外文翻譯--日本鋼結(jié)構(gòu)橋梁目前現(xiàn)狀和發(fā)展前景(英文）

1、Journal of Constructional Steel Research 62 (2006) 1192–1198www.elsevier.com/locate/jcsrConsiderations on recent trends in, and future prospects of, steel bridge construction in JapanToshiyuki Kitada?Department of Civil

2、Engineering, Osaka City University, Osaka, JapanAbstractIn this paper, consideration is given on recent trends in, and requirements for a bright future of, steel bridge construction in Japan. As far as recent trends are

3、concerned, it is observed that the construction of long and big steel bridges has practically been completed. Consequently, the focus of recent main works is the maintenance of superannuated (overaged) bridges and the se

4、ismic retrofitting of existing bridges. The refreshment and regeneration of some superannuated bridges is also needed recently in order to mitigate the uncomfortable influence of these bridges on their surrounding enviro

5、nment. As for a bright future in steel bridge construction, first and foremost it is emphasized that the steel bridge industry should be able to attract, train and retain better students and engineers. For this purpose,

6、maintenance and retrofitting works should be economically reasonable jobs. The necessity and importance of these works should be understood by the nation through retrofitting existing bridges against disasters and mitiga

7、ting the unfavourable influence of bridge structures on the bridge environment on the basis of the code of ethics for civil engineers promulgated by JSCE. Moreover, bridge engineers should seek better social status and t

8、he bridge engineering field should become attractive to young students who will bear the future of this field. c ? 2006 Elsevier Ltd. All rights reserved.Keywords: Steel bridge construction; Maintenance; Bridge environme

9、nt; Civil engineering ethics; State of the art1. IntroductionThe Akashi Kaikyo Bridge is now crossing the Akashi Strait with a centre span length of 1991 m, making it the longest suspension bridge in the world. Tatara Br

10、idge, the longest cable-stayed bridge, with a main span length of 890 m, is standing now on one of the cross-sea routes connecting the Honshu and Shikoku Islands. Technological and financial backgrounds have permitted th

11、e accomplishment of many large projects pertaining to the construction of these large-scale steel bridges in bay routes and cross-sea highways. At the time of their inception, Japan was still a developing country and mor

12、e infrastructure was needed. These days, however, the planning for the construction of long-span steel bridges has practically finished due to serious economic recession. In the civil engineering field (which should? Cor

13、responding address: Bridge Engineering Laboratory, Department of Civil Engineering, Osaka City University, 3-3-138 Sugimoto Sumiyoshi-ku, 558-8585 Osaka, Japan. Tel.: +81 6 6605 2734; fax: +81 6 6605 2765. E-mail address

14、: kitada@civil.eng.Osaka-cu.ac.jp.be distinguished from the building industry), new construction is not large scale; in the fairly well developed Japan, it is no longer considered a main industrial sector [1]. In Japan,

15、many bridges were intensively constructed in the 1960s–80s, during the period of high economic growth, with the number of bridges constructed per year decreasing recently to half of the overall peak. More specifically, t

16、he steel bridge industry reached the golden age in the latter half of the 1960s. However, the latest data indicates that the recent number of constructed steel bridges has declined to approximately 40% of its peak, thoug

17、h the number of constructed RC and PC bridges remains almost constant from the beginning of 1960 to date. After the construction of many bridges as one of the impor- tant infrastructures, bridges were constructed predomi

18、nantly in places of direct need. Recently, it is observed that various kinds of damage have occurred to many bridges mainly constructed in the 1960s. Especially following the investigation of damage to steel structures d

19、ue to the Hyogo-ken Nambu Earthquake which occurred in 1995, importance has been attached to seismic design for the construction of new bridges and to seismic0143-974X/$ - see front matter c ? 2006 Elsevier Ltd. All righ

20、ts reserved.doi:10.1016/j.jcsr.2006.06.0161194 T. Kitada / Journal of Constructional Steel Research 62 (2006) 1192–1198(14) Furthermore, many drivers now complain about the uncomfortable feeling in driving over some brid

21、ges due to big gaps and misalignments at their expansion joints. Many neighborhoods in close proximity to some superannuated bridges also complain about noise and vibration from the bridges.(15) Considering these circums

22、tances, the refreshment and re-creation of some superannuated bridges seems to be needed to address issues related to bridge safety and to the uncomfortable influence of the bridges on their surrounding environment.(16)

23、Recently jobs in steel bridge industry have declined substantially.2.2. Recent main works(1) Construction of new bridges In the new construction sector, there is severe competition between the steel bridge and concrete b

24、ridge industries. This is because the construction of long-span and big bridges, which occupied the steel bridge industry, has declined and, consequently, the steel bridge industry tries to win jobs mainly in the constru

25、ction of mid-span bridges, typically with a span length of 40–80 m. As a result, many economical, rational and mid-span bridges with new types of structures have been developed by both steel and concrete bridge industrie

26、s. The following new types of steel bridges were developed in seeking to expand the market for new construction, to include bridges with medium span length:– Plate girder bridges made of thick steel plates, with fewer st

27、iffeners and less welding lines for cost reduction.– Two-main-plate girder bridges with PC decks. – Continuous, composite and two-main-plate girder bridges. – Two-narrow-box-girder bridges. – Continuous composite two-nar

28、row-box-girder bridges strengthened by cables to increase their economical span length.– Cable stayed bridges with main girders of H-shaped steels. – Steel bridges consisting of box girders in the vicinity of the interio

29、r supports and plate girders in the other parts.– Open-box-girder bridges without stiffened upper flanges.On the other hand, the following new types of PC bridges have also been developed in order to face the competition

30、 from the steel bridge industry:– PC box girder bridges with corrugated steel webs. – Compound truss bridges with steel diagonal members and PC flanges.– Extra-dosed PC bridges with PC cables similar to the cables of cab

31、le stayed bridges.– Cable stayed PC box girder bridges with corrugated steel webs.(2) Other developments in steel bridge industry(i) Repair and strengthening works against fatigue damage and cracks in the following types

32、 of bridge members: – Fatigue cracks of secondary steel bridge members.– Fatigue cracks of RC slabs. – Fatigue cracks of steel decks (some cracks along welding parts between deck plates and trough ribs but a few cracks p

33、enetrating deck plates from the welding parts).– Many cracks at ends of welding parts between the flange plates of column members and the lower flange plates of horizontal members in steel bridge piers. Repair and streng

34、thening works of these cracks are carried out now.(ii) Retrofitting works against increased design live load.– Maximum design live load was changed from 200 kN to 250 kN.(iii) Retrofitting works due to revised design spe

35、cifications.– For example, there was no design method for stiffened plates in JSHB about 40 years ago.(iv) Seismic retrofitting works. (v) Development of bridge management systems based on Life Cycle Cost (LCC) and asset

36、 management.(vi) Repair and strengthening works of damage to bridge bearings and expansion joints.(vii) Maintenance works on deterioration of pavement and grade-up to permeable pavements.(viii) Maintenance works on damag

37、e to lighting and informa- tion poles on bridges mainly due to fatigue by traffic and wind loads.2.3. MaintenanceRegarding the maintenance of bridges, there are many issues that can be solved by the bridge engineering co

38、mmunity, though there are also many political and economical problems which cannot be solved by the bridge engineering community alone. Issues and problems of bridge maintenance are listed below:(1) Definition of termino

39、logy and life cycle.– Definition of bridge maintenance. – Unification of the terminology on bridge maintenance. – Decision of the life cycle of bridges, members and their parts.(2) Inspection and monitoring.– Labour savi

40、ng of inspection for maintenance through monitoring bridges, members and their parts.– Rationalization and cost reduction of inspection methods. – Education for maintenance engineers. – Collection and storage of maintena

41、nce data by utilizing IT technology.(3) Evaluation/assessment methods.– Establishment of methods for evaluating the safety and durability of existing bridges and the public announcement and communication of evaluated res

42、ults.– Development of method for deciding the priority ranking of repair and retrofitting of existing bridges.(4) Maintenance system, and repair and retrofitting technique.– Development of bridge maintenance system inclu