A suction anchor for anchoring a floating offshore structure

Abstract

A new suction anchor for anchoring offshore floating structures, comprising an anchor body and a steel strip root; the anchor body is a steel cylindrical structure with a closed top and an open bottom, the outer wall of the anchor body is provided with vertical long strip grooves, the upper end of the strip groove is reserved for air bag installation area and root bonding area, and the lower end is provided with a permanent fixed buckle; the root is composed of a rubber soft rope near the anchor end and a steel strip far from the anchor end, wherein the root near the anchor end is fixed at the lower end of the strip groove by the permanent fixed buckle, and the far end is fixed in the bonding area by water-based adhesive, and the air bag is installed in the air bag installation area and kept in a flat state. During the sinking process, the steel strip root is completely folded in the strip groove, after the sinking installation is completed, the water-based adhesive in the bonding area loses adhesion in seawater, at this time the far end of the steel strip root loses constraint, then the air bag continues to inflate, slightly lifts the far end of the steel strip root, realizes the separation of the far end of the steel strip root from the anchor body, and slightly expands when the suction anchor produces upward displacement, greatly increases the contact area of the entire suction anchor and the soil, and improves the uplift capacity.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering and is applicable as an anchoring foundation for floating marine structures. Background Technology

[0002] Suction anchors are a type of foundation used for anchoring floating marine structures. They are widely used in the construction of deep-sea oil and gas platforms and are now increasingly being applied to floating offshore wind power, marine cages, and offshore converter stations. When a suction anchor foundation for a floating marine structure is in service, the primary load is the pull-out load transmitted from the superstructure through the anchor chain; therefore, the pull-out bearing capacity of the anchor foundation is the primary load. To improve the pull-out bearing capacity of suction anchor foundations, a suction anchor for anchoring floating marine structures has been proposed. This suction anchor foundation has steel root-like tendrils on its sidewalls, which can remain closed during sinking and open after sinking to a designated position, increasing the contact area between the suction anchor foundation and the soil and improving the pull-out bearing capacity. Furthermore, when the suction anchor foundation experiences upward displacement, the angle between the distal end of the steel root tendrils and the anchor body gradually increases under the anchor-soil action, and penetrates the soil with increasing upward height, resulting in a continuous increase in pull-out resistance. This invention not only improves the pull-out bearing capacity of the original suction anchor foundation, but also achieves protection against pull-out slippage failure of the suction anchor. Summary of the Invention

[0003] To improve the pull-out bearing capacity of traditional suction anchor foundations, a suction anchor for anchoring floating structures at sea is proposed. This foundation can increase the contact area with the soil. When encountering pull-out loads, if pull-out displacement occurs, the angle between the far end of the steel bar root and the anchor body will gradually increase under the action of the anchor soil, thereby increasing the pull-out resistance.

[0004] The present invention adopts the following technical solution:

[0005] A suction anchor for anchoring floating structures at sea includes an anchor body and steel bar roots. The anchor body is a cylindrical steel structure that is closed at the top and open at the bottom. The outer wall of the anchor body is provided with a vertically elongated groove. The upper end of the groove is reserved for an airbag installation area and a bonding area for the steel bar roots, and the lower end is provided with a permanent fixing buckle. The steel bar roots consist of a rubber soft rope near the anchor end and a steel bar at the far anchor end. The near anchor end of the steel bar roots is fixed to the lower end of the groove by the permanent fixing buckle, and the far anchor end is fixed to the bonding area of ​​the steel bar roots by a water-based adhesive. The airbag is installed in the airbag installation area and kept flat.

[0006] The advantages of this invention are as follows: the suction anchor foundation sidewall has steel root-like tendrils similar to plant roots, which can remain closed during the sinking process and open after sinking to the designated position, increasing the contact area between the suction anchor foundation and the soil and improving the pull-out bearing capacity. Furthermore, when the suction anchor foundation undergoes upward displacement, the angle between the distal end of the steel root-like tendrils and the anchor body gradually increases under the anchor-soil action, and penetrates the soil with increasing upward height, resulting in a continuous increase in pull-out resistance.

[0007] In this invention, a suction anchor for anchoring floating structures at sea is described, wherein the steel bar root is fixed in the strip-shaped groove during the sinking process and remains in a retracted state, and the far end of the steel bar root separates from the anchor body after the sinking is completed.

[0008] In this invention, a suction anchor for anchoring floating structures at sea is described, wherein the airbag is placed in the airbag installation area and expands via electronic signal-controlled ignition.

[0009] In this invention, a suction anchor for anchoring floating structures at sea is provided, wherein the steel bar root distal end is connected to the bonding area by a water-based adhesive, and the upper part of the bonding area is the airbag installation area.

[0010] In this invention, a suction anchor for anchoring floating structures at sea is provided, wherein the permanent fixing buckle consists of a rotating shaft and a fixed end, and the near-anchor end is mounted on the permanent fixing buckle via the rotating shaft.

[0011] In this invention, a suction anchor for anchoring floating structures at sea is described, wherein the steel bar root is sharpened at the far end of the anchor. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall suction anchor.

[0013] Figure 2 This is a schematic diagram showing the installation location of the flexible root system;

[0014] Figure 3 Sectional view of suction anchor

[0015] Figure 4 This is a schematic diagram of a steel bar root structure;

[0016] Figure 5 A schematic diagram showing the connection between the anchor body sidewall and the steel bar root (in the retracted state);

[0017] Figure 6 A schematic diagram showing the connection between the anchor body sidewall and the steel bar root (open state);

[0018] In the diagram: 1-Anchor body; 101-Anchor top; 102-Anchor bottom; 2-Steel bar root; 201-Steel bar root distal end; 202-Steel bar root near end; 203-Permanent fixing clip; 3-Anchor body sidewall; 301-Strip groove bonding area; 302-Lower end of strip groove; Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] Combination Figure 1 and Figure 2 The suction anchor for anchoring floating structures at sea includes an anchor body and steel bar anchors. Its installation method is as follows: Before penetrating the seabed, the steel bar anchors are kept in a contracted state around the anchor body; that is, the far end of the steel bar anchor is fixed to the strip-shaped groove bonding area via the water-based adhesive, and the near end is connected to the permanent fixing buckle via the rotating shaft. The steel bar anchors are tightly fitted to the strip-shaped groove. Then, penetration into the seabed begins, divided into two parts: self-weight penetration and suction penetration. First, the suction anchor penetrates to a certain depth into the seabed under its own weight, and then the suction... The anchor begins to sink under the suction force. During the sinking process, the steel bar roots remain in a contracted state. After sinking to the predetermined position, the construction personnel issue an electrical signal to inflate the airbag, slightly lifting the far end of the steel bar roots. At this time, the steel bar roots are no longer tightly attached to the strip-shaped groove, but are in an open state, increasing the contact area with the soil. When encountering an uplift load, if an uplift displacement occurs, the angle between the far end of the steel bar roots and the anchor body will gradually increase under the action of the anchor soil, thereby increasing the pull-out resistance.

[0021] Furthermore, the steel bar root remains in a contracted state throughout the sinking process, and after sinking to the predetermined position, the airbag begins to lift the far anchor end of the steel bar root.

[0022] Furthermore, the suction anchor used for anchoring floating structures at sea has a tapered opening to reduce sinking resistance, and no steel bar roots are installed within the bottom 1 / 5 of the anchor body to ensure the smooth sinking process under its own weight.

[0023] The above embodiments further illustrate the purpose, technical solution, and advantages of the present invention in detail. It should be understood that the above description is only one embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A suction anchor for anchoring offshore floating structures, comprising an anchor body and a steel bar root; the anchor body is a steel cylindrical structure with a closed top and an open bottom, the outer wall of the anchor body is provided with a vertical long groove, the upper end of the long groove is provided with an air bag mounting area and a steel bar root bonding area, and the lower end is provided with a permanent fixing buckle; the steel bar root is composed of a rubber soft rope near the anchor end and a steel bar far from the anchor end, wherein the steel bar root near the anchor end is fixed at the lower end of the long groove through the permanent fixing buckle, and the far anchor end is fixed in the bonding area through water-based adhesive, and the air bag is mounted in the air bag mounting area and kept in a flat state; the steel bar root is fixed in the long groove during sinking and keeps a folded state, and the far anchor end of the steel bar root is separated from the anchor body after sinking; the air bag is placed in the air bag mounting area and is ignited to expand through electronic signal control; the far anchor end of the steel bar root is connected to the bonding area through water-based adhesive, and the upper part of the bonding area is the air bag mounting area; the permanent fixing buckle is composed of a rotating shaft and a fixed end, and the near anchor end is mounted on the permanent fixing buckle through the rotating shaft; the far anchor end of the steel bar root is sharpened, and the bottom opening of the anchor body is also sharpened to reduce the sinking resistance, and no steel bar root is arranged within 1 / 5 of the bottom of the anchor body to maintain self-weight sinking; the sinking installation method of the suction anchor is as follows: the far anchor end of the steel bar root is fixed in the long groove bonding area through the water-based adhesive, the near anchor end is connected to the permanent fixing buckle through the rotating shaft, and the steel bar root is tightly attached to the long groove; then the suction anchor starts to sink under the action of suction, the steel bar root keeps a folded state during sinking, and after sinking to a predetermined position, the construction personnel sends an electrical signal instruction to make the air bag start to expand, slightly lifting the far anchor end of the steel bar root, at this time the steel bar root is no longer tightly attached to the long groove and presents an open state, increasing the contact area with the soil body, when encountering an upward load, if upward displacement occurs, the angle between the far anchor end of the steel bar root and the anchor body will gradually increase under the action of anchor soil, realizing the increase of the pullout resistance.

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