In-situ ice ridge scour tests: experimental set up and basic results

An in-situ program was carried out in the Van Mijen fjord on Spitsbergen during the 2002 and 2003 winter seasons to investigate the ice ridge scour process. Two ice scour tests and one shear off test were performed. Ice ridges with dimensions of up to 4.0×4.0×2.45 m were artificially made by cutting the level ice into pieces to produce ice rubble. The ridges were left to consolidate for up to 4 weeks and then pulled towards the beach scouring the seabed that consisted of clayey sediments (ice scour tests). The ice ridge for the shear off test was built up in a pre-excavated trench in hard moraine. During pulling the keel of the ice ridge was sheared off by the sidewall of the trench. The pulling force, displacements, failure of the keel and resulting plough marks were measured. This paper provides a description of the test arrangement and the basic experimental results.