An approach to evaluation of field CPTU dissipation data in overconsolidated fine-grained soils

  • Author(s) / Creator(s)
  • Abstract: Dissipation of excess pore pressures during piezocone testing in firm to stiff overconsolidated fine-grained soils provides data curves that cannot be interpreted using published theoretical solutions. Available solutions are based on either cavity-expansion or strain-path methods, which have been developed for soft, normally consolidated soils and do not adequately model the response in overconsolidated soils. During penetration in overconsolidated soils, large pore-pressure gradients and unloading can exist as the soil moves past the singularity at the cone tip shoulder; these gradients modify the initial pore-pressure distribution around the tip and along the friction sleeve and give rise to nonstandard dissipation curves. The different types of response resulting from the modified pore-pressure distribution are discussed and classified and a correction technique is proposed. In this way, the application of available theoretical models can be used to evaluate in situ flow characteristics. Examples of the different types of pore-pressure response are presented from various sites worldwide.

  • Date created
    1999
  • Subjects / Keywords
  • Type of Item
    Article (Published)
  • DOI
    https://doi.org/10.7939/R3W08WH0F
  • License
    © 1999 NRC Research Press (Canadian Science Publishing). This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.
  • Language
  • Citation for previous publication
    • Sully, J., Robertson, P., Campanella, R., & Woeller, D. (1999). An approach to evaluation of field CPTU dissipation data in overconsolidated fine-grained soils. Canadian Geotechnical Journal, 36(2), 369-381. DOI: 10.1139/cgj-36-2-369.