Phase II: Method Development for Construction Design in Diatomaceous Soils

Diatomaceous soils, which contain silica frustules from ancient algae blooms, are prevalent in eastern and central Oregon, including in areas of Oregon Department of Transportation (ODOT) right-of-way. For engineering projects built on top of or in these deposits, problems such as excessive settlement of embankments, slope instability, and construction difficulties with drilled shafts and driven piles have been observed (ex. Wickiup Junction, Buck Creek Bridge). Lack of a robust understanding of the behavior of diatomaceous soils is often cited as the reason for this poor design performance. Complicating matters further, relatively little is documented in the literature regarding the performance of piles in diatomaceous soils. To begin to understand the behavior of diatomaceous soils, ODOT recently invested in a research program (SPR820) to develop predictive estimating models for geotechnical properties of Oregon’s diatomaceous silt, leveraging available data from existing ODOT diatomaceous projects together with targeted field-directed geotechnical testing including an array of in-situ tests at select sites in diatomaceous deposits. These materials have been further characterized through an extensive laboratory testing program. A full-scale field test is now required to develop and validate necessary empirical design methods for deep foundations in diatomaceous silt.

Language

• English

Project

• Status: Active
• Contract Numbers:

  SPR 879

• Sponsor Organizations:

  Federal Highway Administration

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

  Oregon Department of Transportation

  355 Capital St NE MS42
  Salem, Oregon  United States  97301
• Project Managers:

  Glover-Cutter, Kira

• Performing Organizations:

  Oregon State University, Corvallis

  101 Kearney Hall
  Corvallis, OR  United States  97331
• Principal Investigators:

  Evans, Matt

• Start Date: 20231101
• Expected Completion Date: 20270131
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Geotechnical engineering; Pile foundations; Silts; Soil tests; Soils
• Geographic Terms: Oregon
• Subject Areas: Bridges and other structures; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 01964197
• Record Type: Research project
• Source Agency: Oregon Department of Transportation
• Contract Numbers: SPR 879
• Files: RIP, STATEDOT
• Created Date: Aug 28 2025 3:33PM