Rubble Ice Transport on Arctic Offshore Structures (RITAS), part I: Scale-Model Investigations of Level Ice Action Mechanisms

A model scale experiment on the interaction between level ice and an arctic offshore structure with a downward bending hull was conducted in April 2012 in the large ice tank of HSVA (Hamburg Ship Model Basin). The experiment investigated the different mechanical processes contributing to the ice action. The present paper is completed by a companion paper “Rubble Ice Transport on Arctic Offshore Structures (RITAS), part II: 2D scale-model study of the level ice action”. Detailed investigations on special aspects of the level ice action mechanisms are presented in “Rubble Ice Transport on Arctic Offshore Structures (RITAS), part III: Analysis of scale-model rubble ice stability” and “Rubble Ice Transport on Arctic Offshore Structures (RITAS), part IV: Tactile sensor measurement of the level ice load on inclined plate”. The structure is inclined at the waterline and promotes a downward bending failure of the level ice. Several parameters are varied: structure width, ice incidence, ice thickness, ice elastic modulus, ice density, ice velocity. The structure front is vertically divided in three sections allowing independent measurement of the load at the waterline and the load from the accumulated ice rubble. The experimental results show that the level ice load is affected by the ice rubble accumulation up to a certain ice rubble amount. A lower ice density increases the ice load due to the increased ice rubble buoyancy. For the selected aspect ratios, a doubling of the structure width increased the rubble load but not the waterline load.