Determine Forces Required to Uplift Marine Piles due to Water Level Changes

摘要

All previous work on uplifting ice forces, theoretical as well as experimental, has focused on the forces necessary to extract a pile from an ice sheet in one pull-out. In the present test series, the piles were cycled up and down in hundreds of cycles in order to stimulate natural conditions throughout a winter. The results of this program may be summarized as follows: a) Evaluation of theoretical formulae for predicting the ice-induced vertical forces in a pile; b) Evaluation of theoretical formulae for predicting the ice-induced vertical forces in an interacting group of piles; c) Laboratory verification of successive processes responsible for step-wise jacking of piles by ice; d) Establishment of a theory on the refreezing of cracks, and derivation of an empirical formula to predict the relative flexural strength of a particularly refrozen crack.