EFFECTS OF METHODS A AND B BACKFILL ON FLEXIBLE CULVERTS UNDER HIGH FILLS

Two large-diameter; structural steel plate pipes embedded in deep embankments were instrumented and tested to assess circumferential soil stress distributions, deformations, and internal strains. Construction techniques included the "imperfect trench" method (method B backfill) and positive projection (method A backfill). Method B uses layers of baled straw over a 114-in. (290-cm) pipe under 89 ft (27 m) of overfill. Method A consists of ordinary embankment materials surrounding twin, 108-in. (274-cm) pipes under 160 feet (49 m) of overfill. Method B soil stress-fill height functions were nonlinear; strains and strain gradients in the pipe walls were larger than those observed for the method A installation. Radial displacements were smaller than those observed for the method A installation. Method A soil stress-fill height functions were essentially linear. Observed deformations and stresses were compared with theoretical values obtained from Marston's theory, the Iowa deflection formula, and the ring compression method. The ring compression method provided correlations that were sufficient for design purposes. Internal strains were correlated with external, measured pressures by nautral point and finite element methods. Baled straw inclusions are not recommended for future designs of flexible pipe culverts. Design can be based on ring compression with a safety factor of 4, but a 70 percent increase in soil densities may be anticipated over a period of time after fill completion.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1974/510/510-004.pdf
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=EFFECTS+OF+METHODS+A+AND+B+BACKFILL+ON+FLEXIBLE+CULVERTS+UNDER+HIGH+FILLS&author=D.+Spannagel&author=R.+Davis&author=A.+Bacher&publication_year=1974
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03611981
• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Subsurface Soil-Structure Interaction. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Spannagel, David W
  • Davis, Raymond E
  • Bacher, Alfred E
• Conference:
  • 53rd Annual Meeting of the Highway Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1974-1-21 to 1974-1-25
• Publication Date: 1974

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 41-55
• Monograph Title: SOIL MECHANICS
• Serial:
  • Transportation Research Record
  • Issue Number: 510
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Backfilling; Compression tests; Culverts; Deflection; Deformation; Deformation curve; Density; Fills; Finite element method; Formulas; Methodology; Pipe culverts; Pressure; Prototypes; Triaxial shear tests
• Old TRIS Terms: Backfills; Culvert pressure; Imperfect trench method; Ring compression and flexibility factor; Stress distribution (Soils)
• Subject Areas: Bridges and other structures; Construction; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00081326
• Record Type: Publication
• ISBN: 0309023548
• Files: TRIS, TRB
• Created Date: Mar 26 1975 12:00AM