Bridge Hydraulic Assessment and Design Using Two-Dimensional Finite Element Models

Arthur Parola

Two-dimensional flow analysis using the shallow water flow equations with such programs as FESWMS 2-DH and RMA2 is becoming routine. However, the utility of the programs, methodologies for obtaining high quality results and program limitations are still not widely known. This presentation will provide illustrative examples of their use in several analysis conducted for practical and research problems. The examples will include bridge scour analysis, skewed bridges, complex splitting flows around islands and around pier walls, flood elevation increases associated with large piers in the Ohio River, evaluation of the impacts of Natural Channel Design and habitat enhancement structures, and design of efficient bridge embankment shapes. Each example will illustrate the utility, limitations and specific methodologies that are required to develop effective finite element method (FEM) meshes and flow parameters. The presentation will also include information on the quality of topographic data, FEM meshes and the interpretation of results.