（節(jié)選）橋梁工程外文翻譯--橋梁環(huán)境生命周期評(píng)估（原文）

1、Environmental Life Cycle Assessment of BridgesJohanne Hammervold1; Marte Reenaas2; and Helge Brattebø3Abstract: This paper presents a detailed comparative environmental life cycle assessment (LCA) case study of thre

2、e built bridges in Norway. To encompass a wide scale of bridge designs, the analysis dealt with a steel box girder bridge, a concrete box girder bridge, and a wooden arch bridge. This study presents the first LCA of road

3、 bridges using a standardized bridge classification. The LCA includes a wide range of pollutants and a high level of detail in life cycle material and energy consumption. Findings here and from earlier LCAs on bridges ar

4、e together used as bases for general recommendations on conducting LCAs on bridges. The study shows that it is the production of materials for the main load- carrying systems (i.e., the bridge superstructure) and the abu

5、tments that accounts for the main share of the environmental impacts, as these parts require large quantities of materials, with a limited number of materials being the important ones. The construction phase accounts for

6、 relatively fewer impacts. The use phase contributes more significantly, mainly because of resurfacing with asphalt. Use of building equipment and trans- port of personnel in all the life cycle phases are of minor import

7、ance, as are the use of formwork, mastic, blasting, and the end-of-life incineration of wood. The environmental issues of global warming, abiotic depletion, and acidification are found to be the most important given the

8、assump- tions made in this study. A comparison of the three bridges shows that the concrete bridge alternative performs best environmentally on the whole, but when it comes to global warming, the wooden bridge is better

9、than the other two. The results support the idea that it is possible to decide upon environmentally effective design alternatives, at a fair level of accuracy, at different stages of the bridge design process, a target t

10、hat is now becoming more and more emphasized in the bridge-engineering sector. DOI: 10.1061/(ASCE)BE.1943-5592.0000328. © 2013 American Society of Civil Engineers.CE Database subject headings: Bridges; Construction;

11、 Life cycles; Environmental issues; Decision making.Author keywords: Bridge construction; Bridge management; Life cycle assessment; Environmental impact; Decision-making support.IntroductionA Finnish, Swedish, and Norweg

12、ian research collaboration, the ETSI project (Salokangas 2010), was launched in 2006 and also included Denmark from 2009 onwards. This project aims at bridge life cycle optimization and includes economic, environmental,

13、and aesthetic issues spanning the entire lifetime of the bridge. The Norwegian group has been working on the environmental issues and has developed a tool for environmental life cycle assessment (LCA) of bridges, called

14、BridgeLCA (Brattebø et al. 2009). This tool allows for detailed LCAs of bridges, revealing what materials and parts cause impacts and at what stage in the lifetime of the bridge these impacts occur. This article pre

15、sents a case study of three bridges and gives recommendations about particularly im- portant parameters for the environmental performance of these three types of bridges.Earlier LCA studies on bridges have been reviewed,

16、 and the main findings from these studies are presented in this paper. Few LCA studies on bridges have been carried out, and the case studies pre- sented here can be regarded as a systematic and detailed extension to the

17、 earlier studies in the identification of the most important parameters regarding the environmental performance of bridges. We believe that this is indeed important in the current process of im- proved environmental desi

18、gn among bridge engineers, particularly in the early phases of the design process, where little information might be available and yet there may be good opportunities to in- fluence a good design strategy. The three brid

19、ges analyzed in this paper—a steel box girder bridge, a concrete box girder bridge, and a wooden arch bridge—are already built and in use in western Norway. This means that one could also get a hold of detailed facts abo

20、ut the consumption of various types of resources in the production and construction phases of the bridges. Most of the energy and material consumption throughout the life cycles of the bridges is accounted for, and sever

21、al environmental impact categories are included. The bridges have been analyzed on the basis of the contributions of materials, bridge components, and life cycle phases to environmental impacts.LiteratureComparison of Di

22、fferent Bridge AlternativesA prestressed concrete box girder bridge and a steel-concrete composite I-girder bridge were compared in Gervásio and da Silva (2008). The emissions considered are carbon dioxide (CO2), su

23、lfur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOC), carbon monoxide (CO), methane (CH4), and1Ph.D. Student, Dept. of Hydraulic and Environmental Engineering, Industrial Ecology Programme, The Nor

24、wegian Univ. of Science and Technology, N-7491 Trondheim, Norway (corresponding author). E-mail: johanne.hammervold@ntnu.no 2Ph.D. Student, Dept. of Hydraulic and Environmental Engineering, Industrial Ecology Programme,

25、The Norwegian Univ. of Science and Technology, N-7491 Trondheim, Norway. 3Professor, Dept. of Hydraulic and Environmental Engineering, In- dustrial Ecology Programme, The Norwegian Univ. of Science and Technology, N-7491

26、 Trondheim, Norway. Note. This manuscript was submitted on February 2, 2011; approved on October 20, 2011; published online on October 24, 2011. Discussion period open until July 1, 2013; separate discussions must be sub

27、mitted for in- dividual papers. This paper is part of the Journal of Bridge Engineering, Vol. 18, No. 2, February 1, 2013. ©ASCE, ISSN 1084-0702/2013/2- 153e161/$25.00.JOURNAL OF BRIDGE ENGINEERING © ASCE / FEB

28、RUARY 2013 / 153J. Bridge Eng. 2013.18:153-161.Downloaded from ascelibrary.org by Changsha University of Science and Technology on 06/19/14. Copyright ASCE. For personal use only; all rights reserved.that no study has, a

29、s yet, documented the environmental life cycle performance of bridges, comparing different designs by using a standardized bridge design classification, where the consumption of materials and energy is related to the var

30、ious bridge components in a more systematic way.MethodologyThis study aims at identifying important parameters affecting the environmental performance of three bridges constructed of different materials, steel, concrete,

31、 and wood, as inputs to a methodology of a more life cycle-optimized design for bridges. Hence, one would like to know where in the life cycle of a bridge major environmental impacts occur and what types of environmental

32、 impact categories dominate, which materials and activities are they mainly related to, and in which components of the bridge are they to be found? The deck surface area of the bridges is the effective area in use. The u

33、se phase of 100 years and the demolition phase are included, and the functionalunitishencedefinedas“1 m2 effective bridge surface area through a lifetime of 100 years.” This enables comparison among differentbridgesdespi

34、tethefactthattheyarebuiltatdifferentlocations with different sizes (span, length, and width). The bridges are also analyzed individually for the identification of important parameters. The material and energy consumption

35、 throughout the lifetimes of the bridges is, as much as possible, gathered and entered into the BridgeLCA software, which is a tool developed in MATLAB and fed with data on each specific bridge from Excel files. The envi

36、- ronmental data for the various materials used in the calculations are obtained by the use of the SimaPro LCA software tool, the Ecoinvent database (Ecoinvent 2008), and collected data. As environmental data related to

37、all included material and energy use throughout the bridges’ lifetimes are gathered, they are charac- terized using the CML impact assessment method (CML 2001), yielding results for the following six environmental catego

38、ries: acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), ozone-layer depletion potential (ODP), photochemical ozone-creation potential (POCP), and abiotic de- pletion potential (

39、ADP). The CML methodology additionally includes four more impact categories, namely, human toxicity potential, freshwater eco-toxicity potential, marine aquatic eco- toxicity potential, and terrestrial eco-toxicity poten

40、tial. These categories were omitted from this study, because of unacceptably high uncertainty in the toxicity data, particularly for the impreg- nated wooden arch bridge. Midpoint results for the six impact categories ar

41、e further nor- malized using European normalization figures (Huijbregts et al. 2003) and weighted using weighting factors developed by the EPA in the United States for comparison of total scores of the case bridges (EPA

42、2010). Quantitative data for each bridge were gathered from drawings, tender documents, and project reports. Hence, it was possible to acquire detailed and specific data for each bridge and compare dif- ferent designs by

43、 using a standardized bridge design classification, where consumption of materials and energy is related to the various bridge components in a more systematic way.Bridges Considered in the Case StudyThe bridges studied a

44、re already built at different locations in west- ern Norway. The bridges are the Klenevaagen steel box girder bridge, Fretheim wooden arch bridge, and Hillersvika concrete box girder bridge. The main size parameters for

45、the bridges are given in Table 1.Hillersvika is the largest bridge, with a deck area of 417 m2. This bridge has two traffic lanes and one pavement, while Klenevaagen has two traffic lanes and no pavement, and Fretheim ha

46、s one traffic lane and one pavement. Klenevaagen has a surface area of 321 m2and Fretheim, 229 m2. These three bridges were chosen, because they represent bridges of three different materials, namely, steel, concrete, an

47、d wood. In this way, important parameters affecting the environmental performance for these types of bridges can be identified. The main load-bearing system in the Klenevaagen Bridge con- sists of a 67.2-t steel box gird

48、er, which is blast-cleaned, galvanized, and painted with epoxy and polyurethane paint for corrosion pro- tection. The bridge deck consists of RC. This deck is protected from water intrusion by a layer of mastic and aspha

49、lt membrane, and atop this, there is the surfacing layer of asphalt, which is assumed to be composed of 94.4% gravel and 5.6% bitumen. The steel box was produced locally and transported 75 km by boat to the bridge site.

50、It is assumed that the concrete was produced at a local mixing plant and transported 20 km by truck, and the reinforcement was produced in Bergen and transported 90 km by truck. The parapets are made of 6.85 t of galvani

51、zed steel. The main load-bearing system in the Fretheim Bridge is a wooden arch, consisting of salt-impregnated, glue-laminated wood, treated with a mordant of oil. The top of the arches is protected from rainfall by thi

52、n copper sheets. There are also some steel parts in the bridge, specifically the cross beams under the deck and the bars connecting these to the arch. The bridge deck is made of creosote-impregnated wooden planks. The im

53、pregnation process of these planks is in- cluded in the study, while creosote leakage throughout the lifetime of the bridge is not included. The reason for this is the lack of a satis- factory method for calculating the

54、amount of creosote leaked and the consequential environmental impacts. The glue-laminated wooden arches were transported 280 km by truck from the production plant to the bridge site. The transportation of the constructio

55、n wood is as- sumed to be by truck over a distance of 50 km. The concrete is as- sumed to be produced at a local mixing plant and transported 20 km by truck. The Hillersvika Bridge mainly consists of RC, with a concrete

56、box girder as the main load-bearing system and a concrete deck. The deck is waterproofed and topped with a surface layer similar to that of the Klenevaagen Bridge. The box girder consists of 330 m3 of concrete and 17 t o

57、f reinforcement, and the abutments contain 83 m3of concrete and 86.4 t of reinforcement. The concrete was produced nearby and transported 0.5 km by truck. The reinforcement was produced 130 km from the bridge site and tr

58、ansported by truck. The parapets are made of 6.05 t of galvanized steel. The material and energy consumption included in the study is taken from tender documents for the bridges, and some additional assumptions are made

59、according to earlier bridge-engineering experiences. The material and energy consumption included in the study is described later in the paper for each life cycle phase.Table 1. Size Parameters for the Bridges Considered

60、Variable Klenevaagen Fretheim HillersvikaType Steel box girder Wooden arch Concrete box girderBridge span 42.8 m 37.9 m 39.3 m Effective width 7.5 m 6.1 m 10.6 m Traffic lanes 2 1 2 Pavement 0 1 1 Bridge deck area 321 m2

61、 229 m2 417 m2JOURNAL OF BRIDGE ENGINEERING © ASCE / FEBRUARY 2013 / 155J. Bridge Eng. 2013.18:153-161.Downloaded from ascelibrary.org by Changsha University of Science and Technology on 06/19/14. Copyright ASCE. Fo