DOI QR코드

DOI QR Code

Analysis of the variability of deflection of a prestressed composite bridge deck

  • Staquet, Stephanie (Department of Civil Engineering, CP194/4, Universite Libre de Bruxelles) ;
  • Detandt, Henri (Department of Civil Engineering, CP194/4, Universite Libre de Bruxelles) ;
  • Espion, Bernard (Department of Civil Engineering, CP194/4, Universite Libre de Bruxelles)
  • Received : 2004.01.31
  • Accepted : 2004.10.05
  • Published : 2004.10.25

Abstract

Nearly 400 composite railway bridge decks of a new kind belonging to the trough type with U-shaped cross section have been constructed in Belgium over the last fifteen years. The construction of these bridge decks is rather complex with the preflexion of precambered steel girders, the prestressing of a concrete slab and the addition of a 2nd phase concrete. Until now, they have been designed with a classical computation method using a pseudo-elastic analysis with modular ratios. Globally, they perform according to the expectations but variability has been observed between the measured and the computed camber of these bridge decks just after the transfer of prestressing and also at long-term. A statistical analysis of the variability of the relative difference between the measured camber and the computed camber is made for a sample of 36 bridge decks using no less than 10 variables. The most significant variables to explain this variability at prestressing are the ratio between the maximum tensile stress reached in the steel girders during the preflexion and the yield strength and the type of steel girder. For the same sample, the long-term camber under permanent loading is computed by two methods and compared with measurements taken one or two years after the construction. The camber computed by the step-by-step method shows a better agreement with the measured camber than the camber computed by the classical method. The purpose of the paper is to report on the statistical analysis which was used to determine the most significant parameters to consider in the modeling in order to improve the prediction of the behaviour of these composite railway bridge decks.

Keywords

References

  1. CEB-FIP Model Code 1990 (1993), Bulletin CEB, $N^{\circ}$213/214, Thomas Telford, London.
  2. Ghali, A., Favre, R. and Elbadry, M. (2002), Concrete Structures: Stresses and Deformations. (3rd ed.), E&FN Spon, London and New York.
  3. fib-CEB-FIP (1999), Structural Concrete Volume 1, Bulletin fib, $N^{\circ}$1.
  4. NBN5 (1987), Steel Bridges, draft for the part: Composite Bridges, Doc.270/43 F*, Belgian Institute for Standards, Brussels (in French).
  5. Staquet, S., Detandt, H. and Espion, B. (2001),"Time-dependent behaviour of a railway prestressed composite bridge deck", Proc. of the Conf. on Creep, Shrinkage and Durability Mechanics of Concrete and Other Quasibrittle Materials, Cambridge (Ma), USA, 20-22 August 2001, Elsevier, 373-378.
  6. Staquet, S., Espion, B and Detandt, H. (2002a),"A new kind of composite railway bridge deck", Proc. of the 1st fib Congress Concrete Structures in the 21st Century, Osaka, Japan, 13-19 October 2002, Vol.4, session 5, 75-84.
  7. Staquet, S., Detandt, H. and Espion, B. (2002b),"Analysis of the camber at prestressing of a new kind of composite railway bridge deck", Proc. of the 3rd Int. Conf. on Advances in Steel Structure ICASS'02, Hong Kong, China, 9-11 December 2002, Elsevier, 783-790.
  8. Staquet, S., Espion, B and Detandt, H. (2003),"Analysis of variability of the long term deflection of a new kind of composite bridge deck", Proc. of the Int. Conf. on Advances in Structures ASSCCA03, Sydney, Australia, 23-25 June 2003, Balkema, 825-832.

Cited by

  1. Field testing of a 30-year-old composite Preflex railway bridge vol.160, pp.2, 2007, https://doi.org/10.1680/bren.2007.160.2.89