Comparison of Kemi-I and Confederation Bridge cone ice load measurement results

Abstract

A Joint Finnish Industry Project in 1983–87 measured cone ice loads by installing an instrumented cone around the Kemi-I lighthouse in the Gulf of Bothnia. A Canadian University/Joint Industry Project has been conducting cone ice load measurements since 1997 on two instrumented piers of the Confederation Bridge, in the Southern Gulf of St Lawrence. The diameters of the cones at the waterline are 10 and 14 m respectively. Ice conditions are more severe at Kemi-I but ice movement is faster and ridge encounters more frequent at Confederation Bridge. However, all types of first year ice features have been encountered at both locations. The cone ice load measurements and observations indicate that ice failure patterns and broken floe clearing mechanisms are, in general, similar. Comparisons with reference to ice thickness, temperature, and velocity, are made on: rubble formation, rubble surcharge height, rubble jamming, pressure ridge failure modes, dynamic effects, and measured and predicted ice loads. The results pave the way for a better understanding of ice failure against cones and cone ice load design.