Formation of soil plug in open-ended pipe piles in sandy soils

Abstract

Open-ended pipe piles are commonly used for the foundations of offshore jacket platforms, mooring piles, offshore wind turbines and, in general, for pile foundations like micro piles, etc. Driveability of open-ended piles is greatly affected by the formation of soil plug during the driving, particularly in sandy soils. In order to study the behaviour of formation of soil plug during driving, open ended model piles were driven into uniformly graded sand in a calibration chamber in the laboratory scale as well as in the field. The influence of the pile diameter, hammer energy and pile penetration depth were studied. The results of the model pile tests showed that the incremental filling ratio (IFR, which indicates the degree of plugging) during driving decreased with pile penetration and increased with increase in hammer energy. IFR has also increased with increase in pile diameter. A correlation between plug length ratio (PLR, percentage plug height with respect to total penetration) and IFR is proposed based on the laboratory experiments.