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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

Overview

 

Research and Development (R&D) Project Sites

Project Information
Project ID:   FHWA-PROJ-09-0004
Project Name:   Reevaluation of the Adjustment Factor for Coarse Bed Material Under Clear-Water Scour Condition
Project Status:   Completed
Start Date:  February 1, 2009
End Date:  September 30, 2011
Contact Information
Last Name:  Kerenyi
First Name:  Kornel
Telephone:  202-493-3142
E-mail:  kornel.kerenyi@dot.gov
Office:   Office of Infrastructure Research and Development
Team:   Hazard Mitigation Team [HRDI-50]
Program:   Innovative Bridge Research and Deployment
Laboratory:   J. Sterling Jones Hydraulics Laboratory
Project detail
Roadmap/Focus area(s):   Infrastructure Research and Technology Strategic Plan and Roadmap
Project Description:   The study will analyze the effect of pier scour coarse bed material. If the riverbed material has more large sand particles than fine sand, pier scour will be reduced because large particles will withstand the hydraulic dislodging forces and therefore armor the scour hole. If the particle distribution consists of more fine sand than large particles, pier scour will be greater. This research will study the influence of sand particle distribution on bridge pier scour. The goal is to develop an improved scour equation for coarse sand particle distribution by revisiting and improving the methodology suggested in Hydraulic Engineering Circular No. 18; a methodology that is difficult to apply.
Goals:   The study will develop a new pier scour equation for course bed material. The new design procedure will replace the outdated coarse bed material adjustment factor in the current pier scour equation in Hydraulic Engineering Circular No. 18 "Evaluating Scour at Bridges."
Product Type:   Research report
Test Methodology:   The research study will consist of laboratory experiment, field data, and computational fluid dynamics simulations to derive the new equation. The influence of gradation of bed material, such as gravel, sand, and fine sediment, will be expressed in terms of an improved Froude number, the densimetric Froude number, or Hager number.
Expected Benefits:   The expected benefit is that the research will improve the bridge pier scour prediction design procedure in course bed material.
Deliverables: Name: Bridge pier scour design equation for course bed material.
Product Type(s): Research report
Description: The study will develop a new pier scour equation for course bed material. The new design procedure will replace the outdated coarse bed material adjustment factor in the current pier scour equation in Hydraulic Engineering Circular No. 18 "Evaluating Scour at Bridges."
FHWA Topics:   Roads and Bridges--Hydraulics
TRT Terms:   Scour
Infrastructure
Bridges
Research
Froude Number
Sediments
FHWA Disciplines:   Hydraulics
Subject Areas:   Hydraulics and Hydrology

 

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