JP2011226111A - Reinforcement member and reinforcement method for underwater structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method which is excellent in workability for increasing load bearing ability of an underwater structure by connecting piles of the underwater structure together using a reinforcement body in water to enhance the rigidity of a whole pier.SOLUTION: A strutt member for reinforcement connects piles of an underwater structure that is supported on the ground in water by piles. The strutt member consists of a strutt 1 and a pile connecting member 2 connected with both ends of the strutt 1. The strutt 1 is a multi-pipe configuration with the length of the strutt being adjustable, and in the strutt, a plurality of tubular strutt elements are nested. At both ends of the strutt, fulcrum material (A)8 as a pivoting shaft is formed. The pile connecting member 2 constitutes a lid with which a pile connecting member 6 can be opened and closed, by a pile connecting member 5 and the pile connecting member 6 being hinge connected. When the lid is closed, the pile connecting member 5 and the pile connecting member 6 surround the perimeter of the pile. On the outside wall of the pile connecting member 5, a fulcrum material as a bearing of the strutt fulcrum material 8 is provided to journal the fulcrum material 8.

Description

  The present invention relates to a reinforcing member and a reinforcing method for reinforcing an underwater structure such as an existing jetty, particularly a pile-type jetty in which an upper structure is supported by a plurality of piles.

In harbors and fishing ports, various underwater structures such as piers are provided for mooring ships. These underwater structures consist of a lower structure that has multiple stakes that are driven into the ground and project above the water surface, and an upper structure that is supported by these piles and laid above the water surface. Composed of things.
The pile as the substructure is generally constructed by driving a plurality of pile groups in the vertical direction or oblique direction on the ground such as the seabed or lake bottom. Moreover, the above-mentioned superstructure is generally constructed by laying a plurality of beams on the upper ends of these pile groups and stretching a floor board between these beam groups.

By the way, about an existing underwater structure, it is necessary to reinforce an underwater structure for the reason described below.
・ Decrease in yield strength of underwater structures due to thickness reduction of piles due to corrosion ・ Responding to increased loading load ・ Improved seismic performance In particular, many of the underwater structures such as pile-type piers installed in the past have been assumed in recent years. It has not been designed to withstand major earthquakes that have become possible, and it is highly likely that underwater structures will be damaged by large earthquakes in the future, which will greatly affect social functions. It will be. In addition, underwater structures perform very important functions in the transportation of personnel and supplies for the rapid recovery of social functions after an earthquake.
For this reason, as a countermeasure against a large earthquake that is expected to occur in the future, there is an increasing need for seismic reinforcement of underwater structures such as existing pile-type piers.
And many proposals are conventionally made as a construction method for the above-mentioned reinforcement.

  Patent Document 1 describes that a reinforcing material for reinforcing an existing pier is unitized, manufactured in advance, and attached between piles at a construction site so as to minimize the site construction period. Has been. This reinforcing unit is composed of a rectangular frame-shaped frame, a brace provided in the frame, and a damper 8 provided between the brace and the frame.

  In Patent Document 2, a floater is attached to a strut member used to reinforce a pile on a jetty so that it floats on the water surface. The strut member is towed between pile groups, and then struts are placed at predetermined positions in the vertical direction of the pile group. A reinforcing method for joining both ends of the member is described. Patent Document 2 also describes that the strut members can be nested to make them extendable.

  In Patent Document 3, in a jetty that supports a floor set with pedestal columns, a seismic brace as diagonal material is provided between the pedestal columns to reduce the maximum bending moment acting on the pedestal and reduce the burden on the pedestal. In addition, it is described that the required pedestal diameter is reduced.

In Patent Document 4, a horizontal pipe for reinforcement is installed by installing a sheath pipe on each pile, and joining a hollow connection pipe protruding from the sheath pipe with a hollow connection pipe in a sheath pipe installed on an adjacent pile. It is described to form.
However, none of the above methods can be said to have good workability from the viewpoint of adjusting the reinforcing member to the local pile, and is not sufficient in terms of application to the diagonal pile.

Japanese Patent Laid-Open No. 2007-217952 JP 2008-223384 A JP-A-11-269845 JP 2008-297815 A

  The present invention provides a construction method excellent in workability for improving the load bearing capacity of the underwater structure by increasing the rigidity of the entire pier by connecting the piles of the existing underwater structure with a reinforcing body underwater. Objective.

The inventors of the present invention are configured such that the reinforcing body is composed of a strut member, and the strut member includes a strut and a pile connection member connected to both ends of the strut. The strut includes a plurality of tubular strut elements nested. It has a multi-pipe structure, the length of the strut can be adjusted, and the fulcrum material (A) that serves as the pivot shaft is provided horizontally at both ends of the strut. The pile connection material (A) and the pile connection material (B) are hinge-coupled as members, and the pile connection member (A) and the pile connection material (B) are hinge-coupled as pile connection members. The material (B) constitutes a lid that can be opened and closed. When the lid is closed, the pile coupling material (A) and the pile coupling material (B) surround the periphery of the pile, and the pile coupling material (A) The fulcrum material (A) which becomes the bearing of the fulcrum material (A) of the strut on the outer wall ) Is to be pivotally supporting point member (A) is provided, and completed the present invention have found that it is possible to solve the above problems by the use of this strut member as a reinforcing member.
That is, the present invention is a strut member for reinforcement as described below and a reinforcement method using the same.

(1) For reinforcement that connects a pile and a pile in order to reinforce an underwater structure having a plurality of piles whose lower ends are embedded in the underwater ground and an upper structure supported by the plurality of piles A strut member,
The strut member is composed of a strut and a pile connecting member connected to both ends of the strut,
The strut has a multi-tube structure in which a plurality of tubular strut elements are nested, and the length of the strut can be adjusted, and a fulcrum material (A ) In the horizontal direction,
In the pile connecting member, the pile connecting material (A) and the pile connecting material (B) are hinged, and the pile connecting material (B) constitutes a lid that can be opened and closed, and the lid is closed. The pile connecting material (A) and the pile connecting material (B) surround the periphery of the pile,
A fulcrum material (B) serving as a bearing for the fulcrum material (A) of the strut is provided on the outer wall of the pile connection material (A), and the fulcrum material (A) is pivotally supported. Reinforcing strut member.
(2) The reinforcing strut member according to (1), wherein the tubular strut element is rotatable in a circumferential direction of the strut.
(3) The strut member consists of two or more struts and three or more pile connecting members,
The strut member for reinforcement according to (1) or (2), wherein all struts are connected to one of the pile connecting members.
(4) The fulcrum material (B) is provided in two or more upper and lower stages on one side of the outer wall of the pile connection material (A) of at least one pile connection member, and the fulcrum material provided in two or more upper and lower stages. The reinforcing strut member according to (3), wherein a fulcrum material (A) provided at each end of each of the plurality of struts is pivotally supported on (B).
(5) The fulcrum material (B) is provided in one or two or more upper and lower tiers on one side and the opposite side of the outer wall of the pile linking material (A) of at least one pile linking member. The reinforcing strut member according to (3), wherein a fulcrum material (A) provided at each end of each of the plurality of struts is pivotally supported on (B).
(6) The inner peripheral surface of the strut (A) and / or the outer peripheral surface of the strut (B), the surface facing the pile of the pile connection material (A) and the pile connection material (B), and the fulcrum material (B) is the fulcrum material. The reinforcing strut member according to any one of (1) to (5), wherein an anchor member for preventing grout displacement is provided on a surface facing (A).
(7) The reinforcing strut member according to any one of (1) to (6), wherein the strut member is provided with a wire for guiding the strut member to a predetermined pile.
(8) The reinforcing strut member according to any one of (1) to (7), further including a buoyancy member.
(9) The reinforcing strut member according to any one of (1) to (8), wherein the buoyancy member is built in or externally attached to the strut member.
(10) The reinforcing member according to any one of (1) to (9), wherein the buoyancy member is a container into which a liquid can be injected, and the buoyancy can be adjusted by an injection amount of the liquid. Strut member.
(11) Using the strut member according to any one of (1) to (10) as a reinforcing body, a plurality of piles having lower ends embedded in the underwater ground, and an upper structure supported by the plurality of piles A reinforcing method for reinforcing an underwater structure having a body,
Guiding the strut member to the position of the two piles to which the strut member is to be attached;
Adjusting the strut length of the strut member;
A step of surrounding the two piles with a pile coupling member (A) and a pile coupling member (B) of a pile coupling member provided at both ends of the strut member;
And a step of constructing and integrating the grout between the strut (A) and the strut (B), between the fulcrum material (A) and the fulcrum material (B), and between the pile and the pile connecting member. Reinforcement method characterized by that.
(12) A strut member having a buoyancy member is floated on the water surface, a plurality of wires for guiding the strut member are attached to the strut member, and the strut member is guided to a predetermined position by operating the wires. The reinforcing method according to (11), which is characterized.
(13) A liquid is injected into the buoyancy member, and the pile connecting members at one end or both ends of the reinforcing strut member are allowed to sink to a predetermined depth to fix the pile connecting members to the piles (11 ) Or the reinforcing method described in (12).

The construction method of the present invention can be reinforced without newly installing an underwater structure, and has little influence on the work of the underwater structure in service. In addition, since the reinforcing body is attached to the pile by a wiring operation using buoyancy, it is easy to construct without requiring a large work ship, and the in-service period of the quay can be extremely shortened.
Further, the reinforcing body is joined using a grout and a stopper and no bolt is used, so that the work is easy and rapid construction is possible.
Furthermore, it can reinforce with the strut of a free angle by providing the fulcrum material in the pile connection member. In addition, a pile with poor verticality can be easily attached, and the underwater structure of the diagonal pile can be easily reinforced.

It is a figure which shows an example of the strut member for reinforcement. It is a figure which shows the example of the slip prevention of a grout. They are the radial cross-sectional view (a) and axial direction sectional view (b) of the part where the pile connection material (A) and the pile connection material (B) after grouting construction oppose. It is a figure which shows the other example of the strut member for a reinforcement. It is a figure which shows the other example of the strut member for a reinforcement. It is a figure which shows the other example of the strut member for a reinforcement. It is a figure which shows the mode of the attachment operation | work of the strut member for a reinforcement. It is a figure which shows a mode that the strut member for reinforcement was attached between the diagonal piles. It is a figure which shows a mode that the strut member for reinforcement was attached between the diagonal piles. It is a figure which shows the state before guide | inducing a strut member to a predetermined position. It is a figure which shows the state after guide | inducing a strut member to a predetermined position. It is a figure which shows the state which the pile connection member surrounded the pile. It is a figure which shows a mode that one pile connection member of the strut member was settled to predetermined depth.

FIG. 1 shows the reinforcing strut member of the present invention. The strut member is composed of a strut 1 and a pile connecting member 2 connected to both ends of the strut.
The strut has a multiple tube structure in which a plurality of tubular strut elements are nested.
The number of tubular strut elements constituting the strut can be two or three or more depending on the required expansion / contraction length, and may be circular or rectangular. However, the tubular shape is preferable from the viewpoint of processing cost and strength. In addition, by making at least one of the tubular strut elements rotatable in the circumferential direction, the workability is improved because the degree of freedom of movement of the pile connecting member is increased.
In FIG. 1, the strut includes a strut (A) 3 which is a tubular strut element and a strut (B) 4 which is a tubular strut element slidably disposed in the strut (A) 3. It has a double pipe structure.
One end of the strut (A) 3 is provided with a fulcrum material (A) 8 serving as a rotation shaft. Similarly, one end of the strut (B) 4 is provided with a fulcrum material (A) serving as a rotation shaft. ) 8 is provided.

  A predetermined space is provided between the inner surface of the strut (A) and the outer surface of the strut (B), and a space for injecting grout is formed. The grout is injected into the strut (A). And the strut (B) can be integrated. Further, a grout seal 10 as shown in the figure is provided to stop leakage of the injected grout.

The pile connecting member 2 has a shape that is obtained by dividing a tubular body having a diameter that can surround the pile 11 into two parts, and includes a pile connecting material (A) 5 and a pile connecting material (B) 6. Each end part is couple | bonded by the hinge 7, it attaches to the pile 11 in the state which opened the hinge 7, and surrounds a pile by closing a hinge.
A fulcrum material (B) 9 serving as a bearing for the fulcrum material (A) 8 of the strut is provided on the outer wall of the pile connection material (A) 5, and the fulcrum material (B) 9 serves as a fulcrum material (A). By supporting the shaft 8, the strut 1 can rotate about the fulcrum material (A) 8 as a fulcrum.

Grout shift can be prevented by providing an anchor member for preventing the shift of the grout as shown in FIG. 2 on the inner peripheral surface of the strut (A) and / or the outer peripheral surface of the strut (B).
2 (a) shows a stud provided on the strut wall surface, FIG. 2 (b) shows a steel bar fixed to the strut wall surface by welding, and FIG. 2 (c) shows a weld bead formed on the strut wall surface. Is.

  By injecting grout between the fulcrum material (A) and the fulcrum material (B), the pile connecting member and the strut can be integrated. In addition, by providing anchor members for preventing grout misalignment on the surface of the pile connection material (A) and the pile connection material (B) facing the pile, the surface of the fulcrum material (B) facing the fulcrum material (A). Grout shift can be prevented.

The grout is also injected into the gap between the pile 11 and the pile connecting member 2 to integrate the pile 11 and the pile connecting member 2. In order to stop leakage of the injected grout, grout seals 10 as shown in the figure are provided at the upper end of the inner wall and the lower end of the inner wall of the pile connecting member 2.
Grout displacement can be prevented by providing an anchor member for preventing grout displacement on the surface of the pile coupling material (A) and the pile coupling material (B) facing the pile.
FIG. 3 shows a structure for integrating the pile connection material (A) and the pile connection material (B) with a grout. Fig.3 (a) is a cross-sectional view of the radial direction of the part which the pile connection material (A) and the pile connection material (B) oppose after grout construction, FIG.3 (b) is a longitudinal cross-sectional view of an axial direction. It is.
The pile connection material (A) 5 is provided with a support plate 22 erected with a plurality of anchor studs 21 in the longitudinal direction, and the pile connection material (B) 6 is connected to the pile when the pile connection material (B) is closed. A bearing plate 23 provided with a slit 24 for preventing the anchor stud 21 of the material (A) from interfering is provided. The temporary fixing bolt 26 is for maintaining the closed state of the pile connecting material (B) 6.
By adopting such a structure, the pile connection members are resisted by tension between the anchor stud and the support plate via the grout against the tension between the pile connection members, and resisted by the grout in the connection material against the compressive force. To do.

As another embodiment of the strut member, as shown in FIG. 4, the strut member can have two struts.
In this aspect, the strut member is composed of two struts and three pile connecting members, and the outer wall of the pile connecting material (A) of one pile connecting member serves as a bearing for the fulcrum material (A) of the strut. The fulcrum material (B) is provided in two upper and lower tiers, and each of the fulcrum materials (B) provided in the two upper and lower tiers supports the respective fulcrum materials (A) of the two struts, and the other two One fulcrum material (B) serving as a bearing for the fulcrum material (A) of the strut is provided on the outer wall of the pile linking material (A) of the two pile linking materials. Each of the fulcrum materials (A) of the struts is pivotally supported by the fulcrum material (B).
Thus, the number of parts can be reduced by sharing one pile connecting member by two struts.

FIG. 5 is a view showing another embodiment of the strut member.
In this aspect, the strut member is composed of three struts and four pile connecting members.
On one side of the outer wall of the pile connecting member 2b attached to the pile 11b, a fulcrum material (B) serving as a bearing for the fulcrum material (A) of the strut is provided in one stage, and this fulcrum material (B) A fulcrum material (A) provided on the strut (A) of the strut is pivotally supported. And the fulcrum material (A) of the other end of this strut is pivotally supported by the fulcrum material (B) provided in the outer wall of the pile connection member 2a attached to the pile 11a.
Further, a fulcrum material (B) is provided in two stages on the opposite side of the outer wall of the pile connecting member 2b, and the fulcrum materials (A) of the two struts are pivotally supported by the fulcrum material (B). ing. And the fulcrum material (A) of the other end of these two struts is pivotally supported by the fulcrum material (B) of the pile connection members 2c1 and 2c2 attached to the pile 11c.

FIG. 6 is a view showing another embodiment of the strut member.
In this aspect, the strut member is composed of four struts and five pile connecting members, and one of the outer walls of the pile connecting member 2b1 on the upper side among the two pile connecting members attached to the central pile 11b. The fulcrum material (B) 9 is provided in two upper and lower stages on the side, and the fulcrum material (A) of the strut (B) 4 of the two struts is pivotally supported by the two fulcrum materials (B) 9. The fulcrum material (A) provided on the strut (A) 3 of the strut is pivotally supported by the fulcrum materials (B) of the pile connecting materials 2c1 and 2c2 attached to the pile 11c.
Further, a fulcrum material (B) 9 is provided in one stage on the opposite side of the outer wall of the pile connecting member 2b1, and the fulcrum material (A) of the strut (A) of one strut is pivotally supported by this fulcrum material B. ing.
Moreover, the fulcrum material (B) 9 is provided in two steps on the outer wall of the pile connecting member 2a attached to the pile 11a, and the fulcrum material of the struts (B) of the two struts (B) by this fulcrum material (B) ( A) is pivotally supported, and one of the two struts is a fulcrum material (B) of the pile connecting member 2b1 provided on the pile 11b, and the other one is a fulcrum material of the pile connecting member 2b2 ( It is supported by B).

FIG. 7 is a view showing a state of attachment work of the reinforcing strut member.
FIG.7 (b) has shown a mode that a pile connection member (B) 6 is closed by attaching a pile connection member to a pile (11). Fig.7 (a) has shown the state which injected grout into the clearance gap between a pile connection member and a pile.
FIG. 7 (c) shows a state in which the reinforcing strut member is attached in a floating state, and FIG. 7 (d) shows a state in which one pile connecting member is set to a predetermined depth.

Even if the piles to be reinforced are constructed so that they are parallel to each other, the piles after construction are not necessarily parallel because of their poor verticality, and generally there are many piles constructed obliquely.
In order to reinforce a pile having such poor verticality or slanting, a strut member in which a strut as in the present invention is pivotally supported by a fulcrum material (B) of a pile connection material (A) is suitable. .
FIG. 8 shows an embodiment in which the strut member of the present invention is applied to a diagonal pile.
As shown in FIG. 8, the fulcrum material 8 of the strut in the present invention is pivotally supported by the fulcrum material of the pile connection material, and the strut can be rotated around the fulcrum material (A) 8 as a rotation axis. The member 2 can easily surround the diagonal pile 11 '.

Another embodiment of the strut member of the present invention is shown in FIG.
The strut member shown in FIG. 9 has a strut composed of three strut elements, and the strut member can be further extended in length compared to a strut composed of two elements.
For example, when strut members are used to reinforce slant piles, if the strut members are moved (sinked) from the water surface to the reinforcing position, the distance between the piles increases toward the bottom, so the strut length needs to be further increased. For this reason, as shown in the drawing, the strut has a triple pipe structure so that it can follow the pile interval.

Next, the work procedure of the method of attaching the strut member to the pile will be described.
FIG. 10 shows a state in which the strut member is guided to a predetermined position. FIG. 10 (a) is a front view and FIG. 10 (b) is a plan view. The strut member is floated on the water surface by a buoyancy member (not shown).

  The buoyancy member is not limited as long as it imparts buoyancy to the strut member. The buoyancy member may be built in the strut member or may be externally attached. For example, the case of using the internal space of the strut can be cited. Since the strut is tubular, buoyancy can be generated by making the strut watertight.

  As shown in FIG. 10B, the strut member is provided with four wires W for guiding the strut member to a predetermined position. The strut member can be guided to the position of the target pile by pulling the wire around the appropriate pile, and the pile can be accommodated in the pile connection material (A).

FIG. 11 is a view showing a state after the strut member is guided to a predetermined position, and the pile is accommodated in the concave portion of the pile connecting material (A) of the strut member guided to the predetermined pile by wire operation.
Then, as shown in FIG. 12, the pile connection material (B) hinged to the pile connection material (A) is closed and the pile is surrounded by the pile connection member.

  In some cases, liquid (water, seawater, etc.) may be injected into the buoyancy member, and the pile connecting member at one end of the strut member may be allowed to sink to a predetermined depth as shown in FIG. In this case, the strut (B) slides and the strut has a predetermined length. Moreover, you may sink both pile connection members, respectively.

  After the above work is completed, in order to integrate the strut member and the pile, between the strut (A) and the strut (B), between the fulcrum material (A) and the fulcrum material (B), and the pile The grout is injected between the pile connecting members and solidified to complete the reinforcement work.

  According to the reinforcing method of the present invention, since the work is easy and rapid construction is possible, there is little influence on the work of underwater structures such as a pier in service, and the reinforcing body is a wire while using buoyancy. Since it is attached to the pile by operation and does not require a large work boat and is easy to construct, it is suitable as a method for reinforcing underwater structures such as pile-type piers.

1 Strut 2 Pile connecting member 3 Strut (A)
4 Struts (B)
5 Pile connecting material (A)
6 Pile connecting material (B)
7 Hinge 8 Support material (A)
9 Support material (B)
10 Grout seal 11 Pile 12 Winch 21 Anchor stud 22 Support plate 23 Bearing plate 24 Slit 25 Grout 26 Temporary fixing bolt W Wire

Claims (13)

A reinforcing strut member for connecting a pile and a pile to reinforce an underwater structure having a plurality of piles having lower ends embedded in the underwater ground and an upper structure supported by the plurality of piles. There,
The strut member is composed of a strut and a pile connecting member connected to both ends of the strut,
The strut has a multi-tube structure in which a plurality of tubular strut elements are nested, the strut length can be adjusted, and fulcrum materials (A ) In the horizontal direction,
In the pile connecting member, the pile connecting material (A) and the pile connecting material (B) are hinged, and the pile connecting material (B) constitutes a lid that can be opened and closed, and the lid is closed. The pile connecting material (A) and the pile connecting material (B) surround the periphery of the pile,
A fulcrum material (B) serving as a bearing for the fulcrum material (A) of the strut is provided on the outer wall of the pile connection material (A), and the fulcrum material (A) is pivotally supported. Reinforcing strut member.   The reinforcing strut member according to claim 1, wherein the tubular strut element is rotatable in a circumferential direction of the strut. The strut member consists of two or more struts and three or more pile connecting members,
The strut member for reinforcement according to claim 1 or 2, wherein all the struts are connected to one of the pile connecting members. The fulcrum material (B) is provided on one side of the outer wall of the pile connection material (A) of at least one pile connection member in two or more upper and lower stages, and the fulcrum material (B) provided in two or more upper and lower stages. The reinforcing strut member according to claim 3, wherein a fulcrum material (A) provided at each end of each of the plurality of struts is pivotally supported on each of the strut members. The fulcrum material (B) is provided in one stage or two or more upper and lower tiers on one side and the opposite side of the outer wall of the pile coupling material (A) of at least one pile coupling member, and these fulcrum materials (B) The reinforcing strut member according to claim 3, wherein a fulcrum material (A) provided at each end of each of the plurality of struts is pivotally supported on each of the strut members.   The inner peripheral surface of the strut (A) and / or the outer peripheral surface of the strut (B), the surface facing the pile of the pile connection material (A) and the pile connection material (B), the fulcrum material (B) is the fulcrum material (A) The reinforcing strut member according to any one of claims 1 to 5, wherein an anchor member for preventing grout misalignment is provided on a surface opposed to the strut member.   The reinforcing strut member according to any one of claims 1 to 6, wherein a wire for guiding the strut member to a predetermined pile is provided on the strut member.   The reinforcing strut member according to claim 1, further comprising a buoyancy member.   The reinforcing strut member according to any one of claims 1 to 8, wherein the buoyancy member is built in or externally attached to the strut member.   The reinforcing strut member according to any one of claims 1 to 9, wherein the buoyancy member is a container into which a liquid can be injected, and the buoyancy can be adjusted by an injection amount of the liquid. Using the strut member according to any one of claims 1 to 10 as a reinforcing body, an underwater having a plurality of piles whose lower ends are embedded in an underwater ground and an upper structure supported by the plurality of piles. A reinforcing method for reinforcing a structure,
Guiding the strut member to the position of the two piles to which the strut member is to be attached;
Adjusting the strut length of the strut member;
A step of surrounding the two piles with a pile coupling member (A) and a pile coupling member (B) of a pile coupling member provided at both ends of the strut member;
And a step of constructing and integrating the grout between the strut (A) and the strut (B), between the fulcrum material (A) and the fulcrum material (B), and between the pile and the pile connecting member. Reinforcement method characterized by that.   A strut member having a buoyancy member is floated on a water surface, a plurality of wires for guiding the strut member are attached to the strut member, and the strut member is guided to a predetermined position by operating the wire. The reinforcing method according to claim 11.   The liquid is injected into the buoyancy member, and the pile connecting members at one end or both ends of the reinforcing strut member are set to a predetermined depth to fix the pile connecting members to the piles. Reinforcing method described in 1.

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