design : convenience(serviceability) ,appearance , and endurance(strength) . several timber truss bridges were constructed in western Europe beginning in the 1750s with spans up to 200 feet (61m) supported on stone substructures .Significant progress was possible in the United States and Russia during the nineteenth century ,prompted by the need to cross major rivers and by an abundance of suitable timber . Favorable economic considerations included initial low cost and fast construction .The transition from wooden bridges to steel types probably did not begin until about 1840 ,although the first documented use of iron in bridges was the chain bridge built in 1734 across the Oder River in Prussia . The first truss completely made of iron was in 1840 in the United States , followed by England in 1845 , Germany in 1853 , and Russia in 1857 . In 1840 , the first iron arch truss bridge was built across the Erie Canal at Utica .The Impetus of AnalysisThe theory of structuresThe theory of structures ,developed mainly in the ninetheenth century,focused on truss analysis, with the first book on bridges written in 1811. The Warren triangular truss was introduced in 1846 ,supplemented by a method for calculating the correcet forces .I-beams fabricated from plates became popular in England and were used in short-span bridges.In 1866, Culmann explained the principles of cantilever truss bridges, and one year later the first cantilever bridge was built across the Main River in Hassfurt, Germany, with a center span of 425 feet (130m) . The first cantilever bridge in the United States was built in 1875 across the Kentucky River.A most impressive railway cantilever bridge in the nineteenth century was the First of Forth bridge , built between 1883 and 1893 , with span magnitudes of 1711 feet (521.5m). At about the same time , structural steel was introduced as a prime material in bridge work , although its quality was often poor . Several early examples are the Eads bridge in St.Louis ; the Brooklyn bridge in New York ; and the Glasgow bridge in Missouri , all completed between 1874 and 1883.Among the analytical and design progress to be mentioned are the contributions of Maxwell , particularly for certain statically indeterminate trusses ; the books by Cremona (1872) on graphical statics; the force method redefined by Mohr; and the works by Clapeyron who introduced the three-moment equations.The Impetus of New MaterialsSince the beginning of the twentieth century , concrete has taken its place as one of the most useful and important structural materials . Because of the coMParative ease with which it can be molded into any desired shape , its structural uses are almost unlimited . Wherever Portland cement and suitable aggregates are available , it can replace other materials for certain types of structures, such as bridge substructure and foundation elements .In addition , the introduction of reinforced concrete in multispan frames at the beginning of this century imposed new analytical requirements . Structures of a high order of redundancy could not be analyzed with the classical methods of the nineteenth century .The importance of joint rotation was already demonstrated by Manderla (1880) and Bendixen (1914) , who developed relationships between joint moments and angular rotations from which the unknown moments can be obtained ,the so called slope-deflection method .More simplifications in frame analysis were made possible by the work of Calisev (1923) , who used successive approximations to reduce the system of equations to one simple expression for each iteration step . This approach was further refined and integrated by Cross (1930) in what is known as the method of moment distribution .One of the most import important recent developments in the area of analytical procedures is the extension of design to cover the elastic-plastic range , also known as load factor or ultimate design. Plastic analysis was introduced with some practical observations by Tresca (1846) ; and was formulated by Saint-Venant (1870) , The concept of plasticity attracted researchers and engineers after World War Ⅰ, mainly in Germany , with the center of activity shifting to England and the United States after World War Ⅱ.The probabilistic approach is a new design concept that is expected to replace the classical deterministic methodology.A main step forward was the 1969 addition of the Federal Highway Adiministration (FHWA)”Criteria for Reinforced Concrete Bridge Members “ that covers strength and serviceability at ultimate design . This was prepared for use in conjunction with the 1969 American Association of State Highway Offficials (AASHO) Standard Specification, and was presented in a format that is readily adaptable to the development of ultimate design specifications .According to this document , the proportioning of reinforced concrete members ( including columns ) may be limited by various stages of behavior : elastic , cracked , andultimate . Design axial loads , or design shears . Structural capacity is the reaction phase , and all calculated modified strength values derived from theoretical strengths are the capacity values , such as moment capacity ,axial load capacity ,or shear capacity .At serviceability states , investigations may also be necessary for deflections , maximum crack width , and fatigue . Bridge TypesA notable bridge type is the suspension bridge , with the first example built in the United States in 1796. Problems of dynamic stability were investigated after the Tacoma bridge collapse , and this work led to significant theoretical contributions Steinman ( 1929 ) summarizes about 250 suspension bridges built throughout the world between 1741 and 1928 .With the introduction of the interstate system and the need to provide structures at grade separations , certain bridge types have taken a strong place in bridge practice. These include concrete superstructures (slab ,T-beams,concrete box girders ), steel beam and plate girders , steel box girders , composite construction , orthotropic plates , segmental construction , curved girders ,and cable-stayed bridges . Prefabricated members are given serious consideration , while interest in box sections remains strong .Bridge Appearance and AestheticsGrimm ( 1975 ) documents the first recorded legislative effort to control the appearance of the built environment . This occurred in 1647 when the Council of New Amsterdam appointed three officials . In 1954 , the Supreme Court of the United States held that it is within the power of the legislature to determine that communities should be attractive as well as healthy , spacious as well as clean , and balanced as well as patrolled . The Environmental Policy Act of 1969 directs all agencies of the federal government to identify and develop methods and procedures to ensure that presently unquantified environmental amentities and values are given appropriate consideration in decision making along with economic and technical aspects .Although in many civil engineering works aesthetics has been practiced almost intuitively , particularly in the past , bridge engineers have not ignored or neglected the aesthetic disciplines .Recent research on the subject appears to lead to a rationalized aesthetic design methodology (Grimm and Preiser , 1976 ) .Work has been done on the aesthetics of color ,light ,texture , shape , and proportions , as well as other perceptual modalities , and this direction is both theoretically and empirically oriented .Aesthetic control mechanisms are commonly integrated into the land-use regulations and design standards . In addition to concern for aesthetics at the state level , federal concern focuses also on the effects of man-constructed environment on human life , with guidelines and criteria directed toward improving quality and appearance in the design process . Good potential for the upgrading of aesthetic quality in bridge superstructures and substructures can be seen in the evaluation structure types aimed at improving overall appearance .LOADS AND LOADING GROUPSThe loads to be considered in the design of substructures and bridge foundations include loads and forces transmitted from the superstructure, and those acting directly on the substructure and foundation .AASHTO loads . Section 3 of AASHTO specifications summarizes the loads and forces to be considered in the design of bridges (superstructure and substructure ) . Briefly , these are dead load ,live load , iMPact or dynamic effect of live load , wind load , and other forces such as longitudinal forces , centrifugal force ,thermal forces , earth pressure , buoyancy , shrinkage andlong term creep , rib shortening , erection stresses , ice and current pressure , collision force , and earthquake stresses .Besides these conventional loads that are generally quantified , AASHTO also recognizes indirect load effects such as friction at expansion bearings and stresses associated with differential settlement of bridge components .The LRFD specifications divide loads into two distinct categories : permanent and transient .Permanent loadsDead Load : this includes the weight DC of all bridge components , appurtenances and utilities, wearing surface DW and future overlays , and earth fill EV. Both AASHTO and LRFD specifications give tables summarizing the unit weights of materials commonly used in bridge work .Transient LoadsVehicular Live Load (LL)Vehicle loading for short-span bridges :considerable effort has been made in the United States and Canada to develop a live load model that can represent the highway loading more realistically than the H or the HS AASHTO models . The current AASHTO model is still the applicable loading.桥梁工程和桥梁美学桥梁工程的发展概况早在公元前1世纪，Marcus Vitrucios Pollio 的著作中就有关于建筑材料和结构类型的记载和评述。
大跨度桥梁发展趋势(中英版)
向索结构发展方向To cable structure development特大跨桥梁采用以斜缆为主的空间网状承重体系或采用悬索加斜拉的混合体系。
Super-large bridge across the inclined cable to the space that give priority to mesh withsuspension cable bearing system or add the batter mix system采用流线型钢箱或采用轻型而刚度大的复合材料作为加劲梁。
The streamline steel box or use light and rigidity of composite materials as stiffening girder 采用自重小强度高的碳纤维材料做主缆。
The dead weight of the high strength carbon fiber materials small family cable斜拉桥在密索体系的基础上采用开口截面，减小梁的高跨比。
大跨度桥梁上部结构轻型化问In the system of the cable-stayed bridge dense based on the open section, and reduce the depth-span ratio of the trabecular meshwork large span bridge light-duty upper structure新型材料的开发应用For the development and application of new materials∙随着城市化的发展，建筑物的高层化和超高层化、大跨度桥梁等各种新型构筑物将不断出现，使用高性能混凝土是现代发展的必然趋势。
∙With the development of the city , more and more tall buildings , skyscrapers and large span bridges appear , so the need for highperformance concrete in the modern constructive become even popular新材料具有高强度，高弹性模量，轻质的特点。
大跨度桥梁的外文翻译
本科毕业设计外文翻译大跨度桥梁1．悬索桥悬索桥是现行的跨径超过600m大桥的唯一解决方案，而且对跨径在300m以上的桥梁它也是被认为是一种很有竞争力的方案。
现在世界上最大跨径的桥梁是纽约的威拉查诺（Verrazano）海峡大桥，另一个是英国的塞温（Savern）大桥。
悬索桥的组成部分有：柔性，主塔，锚碇，吊索（挂索），桥面板和加劲桁架。
主缆是有一组平行的单根高强钢丝在现场扭在一起并绑扎成型的钢丝束组成的。
每根钢丝都是经过渡锌处理的，并且整个用保护层覆盖着。
所用的钢丝应该是冷拔钢丝而不是经过热处理的各种钢丝。
在进行主塔设计时应该特别注意其在美学上的要求。
主塔很高而且具有足够的柔性，使其每一座塔顶都可认为是与主缆铰接。
主缆的两端很安全的锚固在非常坚实的锚碇上。
吊索把桥面板上的荷载传递到主主缆上。
吊索也是有高强钢丝制成的而且通常是竖直的。
桥面板通常是有加劲钢板，肋或槽型板，横梁制成的异性结构。
提供一些加劲梁连接在其主塔之间，能够起到控制空气动力运动并限制桥面板局部倾角变化。
如果加劲系统不适当，由于风引起的竖向振动也许会导致结构倾斜，就像塔科玛（Tacoma）海峡大桥的悲剧性的破坏所表明的那样。
边跨与主跨的跨径比的变化范围是0.17~0.50。
在现有的采用加劲梁的桥梁上，当跨径高大1000米时跨径与桥梁的建筑高度之比为85与100之间。
现有的桥梁的跨径与桥面板宽度之比约为20~56。
桥梁结构的空气动力稳定性必须得通过对其模型的风洞试验及细部分析进行全面的研究。
2．斜拉桥体系在过去的十年间，斜拉桥得以广泛的应用，尤其实在欧洲，而在世界其它地区，应用相对少一些。
在现代桥梁工程中，斜拉桥体系的重新兴旺起来是由于欧洲（主要是德国）的桥梁工程师有一种趋势，即从因为战争而短缺的材料上获得最佳的结构性能。
斜拉桥是有按各向异性桥面板和由吊索支撑的连续梁构成的体系建造起来的，这些吊索是一些穿过或固定的位于主桥墩的索塔顶上的倾斜主缆。
梁桥外文翻译
英文翻译:BEAMBRIDGEIn designing a bridge, preference is often given to beam structure, unless it has a very long span. Simple in structure, convenient to fabricate and erect, easy to maintain, and with less construction time and low cost, beam structure has found wide application in bridgework. In 1937, over the Qiantang River, in the city of Hangzhou, was erected a railway-highway bi-purpose bridge, with a total length of 1453m, the longest span being 67m. Whencompleted, it was a remarkable milestone of the beambridges designed and built by Chinese engineers themselves before liberation. Since 1949, this kind of bridge has made giant strides.Reinforced concrete beam structure is the most commonly used for short- and medium-span bridges. A representative masterpiece is the RongJiangBridge completed in 1964 in the city of Nanning, the provincial capital of Guangxi Zhuangzu Autonomous Region. The bridge, with a main span of 55m and its cross section of a thin-walled box with continuous cells, was designed in accordance with closedthin-walled membertheory, the first of its kind in China.Pre-stressed concrete girder bridges cover a wide range of spans and types. In the short span range, pre-cast AASHTO beams with a composite cast-in-place non pre-stressed concrete slab are frequently used for simple spans. A similar form of construction is used for partially continuous spans using I-girders and box girder in the medium span range .In the medium to long span range, continuous pre-cast segmental box girders are common, while the longest spans are generally cast-in-place segmental box girders.For cost-in-place construction, the girders and slab are generally formed together and both cast before formwork and supports are removed. This construction is fully composite for dead load and live load. The usual cross sections are T-beams and box girders. Spans are usually continuous, and transverse post-tensioning of the slab is frequently prescribed to allow the use of thinner slabs or a reduced number of longitudinal girders at a larger spacing. Since longitudinal post-tensioning is required on site, transverse post-tensioning is usually economical and normally used.The design and analysis items given for reinforced concrete girder bridges also apply to pre-stressed girder bridges. For the box girder section, a detailed transverse live load analysis of the section should be carried out. Temperature effects are important for box girder, due to the possibility of large differential temperatures between the top and bottom slabs.For cast-in-place segmental construction built by the balanced cantilever method, a knowledge of the exact construction loads is necessary, in order to calculate stresses and deformations at each stage. A knowledge of the creep characteristics of the concrete is essential for calculating deformations after the addition of each segment,and also to calculate the redistribution of moments after completion and final stressing.Standard pre-cast, pre-stressed beamscover spans up to the 140ft (43m) range. After the beamsare erected, forms for the slabs are placed between the beamsand a reinforced concrete slab cast in place. The slab and beams act compositely for superimposed dead load and live load. Intermediate diaphragms are not normally used , and the design and analysis items given for reinforced concrete girder bridges, also apply to pre-stressed multi-beam type bridges.Pre-cast pre-stressed beams can be made partially continuous for multi-span bridges. This system is not only structurally efficient, but has the advantage of reducing the number of deck joints. Support moments are developed due to superimposed dead load, live load, differential temperature, shrinkage and creep. Continuity for superimposed dead load and for live load can be achieved by casting diaphragms at the time the deck concrete is placed. Reinforced steel placed longitudinally in the deck slab across the intermediate pier will resist the tension from negative moment at the supports. At the diaphragms, the bottom flanges of adjacent beams should be connected to resist the tensile stress due to positive momentsgenerated by differential temperature, shrinkage and creep. Continuous spans , beyond the range of the type pre-cast girder, temporarily supported on bends, with joints near points of minimummoment, are post-tensioned for continuity after placement of the deck slab. The maximumlengths of segments are usually determined by shipping length and weight restriction.Pre-cast segmental construction employs single or multiple cell boxes with transverse segments post-tensioned together longitudinally. For medium sans, the segments may be erected for the full span on falsework before post-tensioning. Longer spans are usually erected by the balanced cantilever method, where each segment is successively stressed after erection. The design and analysis considerations given for cast-in-place segmental construction also apply to pre-cast segmental construction. The deformation of the structure during cantilever erection is dependent upon the time difference between segment pre-casting and erection. The design calculations mayneed to be repeated if the construction schedule differ from that assumed at the design stages.Pre-stressed con crete beam bridge is a new type of structure.Chi na bega n to makeresearches and develop its con struct ion in the fifties.In early 1956, a simply-supported prestressed con crete beam bridge with a main spa n of 23.9m -a railway bridge -was erected over the Xiny iRiver along the Longhai Railway line. Completed at the sametime, the first P.C. highway bridge was the Jin gzhouHighwayBridge. The Ion gest simply-supported P.C. beam which reaches 62m bel ongs to theFeiy un RiverBridge in Ruan'an, Zhejia ngPro vin ce, built in 1988. Ano ther example is the 4475.09mYellow RiverBridge, built in the city of Kaifeng, HenanProvince in 1989.77 of its spa ns are 50msimply-supported P.C. beams and its continuous deck extends to 450m. It is also noticeable that the bridge is designed on the basis of partially prestressed concrete theory.Elastic an alysis and beam theory are usually used in the desig n of segme ntalbox girder structures. For box girders of unu sual proporti on, other methods of an alysis which con sider shear lag should be used to determ ine the porti on of the cross secti on effective in resist ing Iongitudinal bending. Possible reserve shearing stress in the shear keysshould be investigated, particularly in segments near a pier. At time oferecti on, the shear stress carried by the key should not exceedThe prestressed concrete rigid T-frame bridge was primarily developed and built in China in the sixties. This kind of structure is most suitable to be erected by bala need can tilever con struct ion process, either by can tilever segme ntal con creti ng with suspe nded formwork, or by can tilevererecti on with segme nts of precast con crete. The first example of can tilever erect ion is the WeiRiverBridge (completed in 1964) in Wuli ng, Henan Provi nee, while the Liujia ngBridge (completed in 1967) in Liuzhou in Guan gxi Zhua ngzu Aut onom ous Regi on is the first by can tilever casti ng. Nevertheless, the Yan gtze RiverBridge at Chongqing (completed in 1980), hav ing a main spa n of 174m, is regarded as the largest of this kind at prese nt.On the basis of the desig n and con structi on of P.C. rigid T-frame bridges, was developed multi P.C. continuous beam and continuous rigid frame bridges, which can have Ion ger spa ns and offer better traffic con diti ons. Among the others, the LuoxiBridge in Guan gzhou, Guangdong Province (completed in 1988) features a180m main span. And the Huan gshiBridge cross ing the Yan gtze River in HubeiPro vin ce, which is still un der con struct ion, has a spa n of 245 meters. The represe ntive of P.C. continu ous girder railway bridge, the sec ond bridge over the QiantangRiver (finished in 1991), boasts its large span and its great len gth, its main spa n being 80m long and con tin uity over 18 spa ns. Its erecti on is an arduous task as the structure was subjected to a wave height of 1.96m and a tidal pressure of 32kPa whe n un der con struct ion. The exte nsive con struct ion of continu ous beam bridges has led to theapplication of incremental launching method especially to straight and plane curved bridges. Besides, large capacity (500t) floating crane installation and movable slip forms as well as span by span erection scheme have also attained remarkable advancement.In order to optimize the bridge configuration, to cut off the peak moment value at supports, and to diminish the constructional height, V-shaped or Y-shaped piers are developed for P.C. continuous beam, cantilever or rigid frame bridges. The prominent examples are the medium or the short Bridge (1981) in TaiwanProvince and the LijiangBridge (1987) at Zhishan in the city of Guilin.Steel structure is employed primarily for railway-highway bi-purpose bridges. The longest steel highway bridge is the BeizhenYellow RiverBridge in ShandongProvince (1972), its main span being 113m long. It has a rivet-connected continuous truss. The foundation is composedof f1.5m concrete boring piles, whose penetration depth into subsoil reaches 107m, the deepest pile ever drilled in our country. A new structure of field bolting welded box girder paved with orthotropic steel deck was first introduced in the North RiverHighwayBridge at Mafang, Guangdong Province, which was completedin 1980. In 1957, in the city of Wuhan, over the Yangtze River waserected arailway-highway bi-purpose superstructure, another milestone in China's bridge construction history. The bridge has a continuous steel truss with a 128mmain span. The rivet-connected truss is made of No. 3 steel. A newly developed cylinder shaft of 1.55m In diameter was initially used in the deep foundation. (Later in 1962, f5.8m cylinder shaft foundation was laid in the Ganijang South Bridge in Nanchang, Jiangxi Province.) In 1968, another wonder over the Yangtze River -the NanjingYangtze RiverBridge- cameinto being. The whole project, including its material, design and installation, was completed through the Chinese own efforts. It is a rivet-connected continuous truss with a 160m main span. The material used is high quality steel of 16 Mnq. In erection, deep water foundation was developed. Open caissons were submerged to a depth of 54.87m, and pretensioned concrete cylinder shafts 3.6m in diameter were laid, thus forming a newtype of compoundfoundation. And subwater cleaning was performed in a depth of 65m.Another attractive and gigantic structure standing over the Yangtze River is the JiujiangBridge completed in 1992. Chinese-made 15 MnVNqsteel was used andshop-welded steel plates 56mmthick were bolted on site. The main span reaches 216m. The continuous steel truss is enforced by flexible stiffening arch ribs. In laying the foundation, a double-walled sheet piling cofferdam was built, in which concrete bored pile cast-in-situ was set up. Whenerecting the steel beams, double suspended cable frame took the place of single one, which is another innovation.梁桥梁桥构造简单、施工方便、工期短、造价低、且维修容易，除特大跨度桥梁外，是设计中优先考虑的结构体系，应用甚广。
桥梁设计外文翻译文献
桥梁设计外文翻译文献(文档含中英文对照即英文原文和中文翻译) 原文：A Bridge For All CenturiesAn extremely long-and record setting-main span was designed for the second bridge to across the Panama Canal in order to meet the owner’s requirement that no piers be placed in the water.Because no disruption of canal traffic was permitted at any time,the cable-stayed bridge of cast-in-place cancrete was carefully constructed using the balanced-cantilever method.In 1962 ,the Bridge of Americas(Puente de las America) opened to traffic,serving as the only fixed link across the Panama Canal .The bridge was designed to carry 60,000 vehicles per day on four lanes, but it has beenoperating above its capacity for many years.Toalleviate bottlenecks on the route that the bridge carries over the canal-the Pan-AmericanHighway(Inter-American Highway)-and promotegrowth on the western side of Panama,the country’s Ministry of Public Works(Ministerio de Obras Publicas,or MOP )decided to build a new highway systerm linking the northern part of Panama City,on the eastern side of the canal, to the town of Arraijan,located on the western side of the canal.The Centennial Bridge –named to commemorate 100 years of Panamanian independence-has noe been constructed and, when opend, will carry six lanes of traffic. This cable-stayed bridge of cast-in-place cancrete features a main span of 420m,the longest such span for this type of bridge in the Western Hemisphere.In 200 the MOP invited international bridge design firms to compete for the design of the crossing, requesting a two-package proposal:one techinical, the other financial. A total of eight proposals were received by December 2000 from established bridge design firms all over the world. After short-listing three firms on the basis of the technical merits of their proposals, the MOP selected T.Y.Lin International, of San Francisco, to prepare the bridge design and provide field construction support based on the firm’s financial package.The Centennial Bridge desige process was unique and aggressive,incorporating concepts from the traditional design/build/bid method, the design/build method , and the sa-called fast-track design process.To complete the construction on time-that is ,within just 27 months-the design of the bridge was carried out to a level of 30 percent before construction bidding began, in December 2001.The selected contractor-the Wiesbaden,Germany,office of Bilfinger Berger,AG-was brought on board immediately after being selected by the MOP ,just as would be the case in a fast-track approach. The desige of the bridge was then completed in conjunction with construction , a process that id similan to desige/build.The design selected by the client features two single-mast towers,each supporting two sets of stay cables that align in one vertical plane.Concrete was used to construct both the towers and the box girder deck,as well as the approach structures.The MOP , in conjunction with the Panama Canal Authority,established the following requirements for the bridge design :A 420m,the minimum length for the main span to accommodate the recently widened Gaillard Cut,a narrow portion of the canal crossing the Continental Divide that was straightened and widened to 275m in 2002;A navigational envelope consisting of 80m of vertical clearance and 70mof horizontal clearance to accommodate the safe passage of a crane of World War 11 vintage-a gift from the ernment that is used by the Panama Canal Authority to maintain the canal gates and facilities;A roadway wide enough to carry six lanes of traffic, three in each direction;A deck able to accommodate a 1.5m wide pedestrian walkway;A design that would adhere to the American Association of State Highway and Transportation Official standard for a 100-year service life and offer HS-25 truck loading;A structure that could carry two 0.6m dianeter water lines;A construction method that would not cross the canal at any time or interrupt canal operationa in any way.Because of the bridge’s long main span and the potential for strong seismic activity in the area,no single building code covered all aspects of the project.Therefore the team from T.Y. Lin International determinded which portions of several standard bridge specifications were applicable and which were not.The following design codes were used in developing the design criteria for the bridge，it is standard specifications for highway bridge ,16th ed,1996It was paramount that the towers of the cable-stayed structucture be erected on land to avoid potential ship collision and the need to construct expensive deep foundation in water. However, geological maps and boring logs produced during the preliminary design phrase revealed that the east and west banks of the canal, where the towers were to be located, featured vastly different geologicaland soil conditions. On the east side of the canal, beneath shallow layers of overburden that rangs in consistency from soft to hard, lies a block of basalt ranging from medium hard to hard with very closely spaced joint.The engineers determined that the basalt would provide a competent platform for the construction of shallow foundation for tower, piers, and approach structures on this side of bridge.The west side, however,featured the infamous Cucaracha Formation, which is a heterogeneous conglomerate of clay shale with inclusions of sandstone, basalt,and ash that is prone to landslide. As a sudsurface stratum the Cucaracha Formation is quite stable,but it quickly erodes when exposed to the elements. The engineers determined that deep foundations would therefore be needed for the western approach structure,the west tower,and the western piers.Before a detailed design of the foundationa could be developed,a thorough analysis of the seismic hazards at the site was required,The design seismic load for the project was developed on the basis of a probabilistic seismic hazard assessment that considered the conditions at the site.Such an assessment establishes the return period for a given earthquake and the corresponding intensity of ground shaking in the horizontal directtion in terms of an acceleration response spectrum.The PSHA determined two dominant seismic sources: a subduction source zone associated with the North Panama Deformed Belt capable of producing a seimic event as strong as 7.7MW,and the Rio Gatun Fault, capable of producing an event as strong as 6.5MW.The 7.7MW NPDB event was used as the safety evluation earthquake,that is,the maximum earthquake that could strike without putting the bridge out of service.The damage to the bridge would be minor but would require some closures of the bridge.The 6.5MWRio Gatun Fault event was used as the foundational evaluation earthquake,a lower-level temblor that would cause minimal damage to the bridge and would not require closures.For the FEE load case,the SEE loading was scaled back by two-thirds.The FEE is assumed to have a peak acceleration of 0.21g and a return period of 500 years; the probability that it will be exceeded within 50 years is 10 pencent and within 100 years,18 persent.The SEE is assumed to have a peak acceleration of 1.33g and a return period of 2,500 years;the probability that it will be exceeded within 50 years is 2 pencent and within 100 years,4 persent.Because of uncertainty about the direction from which the seismic waves would approach the site, a single response spectrum-a curve showing the mathematically computed maximum response of a set of simple damped harmonic oscillators of different natural frequencies to a particular earthquake ground acceleration-was used to characterize mitions in two mutually orthogonal directions in the horizontal plane.To conduct a time-history analysis of the bridge’s multiple supports,a set of synthetic motions with three components-longitudinal,transverse,and vertical-was developd using an iterative technique.Recorded ground motions from an earthquake in Chile in 1985 were used as “seed”motions for the sythesis process.A time delay estimate-that is,an estimate of the time it would take for the motions generated by the SEEand FEE earthquakes to travel from one point to the next-was create using the assumed seismic wave velocity and the distance between the piers of the ing an assumed was velocity of approximately 2.5km/s,a delay on the order of half a second to a secondis appropriate for a bridge 1 to 2km long.Soil-foundation interaction studies were performed to determine the stiffness of the soil and foundation as well as the seismic excitation measurement that would be used in the dynamic analyses.The studieswere conducted by means of soil-pile models using linear and nonlinear soil layera of varying depths.The equivalent pile lengths in the studies-that is, the lengths representing the portions of a given pile that would actually be affected by a given earthquake-induced ground motion-ranged from2to10m.In such a three-dimensional model,there are six ways in which the soil can resist the movement of the lpile because of its stiffness:throngh axial force in the three directions and through bending moments in three directions.Because the bridge site contains so many layers of varying soil types,each layer had to be represented by a different stiffness matrix and then analyzed.Once the above analyses were completed,the T.Y.Lin International engineers-taking into consideration the project requirements developedby the owener-evaluated several different concrete cable-stayed designs.A number of structural systems were investigated,the main variables,superstructure cross sections,and the varying support conditions described above.The requirement that the evevation of the deck be quite high strongly influenced the tower configuration.For the proposed deck elevation of more than 80m,the most economical tower shapes included single-and dual-mast towers as well as “goal post”towers-that is,a design in which the two masts would be linked to each other by crossbeams.Ultimately the engineers designd the bridge to be 34.3m wide with a 420mlong cable-stayd main span,two 200mlong side spans-one on each side of the main span-and approach structures at the ends of the side spans.On the east side there is one 46m long concrete approach structure,while on the west side there are three,measuring 60,60,and 66m,for a total bridge length of 1,052m.The side spans are supported by four piers,referred to,from west to east,as P1.P2,P3,and P4.The bridge deck is a continuous single-cell box girder from abutment to abutment; the expansion joints are located at the abutments only. Deck movements on the order of 400 mm are expected at these modular expansion joints Multidirectional pot bearings are used at the piers and at the abutments to accommodate these movements.The deck was fixed to the two towers to facilitate the balanced-cantilevermethod of construction and to provide torsional rigidity and lateral restraint to the deck.. Transverse live loads, seismic loads, and wind loads are proportionally distributed to the towers and the piers by the fixity of the deck to the towers and by reinforced-concrete shear keys located at the top of P1, P3, and P4. The deck is allowed to move longitudinally over the abutments and piers. The longitudinal, seismic, live, and temperature loads are absorbed by what is known as portal frame structural behavior, whereby the towers and the deck form a portal-much like the frame of a door in a building-that acts in proportion to the relative stiffness of the two towers.As previously mentioned, the presence of competent basalt on the east side of the site meant that shallow foundations could be used there; in particular, spread footings were designed for the east tower, the east approach structure, and the east abutment. The west tower, the west approach structure, and the western piers (P2 and P3), however, had to be founded deep within the Cucaracha Formation. A total of 48 cast-in-drilled-hole (CIDH) shafts with 2 m outer diameters and lengths ranging from 25 to 35 m were required. A moment curvature analysis was performed to determine the capacity of the shafts with different amounts of longitudinal steel rebar. The results were plotted against the demands, and on the basis of the results the amount of required longitudinal reinforcing steel was determined to be 1 percent of the amount of concrete used in the shafts. The distribution of the longitudinal reinforcing steel was established by following code requirements, with consideration also given to the limitations of constructing CIDH piles with the contractor’s preferred method, which is the water or slurry displacement method.A minimum amount of transverse steel had to be determined for use in the plastic regions of the shaft-that is, those at the top one-eighth of eighth of each shaft and within the shaft caps, which would absorb the highest seismic demands. Once this amount was determined, it was used as the minimum for areas of the shafts above their points of fixity where large lateral displacements were expected to occur. The locations of the transverse steel were then established by following code requirements and by considering the construction limitations of CIDH piles. The transverse steel was spiral shaped.Even though thief foundation designs differed, the towers themselves were designed to be identical. Each measures 185.5 m from the top of its pile cap and is designed as a hollow reinforced-concrete shaft with a truncated elliptical cross section (see figure opposite). Each tower’s width in plan varies along its height, narrowing uniformly from 9.5 m at the base of the tower to 6 m at the top. In the longitudinal direction, each pylon tapers from 9.5 m at the base to about 8 m right below the deck level,which is about 87 m above the tower base. Above the deck level the tower’s sections vary from 4.6 m just above the deck to 4.5 m at the top. Each tower was designed with a 2 by 4 m opening for pedestrian passage along the deck, a design challenge requiring careful detailing.The towers were designed in a accordance with the latest provisions of the ATC earthquake design manual mentioned previously (ATC-32). Owing to the portal frame action along the bridge’s longitudinal axis, special seismic detailing was implemented in regions with the potential to develop plastic hinges in the event of seismic activity-specifically, just below the deck and above the footing. Special confining forces and alternating open stirrups-with 90 and 135 degree hooks-within the perimeter of the tower shaft.In the transverse direction, the tower behaves like a cantilever, requiring concrete-confining steel at its base. Special attention was needed at the joint between the tower and the deck because of the central-plane stay-cable arrangement, it was necessary to provide sufficient torsional stiffness and special detailing at the pier-to-deck intersection. This intersection is highly congested with vertical reinforcing steel, the closely spaced confining stirrups of the tower shaft, and the deck prestressing and reinforcement.The approach structures on either side of the main span are supported on hollow reinforced-concrete piers that measure 8.28 by 5 m in plan. The design and detailing of the piers are consistent with the latest versions of the ATC and AASHTO specifications for seismic design. Capacity design concepts were applied to the design of the piers. This approach required the use of seismic modeling with moment curvature elements to capture the inelastic behavior of elements during seismic excitation. Pushover analyses of the piers were performed to calculate the displacement capacity of the piers and to compare them with the deformations computed in the seismic time-history analyses. To ensure an adequate ductility of the piers-an essential feature of the capacity design approach-it was necessary to provide adequate concrete-confining steel at those locations within the pier bases where plastic hinges are expected to form.The deck of the cable-stayed main span is composed of single-cell box girders of cast-in-place concrete with internal, inclined steel struts and transverse posttensioned ribs, or stiffening beams, toward the tops. Each box girder segment is 4.5 m deep and 6 m long. To facilitate construction and enhance the bridge’s elegant design, similar sizes were used for the other bridge spans. An integral concrete overlay with a thickness of 350 mm was installed instead of an applied concrete overlayon the deck. In contrast to an applied overlay, the integral overlay was cast along with each segment during the deck erection. Diamond grinding equipment was used to obtain the desired surface profile and required smoothness. The minimum grinding depth was 5 mm.A total of 128 stay cables were used, the largest comprising 83 monostrands. All cables with a length of more than 80 m were equipped at their lower ends with internal hydraulic dampers. Corrosion protection for the monostrands involved galvanization of the wires through hot dipping, a tight high-density polyethylene (HDPE) sheath extruded onto each strand, and a special type of petroleum wax that fills all of the voids between the wires.The stays are spaecd every 6 m and are arranged in a fan pattern.They are designed to be stressed from the tower only and are anchored in line with a continuous stiffening beam at the centerline of the deck.The deck anchorage system is actually a composite steel frame that encapsulates two continous steel plates that anchor the stays and transfer the stay forces in a continuous and repetitive system-via shear studs-throuthout the extent of the cable-supported deck (see figure above).A steel frame was designed to transfer the stays’horizontal forces to the box girders through concrete-embedded longitudinal steel plates and to transfer the boxes’ vertical forces directly through the internal steel struts.This innovative and elegant load transfer system made rapid construction of the concrete deck segments-in cycles of three to five days-possible.In addition to the geotechnical and seismic analyses,several structural analyses were performed to accurately capture the behavior of this complex bridge.For the service-load analysis,which includes live,temperature,and wind loads,the engineers used SAP2000, a computer program created and maintained by Computers &Structrures,Inc.(CSI), of Berkeley, California.This program was selected for its ability to easily model the service loads and to account for tridimensional effects.For correct SAP2000 modeling, it was necessary to define a set of initial stresses on the cables, deck, and tower elements to capture the state of the structure at the end of construction.For the calculation of those initial stresses, a series of iterations on the basic model were performed to obtain the stay forces in the structure that balance both the bridges’s self-weight and the superimposed dead loads. Once the correct cable stiffness and stress distribution were obtained, all subsequent service-load analyses were performed to account for the geometric stiffness and P-deltaeffects, which consider the magnitude of an applied load (P) versus the displacement(delta).The seismic analysis of the structure was conducted using the SADSAP structural analysis program, also a CSI product, based on the differences in seismic motions that will be experienced at the different piers based on their distance from one another.This sophisticated program has the capability to model inelastic behavior in that flexural plastic hinges can readily be simulated.Plastic hinge elements were modeled at varous locations along the structure where the results from a preliminary response spectrum analysis in SAP2000 indicated that inelastic behavior might be expected.The time-history records pertaining to the site were used in conjunction with the SADSAP model to botain a performace-based design of the piers and towers and to verifh the design of several deck stctions.As previously mentioned,the construction contractor was brought on board early in the process;the company’s bid of $93 million was accepted and the project was awarded in March 2002.To guarantee unimpeded canal traffic,the bridge had to be constructed without the use of the canal waters.To accomplish this, the cast-in-place main-pain superstructure was erected using the balanced-cantilever method.Form travelers were used to accomplish this, and they were designed in such a way that they could be used as an integral part of the pier tables’falsework.After assembly on the ground, two 380 Mg form travelers were raised independently into the pier table casting position and connected to each other.After an initial learning period, the contractor was able to achieve a four-day cycle for the casting of the cantilevered deck segments, an achievement that greatly enhanced the ability of the team to construct the project on time.Once the side-span and mai-span closures were cast, the travelers had to be removed from locations adjacent to the towers rather than over water so as to avoid any influence on canal traffic.To save time, the towers approach structure, and piers were built simultaneously.The approach viaducts were designed and built using the span-by-span erection method by means of an underslung suupport truss.The east viaduct span was built first and the support truss was then removed and transferred to the west side so that it could be used to build the three spans of the west viaduct, one span at a time.The bridge construction was completeed in Auguse 2004 at a cost of approximately $2,780 per square meter.Its opening awaits the completion of the rest of the highway it serves.跨越世纪之桥1962年，横跨巴拿马运河的美国大桥作为仅有的固定连接开放交通车。
英文桥梁设计调查报告
英文桥梁设计调查报告原文With the continuous improvement of highway bridge technical level, large span bridge engineering increases year by year. In the process of highway bridge design, large span bridge is an important part of it, which is closely related to the use of highway bridge, so it is very important to ensure the design quality of highway bridge long span bridge. Therefore, in the design process of large-span bridge design, we should fully consider various factors, and seize the key points of large-span bridge design, and reasonably optimize the bridge structure, so as to ensure the safety of large-span bridge. 1. Design key points of long-span bridge design 1.1 Key design points of long-span cable-stayed bridge Large-span cable-stayed bridge has many advantages, including stability and strong carrying capacity, and has a strong crossing capacity. The large-span cable-stayed bridge is mainly composed of three parts, including the main beam, cable tower and cable cable. In the conceptual design process of the pull bridge, the designers combined these three parts into afloating system, semi-floating system, tower girder joint system and rigid structure system. In the design process of the bridge cable plane, the bridge cable plane can be designed into a single cable plane, vertical double cable plane, inclined double cable plane and spatial cable plane. The cable-stayed bridge has the characteristics of self-anchored, and most of the cable-stayed Bridges are self-anchored system. Only in special cases such as the main span is very large side span is very small, a few cable-stayed Bridges use partial anchor anchor system. In general, the large-span cable-stayed bridge structure should be applied in the construction of a river or canyon bridge between 200 and 800m.翻译随着公路桥梁技术水平的不断提升，大跨度桥梁工程逐年增加，在公路桥梁设计过程中，大跨度桥梁是其重要组成部分，与公路桥梁的使用息息相关，所以保证公路桥梁大跨度桥梁设计质量至关重要。
桥梁结构设计外文文献翻译
桥梁结构设计外文文献翻译(文档含中英文对照即英文原文和中文翻译)结构设计Augustine J.Fredrich摘要：结构设计是选择材料和构件类型，大小和形状以安全有用的样式承担荷载。
一般说来，结构设计暗指结构物如建筑物和桥或是可移动但有刚性外壳如船体和飞机框架的工厂稳定性。
设计的移动时彼此相连的设备（连接件），一般被安排在机械设计领域。
关键词：结构设计结构分析结构方案工程要求Abstract: Structure design is the selection of materials and member type ,size, and configuration to carry loads in a safe and serviceable fashion .In general ,structural design implies the engineering of stationary objects such as buildings and bridges ,or objects that maybe mobile but have a rigid shape such as ship hulls and aircraft frames. Devices with parts planned to move with relation to each other(linkages) are generally assigned to the area of mechanical .Key words: Structure Design Structural analysis structural scheme Project requirementsStructure DesignStructural design involved at least five distinct phases of work: project requirements, materials, structural scheme, analysis, and design.For unusual structures or materials a six phase, testing, should be included. These phases do not proceed in a rigid progression , since different materials can be most effective in different schemes , testing can result in change to a design , and a final design is often reached by starting with a rough estimated design , then looping through several cycles of analysis and redesign . Often, several alternative designs will prove quite close in cost, strength, and serviceability. The structural engineer, owner, or end user would then make a selection based on other considerations.Project requirements. Before starting design, the structural engineer must determine the criteria for acceptable performance. The loads or forces to be resisted must be provided. For specialized structures, this may be given directly, as when supporting a known piece of machinery, or a crane of known capacity. For conventional buildings, buildings codes adopted on a municipal, county , or , state level provide minimum design requirements for live loads (occupants and furnishings , snow on roofs , and so on ). The engineer will calculate dead loads (structural and known, permanent installations ) during the design process.For the structural to be serviceable or useful , deflections must also be kept within limits ,since it is possible for safe structural to be uncomfortable “bounce”Very tight deflection limits are set on supportsfor machinery , since beam sag can cause drive shafts to bend , bearing to burn out , parts to misalign , and overhead cranes to stall . Limitations of sag less than span /1000 ( 1/1000 of the beam length ) are not uncommon . In conventional buildings, beams supporting ceilings often have sag limits of span /360 to avoid plaster cracking, or span /240 to avoid occupant concern (keep visual perception limited ). Beam stiffness also affects floor “bounciness,”which can be annoying if not controlled. In addition , lateral deflection , sway , or drift of tall buildings is often held within approximately height /500 (1/500 of the building height ) to minimize the likelihood of motion discomfort in occupants of upper floors on windy days .Member size limitations often have a major effect on the structural design. For example, a certain type of bridge may be unacceptable because of insufficient under clearance for river traffic, or excessive height endangering aircraft. In building design, ceiling heights and floor-to-floor heights affect the choice of floor framing. Wall thicknesses and column sizes and spacing may also affect the serviceability of various framing schemes.Materials selection. Technological advances have created many novel materials such as carbon fiber and boron fiber-reinforced composites, which have excellent strength, stiffness, and strength-to-weight properties. However, because of the high cost anddifficult or unusual fabrication techniques required , they are used only in very limited and specialized applications . Glass-reinforced composites such as fiberglass are more common, but are limited to lightly loaded applications. The main materials used in structural design are more prosaic and include steel, aluminum, reinforced concrete, wood , and masonry .Structural schemes. In an actual structural, various forces are experienced by structural members , including tension , compression , flexure (bending ), shear ,and torsion (twist) . However, the structural scheme selected will influence which of these forces occurs most frequently, and this will influence the process of materials selection.Tension is the most efficient way to resist applied loads ,since the entire member cross section is acting to full capacity and bucking is not a concern . Any tension scheme must also included anchorages for the tension members . In a suspension bridge , for example ,the anchorages are usually massive dead weights at the ends of the main cables . To avoid undesirable changes in geometry under moving or varying loads , tension schemes also generally require stiffening beams or trusses.Compression is the next most efficient method for carrying loads . The full member cross section is used ,but must be designed to avoid bucking ,either by making the member stocky or by adding supplementary bracing . Domed and arched buildings ,arch bridges andcolumns in buildings frames are common schemes . Arches create lateral outward thrusts which must be resisted . This can be done by designing appropriate foundations or , where the arch occurs above the roadway or floor line , by using tension members along the roadway to tie the arch ends together ,keeping them from spreading . Compression members weaken drastically when loads are not applied along the member axis , so moving , variable , and unbalanced loads must be carefully considered.Schemes based on flexure are less efficient than tension and compression ,since the flexure or bending is resisted by one side of the member acting in tension while the other side acts in compression . Flexural schemes such as beams , girders , rigid frames , and moment (bending ) connected frames have advantages in requiring no external anchorages or thrust restrains other than normal foundations ,and inherent stiffness and resistance to moving ,variable , and unbalanced loads .Trusses are an interesting hybrid of the above schemes . They are designed to resist loads by spanning in the manner of a flexural member, but act to break up the load into a series of tension and compression forces which are resisted by individually designed tension and have excellent stiffness and resistance to moving and variable loads . Numerous member-to-member connections, supplementary compression braces ,and a somewhat cluttered appearance are truss disadvantages .Plates and shells include domes ,arched vaults ,saw tooth roofs ,hyperbolic paraboloids , and saddle shapes .Such schemes attempt to direct all force along the plane of the surface ,and act largely in shear . While potentially very efficient ,such schemes have very strict limitations on geometry and are poor in resisting point ,moving , and unbalanced loads perpendicular to the surface.Stressed-skin and monologue construction uses the skin between stiffening ribs ,spars ,or columns to resist shear or axial forces . Such design is common in airframes for planes and rockets, and in ship hulls . it has also been used to advantage in buildings. Such a design is practical only when the skin is a logical part of the design and is never to be altered or removed .For bridges , short spans are commonly girders in flexure . As spans increase and girder depth becomes unwieldy , trusses are often used ,as well as cablestayed schemes .Longer spans may use arches where foundation conditions ,under clearance ,or headroom requirements are favorable .The longest spans are handled exclusively by suspension schemes ,since these minimize the crucial dead weight and can be erected wire by wire .For buildings, short spans are handled by slabs in flexure .As spans increase, beams and girders in flexure are used . Longer spans require trusses ,especially in industrial buildings with possible hung loads . Domes ,arches , and cable-suspended and air –supported roofs can beused over convention halls and arenas to achieve clear areas .Structural analysis . Analysis of structures is required to ensure stability (static equilibrium ) ,find the member forces to be resisted ,and determine deflections . It requires that member configuration , approximate member sizes ,and elastic modulus ; linearity ; and curvature and plane sections . Various methods are used to complete the analysis .Final design .once a structural has been analyzed (by using geometry alone if the analysis is determinate , or geometry plus assumed member sizes and materials if indeterminate ), final design can proceed . Deflections and allowable stresses or ultimate strength must be checked against criteria provided either by the owner or by the governing building codes . Safety at working loads must be calculated . Several methods are available ,and the choice depends on the types of materials that will be used .Pure tension members are checked by dividing load by cross-section area .Local stresses at connections ,such as bolt holes or welds ,require special attention . Where axial tension is combined with bending moment ,the sum of stresses is compared to allowance levels . Allowable : stresses in compression members are dependent on the strength of material, elastic modulus ,member slenderness ,and length between bracing points . Stocky members are limited by materials strength ,while slender members are limited by elastic bucking .Design of beams can be checked by comparing a maximum bending stress to an allowable stress , which is generally controlled by the strength of the material, but may be limited if the compression side of the beam is not well braced against bucking .Design of beam-columns ,or compression members with bending moment ,must consider two items . First ,when a member is bowed due to an applied moment ,adding axial compression will cause the bow to increase .In effect ,the axial load has magnified the original moment .Second ,allowable stresses for columns and those for beams are often quite different .Members that are loaded perpendicular to their long axis, such as beams and beam-columns, also must carry shear. Shear stresses will occur in a direction to oppose the applied load and also at right angles to it to tie the various elements of the beam together. They are compared to an allowable shear stress. These procedures can also be used to design trusses, which are assemblies of tension and compression members. Lastly, deflections are checked against the project criteria using final member sizes.Once a satisfactory scheme has been analyzed and designed to be within project criteria, the information must be presented for fabrication and construction. This is commonly done through drawings, which indicate all basic dimensions, materials, member sizes, the anticipatedloads used in design, and anticipated forces to be carried through connections.结构设计结构设计包含至少5个不同方面的工作：工程要求，材料，结构方案，分析和设计。
桥梁工程英语词汇
结构控制structural controlstructure control结构控制: structural control結構控制: structural control结构控制剂: constitution controller裂缝宽度容许值裂缝宽度容许值: allowable value of crack width装配式预制装配式预制: precast装配式预制的: precast-segmental装配式预制混凝土环: precast concrete segmental ring安装预应力安装预应力: prestressed最优化optimization最优化: Optimum Theory|optimization|ALARA 使最优化: optimized次最优化: suboptimization空心板梁空心板梁: hollow slab beam主梁截面主梁截面: girder section边、中跨径边、中跨径: side span &middle spin主梁girder主梁: girder|main beam|king post 桥主梁: bridge girder主梁翼: main spar单墩单墩: single pier单墩尾水管: single-pier draught tube单墩肘形尾水管: one-pier elbow draught tube结构优化设计结构优化设计: optimal structure designing扩结构优化设计: Optimal Struc ture Designing 液压机结构优化设计软件包: HYSOP连续多跨多跨连续梁: continuous beam on many supports拼接板splice barsplice plate拼接板: splice bar|scab|splice plate 端头拼接板: end matched lumber销钉拼接板: pin splice裂缝crack crevice跨越to step acrossstep over跨越: stride leap|across|spanning跨越杆: cross-over pole|crossingpole 跨越点: crossing point|crossover point刚构桥rigid frame bridge刚构桥: rigid frame bridge形刚构桥: T-shaped rigid frame bridge连续刚构桥: continuous rigid frame bridge刚度比stiffness ratioratio of rigidity刚度比: ratio of rigidity|stiffness ratio 动刚度比: dynamic stiffenss ratio刚度比劲度比: stiffnessratio等截面粱uniform beam等截面粱: uniform beam|uniform cross-section beam桥梁工程bridge constructionbridgework桥梁工程: bridgeworks|LUSAS FEA|Bridge Engineering 桥梁工程师: Bridge SE铁路桥梁工程: railway bridge engineering悬索桥suspension bridge悬索桥: suspension bridge|su e io ridge 懸索橋: Suspension bridge|Puente colgante 加劲悬索桥: stiffenedsuspensionbridge预应力混凝土prestressed concrete预应力混凝土: prestressed concrete|prestre edconcrete 预应力混凝土梁: prestressed concrete beam预应力混凝土管: prestressed concrete pipe预应力钢筋束预应力钢筋束: pre-stressing tendon|pre-stre ingtendon 抛物线型钢丝束(预应力配钢筋结构用): parabolic cable最小配筋率minimum steel ratio轴向拉力axial tensionaxial tensile force轴向拉力: axial tension|axial te ion 轴向拉力, 轴向拉伸: axial tension轴向拉力轴向张力: axialtensileforce承台cushion cap承台: bearing platform|cushioncap|pile caps 桩承台: pile cap|platformonpiles低桩承台: low pile cap拱桥arch bridge拱桥: hump bridge|arch bridge|arched bridge 拱橋: Arch bridge|Puente en arco|Pont en arc 鸠拱桥: Khājū强度intensitystrength强度: intensity|Strength|Density刚强度: stiffness|stiffne|westbank stiffness 光强度: light intensity|intensity箍筋hooping箍筋: stirrup|reinforcement stirrup|hooping 箍筋柱: tied column|hooped column形箍筋: u stirrup u预应力元件预应力元件: prestressed element等效荷载equivalent load等效荷载: equivalent load等效荷载原理: principle of equivalent loads 等效负载等效荷载等值负载: equivalentload模型matrix model mould pattern承载能力极限状态承载能力极限状态: ultimate limit states正常使用极限状态serviceability limit state正常使用极限状态: serviceability limit state正常使用极限状态验证: verification of serviceability limit states弹性elasticityspringinessspringgiveflexibility弹性: elasticity|Flexibility|stretch 彈性: Elastic|Elasticidad|弾性弹性体: elastomer|elastic body|SPUA平截面假定plane cross-section assumption平截面假定: plane cross-section assumption抗拉强度intensity of tension tensile strength安全系数safety factor标准值standard value标准值: standard value,|reference value作用标准值: characteristic value of an action 重力标准值: gravity standard设计值value of calculationdesign value设计值: design value|value|designed value 作用设计值: design value of an action荷载设计值: design value of a load可靠度confidence levelreliabilityfiduciary level可靠度: Reliability|degree of reliability 不可靠度: Unreliability高可靠度: High Reliability几何特征geometrical characteristic几何特征: geometrical characteristic配位几何特征: coordinated geometric feature 流域几何特征: basin geometric characteristics塑性plastic nature plasticity应力图stress diagram应力图: stress diagram|stress pattern 谷式应力图: Cremona's method机身应力图: fuselage stress diagram压应力crushing stress压应力: compressive stress|compression stress 抗压应力: compressive stress|pressure load内压应力: internal pressure stress配筋率ratio of reinforcement reinforcement ratioreinforcement percentage配筋率: reinforcement ratio平均配筋率: balanced steel ratio纵向配筋率: longitudinal steel ratio有限元分析finite element analysis有限元分析: FEA|finite element analysis (FEA)|ABAQUS 反有限元分析: inverse finite element analysis有限元分析软件: HKS ABAQUS|MSC/NASTRAN MSC/NASTRAN有限元法finite element method有限元法: FInite Element|finite element method 积有限元法: CVFEM线性有限元法: Linear Finite Element Method裂缝控制裂缝控制: crack control控制裂缝钢筋: crack-control reinforcement检查，核对，抑制，控制，试验，裂缝，支票，账单，牌号，名牌: check应力集中stress concentration应力集中: stress concentration应力集中点: hard spot|focal point of stress 应力集中器: stress concentrators主拉应力principal tensile stress主拉应力: principal tensile stress非线性nonlinearity非线性振动nonlinear oscillationsnonlinear vibration非线性振动: nonlinear vibration非线性振动理论: theory of non linear vibration 非线性随机振动: Nonlinear random vibration弯矩flexural momentment of flexion (moment of flexure) bending momentflexural torque弯矩: bending moment|flexural moment|kN-m 弯矩图: bending moment diagram|moment curve 双弯矩: bimoment弯矩中心center of momentsmoment center弯矩中心: center of moments|momentcenter弯矩分配法moment distributionmomentdistribution弯矩分配法: hardy cross method|cross method弯矩图bending moment diagrammoment curvemoment diagram弯矩图: bending moment diagram|moment curve 最终弯矩图: final bending moment diagram最大弯矩图: maximum bending moment diagram剪力shearing force剪力: shearing force|shear force|shear剪力墙: shear wall|shearing wall|shear panel 剪力钉: shear nails|SHEAR CONCRETE STUD弹性模量elasticity modulus young's modulus elastic modulus modulus of elasticity elastic ratio剪力图shear diagram剪力图: shear diagram|shearing force diagram剪力和弯矩图: Shear and Moment Diagrams绘制剪力和弯矩图的图解法: Graphical Method for Constructing Shear and Moment Diagrams剪力墙shear wall剪力墙: shear wall|shearing wall|shear panel 抗剪力墙: shearwall剪力墙结构: shear wall structure轴力轴力: shaft force|axial force螺栓轴力测试仪: Bolt shaft force tester 轴向力: axial force|normal force|beam框架结构frame construction等参单元等参数单元等参元: isoparametricelement板单元板单元: plate unit托板单元: pallet unit骨板骨单元: lamella/lamellaeosteon梁(surname) beam of roof bridge桥梁bridge曲率curvature材料力学mechanics of materials结构力学structural mechanics结构力学: Structural Mechanics|theory of structures 重结构力学: barodynamics船舶结构力学: Structual Mechamics for Ships弯曲刚度flexural rigiditybending rigidity弯曲刚度: bending stiffness|flexural rigidity 截面弯曲刚度: flexural rigidity of section弯曲刚度，抗弯劲度: bending stiffness钢管混凝土结构encased structures钢管混凝土结构: encased structures极限荷载ultimate load极限荷载: ultimate load极限荷载设计: limit load design|ultimate load design 设计极限荷载: designlimitloadDLL|design ultimate load极限荷载设计limit load designultimate load analysisultimate load design极限荷载设计: limit load design|ultimate load design 设计极限荷载: designlimitloadDLL|design ultimate load板壳力学mechanics of board shell板壳力学: Plate Mechanics板壳非线性力学: Nonlinear Mechanics of Plate and Shell本构模型本构模型: constitutive model体积本构模型: bulk constitutive equation 本构模型屈服面: yield surface主钢筋main reinforcing steelmain reinforcement主钢筋: main reinforcement|Main Reinforcing Steel 钢筋混凝土的主钢筋: mainbar悬臂梁socle beam悬臂梁: cantilever beam|cantilever|outrigger 悬臂梁长: length of cantilever双悬臂梁: TDCB悬链线catenary悬链线: Catenary,|catenary wire|chainette 伪悬链线: pseudocatenary悬链线长: catenary length加劲肋ribbed stiffener加劲肋: stiffening rib|stiffener|ribbed stiffener 短加劲肋: short stiffener支承加劲肋: bearing stiffener技术标准technology standard水文水文: Hydrology水文学: hydrology|hydroaraphy|すいもんがく水文图: hydrograph|hydrological maps招标invite public bidding投标(v) submit a bid bid for连续梁through beam连续梁: continuous beam|through beam多跨连续梁: continuous beam on many supports 悬臂连续梁: gerber beam加劲梁stiff girder加劲梁: stiffening girder|buttress brace 加劲梁节点: stiff girder connection支撑刚性梁，加劲梁，横撑: buttress brace水文学hydrology水文学: hydrology|hydroaraphy|すいもんがく水文學: Hydrologie|水文学|??? ??????古水文学: paleohydrology桥梁抗震桥梁抗震加固: bridge aseismatic strengthening抗风wind resistance抗风: Withstand Wind|Wtstan Wn|wind resistance 抗风锚: weather anchor抗风性: wind resistance基础的basal桥梁控制测量bridge construction control survey桥梁控制测量: bridge construction control survey桥梁施工桥梁施工控制综合程序系统: FWD桥梁最佳施工指南: Bridge Best Practice Guidelines桥梁工程施工技术咨询: Bridge Construction Engineering Service总体设计overall designintegrated design总体设计: Global|overall design|general arrangement 总体设计概念: totaldesignconcept工厂总体设计图: general layout scheme初步设计predesign preliminary plan技术设计technical design技术设计: technical design|technical project 技术设计员: Technical Designer|technician技术设计图: technical drawing施工图设计construction documents design施工图设计: construction documents design施工图设计阶段: construction documents design phase基本建设项目施工图设计: design of working drawing of a capital construction project桥台abutment bridge abutment基础foundation basebasis结构形式structural style结构形式: Type of construction|form of structure 表结构形式: list structure form屋顶结构形式: roof form地震earthquake地震活动earthquake activityseismic activityseismic motionseismicity地震活动: Seismic activity|seismic motion 地震活动性: seismicity|seismic地震活动图: seismicity map支撑体系支撑体系: bracing system|support system 物流企业安全平台支撑体系: SSOSP公路桥涵公路施工手册-桥涵: Optimization of Road Traffic Organization-Abstract引道approach roadramp wayapproach引道: approach|approach road引道坡: approach ramp|a roachramp 引道版: Approach slab装配式装配式桥: fabricated bridge|precast bridge 装配式房屋: Prefabricated buildings装配式钢体: fabricated steel body耐久性wear耐久性: durability|permanence|endurance不耐久性: fugitiveness耐久性试验: endurance test|life test|durability test持久状况持久状况: persistent situation 短暂状况短暂状况: transient situation 偶然状况偶然状况: accidental situation永久作用永久作用: permanent action永久作用标准值: characteristic value of permanent action可变作用可变作用: variable action可变作用标准值: characteristic value of variable action 可变光阑作用: iris action偶然作用偶然作用: accidental action偶然同化（作用）: accidental assimilation作用效应偶然组合: accidental combination for action effects作用代表值作用代表值: representative value of an action作用标准值作用标准值: characteristic value of an action地震作用标准值: characteristic value of earthquake action 可变作用标准值: characteristic value of variable action作用频遇值作用频遇值 Frequent value of an action安全等级safe class安全等级: safety class|Security Level|safeclass 生物安全等级: Biosafety Level生物安全等級: Biosafety Level作用actionactivity actionsactseffectto play a role设计基准期design reference period设计基准期: design reference period作用准永久值作用准永久值: quasi－permanentvalueofanaction作用效应作用效应: effects of actions|effect of an action 互作用效应: interaction effect质量作用效应: mass action effect作用效应设计值作用效应设计值 Design value of an action effect分项系数分项系数: partial safety factor|partial factor作用分项系数: partial safety factor for action抗力分项系数: partial safety factor for resistance作用效应组合作用效应组合: combination for action effects作用效应基本组合: fundamental combination for action effects 作用效应偶然组合: accidental combination for action effects结构重要性系数结构重要性系数Coefficient for importance of a structure桥涵桥涵跟桥梁比较类似，主要区别在于:单孔跨径小于5m或多孔跨径之和小于8m的为桥涵,大于这个标准的为桥梁公路等级公路等级: highway classification标准:公路等级代码: Code for highway classification标准:公路路面等级与面层类型代码: Code for classification and type of highway pavement顺流fair current设计洪水频率设计洪水频率: designed flood frequency水力water powerwater conservancyirrigation works水力: hydraulic power|water power|water stress水力学: Hydraulics|hydromechanics|fluid mechanics 水力的: hydraulic|hydrodynamic|hyd河槽river channel河槽: stream channel|river channel|gutter 古河槽: old channel河槽线: channel axis河岸riversidestrand河岸: bank|riverside|river bank 河岸林: riparian forest河岸权: riparian right河岸侵蚀stream bank erosion河岸侵蚀: bank erosion|stream bank erosion 河岸侵蚀河岸侵食: bank erosion河岸侵蚀, 堤岸冲刷: bank erosion高架桥桥墩高架桥桥墩: viaduct pier桥梁净空高潮时桥梁净空高度: bridge clearance行车道lane行车道: carriageway|traffic lane|Through Lane 快行车道: fast lane西行车道: westbound carriageway一级公路A roadarterial roadarterial highway一级公路: A road arterial road arterial highway 一级公路网: primaryhighwaysystem二级公路b roadsecondary road二级公路: B road, secondary road涵洞culvert涵洞: culvert梁涵洞: Beam Culverts 木涵洞: timber culvert河床riverbedrunway河床: river bed|bed|stream bed冰河床: glacier bed型河床: oxbow|horseshoe bend|meander loop河滩flood plainriver beach河滩: river shoal|beach|river flat 河滩地: flood land|overflow land 河滩区: riffle area高级公路high-type highway高级公路: high-typehighway高架桥trestleviaduct高架桥: viaduct|overhead viaduct 高架橋: Viadukt|Viaducto|高架橋高架桥面: elevated deck洪水流量volume of floodflood dischargeflooddischarge洪水流量: flood discharge|flood flow|peak discharge 洪水流量预报: flooddischargeforecast平均年洪水流量: average annual flood设计速度design speed设计速度: design speed|designed speed|design rate设计速度，构造速度: desin speed|desin speed <haha最大阵风强度的设计速度: VB Design Speed for Maximum Gust Intension跨度span紧急停车emergency shutdown (cut-off)emergency cut-off紧急停车: abort|panic stop|emergency stop 紧急停车带: lay-by|emergency parking strip 紧急停车阀: emergency stop valve减速gear downretardment speed-down deceleration slowdown车道traffic lane路缘带side tripmarginal stripmargin verge路缘带: marginal strip|side strip|margin verge路肩shoulder of earth body路肩: shoulder|verge|shoulder of road 硬路肩: hard shoulder|hardened verge 软路肩: Soft Shoulder最小值minimum value最小值: minimum|Min|least value 求最小值: minimization找出最小值: min最大值max.最大值原理principle of the maximummaximum principlemaximal principle最大值原理: maximum principle,|maximal principle 离散最大值原理: discrete maximum principle极大值原理，最大值原理: maximum principle车道宽度车道宽度: lane-width自行车道cycle-track自行车道: bicycle path|cycle path|cycle track旗津环岛海景观光自行车道: Cijin Oceanview Bike Path 自行车道专供自行车行驶的车道。
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Long and light——《Bridge design & engineering》Closure of the main span on the SundoyaBridge in Norway is expected to take place in the first week after Easter. This graceful crossing, the second longest of its type in the world, is being built in situ using high performance concreteSundoyaBridge is situated in one of Norway's most scenic areas, only 100km south of the Arctic Circle. The 538m-long bridge spans Sundet, and when it is complete will provide a ferry-free road connection between Sundoya and the mainland. It is located some 35km west of the city of Mosjoen, close to highway 78 between Mosjoen and Sandnessjoen.It will be the second large bridge project connecting Alstenoya to the mainland, coming more than 12 years after the HelgelandBridge was opened. The region is no stranger to world-record scale bridges ?the Helgeland Bridge's 425m long main span was the longest cable-stayed span in the world when it opened in 1992.SundoyaBridge is divided into three spans; it has a main span of 298m and two side spans of 120m. The main span will be the second longest span in the world for a continuous post-tensioned cast in place box section concrete bridge.In terms of its design, consultant Dr Ing Aas-Jakobsen has followed a similar approach to that taken for the RaftsundetBridge, opened in 1998, to which the SundoyaBridge will almost be a twin. The two bridges have identical main spans, but Raftsundet has four spans as opposed to Sundoya's three. Contractor AS Anlegg, which is part of the joint venture building Sundoya, was also the contractor on the RaftsundetBridge, and architect Boarch Arkitekter has also worked on the two schemes.In January 2001 the joint venture company AF Sundoybrua won the contract from client Statens Vegvesen to build the SundoyaBridge. This joint venture consisted of the contractors Reinertsen Anlegg and NCC Construction.High performance concrete is central to the design of the bridge ?both normal weight HPC and lightweight HPC. Normal weight concrete, at approximately 2500kg/m3, is used for the 120m side spans, while lightweight concrete, which weighs in at about 1970kg/m3, is used for construction of the 298m main span. This enables construction to proceed using the balanced cantilever method.Local rock from Norway is used as the aggregate for the normal weight concrete, but the lightweight concrete required an imported solution. Normally the aggregate used for lightweight concrete in Europe is expanded clay or shale, but this material has high levels of absorption and for this reason, regulations prevent such concrete from being pumped.In order to address this, the contractor adopted a similar solution to that used on RaftsundetBridge ?importing Stalite aggregate from South Carolina in the USA. Stalite is produced through thermal expansion of high quality slate, and results in a lightweight aggregate that gives concrete of very high strength at low unit weights. Its low absorption of approximately 6% and high particle strength are two of the factors that allow Stalite to achieve high strength concrete in excess of 82.7MPa, the manufacturer says. The bondand compatibility of the aggregate with cement paste reduce micro-cracking and enhance durability, and its low absorption makes it easy to mix and pump.According to AF Sundoybrua quality manager Jan-Eirik Nilsskog, this material has given a very good result. It produces concrete that is easy to pour into the formwork and it gives a good surface finish, he says. It is being pumped some 120m along the bridge deck to the concreting position. Concrete is produced by a transportable mobile plant located only 1km from the bridge site. Constant monitoring of the concrete weight is necessary to ensure that the cantilevers are properly balanced. This is tested for each pour.The project began in January 2001 at Aker Verdal with the production of caissons for the pier bases. In May 2001 the two caissons were towed 500km north to the bridge site.The bridge is being poured in situ using special mobile construction equipment developed by NRS. The cycle for construction of each 5m wide bridge segment is a week, and two mobile units are being used on the SundoyaBridge. These particular units were built for AS Anlegg to use on the VaroddenBridge in Kristiansand in Norway, and they have also been used by the same contractor on the RafsundetBridge. The design of the central part of the main span of the bridge is based on the use of lightweight concrete LC60 while other parts of the structure use the more standard type C65. Because of the aggressive marine environment, the quality of the concrete must be particularly good.The structure is a single cell, prestressed rectangular box girder, largely built using the travelling formwork system from NRS. The box width is 7m and its depth varies from 3m at the centre of the span to 14.5m over the piers. Close to the abutments, concrete of quality C25 will be used inside the box girder as ballast. In addition, the designers have included the necessary elements inside the box girder in order to allow the possible addition of post-tensioning cables in the future. The long-term behaviour of such large spans is not fully known, so the possibility that the main span may sag over time has to be taken into account. The width of the road is a constant 7.5m from the barrier on one side to that on the other, and the total width of the bridge is some 10.3m. There is a 2m wide footway included in the width of the structure.The pier shaft is formed with twin legs, which are hollow inside. The pier shafts incorporate permanent prestressing cables and they have a constant wall thickness and a width that varies parabolically over their height.Temporary tie-down piers are used to construct the bridge - they are located 35m into each 120m-long side span from the main piers. Each consists of an I-shaped shaft, which is tied down to the ground using rock anchors and connected to the box girder by means of prestressing cables. The purpose of these structural elements is to support the cantilever and prevent rotation in strong winds. Once the bridge superstructure is complete and the main pier prestressing is fully tensioned, the temporary tie-down pierswill be removed piece by piece.The location of the bridge, only about 100km south of the Arctic Circle, has meant that special measures have to be introduced to allow construction work to continue all year round. Apart from the obvious need to provide site lighting for much of the wintertime, the challenge of concreting in temperatures which can be as low as 0 C has to be overcome. Hot concrete is produced for the bridge ?sometimes up to 30 C and the formwork has to be insulated to keep the concrete warm. Electric heating cables are also used on the end of the previous pour to warm up the concrete before casting.Construction of the new bridge began in January 2000 and is expected to be complete in September this year. The construction of the cantilever started in summer last year and is due to be finished in April. When Bd&e went to press, the project was on schedule for opening to traffic in late autumn.Project TeamClient: Statens VegvesenContractor: AF Sundoybrua (AS Anlegg, NCC Construction)Consultant: Dr Ing Aas-JakobsenArchitect: Boarch Arkitekter超轻大跨度桥——Sundoya挪威的在Sundoya 桥上的主跨有望在复活节的后第一个星期望合龙. 它是一座大跨度的，在世界的它的同类型中第二长,建造在situ 的长大桥。