One of the governing design aspects of a bottom founded structure on the Grand Banks is the impact of icebergs. A Gravity Base Structure (GBS) caisson will be designed to withstand iceberg impacts, but the platform topsides are not designed to withstand iceberg impacts. Therefore, the topsides structure must be designed in a manner such that the specified target safety levels set by ISO 19906:2010 are met. This paper presents an analytical model to estimate the probability of an iceberg impacting the topsides based on a three-dimensional model of the GBS caisson and topsides, including the extent of topsides overhang relative to the caisson and the caisson size. The impact model is implemented using a Monte Carlo simulation to ensure the risk of icebergs impacting the topsides satisfies ISO 19906:2010 requirements.

Keywords:
upstream oil & gas, caisson, topsides, iso 19906, iceberg impact, safety level, impact frequency, iceberg, exceedance probability, waterline length
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Copyright 2014, The Society of Naval Architects and Marine Engineers
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