FIELD STUDIES OF AN INSTRUMENTED MODEL PILE IN CLAY

An instrumented model pile was used to investigate the fundamental behavior of driven cyclindrical steel piles in clay soils. Data are given from the test-bed sites, one with heavily overconsolidated clay, and one with normally consolidated clay. These confirm that a residual shear surface is formed adjacent to the pile shaft during installation. Comparisons with other site investigation data and cavity expansion theoretical predictions suggest that stress relief immediately behind the pile tip during installation gives rise to total radial stress, and pore pressure measurements on the shaft which are lower than the simple cavity expansion model predicts. However, the data did indicate that the radial effective stress might be successfully predicted. During reconsolidation, the radial effective stress drops initially, followed by a slow recovery which was insufficient in the 2 clays investigated for the final value to reach that during installation. On undrained loading, the clay adjacent to the pile did not reach a critical state as failure occurred on the residual surface created during installation. The generation of negative excess pore pressures on the shear surface during undrained loading caused an increase in the radial effective stress. In the normally consolidated clay this was solely responsible for the large set-up of pile shaft capacity by comparison with that during installation. The same capacity increase may not be seen in these clays if loading were drained.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00168505
• Corporate Authors:

  Thomas Telford Limited

  London,   United Kingdom 
• Authors:
  • COOP, M R
  • Wroth, C P
• Publication Date: 1989-12

Media Info

• Features: Figures; References;
• Pagination: p. 679-696
• Serial:
  • GEOTECHNIQUE
  • Volume: 39
  • Issue Number: 4
  • Publisher: Thomas Telford Limited
  • ISSN: 0016-8505

Subject/Index Terms

• TRT Terms: Building; Clay; Effective stress; Facilities; Field studies; Forecasting; Installation; Instrumentation; Steel; Stress relieving; Support piles
• Uncontrolled Terms: Driven piles; Steel piling
• Subject Areas: Construction; Geotechnology; Highways; Maintenance and Preservation; I42: Soil Mechanics;

Filing Info

• Accession Number: 00490800
• Record Type: Publication
• Files: TRIS, ATRI
• Created Date: Jan 31 1990 12:00AM