Failure of a Barrette As Revealed in an O-Cell Test

A 1.5 x 2.8 m, 44.5 m deep barrette was constructed in weathered sedimentary rock of the Jurong formation in Singapore with an O-cell assembly of two O-cells installed at 33.5 m depth, 11 m above the barrette toe, chosen presuming that resistance above and below the cell level would balance. When the O-cell test was performed, a proof test at the end of the construction work, the shaft resistance for the section above the O-cell level was surprisingly low; the shaft failed at a load of only about 3 MN. In a re-test, at the maximum O-cell load of 12.5 MN, the upward movement exceeded 100 mm. The barrette was then tested in a conventional head-down test, which first (second test stage) was with the O-cell vented to validate the results of the O-cell test. In a third stage, the opening between the O-cell plates was grouted in order to transfer load across the O-cell level to mobilize the shaft resistance along the lower section of the barrette and the toe resistance. The results of Stage 1 O-cell upward test and Stage 2 head-down test on the pile with free-draining O-cell agreed well, as did the Stage 1 equivalent head-down test and Stage 3 head-down test. Stage 3 test confirmed a 12 MN working load, downgraded from the original 33 MN value. The test results are discussed and referenced to a numerical (FEM) analysis.

• Record URL:
  https://doi.org/10.1061/9780784412084.0023
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784412084
• Supplemental Notes:
  • © 2012 American Society of Civil Engineers.
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Ann, Tan Siew
  • Fellenius, Bengt H
• Conference:
  • GeoCongress 2012
  • Location: Oakland California, United States
  • Date: 2012-3-25 to 2012-3-29
• Publication Date: 2012-3

Language

• English

Media Info

• Media Type: Web
• Pagination: pp 307-321
• Monograph Title: Full-Scale Testing and Foundation Design: Honoring Bengt H. Fellenius

Subject/Index Terms

• TRT Terms: Foundation engineering; Load tests; Pile foundations; Sedimentary rocks
• Uncontrolled Terms: Barrettes; Bored piles; Osterberg cells
• Geographic Terms: Singapore
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01529945
• Record Type: Publication
• ISBN: 9780784412084
• Files: TRIS, ASCE
• Created Date: Jul 1 2014 5:28PM