Method for constructing offshore structure and offshore structure

Abstract

The invention discloses a method for constructing an offshore structure and an offshore structure. The method for constructing an offshore structure comprises the following steps: a manufacturing step of separately manufacturing an upper structure (11) and lower structure (12) of an offshore structure (10); an underwater state keeping step of keeping part or all of the lower structure (12) under water in a standing state; a moving step of moving the upper structure (11) above the lower structure (12) kept in the standing state; an integration step including a lifting step of lifting the lower structure (12) so as to be arranged on the bottom side of the upper structure (11) and / or a lowering step of submerging part of a carrier (20) carrying the upper structure (11) in a state in which the upper structure (11) is held by a pair of arm-like structures (23) in order to lower the upper structure (11) so as to be arranged on the upper side of the lower structure (12); and a joining step of combining the lower structure (12) with the upper structure (11). Therefore, in this method for constructing a spar-type or other type of offshore structure having an installed wind turbine or other apparatus, the offshore apparatus is able to safely be moored at an offshore construction site without using a crane ship.

Description

technical field [0001] The present invention relates to a construction method and an offshore structure part of an offshore structure such as a spar type on which a wind power generator or the like is mounted. Background technique [0002] When installing wind power generation equipment on offshore structures in deep waters, semi-submersibles or tension leg platforms (TLPs) may be considered. Tow to the setting place and be moored by the mooring system. [0003] On the other hand, in the case of a spar-type offshore structure, the spar is an offshore structure that floats in an upright state like a fishing float, and most of the floating body sinks under the sea surface due to ballast water injection or the like. . The spar is capable of supporting a heavier superstructure with less sway. In a spar-type offshore structure including a wind power generation facility, the draft of the floating body is assumed to be about 40 m to 80 m deep, and the floating body part is a lar...

AI Technical Summary

Problems solved by technology

[0007] When such a floating body is moored and the tower is suspended from the moored floating body by a crane ship to be integrated, a crane ship with high usage costs is required, and the tower suspended by the crane ship is vulnerable to damage. Due to the influence of the wind, it is necessary to control the swing of the tower and the floating body, and there is a problem that it is difficult to progress the tower installation work.

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