O-Cell Tests on Two 70 m Long Bored Piles in Vietnam

Static loading tests using single-level O-cells were carried out in mid-2008 on two bored piles constructed at the Binh Loi Bridge, crossing the Saigon River at Ho Chi Minh City, Vietnam. The soils consist of surficial layers of soft clay and silt to 11 and 15 m depth on compact silty sand to about 55 m depth followed by dense to very dense silty sand. Two bored piles, 2.0 m and 1.5 m in diameter, were installed to 73.5 m and 73.0 m depth, respectively, and constructed using reverse circulation technique and bucket drill with casing advanced ahead of the hole. Drilling slurry was composed of polymer slurry for the 2.0-m diameter pile and bentonite slurry for the 1.5-m diameter pile. For both piles, the O-cell assembly was attached to a reinforcing cage lowered into the stabilized hole to 11.4 and 11.6 m, respectively, above the pile toe, five and two days after completing drilling and cleaning, respectively. Each reinforcing cage was instrumented with two pairs of diametrically opposed vibrating wire strain gauges at three levels below and five levels above the O-cell level. The static loading tests were performed 49 and 28 days, respectively, after the piles had been concreted. The strain-gauge records, when based on the nominal pile diameters, indicated Young's modulus values of about 25 GPa for the nominal cross-sections of the piles. Analysis of the records showed that residual load had developed during the wait time. The unit shaft resistance above the O-cell for the 2.0 m diameter, polymer-slurry constructed pile was moderately larger than that for the 1.5-m diameter, bentonite-slurry constructed pile. Detailed analysis showed the shaft resistance to be post-peak softening. The pile toe stress-movement responses were essentially linear and almost identical for the two piles.

• Record URL:
  • https://doi.org/10.1061/9780784413265.039
• Summary URL:
  • http://ascelibrary.org/doi/abs/10.1061/9780784413265.039
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784413265
• Supplemental Notes:
  • © 2014 American Society of Civil Engineers.
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Hai, Nguyen Minh
  • Fellenius, Bengt H
• Conference:
  • Geo-Congress 2014
  • Location: Atlanta Georgia, United States
  • Date: 2014-2-23 to 2014-2-26
• Publication Date: 2014-2

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 482-496
• Monograph Title: From Soil Behavior Fundamentals to Innovations in Geotechnical Engineering

Subject/Index Terms

• TRT Terms: Bridges; Drilling; Load tests; Soft clays; Soil mechanics; Static loads; Strain gages; Support piles
• Uncontrolled Terms: Bored piles; Shaft resistance
• Geographic Terms: Vietnam
• Subject Areas: Bridges and other structures; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics;

Filing Info

• Accession Number: 01522491
• Record Type: Publication
• ISBN: 9780784413265
• Files: TRIS, ASCE
• Created Date: Apr 22 2014 4:07PM