橋梁外文翻譯--大跨度預(yù)應(yīng)力混凝土橋梁結(jié)構(gòu)的豎向撓度預(yù)測（英文）

1、Engineering Structures 27 (2005) 1820–1827www.elsevier.com/locate/engstructPrediction of vertical deflections for a long-span prestressed concrete bridge structureIan N. Robertson?Department of Civil and Environmental En

2、gineering, University of Hawaii, Honolulu, HI 96822, USAAvailable online 1 July 2005AbstractThis paper presents the results of a bridge monitoring program after nine years of data collection. The North Halawa Valley Viad

3、uct on the Hawaiian island of Oahu was instrumented extensively during construction in 1994. The objective of the instrumentation program was to monitor both short-term and long-term behavior of the viaduct. The primary

4、instruments used for vertical deflection, span shortening, and concrete strain monitoring are described. Short-term vertical deflections and bending strains measured during a load test of the structure are compared with

5、analytical predictions using a commercial finite element analysis program. Close agreement is observed for both deflection and strain predictions. Long-term deformations of the viaduct are compared with analytical predic

6、tions using a finite element computer program specially developed for use with segmental construction of prestressed concrete bridge structures. Theoretical predictions based on the original design parameters do not agre

7、e with the measured vertical deflections. Improved creep and shrinkage material properties were determined using recently developed creep and shrinkage models adjusted by means of short-term creep and shrinkage data. The

8、 modified material property data provide considerable improvement in the prediction of viaduct response. A procedure is proposed for prediction of upper and lower bounds for the long-term response of long-span prestresse

9、d concrete bridges. © 2005 Elsevier Ltd. All rights reserved.Keywords: Long-term deflections; Prestressed concrete bridge; Creep; Shrinkage; Analytical predictions1. IntroductionThe North Halawa Valley Viaduct (NHVV

10、) is a 1.5 km box-girder viaduct with span lengths up to 110 m. It is part of the new H-3 freeway on the island of Oahu in Hawaii. The twin inbound and outbound viaducts were built by means of post-tensioned in-situ bala

11、nced cantilever construction as described by Banchik and Khaled [1]. Four spans of Unit 2 IB of the inbound viaduct (70–110 m span lengths) were selected for instrumentation to provide an adequate representation of the v

12、iaduct behavior (Fig. 1). Unit 2 IB is one of three independent units making up the inbound viaduct of the NHVV. Expansion joints at piers 7 and 13 separate this unit for the adjacent Units 1 IB and 3 IB. Unit 2 IB is su

13、pported by 7 piers, with slide bearings at the top? Tel.: +1 808 956 7550; fax: +1 808 956 5014. E-mail address: ianrob@gmail.com.0141-0296/$ - see front matter © 2005 Elsevier Ltd. All rights reserved. doi:10.1016/

14、j.engstruct.2005.05.013of all piers (“Expansion Piers” in Fig. 1), except for piers 9 and 10 where the top of the pier is integrally connected to the box girder (“Fixed Piers” in Fig. 1). The instrumentation program was

15、developed in conjunc- tion with T.Y. Lin International, structural engineers for the viaduct. During construction, all instruments were installed by personnel from the University of Hawaii (UH) and Con- struction Technol

16、ogy Laboratories (CTL) in Skokie, Illinois. The instrumentation used in this project was designed to provide both short-term and long-term monitoring of the structural performance of the viaduct. The measurements require

17、d to achieve the project objectives include concrete strains, concrete and ambient temperatures, concrete creep and shrinkage strains, span shortening, tendon forces, span deflections, and support rotations. Over 200 ins

18、truments were selected and installed to perform these measurements, namely: vibrating wire strain gages, electrical resistance strain gages, thermocouples, span extensometers, tendon1822 I.N. Robertson / Engineering Stru

19、ctures 27 (2005) 1820–1827Fig. 2. Vibrating wire strain gage locations at sections B, C and F.Fig. 3. Vibrating wire strain gage locations at sections A, D, E and G.2.3. Span longitudinal deflectionsSpan extensometers we

20、re installed in the four instru- mented spans to monitor the overall shortening of thebox-girder. Each extensometer consists of a series of graphite rods (6 mm diameter by 6 m long) spliced together to span from pier to