Standard Protocol for Comparing Culvert Hydraulic Modeling Software

Abstract

A survey conducted for this study showed that state departments of transportation do not have a common methodology for selecting hydraulic and hydrologic software. Therefore, a standard protocol is developed here to compare hydraulic modeling software, which is the scope of NCHRP Project 20-07(146). The protocol consists of four evaluation components: functionality, detail, user-friendliness, and credibility. A measuring factor is assigned to each evaluation component based on certain criteria, and then the measuring factors of all four components are averaged to determine an overall evaluation factor. A quantitative comparison system for the overall evaluation factor is proposed for comparing and evaluating the modeling software packages on a scale between 0% and 100%. The protocol is universal in nature and can be applied to hydraulic and hydrologic computer models. In this paper the protocol is applied to compare HEC-RAS and HY-8 models as an example for the classification of computer models used for hydraulic analysis of culverts. The model functionality is assessed by comparing the model results with benchmark test data. For that purpose, four test cases are compiled to provide benchmarks for culvert hydraulics. The test cases comprise experimental data and examples from the FHWA Hydraulic Design Series No. 5. Information provided in the documentation of the software packages is used to assess other evaluation components, such as detail, user-friendliness, and credibility. Then, an overall evaluation factor for each model is determined as described above.

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References

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