Scour Critical Shear Stress of Ohio Soils

Currently, Ohio Department of Transportation (ODOT) assumes all cohesive soils to be granular soil with the same gradation as fine Ottawa sand, which is the most scourable soil material. This is an unreasonable assumption for cohesive soils, and it over-predicts scour to an unrealistic degree, potentially costing Ohio from a few thousand to millions of dollars per bridge foundation at water crossing structures with cohesive foundation soils. According to the Federal Highway Administration (FHWA) "NextScour" program, "The result of this assumption can be too conservative when soils other than the uniformly graded granular soils are encountered and can dramatically increase the cost of many bridge foundations." ODOT needs to develop reasonable scour guidelines and analyses based on soil scour critical shear stress (tc) to provide realistic predictions of scour depth for scour design floods and scour check floods, so that appropriately efficient and economical foundations can be designed for Ohio bridges. ODOT needs an economical and practical way to estimate tc for input into scour analyses, based on common laboratory soil testing index properties, without the need to resort to expensive and time-consuming flume soil testing to measure tc for each project. ODOT proposes to develop better soil scour guidelines and analyses based on scour critical shear stress (tc), including estimation of tc based on common laboratory soil testing index properties through this study.

Language

• English

Project

• Status: Active
• Funding: $1,488,530.94
• Contract Numbers:

  42929

  136993

  123379

• Sponsor Organizations:

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Managing Organizations:

  Ohio Department of Transportation

  Research Program
  1980 West Broad Street
  Columbus, OH  United States  43223
• Project Managers:

  Spriggs, Jennifer

• Performing Organizations:

  Ohio University, Athens

  Department of Civil and Environmental Engineering
  Athens, OH  United States  45701
• Principal Investigators:

  Khoury, Issam

• Start Date: 20250924
• Expected Completion Date: 20290924
• Actual Completion Date: 0
• Source Data: https://www.dot.state.oh.us/Divisions/Planning/SPR/Research/reportsandplans/Lists/Final%20Reports%20All/AllItems.aspx?useFiltersInViewXml=1&FilterField1=Categories&FilterValue1=Geotechnical&FilterType1=MultiChoice&FilterField2=Research_x0020_Organization&

Subject/Index Terms

• TRT Terms: Bridge foundations; Cohesive soils; Scour; Shear stress; Soil tests
• Geographic Terms: Ohio
• Subject Areas: Bridges and other structures; Geotechnology; Highways;

Filing Info

• Accession Number: 01965870
• Record Type: Research project
• Source Agency: Ohio Department of Transportation
• Contract Numbers: 42929, 136993, 123379
• Files: RIP, STATEDOT
• Created Date: Sep 17 2025 8:35AM