Causes and Influence of the Ice Heterogeneity on Loads on Offshore Structures

The influence of heterogeneity of ice properties on loads exerted on offshore structures is examined analytically in the present work. The methodology proposed permits considering the influence of heterogeneity induced by different factors: local factors such as ice strength or ice thickness variations, and large-scale factors such as the existence of ice fields of different ages. Local areas with parameters (strength, thickness, etc) different from parameters of the surrounding ice are treated as inclusions and their influence on loads is investigated. Results of the investigation show that under some conditions the heterogeneity influence is negligible whereas sometimes it can be important and leads to the size effect formation. The methodology of the heterogeneity influence determination and conditions when it is important are discussed in this paper.