INVESTIGATION OF LARGE DEFORMATIONS OF A CORRUGATED METAL PIPE IN SILTY SOIL

A 1.83-m-diameter corrugated metal culvert was installed as part of a flood control project in West Williamson, West Virginia. The culvert was installed in a 3.35-m-wide trench, and its crown was up to 9 m below grade. By the end of construction, the culvert experienced deformations that decreased its vertical diameter by as much as 15% and increased its horizontal diameter by as much as 10%. On the basis of the magnitude of the observed deformations, the owner decided to replace the culvert and to commission a study to determine the cause of the deformation of the pipe. The study was conducted in two phases. The first involved finite element analyses using soil properties based on conventional laboratory tests. The results indicated that the soils in the field must have been considerably more deformable than indicated by the results of the conventional tests. It seemed likely that the deformability of the in situ silty soils at the site might have been increased as a result of the vibratory compaction used to compact the soil around the culvert. The second phase involved finite element analyses using soil parameters from special vibratory loading tests on undisturbed specimens. The laboratory testing program indicated that vibratory loading can cause a significant reduction in the stiffness of silts. The finite element analyses indicated that such a loss of soil stiffness during construction could result in deformations similar to those observed in the field. On the basis of the laboratory test data and the agreement between the results of the analyses and the measured field deformations, it appears that some silts are subject to considerable softening under the influence of vibratory loads. In cases like the one described, where silts are subjected to static loads during vibration, deformations may be considerably larger than those that would occur under the influence of static loads without vibrations.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 3-12
  • Monograph Title: Culvert distress and failure case history and trenchless technology
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00666213
  • Record Type: Publication
  • ISBN: 0309055091
  • Files: TRIS, TRB
  • Created Date: Sep 15 1994 12:00AM