Iowa, as well as other states, has experienced several failures of corrugated metal pipe (CMP) culverts, apparently because of inlet flotation. In Iowa, most of these failures have occurred on secondary roads. In a survey of Iowa county engineers, 31 CMP culvert failures occurred within a 5-year period (1983 to 1988). A survey of state departments of transportation revealed nine CMP failures within the 5 years preceding 1992. Design standards from various states for tiedowns to resist uplift showed resisting forces ranging from 44.5 kN (10 kips) to 293.7 kN (66 kips) for pipes 2.03 m (80 in.) in diameter. Data from the survey of states verified an earlier conclusion based on responses from Iowa county engineers that when end restraint is not provided, there is a potential for uplift failures. Further, standards for existing restraint systems have an unclear theoretical or experimental basis, or both. Discussed here is the initial phase of a research program at Iowa State University, where a design procedure is being developed to determine the necessity and magnitude of restraining force to prevent CMP uplift failures. Theoretical relationships were developed for predicting the longitudinal stiffness, yield moment capacity, and ultimate moment capacity of CMP. Full-scale tests of steel CMPs 1.22 m (4 ft) and 1.83 m (6 ft) in diameter experimentally determined EI factors of 2.49 MN-sq m (869 x 10 to the 6th power sq in.-lb.) and 2.61 MN-sq m (911 x 10 to the 6th power sq in.-lb), respectively (3 x 1 corrugation style). Theoretical results were 2.39 MN-sq m (832 x 10 to the 6th power sq in.-lb) and 2.83 MN-sq m (985 x 10 to the 6th power sq in.-lb) for the two pipes. The agreement of theoretical and experimental results verifies the accuracy of the theoretical relationships which will be used in the development of rational design standards.


  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 1-9
  • Monograph Title: Design and performance of underground pipe
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00715648
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jan 25 1996 12:00AM