Analysis of Deck Slab of Reinforced Concrete Gerber-Girder Bridge Widened by Addition of Continuous Steel-Concrete Composite Girders

Wojciech Siekierski

doi:10.7250/bjrbe.2019-14.443

Analysis of Deck Slab of Reinforced Concrete Gerber-Girder Bridge Widened by Addition of Continuous Steel-Concrete Composite Girders

Authors

Wojciech Siekierski Dept of Bridges, Faculty of Civil and Environmental Engineering, Poznan University of Technology, Poznan, Poland https://orcid.org/0000-0002-1363-3574

DOI:

https://doi.org/10.7250/bjrbe.2019-14.443

Keywords:

analysis, bridge, concrete slab, deck widening, Finite Element Method (FEM), Gerber girder, refurbishment

Abstract

Many Gerber-girder bridges have become obsolete in terms of deck width and load carrying capacity. If bridge replacement is not necessary, additional girders are installed. Sometimes, due to erection convenience, the added girders do not replicate the static scheme of the refurbished structure. Such an arrangement requires special attention to preserve structural durability. An example of the inappropriate arrangement of the widening of a Reinforced Concrete Gerber-girder road bridge is presented together with an alternative concept of refurbishment based on the addition of the continuous steel-concrete girders as the outermost ones. The added deck slab connects the added and the existing parts of the structure. Attention is drawn the static analysis of the added deck slab and the influence of the added outermost girders that do not replicate the static scheme of the existing ones. Due to different static schemes of the existing and the added girders, the traditional method of the deck slab analysis is inappropriate. The Finite Element 3D model is to be applied to access bending moments in the deck slab spans correctly. It is shown that: a) the analysis of the distribution of the bending moments in the existing and the added slab spans, especially near Gerber-hinges, should be based on the Finite Element 3D modelling; b) the analysis should consider live loads acting on the whole width of the Gerber-hinge span; c) the bending moment distribution in the widened deck slab is sensitive to the distance to the Gerber hinge.

References

Bota, A., & Bota, D. (2016). What means external prestressing for an old Gerber structure. Procedia engineering, 156, 48-53. https://doi.org/10.1016/j.proeng.2016.08.266

Croci, G., Santoro, V. M., & Macri, F. (1995). Structural rehabilitation of a reinforced concrete and a prestressed concrete bridge. IABSE reports, 73/1/73/2, 77–82.

Cusens, A. R., & Pama, R. P. (1975). Bridge deck analysis.

Fu, C. C., & Wang, S. (2015). Computational analysis and design of bridge structures. CRC Press.

Gode, G., & Paeglitis, A. (2014). Concrete bridge deterioration caused by de-icing salts in high traffic volume road environment in Latvia. Baltic Journal of Road and Bridge Engineering, 9(2), 200–207. https://doi.org/10.3846/bjrbe.2014.25

Hambly, E. C. (1991). Bridge deck behaviour. CRC Press. Hino, S., Tahara, Y., & Tsutsumi, T. (1999). Strengthening for an existing RC Gerber bridge using external cables. IABSE reports, 83, 236–237.

Holst, K. H. (1993). Brücken aus Stahlbeton Und Spannbeton. Entwirf, Konstruktion Und Berechnung. Ernst & Sohn. Berlin. (in German)

Hong, S., & Park, S. K. (2015). Effect of vehicle-induced vibrations on early-age concrete during bridge widening. Construction and Building Materials, 77, 179-186. https://doi.org/10.1016/j.conbuildmat.2014.12.043

Madaj, A., Mossor, K., & Siekierski, W. (2017). Mosty z przęsłami przegubowymi– trwałość i warunki użytkowania na przykładzie wybranych obiektów. Archives of Institute of Civil Engineering, 24, 187-204. https://doi.org/10.21008/j.1897-4007.2017.24.14 (in Polish)

Marsh, K. (2016). Autodesk Robot Structural Analysis Professional 2016: essentials. Marsh API.

Mohammadi, A., Yakel, A., & Azizinamini, A. (2014). Phase and widening construction of steel bridges (No. BDK80-977-28). Florida International University.

Nie, J. G., Wang, Y. H., Zhang, X. G., Fan, J. S., & Cai, C. S. (2012). Mechanical behavior of composite joints for connecting existing concrete bridges and steel–concrete composite beams. Journal of Constructional Steel Research, 75, 11-20. https://doi.org/10.1016/j.jcsr.2012.02.019

Rybak, M. (1983). Przebudowa i wzmacnianie mostów. Wydawnictwa Komunikacji i Łączności. (in Polish)

Szczygieł, J. (1972). Mosty z betonu zbrojonego i spre̜ żonego. Wydawnictwa komunikacji i ła̜czności. (in Polish)

Wen, Q. J. (2011). Long-term effect analysis of prestressed concrete box-girder bridge widening. Construction and Building Materials, 25(4), 1580-1586. https://doi.org/10.1016/j.conbuildmat.2010.09.041