BRIDGE WATERWAYS ANALYSIS MODEL: RESEARCH REPORT. FINAL REPORT

This report describes WSPRO which is a digital model for water-surface profile computations. Profile computations for open-channel flow are compatible with conventional techniques used in existing step-backwater analysis models. WSPRO incorporates several desirable features from existing models. Profile computations for free-surface flow through bridges are based on relatively recent developments in bridge backwater analysis and recognize the influence of bridge geometry variations. Pressure flow situations (girders partially or fully inundated) are computed using existing Federal Highway Administration techniques. Embankment overtopping flows, in conjunction with either free-surface or pressure flow through the bridge, can be computed. WSPRO is also capable of computing profiles at stream crossings with multiple openings (including culverts). Although specifically oriented toward hydraulic design of stream highway crossings using risk analysis, WSPRO is equally suitable for water-surface profile computations unrelated to highway design. The report provides a detailed discussion of the theory and computational techniques used in the model. Model capabilities and data requirements are described in more general terms. Specific data coding instructions and examples of model applications are to be published in a users manual. Results of model applications to five field-verification sites are discussed, along with a comparison of WSPRO results with results obtained from two existing models. Also presented is a discussion of the applicability of WSPRO to design of bridges with risk analysis.