The influence of piers on the risk of flooding upstream from a bridge

• Autorzy: Sowiński M.
• Języki publikacji: EN

Abstrakty

EN

The objective of this paper is to compare the risk of flooding areas upstream from a bridge without piers and a deck supported only on abutments, with a bridge of the same width with a deck supported on abutments and piers. The additional goal of this paper is to analyze the influence of the width and shape of piers on the risk of flooding. The paper begins with the formulation of performance function used in reliability analysis. Then, after the short characteristic of the methods of this analysis, one of them - the advanced first-order second-moments (AFOSM) method chosen for solution of the problem resulting from objectives of the paper - is presented. The largest part of the paper contains the solution of this problem for an exemplary bridge. After the description of this bridge two models used for computation of hydraulic losses, which are required for determination of the performance function, are characterized. The first is based on an energy equation (the standard step method) and used for a bridge without piers, the second one applied for computation of losses in the inner section of a bridge with piers is based on momentum equation. The solution of the problem was based on computer simulations performed for the compared variants of bridge projects. The computations results were presented graphically in the form of risk curves showing the relations between the return period defined as the reciprocal of risk and stage of water upstream from a bridge. It was found that the reduction of a return period due to: application of piers for support of bridge deck (as an alternative to its support on abutments alone), an extension of piers by 100% or replacing a favourable hydraulical shape (elliptical) of piers by an unfavourable one (with a square nose), is comparable and for considered bridge oscillates around 70% of the initial return period.

Słowa kluczowe

EN

AFOSM method; bridge; piers; risk

• Wydawca: Institute of Hydro-Engineering of Polish Academy of Sciences
• Czasopismo: Archives of Hydro-Engineering and Environmental Mechanics
• Rocznik: 2005
• Tom: Vol. 52, nr 4
• Strony: 287--301
• Opis fizyczny: Bibliogr. 19 poz., il.

Twórcy

autor

Sowiński M.

• Institute of Environmental Engineering, Poznań University of Technology, ul. Piotrowo 5, 60-965 Poznań, Poland,

Bibliografia

• Ang A. H. S., Tang W. H. (1984), Probability Concepts in Engineering Planning and Design, Vol. 2, Decision, Risk and Reliability, Wiley, New York.
• HarrM. E. (1989), Probability estimate for multivariate analysis,Applied Mathematical Modelling, Vol. 13, No. 5, 313–318.
• HEC-RAS River Analysis System: User’s Manual Version 2.2 (1998), U.S. Army Corps of Engineers, Hydrologic Engineering Center CPD 68, Davis, California, USA.
• Li K. S. (1992), Point-estimate method for calculating statistical models, Journal Engineering Mechanics, Vol. 118, No. 7, 1506–1511.
• Lian Y., Yen B. C. (2003), Comparison of risk calculation methods for a culvert, Journal of Hydraulic Eng., Proc. ASCE, Vol. 129, HY 2, 140–152.
• Melching C. S., Yen B. C. (1986), Slope influence on storm sewer risk, [in:] Stochastic and Risk Analysis in Hydraulic Engineering, edit. B. C. Yen, Littleton, Colorado, Water Resources Publications, 79–89.
• Melching C. S. (1992), An improved first-order reliability approach for assessing uncertainties in hydrologic modeling, Journal of Hydrology, Vol. 132, 157–177.
• Plate E. J. (1984), Reliability analysis in hydraulic design, Proc. IAHR IV Symposium on Stochastic Hydraulics, Urbana, Illinois, USA, 37–47.
• Singh S., Melching C. S. (1993), Importance of Hydraulic Model Uncertainty, Flood-Stage Estimation, Hydraulic Engineering ’93, Proceedings ASCE National Conference on Hydraulic Engineering, edit. H.-W. Shen, S.-T. Su, and F. Wen, Vol. 2, 1939–1944.
• Smith G. N. (1986), Probability and Statistics in Civil Engineering, Nicolas Pub. Co.
• Sowiński M., Yusuff M. I. (1995), Composite risk model of Ogee type spillway, [in:] New Uncertainty Concepts in Hydrology and Water Resources, edit. Z. Kundzewicz, Cambridge Univ. Press, Cambridge, 316–322.
• Sowiński M. (2002), Probability of stage exceedance upstream from a hydraulic structure, Proc. CD-ROM, 5th International Conference on Hydroscience and Engineering, Warsaw, Poland.
• Sowiński M., Marlewski A. (2003), Risk of flood stage exceedance upstream a bridge, [in:] Urban Water Management, edit. R. Arsov, J. Marsalek, E. Watt, E. Zeman, Kluwer Academic Publishers, Dordrecht, 125–134.
• SowińskiM. (2004), An uncertainty analysis of flood–stage upstream from a bridge, Proc. 6th International Symposium on System Analysis and Integrated Assessment in Water Management, Beijing, China, 97–105.
• Tang W. H., Yen B. C. (1972), Hydrologic and hydraulic design under uncertainties, Proc. International Symposium on Uncertainties in Hydrologic and Water Resource Systems, Vol. 2, Tucson, Arizona, 868–882.
• Tung Y. K., Mays L. W. (1980), Risk analysis for hydraulic design, Journal of the Hydraulics Division, Proc. ASCE, Vol. 106, HY 5, 893–912.
• Yen B. C. (1970), Risk in hydrologic design of engineering projects, Journal of the Hydraulic Division, Proc. ASCE, Vol. 96, HY 4, 959–966.
• Yen B. C., Cheng S. T., Melching C. S. (1986), First order reliability analysis, [in:] Stochastic and Risk Analysis in Hydraulic Engineering, edit. B. C. Yen, Water Resources Publications, Littleton, Colorado, 1–36.
• Yen B. C., Tung Y. K. (1993), Some recent progress in reliability analysis for hydraulic design, [in:] Reliability and Uncertainty Analysis in Hydraulic Design, edit. B. C. Yen, Y. K. Tung, ASCE Publication, New York, 35–80.