Inclined cut GBS leg

Patent metadata

Field	Value
Publication number	US-11339549-B2
Application number	US-201916966209-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Jan 30, 2018
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

The present invention relates to a gravity based structure 5 with a topside 2 on at least one hollow concrete platform leg 1 with a platform leg wall and a circular cross section. The at least one platform leg, includes an upper leg portion (4) cut off from a lower leg portion 3. The lower leg portion 3 has an upper sloped cut surface 10 inclined at an angle in the range of 1°-10° off a horizontal axis. The upper leg portion 4 has an upper leg sloped cut surface inclined at the same angle as the lower leg sloped cut surface 10 of the lower leg portion 3 whereby the angles are complementary, the sloped cut surfaces forming an inner and an outer obtuse cone with a common vertical longitudinal axis. Furthermore, the invention relates to method of forming a conical cut through a concrete platform leg of a GBS.

First claim

The invention claimed is:

1. A gravity based structure ( 5 ) with a topside ( 2 ) on at least one hollow concrete platform leg ( 1 ) with a platform leg wall and a circular cross section, comprising an upper leg portion ( 4 ) cut off from a lower leg portion ( 3 ), the lower leg portion ( 3 ) being secured to a foundation, wherein the upper leg portion ( 4 ) is separate from and resting on the lower leg portion ( 3 );
wherein the lower leg portion ( 3 ) has an upper sloped cut surface ( 10 ) inclined at an angle in the range of 1°-10° off a horizontal axis; and
wherein the upper leg portion ( 4 ) has an upper leg sloped cut surface inclined at the same angle as the lower leg sloped cut surface ( 10 ) of the lower leg portion ( 3 ) whereby the angles are complementary, the sloped cut surfaces forming an inner and an outer conical portion with a common vertical longitudinal axis.

2. The gravity based structure ( 5 ) of claim 1 , wherein the angle is in the range of 1°-5° off the horizontal axis.

3. The gravity based structure ( 5 ) of claim 1 , wherein the angle is 5° off the horizontal axis.

4. The gravity based structure ( 5 ) of claim 1 , comprising three or more hollow concrete platform legs ( 1 ).

5. The gravity based structure ( 5 ) of claim 1 , wherein the lower leg portion ( 3 ) includes reinforcement steel embedded in the platform leg wall, wherein the reinforcement steel has an upper portion ending a distance below the upper sloped cut surface ( 10 ), whereby cut between the upper leg portion ( 4 ) and the lower leg portion ( 3 ) not extends through the reinforcement steel embedded in the platform leg wall of the lower leg portion ( 4 ).

6. A method of forming a conical cut through a concrete platform leg of a gravity based structure, with a leg wall ( 33 ) and a circular cross-section, comprising;
securing at least one first guide track ( 7 a , 7 b ) in a horizontal plane around the platform leg ( 1 );
forming at least one hole through the leg wall ( 33 );
attaching a machine operated saw onto the horizontal first guide track with a sawing portion ( 9 ) through the hole ( 20 ) of the leg wall ( 33 );
operating the saw with the sawing portion ( 9 ) running at an angle in a range 1°-5° off a horizontal axis while moving the saw along the horizontal guide track ( 7 a , 7 b ) while sawing through the leg wall at the angle in the range 1°-5° off the horizontal axis, while sawing through a full 360° around the platform leg wall ( 33 ) thus dividing the concrete platform leg into an upper leg portion ( 4 ) and a lower leg portion ( 3 ).

7. The method of claim 6 , wherein the machine operated saw is a wire saw with a master saw unit ( 12 ) and a slave unit ( 13 ), the method further comprising securing at least one second guide track ( 8 ) in a horizontal plane around the platform leg ( 1 ) at an opposite side of the first guide track ( 7 a , 7 b );
installing the slave unit ( 13 ) with at least one wire slave wire return wheel ( 23 ) on the at least one second guide track ( 8 ); and
installing a cutting wire ( 15 ) between the master saw unit ( 12 ) and the slave unit ( 13 ).

Assignees

• 1Diamond As
• Quanta Associates Lp

Inventors

• Ramfjord Harald

Classifications

• B23D57/003 Primary

  Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts (constructional features of these parts per se B23Q) · CPC title

• E02B17/0034

  Maintenance, repair or inspection of offshore constructions · CPC title

• E02B2017/0052

  Removal or dismantling of offshore structures from their offshore location · CPC title

• B23D57/0007

  using saw wires · CPC title

• B28D1/088

  Sawing in situ, e.g. stones from rocks, grooves in walls · CPC title