Advanced Ice Model Test Techniques and Services for Future Scenarios of Arctic Logistics and Infrastructure

Abstract

Abstract One consequence of climate change is that sea areas that were usually subjected to harsh ice conditions now become accessible for exploration of oil and gas and other offshore or shipping activities. The average ice extent decreases and the probability of heavy ice conditions decrease steadily in many arctic or subarctic regions. Nevertheless ice occurrence in those regions can never be excluded and extensive theoretical and experimental studies are usually performed to design and optimize floating platforms, coastal and grounded structures or other installations. This paper discusses adaptions and prioritization in engineering approaches to address the needs of future scenarios of arctic maritime activities. Several crucial aspects to be considered when investigating the interaction of sea ice with a floating platform or vessel are reviewed and disussed through an exemplary operation case. The relevance of model tests is discussed with regards to model ice type, ice formation (level ice, broken ice, ice ridges, rubble ice, etc) as well as scaling of ice properties. In a first step the main gaps and uncertainties of state of the art scale model testing and numerical simulations in ice are identified. In a second step the list of open questions and uncertainties is compared to expected requiremnets of future arctic / antarctic activities. A recently developed type of model ice specifically design for better reproduction of crushing failure is also introduced and compared to standard model ice. Furthermore, some complex testing methods such as the combination of wave and ice (marginal ice zone), the proper reproduction of friction (hull-ice, but also concrete-ice, rubber-ice, rubber-steel in port areas) as well as shallow water effects and modeling of ice impact to coastal structures. In close relationship to the testing techniques, the instrumentation of the test set-up is of significant importance, since measuring accurate loads without affecting the quality of the modelling is not trivial. Most relevant/ suitable load measurement techniques (load cells, instrumented pockets, tactile sensors, etc.) are presented. Additionally, the importance of simulation-based design is also discussed. Prior to a model test campaign, simulations can be used to compare several variants and select the most promising one(s) to be investigated further by model tests. Subsequently to testing, a simulation setup can be calibrated to extent numerically the matrix of experimental testing.