The choice of ice conditions for ice model tests to support the industrial development of the Оb’ Вay

Abstract

The Ob’ Bay has long been the main center for the development of the Russian oil industry in the Arctic region. The rapid growth of shipping and the active creation of port infrastructure in this area are an integral part of the strategy for the development of the Russian Arctic. The main feature of the hydrometeorological regime of the Ob’ Bay is the annual presence of ice for a long time. Determining the ice performance of icebreakers, tugboats and heavy-tonnage vessels designed for the region, as well as ice loads on marine platforms and hydraulic structures, is a most important task in the creation thereof.

The paper describes research carried out in the ice model tank of the Krylov State Research Centre over the past twenty years. The research supports the design and operation of new technical facilities intended for the industrial development of the Ob’ Bay. In the completed study, two main areas of research can be distinguished, namely the interaction of ships and engineering structures with ice formations in the Ob’ Bay. The paper emphasizes a significant dependence of the possibility of conducting ice tests and proper analysis of findings on the quality of the initial data, primarily hydrology and ice parameters.

The results of ice model tests analysis, especially the ice impact on offshore and hydraulic structures for the Ob’ Bay, show the need to change approaches to determining theoretical ice loads and, as a result, to expand ice model testing programs. The simulation of the worst-case scenario, when all ice parameters are determined for a given probability and are not consistent with each other, leads to a significant overestimation of ice loads and the physical modeling of unrealistic combinations of ice conditions.

Each ice impact scenario should contain the maximum value of only one main ice parameter corresponding to the probability. The main ice parameters include the thickness, the flexural strength or compression strength and the speed of ice drift. In this case, ice parameters should be selected in accordance with the chosen main one in the modeling scenario. It should not be the result of the same maximum value calculation for the given observation period as for the main ice parameter.