Load transfer and creep behavior of open-ended pipe piles in frozen and unfrozen ground

This paper presents load transfer mechanism and creep behavior of a model open-ended pipe pile installed in frozen ice-rich silt in Gloucester, ON, Canada. Load transfer of this model pile under unfrozen condition is also presented and discussed. The measured pull-out capacity of the test pile in unfrozen condition agreed well with the predicted capacity using a previously published design model. A modified form of this theoretical model was developed to predict the pull-out capacity of the test pile for the frozen condition. The predicted capacity using the modified equation agreed well with the measured field capacity in the frozen soil. The creep behavior of the test pile in frozen soil was dependent on the applied stress and the frozen ground temperature. The creep rate of the test pile increased when the frozen ground became warmer even under a constant creep stress. The pile creep rates measured in the current study compared well with the predicted creep rates from one of the previously published pile creep models.