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Research and Development (R&D) Project Sites

Project Information
Project ID:   FHWA-PROJ-13-0039
Project Name:   Field Data Collection of Truck Spray
Project Status:   Active
Start Date:  September 1, 2013
End Date:  August 1, 2014
Contact Information
Last Name:  Ocel
First Name:  Justin
Telephone:  202-493-3080
E-mail:  justin.ocel@dot.gov
Office:   Office of Infrastructure Research and Development
Team:   Bridge and Foundation Engineering Team [HRDI-40]
Program:   High-Performing Steel Bridge
Laboratory:   J. Sterling Jones Hydraulics Laboratory
Project detail
Roadmap/Focus area(s):   Infrastructure Research and Technology Strategic Plan and Roadmap
Project Description:   This project will collect data from the field to characterize the spray clouds emanating from vehicles as they drive beneath a bridge structure. The data may be in the form of cloud density measurements, particle velocities, or both.
Goals:   Collect the necessary data of vehicular spray clouds that can be used to verify computational fluid dynamics models of the same scenario.
Background Information:   The Federal Highway Administration Office of Bridge Technology has a strong desire to update its 1989 Technical Advisory (TA 5140.22) regarding the application of uncoated weathering steel in bridges. The Technical Advisory (TA) was issued to advise bridge owners where uncoated weathering steel bridges had been susceptible to accelerated corrosion, whether that be from atmospheric or deicing chemicals. One particular scenario where uncoated weathering steel is not advisable is at grade separations in which “the so-called tunnel effect is produced by the combination of narrow depressed roadway sections between vertical retaining walls, narrow shoulders, bridges with minimum vertical clearances and deep abutments adjacent to the shoulders as are found at many urban/suburban grade separations.”  The observation at the time the TA was written was that spray coming off vehicle tires from wet pavement heavily contributed to accelerated corrosion of overhead, uncoated weathering steel bridge structures with a “tunnel-like” configuration. The problem with the existing TA language in that the TA gives no specific guidance regarding the geometrics that define the “tunnel effect,” such as clearance height, girder spacing, distance to walls/piers/embankments, etc. In early 2011, computational fluid dynamics (CFD) analysis of just these types of scenarios was funded through an Interagency Agreement with Argonne National Laboratory. In development of the models, many assumptions had to be made regarding the mass and velocity of the tire spray, which have a broad effect on the analysis outcomes. Generally, real-world data must be collected that could verify the assumptions within the CFD modeling strategy. The objective of this study is to identify a candidate bridge structure, conduct a matrix of test scenarios, and collect data that can give an indication of the tire spray cloud density and/or velocity in the event passage of vehicle(s) beneath an overhead bridge. The data collected can then be compared to CFD models of the testing scenarios for verification.
Test Methodology:   Full-scale field monitoring.
Partners:   Federal Highway Administration: Office of Research, Development, and Technology - Office of Infrastructure Research and Development;
Expected Benefits:   Verification of computational fluid dynamics models so modeling of trucks driving beneath bridges can continue.
FHWA Topics:   Roads and Bridges--Structures
TRT Terms:   Weathering Steel
Steel Bridges
Fluid Dynamics
FHWA Disciplines:   Structures
Subject Areas:   Bridges and other structures


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