Development of new design guidelines for protection against erosion at bridge abutments - Phase V

The present research proposes the use of a numerically-based approach to quantify and understand the effects of the flow becoming pressurized under high flow conditions on the critical discharge and Froude numbers for stone failure of riprap aprons used to protect spill-through abutments. Moreover, the research aims to develop design formulas to estimate the minimum riprap stone size for protection against erosion of spill-through abutments and wing-wall abutments under pressurized flow conditions due to bridge deck overtopping. The mean flow fields predicted using fully 3-D RANS simulations are used to estimate the maximum bed shear stress over the riprap layer and the critical Froude number corresponding to the shear-failure entrainment threshold for the riprap stone. During the first four years, the numerically-based approach was validated for the case of wing-wall abutments placed in a straight channel and two new two-parameter formulas were proposed for riprap design at wing-wall abutments and at spill-through abutments placed in straight or curved channels. Moreover, simulations conducted for wing-wall abutments in straight channels allowed understanding how the critical Froude number varies with increasing flow depth in between open-channel flow and pressurized flow (submerged deck) conditions at the bridge site. For the fifth year, the main goal will be to perform a similar study for spill-through abutments. The second goal will be to develop procedures for riprap sizing at wing-wall and spill-through abutments under pressurized flow conditions. Recommendations will be made for inclusion of the new design formulas in future versions of HEC-23.

• Record URL:
  https://matc.unl.edu/research/research_project.php?researchID=677

Language

• English

Project

• Status: Completed
• Funding: $150393
• Contract Numbers:

  69A3551747107

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Managing Organizations:

  Mid-America Transportation Center

  University of Nebraska-Lincoln
  2200 Vine Street, PO Box 830851
  Lincoln, NE  United States  68583-0851
• Project Managers:

  Stearns, Amy

• Performing Organizations:

  University of Iowa, Iowa City

  IIHR- Hydroscience & Engineering
  307 C. Maxwell Stanley Hydraulics Lab
  Iowa City, Iowa  United States  52242
• Principal Investigators:

  Constantinescu, George

• Start Date: 20220101
• Expected Completion Date: 20221231
• Actual Completion Date: 20230531
• USDOT Program: University Transportation Centers Program
• Source Data: RiP Project 91994-97

Subject/Index Terms

• TRT Terms: Bridge abutments; Bridge design; Erosion; Erosion control; Flood plains; Froude number; Guidelines; Riprap; Shear stress; Simulation; Validation
• Subject Areas: Bridges and other structures; Design; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 01844447
• Record Type: Research project
• Source Agency: Mid-America Transportation Center
• Contract Numbers: 69A3551747107
• Files: UTC, RIP
• Created Date: Apr 30 2022 11:42AM