Now showing 1 - 2 of 2
  • Publication
    Field investigation of the effect of installation method on the shaft resistance of piles in clay
    This paper presents the results of a series of field experiments performed to study the effect of installation method on the shaft resistance developed by a pile installed in soft clayey silt. Tests were performed on piles which experienced different levels of cyclic loading during installation. The test results indicate that the radial total stress, pore water pressure and shear stress on the pile shaft during installation, were strongly affected by the installation procedure; all three were found to increase when the jacking stoke length used during installation increased (or the number of cyclic load applications decreased). However, equalised radial effective stresses which control the long-term pile shaft capacity were found to be insensitive to the installation method. A simple expression is proposed which requires the results of a cone penetration test, laboratory measurements of the interface friction angle and the pile geometry is proposed to calculate the shaft resistance.
      2603ScopusĀ© Citations 23
  • Publication
    Field investigation of base resistance of pipe piles in clay
    (Institution of Civil Engineers, 2010-02-01) ; ;
    This paper presents the results of a series of field tests performed to study the effect of soil plugging during installation on the base resistance developed by an open-ended (pipe) pile in clay. Three instrumented pipe piles were installed in soft clay, and the installation resistance and soil plug development were recorded. The tests revealed that the annular base resistance was equal to the cone penetration test q c resistance and was independent of the soil plug development. In contrast, the soil plug resistance increased from a minimum when the pile was fully coring to a maximum when the pile was fully plugged. A simple expression is proposed that links the plug resistance to the cone penetration test q c value at the specified depth and the incremental filling ratio value developed during installation. This expression is shown to provide reasonable estimates of the plug resistance developed by a large-diameter pipe pile driven into stiff to hard clay in the North Sea. The proposed relationship will be particularly useful for modelling the installation resistance of monopile foundations.
      1115ScopusĀ© Citations 26