In this paper, the authors consider problems of formation of extreme ice loads on structures in terms of the idealized analysis of the basic regularities of both ice drift in water areas and natural driving forces in an ice cover. We offer the deterministic mathematical model of the process of local drift of a single ice floe, interaction of ice floes with each other and with extensive rigid objects. Used in various scenarios of interaction, the kinematic parameters of ice cover were obtained by a numerical solution of differential equations of the single ice floe motion given from the II-type Lagrange equations. With the example of the Sakhalin shelf, we present main kinematic and dynamic parameters of an ice cover in variable time scales together with spatial and time modifications.
When designing structures intended for operation in conditions of the seas with heavy ice regime, it is necessary to consider possible effect of drifting ice features, such as the level ice fields, layered and hummocky ice fields, single hummocks, ridges of hummocks, grounded hummocks, icebergs, icing up masses of ice, their combinations, etc. Analyzed results of examinations of ice effects on marine engineering structures (as well as guidelines of normative sources) showed that they didn't include a sufficient portion of design cases and aspects of the effects which might originate in conditions of the open marine water area. Besides, the analysis of the reference sources (Blanchet& DeFranco, 1996; Croasdale&Kennedy1996; Karna et al, 1997; Nessim et al, 1987; Shkhinek et al, 1994; Wright&Timco, 1994) showed, that in ice loads calculations practice various researchers considered generally only special cases of ice-structure interaction (even or hummocky ice fields, grounded hummocks, icebergs, etc.). Thus the significant scatter in estimation of ice load values was observed.