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/

  • Supplemental Notes:
    • Vol 28, pp 249-259, 12 FIG, 2 TAB, 4 REF
  • Authors:
    • Spangler, M G
    • Shafer, G E
  • Publication Date: 1949

Media Info

  • Monograph Title: Proceedings of the Twenty-Eighth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 7-10, 1948
  • Serial:

Subject/Index Terms

Filing Info

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