JP2000017681A - Corrosionproof band for wall surface of offshore steel structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrosionproof band resisting usage for a prolonged term, capable of being formed by a simple construction method and being formed in a tidal splash zone in the wall surface of an offshore structure. SOLUTION: The corrosionproof band consisting of an underwater inseparable concrete layer 4 in specified thickness and a protecting plate 5 covering the outer circumference of the underwater inseparable concrete layer 4 and being made of a titanium sheet is formed in a tidal splash zone in the wall surface of the offshore structure, in which steel sheet piles are connected mutually. The protecting plate 5 made of the titanium sheet is formed by alternately connecting a large number of peripheral plates 6 and a large number of connecting plates 7 by using sleeves 13 in a C-shaped cross section. It is preferable that the concrete layer 4 and the protecting plate 5 made of the titanium sheet are further stuck fast when anchor metal fittings made of titanium are joined with the peripheral plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION For example, the foundation of an offshore structure is
Steel piles such as steel sheet piles and steel pipe sheet piles are interconnected, driven into the seabed, and formed on vertical wall surfaces. The present invention relates to an anticorrosion zone formed on the ebb and splash zone on the wall.

[0002]

2. Description of the Related Art The tidal splash zone of a steel pile of an offshore structure is highly corroded by seawater. To prevent and reduce this corrosion,
The steel pile is covered with concrete, for example. Conventionally, a. And b. The concrete coating was known. That is, a) a method in which concrete is poured between a steel pile and a form using a form, and then the form is removed. B) A method in which concrete is cast between a steel pile and a formwork using a formwork made of FRP or the like, and thereafter the formwork made of FRP or the like is used as buried without being removed.

[0003] However, the problem (a) is that concrete is in direct contact with seawater, so that the cement component flows out of the seawater, and the seawater flows directly into the cracks in the concrete, corroding the steel piles. is there. Further, since the FRP mold of (b) is embrittled by ultraviolet rays, there is a problem that the mold is destroyed due to collision of a floating substance or the like when used for a long time.

[0004] Although it is not a corrosion protection zone on the wall surface to which steel pipe piles are connected, Japanese Utility Model Publication No. 56-9702, Japanese Patent Application Laid-Open No. Hei 7-1665.
No. 68 describes an anticorrosion zone applied to a single steel pipe. FIG. 4 shows an example. That is, the anticorrosion material impregnated tape 21 or the like is wound around the outer periphery of the single steel pipe 20, the anticorrosion metal impregnated tape 21 is provided with the anticorrosion metal cover 22, and the anticorrosion metal cover 22 is used while being buried. At this time, if the corrosion-resistant metal cover 22 is closely arranged and disposed on the outer surface of the anticorrosion material impregnated tape 21, a preferable anticorrosion zone of the steel pipe is obtained.

[0005] In this single steel pipe anticorrosion band, the anticorrosion metal cover 22 is made of a corrosion-resistant metal plate by making the outer circumference of the anticorrosion material impregnated tape 21 complete and stopping at both ends. Can be placed on the outside. However, when the surface on which the anticorrosion zone is to be applied is a wall surface, as will be described in detail later, the wall surface is formed of a large number of steel piles interconnected by claws. That is, at this time, since the claws are connected to each other, the corrosion-resistant metal plate cannot make a full circumference of each steel pile as shown in FIG.

[0006]

SUMMARY OF THE INVENTION Titanium has excellent corrosion resistance in a tidal splash zone. Also, there is no embrittlement by ultraviolet rays. Thus, the ability to place titanium as a buried formwork on the outer surface of the concrete will protect the concrete for an extended period of time, thereby protecting the steel pile inside from corrosion. However, thick titanium forms are not economical because titanium is expensive. An object of the present invention is to provide an anticorrosion zone on the wall surface of a marine structure, in which a titanium thin plate is embedded and formed as a form and closely attached to the outer surface of concrete.

[0007]

FIG. 1 is an explanatory view of an anticorrosion belt according to the present invention. FIG. 1 (A) is an explanatory cross-sectional view, FIG. 1 (B) is a perspective explanatory view of the structure, and FIG. is there. The present invention is an anticorrosion zone formed in a tidal splash zone on a vertical wall surface of an offshore structure in which steel piles are interconnected. The steel piles 1-1 and 1-2 are connected by combining the male claws 2 and the female claws 3, and each lower end is driven into the seabed to form a vertical wall surface. Steel piles are susceptible to corrosion in the ebb and splash zone. The present invention is an anticorrosion zone for preventing and reducing the corrosion of the tidal splash zone.

The anticorrosion belt of the present invention comprises a submerged concrete layer 4 having a predetermined thickness disposed on the vertical wall, and a protective plate 5 made of a titanium thin plate covering the outer surface of the submerged concrete layer 4. It is formed with. The protective plate 5 made of titanium thin plate alternately includes an outer peripheral plate 6 disposed facing a portion other than the connecting portion of the steel pile and a connecting plate 7 disposed facing the connecting portion of the steel pile. It is formed by connecting.

The outer peripheral plate 6 is formed in a plate shape having a folded portion 8 having a width of 5 to 50 mm opposite to the steel side at the left and right ends.
The connecting plate 7 has a groove shape having flanges 10 and 10 ′ on the left and right sides of the web 9, the inner angle θ with the web 9 being 90 ° or more.
Steel pipe piles 1-1,1-
Folding of 5 to 50 mm width opposite to 2 side 11, 1
1 'is formed, and the web 9 is made of a titanium thin plate having a plurality of bolt fittings 12 formed therein.

The protective plate 5 made of a titanium thin plate is formed by connecting the outer peripheral plate 6 and the connecting plate 7, and this connection is performed by abutting the folded 8 of the outer peripheral plate with the folded plate 11 of the connecting plate.
Using a sheath tube 13 made of titanium having a C-shaped cross section and formed separately, the folded portion 8 of the outer peripheral plate 6 and the connecting plate 7 are folded.
The connection is made by fitting together the folded part 11 of the folded part of the above into the inside of the C-shaped sheath tube 13.

The whole of the protective plate 5 has one end joined to a steel pile, for example 1-2 claws 3, and the other end connected to the other end of a bolt 14 projecting from the underwater inseparable concrete layer 4 to the bolt of the joining plate 7. The fitting hole is fitted and the nut 15 is tightened to hold it on the steel pile.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The anticorrosion belt of the present invention has a large number of steel piles 1 (1-1, 1--1) interconnected by male claws 2 and female claws 3.
The outer plate 6 and the connecting plate 7 are connected to the wall of the ebb and splash zone of the marine structure formed by the sheath pipe 13 at intervals corresponding to the thickness of the water-inseparable concrete by the sheath tube 13. The protection plate 5 made of a thin plate is fixedly arranged with the bolts 14 and the nuts 15, and the protection plate 5 and the steel pile 1 (1-1, 1-2,
During…), inject underwater non-separable concrete. After casting the underwater non-separable concrete, the nut 15 is tightened as necessary to further adhere the titanium thin plate protection plate 5 to the concrete, and thereafter, the titanium thin plate protection plate 5 is buried to form a form. .

Although the protective plate 5 made of a titanium thin plate of the present invention is a thin plate having a plate thickness of 1 mm or less, it has excellent corrosion resistance in a titanium tidal splash zone, and therefore does not wear out over a long period of time. . Furthermore, since the protective plate 5 made of titanium thin plate is arranged in close contact with concrete, it protects concrete for a long period of time and protects the steel pile inside from corrosion.

Since the steel piles are connected to each other by the claws 2 and 3, the corrosion of the wall of the marine structure is hindered by the claws, and the titanium thin plate is rotated around the outer surface of each steel pile. Although not possible, according to the present invention, a concrete layer of a desired uniform thickness is formed on the outer surface of the steel pile,
A protective plate made of a thin titanium plate can be arranged in close contact with the outer surface.

In the present invention, the outer peripheral plate 6 and the connecting plate 7 are
The connection is made using the sheath tube 13, but this connection is simple at the time of on-site construction. Therefore, the anticorrosion zone of the present invention can be easily formed on the wall of a marine structure. When the bolt 14 and the nut 15 are made of steel, for example, a cap filled with a known quick-drying cement or an organic polymer compound is put on a portion protruding from the connecting plate 7 to prevent the corrosion.

In the present invention, the steel pile 1 (1-1,1-
In order to prevent the corrosion of (2,...), It is preferable that the underwater-inseparable concrete layer 4 and the protective plate 5 made of titanium be adhered to each other without generating a large gap. FIG.
Is an explanatory view of the anticorrosion zone of the present invention in which the adhesion is further excellent, (A) is a perspective view for explaining the structure, (B) is a schematic cross-sectional view, (C-1) and (C-2). The figure is a sectional view taken along the line II in FIG. In other words, FIG. 2 is characterized in that the outer peripheral plate 6 is joined to the surface of the steel pipe pile 1 on the surface of the steel pipe pile 1 by the titanium anchor 16 having the same protruding length as the thickness of the concrete layer 4. It is an anticorrosion zone.

The titanium anchor 16 is shown in FIG.
As shown in (B), it is previously joined to the outer peripheral plate 6 by, for example, welding 18. When this anchor 16 is used, the flange 19 of the anchor 16 is fixed to the concrete, so that the anchor 16 holds the outer peripheral plate 6 so that the outer peripheral plate 6 does not separate from the concrete. Since the anchor 16 of FIG. 2 has the same protruding length as the thickness of the concrete layer 4, the steel pile 1 (1-1, 1-2,...)
In addition, it has a function as a spacer for accurately maintaining the interval between the outer peripheral plate 6 and the uniform thickness of the concrete layer 4.

It is preferable that the anchor 16 has openings 17-1, 17-2, and 17-3 as shown in FIG. 2C-1. Alternatively, as shown in FIG. 2C-2, it is preferable not to dispose it over the entire length, but to dispose it intermittently like 16-1, 16-2, 16-3. When the concrete is poured, the concrete flows in the direction P or the direction Q in FIG. At this time, holes 17-1 and 17-
2, 17-3 or anchor 1
6 is intermittently arranged like 16-1, 16-2, 16-3, the flow of the concrete is not hindered at the time of placing the concrete, and the concrete passes through the opening or the missing part. It flows freely in the direction or the Q direction and is uniformly filled.

FIG. 3 is an explanatory view of another example of the present invention in which the underwater non-separable concrete layer 4 and the titanium protective plate 5 are kept in close contact with each other. That is, the outer peripheral plate 6 is an anticorrosion zone in which a titanium anchor 16 ′ having a protruding length shorter than the thickness of the concrete layer 4 is joined to the surface on the side facing the steel pile. At this time, the anchor 16 'is also previously joined to the outer peripheral plate 6 by welding or the like as in the case of FIG. In this anchor 16 ′, the flange 19 ′ of the anchor 16 ′ is buried and fixed in the concrete 4. Therefore, the anchor 16 ′ fixes the outer plate 6 so that the outer plate 6 does not separate from the concrete layer 4. Grasping.

[0020]

The anticorrosion zone of the present invention can protect concrete for a long period of time and protect steel piles inside the concrete from corrosion. In the present invention, titanium is used. However, since it is a thin plate, the amount used is small and the cost does not increase significantly. The anticorrosion zone of the present invention is easy to construct on site, and therefore can be formed on a wide wall surface of an offshore structure.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an anticorrosion zone of the present invention.

FIG. 2 is an explanatory view of an example of an anticorrosion zone of the present invention having excellent adhesion between a concrete layer and a titanium protection plate.

FIG. 3 is an explanatory view of another example of the anticorrosion zone of the present invention in which the adhesion between the concrete layer and the titanium protective plate is excellent.

FIG. 4 is an explanatory view of an example of a conventional anticorrosion band applied to a single steel pipe.

[Explanation of symbols]

1 (1-1, 1-2): steel pile, 2: male nail, 3: female nail, 4: water-inseparable concrete layer, 5: titanium thin plate protection plate, 6: outer peripheral plate, 7: Connecting plate, 8:
9: Web of connecting plate, 10: Flange of connecting plate, 11: Fold of connecting plate, 12: Folding of connecting plate
Bolt fitting hole, 13: sheath tube, 14: bolt, 1
5: Nut, 16 (16-1, 16-2, 16-
3): Titanium anchor fitting 16 ': Titanium anchor fitting 17 (17-1, 17-2, 17-)
3): opening, 18: welding, 19: flange of titanium anchor, 19 ′: flange of titanium anchor, 20: single steel pipe, 21: impregnating tape impregnated with anticorrosive agent, 22: corrosion-resistant metal cover .

Claims (3)

[Claims] An anticorrosion zone formed in a tidal splash zone on a vertical wall formed by interconnecting steel piles, the anticorrosion zone having a predetermined thickness and being formed on the vertical wall. And a protective plate made of titanium sheet covering the outer surface of the underwater non-separable concrete layer. The protective sheet made of titanium sheet is connected to an outer peripheral plate arranged to face a portion other than the connecting portion of the steel pile. The outer peripheral plate is formed at the left and right ends in the opposite direction to the steel pile side by 5 to 5 in the direction opposite to the steel pile side.
Each connecting plate is a grooved shape with a flange whose inner angle with the web is 90 ° or more on the left and right sides of the web, and the side ends of both flanges are opposite to the steel pipe pile side. Folding of 5-50 mm width is formed and the web is made of a thin plate in which a plurality of bolt fitting holes are formed. This is a connection in which a folded portion of the outer peripheral plate and a folded portion of the connecting plate are fitted together into the C-shaped inside using a C-shaped titanium thin plate sheath tube. The bolt is connected to the nail of the steel pile and the other end protrudes from the underwater non-separable concrete layer. The anticorrosion zone on the wall of the marine steel structure. 2. The outer peripheral plate according to claim 1, wherein a titanium anchor having a projection length equal to the thickness of the concrete layer is joined to a surface of the steel pile side. ,
Anticorrosion zone on the wall of a marine steel structure. 3. An anchor plate made of titanium and having a projecting length shorter than the thickness of the concrete layer is joined to a surface of the outer peripheral plate facing the steel pile. 2. The anticorrosion zone on the wall surface of the offshore steel structure according to 1.