Investigation of Flow and Local Scour Characteristics Around Permeable WSDOT Dolotimber Engineered Logjams (ELJ)

Details

• Creators:
  Papanicolaou, A.N. Thanos ; Wyssmann, Micah A ; Merook, Adam ; Mohammadi, Sevin
• Corporate Creators:
  University of Tennessee, Knoxville. Department of Civil and Environmental Engineering
• Contributors:
  Heilman, Julie
• Corporate Contributors:
  Washington State Department of Transportation. Research Office
• Subject/TRT Terms:
  Backwaters Bed Shear Stress Decay Function Biodeterioration Deflection Design Erosion Control Flow Permeable Dolotimber Engineered Logjam (ELJ) Structures Porosity Scour Scour Depth Scour Evolution Scour Volume Shear Stress Structure Porosity

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• Publication/ Report Number:
  WA-RD 821.2
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report
• Contracting Officer:
  Saechao, Lu
• Corporate Publisher:
  Washington State Department of Transportation. Research Office
• Abstract:
  Engineered logjams (ELJs) are permeable flow deflection structures that project out from the streambank and are used to stabilize streambanks, protect roadways, and improve aquatic habitat. Dolotimber ELJs are constructed from interlocking large woody material and concrete dolo components to provide optimal performance in terms of structural stability and ecological benefits. The results from this report focus on two primary aspects of scour around ELJs. Part one focuses on the repeatable equilibrium scour characteristics determined through extensive experimentation. The conical scour hole shape extending from the ELJ structure nose is highlighted. Equilibrium scour characteristics are compared with existing predictive methods and are used to develop new physically-based, semi-empirical formulas that consider the effects of both sediment non-uniformity and structure porosity on scour in addition to flow magnitude. Part two focuses on the complex characteristics of scour and flow co-evolution, which have been monitored directly for the first time around permeable structures in a gravel bed. The decay function for relating flow and scour co-evolution is overviewed and developed using this unique data. Also Large Eddy Simulation (LES) numerical modeling for comparable Reynolds numbers with those found in field conditions was employed to visualize the complex three-dimensional flow features generated in the presence of an apex dolotimber ELJ structure.
• Format:
  PDF
• Funding:
  GCB 1930
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:30aeb48624f200ee20294ceae9e814f9f621fa7176a14137a072a4b4e2249987
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/64325/dot_64325_DS1.pdf
• File Type:
  [PDF - 14.07 MB ]