[雙語翻譯]--橋梁外文翻譯-先簡支后連續(xù)鋼梁橋設計與造價的研究綜述（原文）

1、Design and Costs for Simple-Made-Continuous Rolled Steel Girder Bridges: Literature SurveyA. Stone, A.M.ASCE1; J. W. van de Lindt, M.ASCE2; and S. Chen, M.ASCE3Abstract: The method of simple-made-continuous for steel bri

2、dges is becoming more popular throughout the United States because it enables significant cost savings. Specifically, the method allows one to avoid steel bridge girder splices and design the steel sections for the self

3、weight and the weight of the slab as simply supported and then the addition of live load and remaining dead loads as continuous. This balances the moments between the positive and negative regions allowing for a prismati

4、c section and even adds speed of construction since the field splices are not needed. In 2006, the Colorado DOT sponsored a study to ?1? review current approaches to simple-made- continuous using standard rolled sections

5、 and ?2? develop design charts for rapid sizing of steel bridge beams and cost estimation for simple-made-continuous. This paper presents a state-of-the-art review up until 2007 for this type of construction and focuses

6、on several of the most recent and successful transportation department projects.DOI: 10.1061/?ASCE?SC.1943-5576.0000045CE Database subject headings: Bridge design; Steel beam; Bridges, steel; Costs.Author keywords: Simpl

7、e made continuous; Steel design; Bridge design; Rolled steel beam.IntroductionOver the past 50 years in the mid-western United States, construc- tion of short to medium span steel bridges has declined or, at best, remain

8、ed constant, while prestressed concrete bridge construction has dominated the market ?Azizinamini et al. 2003?. The state of Colorado, in particular, has seen steel bridge construction virtu- ally disappear and the marke

9、t dominated by prestressed bridges ?Wang, T. ?2006? “Colorado Department of Transportation,” per- sonal communication?. One reason for this sharp decline is the lack of steel mills in the region combined with a strong pr

10、esence of precast concrete companies in the state. In addition, a lack of readily available economical and innovative procedures and tools to design and construct steel bridges has hindered the industry in certain areas

11、such as Colorado. During the bidding process for selection of the bridge type, it is mandated that accurate bidding of both steel and concrete be developed. The precast concrete industry has worked to develop tools to ma

12、ke this process easier and subsequently dominated the market in Colorado. These types of tools are not available for bidding steel bridges, thus more work by a design/build contractor is required for the steel option. Th

13、e tendency is forbidders to go with the easier, and over time, more understood option and thus the type selection is routinely dominated by pre- stressed concrete.Simple-Made-Continuous: Economical Steel Bridge Design Me

14、thodThe conventional approach for constructing multispan steel bridges is to design them as continuous girders to distribute the load over all members. In that method, the rolled girders are fabricated and shipped to the

15、 job site where they are assembled by the contractor using a bolted or welded field splice at low stress points. There is a relatively recent method where simply sup- ported beams are specified by the designer and beams

16、are then made continuous at the piers using a concrete diaphragm or a connection plate ?Azizinamini et al. 2005?. In this approach, once the slab and diaphragm are poured, the simply supported beam accounts for its weigh

17、t along with the wet concrete deck. As the concrete diaphragm hardens, making the girders continuous, all other loads ?live, composite dead? are shared through the sys- tem of beams. This latter concept is called simple

18、for dead load, continuous for live load, or simple-made-continuous ?Azizinamini et al. 2005?. Some of the major advantages of the simple-made- continuous method over the field splice method, hereafter referred to as the

19、“conventional method,” are: ?1? it eliminates the need for expensive field splices; ?2? reduces the negative moment at the pier, while increasing the positive moment at mid span; ?3? main- tains a uniform cross section t

20、hroughout span to reduce fabrica- tion effort; leading to minimum detailing of the steel beam; ?4? smaller cranes are required to assemble the beam system; ?5? erection time is reduced without the need for field spices;

21、and ?6? there is minimal traffic interruption compared to the conventional method. As of 2007, several states have begun to implement this type of design and construction for some of their steel bridges. The list of stat

22、es that have built simple-made-continuous steel1Graduate Research Assistant, Dept. of Civil and Environmental En- gineering, Colorado State Univ., Fort Collins, CO 80523-2372. 2Professor and Drummond Chair, Dept. of Civi

23、l, Construction, and Environmental Engineering, Univ. of Alabama, Box 870205, Tuscaloosa, AL 35487-0202 ?corresponding author?. E-mail: jwvandelindt@eng.ua. edu 3Assistant Professor, Dept. of Civil and Environmental Engi

24、neering, Colorado State Univ., Fort Collins, CO 80523-2372. Note. This manuscript was submitted on August 5, 2008; approved on August 5, 2009; published online on July 15, 2010. Discussion period open until January 1, 20

25、11; separate discussions must be submitted for individual papers. This paper is part of the Practice Periodical on Struc- tural Design and Construction, Vol. 15, No. 3, August 1, 2010. ©ASCE, ISSN 1084-0680/2010/3-2

26、31–235/$25.00.PRACTICE PERIODICAL ON STRUCTURAL DESIGN AND CONSTRUCTION © ASCE / AUGUST 2010 / 231Pract. Period. Struct. Des. Constr. 2010.15:231-235.Downloaded from ascelibrary.org by Changsha University of Science

27、 and Technology on 06/05/13. Copyright ASCE. For personal use only; all rights reserved.with a unit weight of structural steel of 37.7 psf. The price of the steel from the low bidder was $0.56/lb in place, significantly

28、lower than their previous design. Construction of the total bridge took only 90 days, without incentives. TDOT also designed two similar bridges, which contained integral abutments. Advantages of the integral abutments i

29、nclude being jointless, reduced mainte- nance, and potentially dampening seismic motion. The first is a five span bridge, taking State Road 210 over Pond Creek. The substructure is skewed at 35° carrying spans of 94

30、, 103, 132, 132, and 118 ft. Five W40?248 grade 50W girders support the 42 ft wide deck. The steel beams were set in 30 days. The second of the two was another large rolled beam bridge constructed in 2006, carrying Churc

31、h Avenue over Route 158 and 71. It consisted of six spans measuring 80, 100, 100, 100, 93, and 90 ft. The 56 ft wide deck is supported by seven lines of W30?173 grade 50W girders, spaced at 8 ft 2 in. The engineers estim

32、ate for the bridge was $80/sq ft, totaling $2.82 million. The low contractor bid came in at $72.93/sq ft, or $2.55 million ?Talbot 2005?. Details of the connection at the pier along with the span of the concrete dia- phr

33、agm can be seen in Fig. 4.OhioThe Ohio DOT installed a simple-made-continuous steel bridge as a replacement bridge in the summer of 2003. The existing struc- ture was a six span ?90 ft approaches with four 112 ft 6 in. m

34、ain spans? 29 ft wide steel stringer bridge crossing the Scioto River in Circleville on U.S. 22 ?Ohio DOT 2003?. Because of time con- straints, the state decided to make the project a design/build fast track job. Five gi

35、rders, spaced at 9 ft, were required to support the bridge, which was widened to 44 ft. High performance steel gird- ers, M270 grade 50W, were designed as simply supported and were made continuous in the field by integra

36、l concrete dia- phragms. The concrete diaphragm was 3 ft wide and was cast across the pier comparable to the Nebraska and Tennessee dia- phragms. The beams and diaphragm also sat on an elastomeric bearing pad and load tr

37、ansfer plate. The beams were constructed as plate girders with a 54 in. web depth and 18 in. flanges. The total construction time for the U.S. 22 Bridge, from demolition to the completed construction of the new bridge, w

38、as 48 days ?Ohio DOT 2003?. The bridge unit cost was $2.11 million, which equated to $75.6/sq ft. Design details obtained from the state of Ohio are presented in Fig. 5.New MexicoThe New Mexico DOT used the simple for de

39、ad continuous for live method to design a five span 525 ft ?105 ft/span?, 34.5 ft wide replacement steel plate girder bridge ?Barber 2006?. The super- structure contained 4 lines of plate girders spaced at 7 ft 6 in. The

40、 plate girder dimensions were a 54 in. web depth, 13.8 in. top flange, and 17.3 in. bottom flange ?Barber 2006?. That bridgecrosses the Rio Grande River on NM 187 and was completed in the summer of 2005. On an earlier pr

41、oject, the simple-made- continuous concept served in a dual-design analysis ?steel versus prestressed concrete? for a bridge on U.S. 70 in southern New Mexico. A design consultant for the U.S. 70 project, Parsons Brincke

42、rhoff, Inc. bid the two alternatives at a difference of only 0.2% out of a total project construction cost of $21 million ?Bar- ber 2006?. An innovative feature on this project were the bolts being placed outside of the

43、concrete diaphragm to allow for tight- ening after the deck and diaphragms were poured. Reinforcing bars were added to the concrete diaphragm to achieve the re- quired negative moment capacity. Bars were also added above

44、 the pier to alleviate stresses on the continuity connection plate and are shown in Fig. 6. The cost of the bridge was $75 per sq. ft. Bids for precast concrete girder bridges of comparable square footage were $68 and $8

45、8 per sq ft each ?Barber 2006?.ColoradoThe Colorado DOT designed and completed its first simple-made- continuous steel bridge in July 2006. The steel bridge replaced an out of date bridge on U.S. 36 that crossed Box Elde

46、r Creek out- side of Denver ?“Steel bridge uses simple-made-continuous con- struction.” 2006?. The new superstructure was 470 ft long with six equal spans, 77 ft/span. The 44 ft wide concrete deck was sup- ported by six

47、lines of W33?152 grade 50W rolled beam girders spaced at 7 ft 4 in. The beams were supplied to the site in pairs with W27?84 diaphragms connected to the bearing stiffeners. These cross frames were spaced at 19 ft on the

48、interior girders and 12 ft 4 in. on the exterior girders and provided stability during erection. Similar steel diaphragms were also designed to run overFig. 4. Tennessee design detail for continuity at pierFig. 5. Concre

49、te diaphragm details at pier on Scioto River BridgeFig. 6. Detail of connection plate on top flanges on NM 187 bridgePRACTICE PERIODICAL ON STRUCTURAL DESIGN AND CONSTRUCTION © ASCE / AUGUST 2010 / 233Pract. Period.