STRESSES AND DEFLECTIONS IN FLEXIBLE PIPE CULVERTS

COMPARISON OF DEFLECTIONS OF FLEXIBLE PIPE COMPUTED BY THE IOWA FORMULA, AS ANNOUNCED IN 1941, WITH MEASURED DEFLECTIONS SECURED AT THE UNIVERSITY OF NORTH CAROLINA PRIOR TO 1929, AND AT IOWA STATE COLLEGE INDICATES VERY CLOSE AGREEMENT BETWEEN MEASURED AND COMPUTED VALUES. THIS RECENT STUDY OF THE NORTH CAROLINA DATA ADDS TO GREATLY NEEDED KNOWLEDGE OF THE QUANTITATIVE NATURE OF THE MODULUS OF PASSIVE PRESSURE OF SOIL. BOTH THE IOWA AND NORTH CAROLINA DATA SUPPORT THE THEORY THAT INCREASE IN LATERAL PRESSURE AT THE SIDES OF A PIPE BEARS A CONSTANT RELATION TO INCREASE IN HORIZONTAL DEFLECTION AS HEIGHT OF FILL INCREASES, ALTHOUGH FURTHER INVESTIGATION IS NEEDED. THERE IS ALSO EVIDENCE, ALTHOUGH NOT CONCLUSIVE, THAT THE MODULUS OF PASSIVE PRESSURE MAY VARY WITH THE INHERENT RIGIDITY OF A PIPE, AND THAT THE MODULUS DECREASES AS THE PIPE DIAMETER INCREASES. THE PAPER ALSO DISCUSSES THE DESIGN CRITERION, THAT DEFLECTION SHOULD BE LIMITED TO SOME CONSTANT PERCENTAGE OF PIPE DIAMETER, IN COMPARISON WITH USE OF A CONSTANT VALUE OF FIBER STRESS FOR THE SAME PURPOSE, AND CONCLUDES THAT ALTHOUGH THE LATTER IS MORE LOGICAL IN SOME RESPECTS IT IS NOT A SUITABLE CRITERION FOR DESIGN. /AUTHOR/

• Record URL:
  https://onlinepubs.trb.org/Onlinepubs/hrbproceedings/28/28-021.pdf
• Supplemental Notes:
  • Vol 28, pp 249-259, 12 FIG, 2 TAB, 4 REF. 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.
• Authors:
  • Spangler, M G
  • Shafer, G E
• Publication Date: 1949

Media Info

• Media Type: Digital/other
• Monograph Title: Proceedings of the Twenty-Eighth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 7-10, 1948
• Serial:
  • Highway Research Board Proceedings
  • Volume: 28
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Deflection; Design; Pipe culverts; Stresses
• Uncontrolled Terms: Design criteria; Lateral pressure
• Old TRIS Terms: Passive pressures
• Subject Areas: Design; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00204363
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Oct 3 1971 12:00AM