METHOD FOR ERECTION OF OFFSHORE STRUCTURE Russian patent published in 2009 - IPC E02B17/00 

FIELD: construction.

SUBSTANCE: invention is related to hydrotechnical construction and is intended for erection of stationary offshore structures with continuous bearing block fixed by piles to sea bottom. Method for erection of offshore structure consists in the fact that bearing block is manufactured on shore out of two sections joined vertically: lower and upper tiers of bearing block. Lower tier of bearing block is installed on bottom and is fixed by "short" piles rammed through its main stands in bottom until they enter compact subsoil and providing stability of bearing block lower tier in initial period of sea erection works. Upper tier of bearing block is installed onto lower tier so that stands of bearing block upper tier are attached to "short" piles, afterwards intratubal soil plug is removed in "short" piles, and "long" piles that bear upper structure are rammed through them and stands of upper tier. In case of underwater joining of bearing block tiers, docking assembly is enveloped by caisson on the outside and sealed with packer or underwater welding. Afterwards water from stand of upper bearing block and caisson is pumped down to the level below attachment seam, which is prepared and welded on the inside of stand by automatic electric welding under normal atmospheric conditions. If stand diameter is considerable, electric welding is done by welder placed on floating pontoon, which is lowered and lifted in stand by supply or drain of outside water. After "long" piles have been rammed and attached to stands of upper tier of bearing block, intratubal space of piles, stands and caissons are filled with mortar.

EFFECT: higher reliability of offshore structures operation due to higher stability and reduction of structure metal intensity by reduction of bearing block upper tier stand diameter and reduction of stand and pile thickness at higher strength of piles, possibility to use crane ships of lower tonnage, and also to leave lower tier of bearing block fixed by piles with underwater end of stands and piles for the period of unfavorable ice conditions.

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