Gravity base structure for an offshore platform in arctic regions

A gravity base structure which can extend from a seabed to above seawater level and protect a deck of an offshore platform having supporting columns extending from seabed to above seawater level from iceberg impacts, said gravity base structure comprising

• a monolithic concrete caisson which includes
• a bottom slab which can rest on the seabed,
• a top slab,
• an inner protective wall which extends between said bottom slab and said top slab and is integral with both said bottom slab and said top slab,
• an outer protective wall which extends between said bottom slab and said top slab and is integral with both said bottom slab and said top slab, said outer wall being substantially concentric with said inner wall,
• a plurality of partition walls which extend between said bottom slab and said top slab and from said inner wall to said outer wall to form therebetween a lattice structure for transmitting impact energy, and
• a plurality of teeth elements which extend outwardly from said outer wall, said teeth elements functioning to absorb impact energy of icebergs and transmit such energy to said caisson,
• said deck supporting column being substantially free of means for transmitting impact energy from said inner and outer protective walls to said columns other than that transmitted by said top and bottom slabs.