The analysis of the offshore environment of the freezing seas showed that in these areas the underwater pipelines and the others buried structures could be damaged with high probability by the drifting ice formations of various origins which directly contacted the bottom in the offshore zone. In this paper the authors analyzed comprehensively the global problems of ice impacts on the sea-bottom and underwater pipelines. The results of this review provide guidance on approaches to estimate the normative burial depth of underwater pipelines in Arctic seas.
As a rule, the pipeline transport is the most economic type of oil and gas transport when developing the sea oil and gas fields within the offshore zone of the World Ocean. In the freezing offshore water areas the hydraulic engineering structures and means of underwater communications in the littoral zone would be in main danger of ice piles formation on the shore and the seabed exaration by the ice formations, such as hummocks, ridges rows, grounded hummocks, icebergs, etc. As a result of this process, the keels (i.e. the underwater parts) of the ice features leave long trenches in the seabed named gouges. Direct contact of a keel to a pipe within the gouge caused damage of the pipeline in most cases because of possible both dynamic and static loadings from ice. In these conditions the pipeline burial into the ground was the basic and the most applied way of the pipeline protection from external ice impacts. Thus, the basic problem in designing a route of the underwater pipeline under ice conditions was the substantiated assignment of its burial depth into the ground of the seabed. The comprehensive engineering analysis of methods of the underwater pipelines burial depth calculation should include the following factors as a minimum.
