Journal of Cold Regions Engineering

The two suction foundation platforms installed in the Bohai Sea have vertical narrow columns passing through the water level. The continuous ice crushing on the columns and thereby the dynamic ice-structure interaction may usually happen during the ice season resulting in sustained violent vibrations of the structures. The paper first introduces the ice-induced vibration analysis of the suction foundation platform by using the self-excited vibration theory. Then the maximum dynamic shear stresses in the soil induced by ice are obtained from the analyses. By comparing the dynamic stresses to the cyclic strength of soil, which can be determined according to soil characteristics and features of the dynamic loading, the potential soil liquefaction is finally assessed.

The influence of enlarging the base of a pile on the total and end bearing capacities of a pile in ice-rich permafrost is evaluated along with the principles used to evaluate the total capacity of uniform diameter and belled piles of the same length in ice-rich soils. Procedures developed by Weaver and Morgenstern in 1981 for predicting the total capacity of straight piles are extended to predict the capacity of belled piles to study the capacity of enlarging the pile base. The total capacity can be substantially improved through the use of belled piles. Techniques to form the bell in different types of permafrost are reviewed with an emphasis on jet cutting. The techniques to allow for installation are described as well as the need for field tests to confirm the proposed installation technique and the predicted increased capacity.