JPH0840351A - Offshore joining method for large-scale floating unit - Google Patents

Abstract

(57) [Abstract] [Purpose] Floating body units that compose a large-scale floating body structure are easily and safely joined offshore. [Structure] The side plate of the submerged portion of the floating body unit 2 or the outer surface of the joint end 8 of the partition wall 5 and the bottom plate 4 has a strength to withstand a water pressure higher than that of water drainage and is deformable and connectable from the inside of the floating body unit 2. A water member 9 and a backing metal 10 are provided, the floating body unit 2 is towed to a construction site, drawn to an existing floating body on the sea and temporarily fixed, and then the stopper 6 is stopped from the inside of the joint 6 of the floating body unit 2. After the water member 9 is connected and the water inside the joint 6 is drained, the joint plate 15 is laid over the backing metal 10 provided at the joint ends 8 of the two floating bodies, and one side back from the inside of the joint 6 in the air. Weld this.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offshore joining method for a floating body unit in the construction of a large-scale floating body structure such as a floating airport, a floating artificial island, etc., where one side in the horizontal direction is several hundred US or more.

[0002]

2. Description of the Related Art In recent years, when planning airport facilities, waste treatment facilities, energy facilities, etc., it is difficult to secure a vast land on land, and there are many oppositions due to the destruction of the natural environment, causing pollution problems such as noise. There is a tendency to use the sea space because it is easy. In addition to these facilities, there are plans for artificial leisure islands such as marine leisure facilities and maritime cities. Since these facilities are deployed offshore from the critical area, there are many plans to install them in deep water. Conventionally, these facilities were mainly constructed by a landfill method, but as the water depth increased, a huge amount of landfill sand was required, and a huge construction fund was required along with the construction of a large-scale revetment. The construction period was long and there were concerns about water pollution in the surrounding sea area during construction, problems such as land subsidence after completion, and loss of fishing grounds. Therefore, artificial islands of various floating structures have been proposed to solve the problems of these landfill systems. This floating structure type artificial island is a structure in which a large number of box-shaped floating units made of steel plates or concrete plates are joined and the inside of the floating structure is floated by buoyancy. This floating body structure requires a large-scale building facility and towing facility in order to construct the entire large-scale floating body structure on a land yard or dock and tow it if the flat area is several hundred ha. It is almost impossible in reality. Therefore, it is necessary to divide into a large number of floating body units for construction and towing, and to join them on site. This floating unit will be a large-scale unit with a horizontal length of several tens to several hundreds of US and a height of several US. It is possible to easily join the floating body units on site by installing a temporary structure and using it, but installing a large-scale temporary structure in the deep water requires huge construction funds. It is uneconomical and requires a long construction period. Therefore, it is more advantageous in terms of economic efficiency and construction period to join the floating body units in a floating state. Conventionally, there is no example of constructing such a large-scale floating body unit by sea joining, but as a possible means in the case of a steel floating body unit, the floating body units to be joined are pulled together and temporarily fixed, and then joined. There is a method of welding and joining the ends.

[0003]

However, with this method, there is not much problem with the air part above the water level, but the side plates, partition walls and bottom plate of the submerged part are strong in terms of strength when underwater welding is performed. It is difficult to secure quality. Therefore, when trying to perform air welding, after attaching a water blocking member from the outer surface of the floating body unit to the joint of the submerged portion by diver work, the water inside is drained and welded. In such a floating body unit, when performing the work of attaching the water blocking member, the diver dives under the floating body unit and reciprocates several hundred US to attach the water blocking member to the joint, which involves dangerous work and is inefficient. was there. Also, because the floating body unit is temporarily fixed while it is in a floating state, accurate positioning of the joint end cannot be obtained due to fluctuations caused by waves, and the line size may change due to the large scale of the floating body unit. The expansion causes a dimensional error, and it is necessary to perform the joining work under the condition that the positioning accuracy of the joining end is also poor from this aspect. The present invention, in the construction of a large-scale floating structure made of steel, when joining a large-scale floating unit, which has never existed in the past, in a floating state on the sea, even under the condition that the positioning accuracy of the joining end cannot be sufficiently secured. The object of the present invention is to provide a method of being able to work efficiently and safely.

[0004]

In order to achieve the above-mentioned object, a method of offshore joining of a large-scale floating body unit according to the present invention comprises a side plate of a submerged portion of a floating body unit 2 or a partition wall 5 and an outer surface of a joining end 8 of a bottom plate 4. In addition, a waterproofing member 9 that has strength to withstand water pressure higher than that of water drainage, is deformable, and can be connected from the inside of the floating body unit 2, and a backing metal 10 are provided, and the floating body unit 2 is floated on a construction site. After being towed and temporarily pulled to an existing floating body on the sea and temporarily fixed, the water stop member 9 is connected from the inside of the joint 6 of the floating body unit 2 to drain the water inside the joint 6 and then the joint ends of the two floats. It is constructed by bridging the joining plate 15 on the backing metal 10 provided on the No. 8 and performing one-side backing welding from the inside of the joining portion 6 in the air.

[0005]

The water-stop member 9 is used to join the floating unit according to the present invention.
Connection, drainage inside the joint 6 and welding work are all performed from inside the joint 6 of the floating unit 2, and even if the positioning accuracy of the joint end 8 of the floating unit 2 is poor, To facilitate welding work,
In addition, the welding work will be done by air welding, which ensures strength. These are made possible by the water blocking member 9, the backing plate 10 and the joining plate 15 which are provided at the joining end 8 when the floating body unit is constructed. That is, by adopting the water blocking member 9 which is deformable and can be connected from the inside of the floating body unit, it is possible to flexibly cope with poor positioning accuracy of the joint end 8 as described above. However, if the water blocking member 9 is made to be easily deformed, it will be broken by external water pressure when draining the internal water or leak water to impair the water blocking function, so that it has the strength to withstand water pressure higher than stiff water. There is a need. A thin steel plate is used as the water blocking member 9 in FIGS. 1, 3 (a) and 3 (b),
As shown in (c), a U-shaped or wavy bent portion 9b is provided,
It is made deformable as shown by the dotted line A, and the connecting piece 9c is formed facing inward. The backing plate 10 provided on the outer surface of the joining end 8 enables the joining plate 15 to be welded on one side from the inside of the floating body unit, and the positioning accuracy of the joining end 8 of both floating body units to be joined can be improved as shown in FIG. Poorly, even if there is a positional deviation (Δ in FIG. 2), the joining plate 15 can be slanted over both backing plates 10 and welded to the backing plate. The water blocking member 9 and the backing plate 10 may be integrally formed or separated.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The large-scale floating structure targeted by the present invention has a side of several hundreds of US or more, and for example, the one shown in this embodiment has a width of 10 mm.
00m, length 5000m, height 5m. As shown in FIG. 8, this large-scale floating structure is divided into large floating units having a width of several tens of US and a length of several hundred US (width of 50 m, length of about 300 m in this embodiment), and is divided into a dry dock and a land yard. It is built on the ground and is towed to the construction site and then joined at sea. A breakwater 35 and mooring equipment 36 are installed in advance at the construction site as shown in FIG. The breakwater 35 reduces the influence of waves during joining work of the floating body unit 2 and after the large-scale floating body structure 1 is completed, when this structure is used as a floating airport or a floating artificial island, the wave external force is reduced to protect it. And reduce the upset. The mooring equipment 36 is provided to prevent the floating body from being swept away by tidal currents and winds during the joining work of the floating body unit 2 and after the large-scale floating body structure 1 is completed. The floating body unit 2 obtained by dividing the large-scale floating body structure 1 into a large number is actually provided with stiffening members, draft tanks, piping, etc.
As shown in FIG. 6, it is composed of a top plate 3, a bottom plate 4, and a large number of partition walls 5 and side plates 5a that partition them. In the present invention, the side plate 5a is provided for the floating unit located below the bottom plate 4 at the joint end 8 with the adjacent floating unit 2 and the outer periphery of the large-scale floating structure, and the outer partition wall 5 is provided for the intermediate floating unit.
The water blocking member 9 and the backing plate 10 are fixed in the vertical direction outside the submerged part. The water blocking member 9 and the backing plate 10 are attached to a dry dock or a land yard when the floating body unit 2 is constructed. FIG. 1 shows the details of the embodiment. In this example, the water blocking member 9 and the backing plate 10 are integrally formed, and the corners of the water blocking member 9 are U-shaped to facilitate deformation. The water blocking member 9 and the backing plate 10 may be separate bodies. The water stop member 9 is made of a thin long steel plate and is connected to the base end portion 9a fixed to the floating body unit and the water stop member 9 adjacent to the bent portion 9b for easy deformation.
The bent portion 9b has a wavy, U-shaped or semicircular cross-sectional shape as shown in FIGS. 3 (a), 3 (b) and 3 (c).
In the figure, the dotted line A indicates the deformed state connecting piece 9a of the water blocking member 9, and the connecting piece 9a projects inward of the floating body unit, and elongated holes 11 for bolt connection are provided at appropriate intervals via packings 18. The reason why the holes are formed is to cope with the deviation of the bolt holes in the joining longitudinal direction of the floating unit 2. Water stop member 9 as described above
By using, even if the positioning accuracy of the joint end 8 is poor, the work of connecting the water blocking member 9 can be easily performed and the watertightness can be secured. The backing metal 10 is welded and fixed to the outer surface of the joint end 8 while protruding from the joint end 8 by several cm. As the joining plate 15 that joins the joining ends 8 of the adjacent floating body units 2, one having a predetermined width with grooves formed on both sides is prepared. A manhole 7 is provided on the top plate 3 of the floating body unit 2 for the entry and exit of workers for joining work, loading and unloading of materials and equipment, drainage, etc., and the partition wall 5 is provided with a trap 16 and a ladder. I need to put it.

Next, the operation of joining the floating unit according to the present invention will be described. First, the first floating body unit 2 that has been float-towed is moored to the mooring equipment 36 such as a mooring dolphin, and the floating body units 2 are sequentially joined. The joining work is performed by the floating body unit 2 which has been towed as shown in FIG. 7 (a).
Is drawn using the eye plate 30, the winch 32, and the wire rope 31 provided on the upper surface plate 3 of the existing floating body first floating body unit or the joined floating body unit.
This pulling operation may be performed by using a tugboat as shown in FIG. Floating body unit 2 to be joined
When the floating body unit 2 approaches the existing floating body, as shown in FIG. 7B, the floating body unit 2 and the floating body are joined and temporarily fixed by a positioning device having a guide 34 and a jack 33. 2 inside the joint 6 and the bolt 13 is inserted into the long hole 11 of the water blocking member 9 provided at the joint 8 of the bottom plate 4 and the outermost partition wall 5 or the side plate 5a, and the washer 12 is inserted. Tighten with the nut 14. Since the water blocking member 9 is provided with the packing 18, both the connecting pieces 9c are connected in a watertight state. The connection work of the water blocking member 9 is performed in a state where seawater is present in the floating body unit, but the positioning accuracy of the joint end 8 is poor, and even if there is a positional deviation (Δ in FIG. 2) or there is some shaking, it stops. Since the water member 9 can be deformed and the bolt hole is the elongated hole 11, it can be easily performed. The connection work of the water blocking member 9 is an underwater work, but if the water depth is about 50 to 70 m or less, it is not so difficult even if it is a normal work, but if the water depth is more than this, it will be done by diving work. Become. When the water stop member 9 is connected to the joint end 8 of the floating body unit 2, the water in the joint portion 6 is drained by using the submersible pump 17 or the like until the water level is below the outer surface of the bottom plate 4. After draining the water in the joint portion 6, the joint portion 8 of the bottom plate, the top plate, the partition wall or the side plate is welded as shown in FIG. 7 (c). Welding is performed by single-sided welding in the air from the inside of the floating body unit 2 by bridging the joining plate 15 on the backing plate 10 provided at the joining end 8, and thus the work can be easily performed even if the joining end 8 is slightly displaced. High quality can be secured because it can be done by air welding. The welding work may be performed manually, but it is more efficient to use rail traveling automatic welding. By the above joining work, all the floating body units are joined to complete a large-scale floating body structure. After the joining is completed, the space of the water blocking member 9 may be filled with a filler such as mortar to prevent corrosion.

[0008]

According to the present invention, when joining a floating body unit in the floating state, the joining end of the submerged portion can be welded by air welding from the inside of the floating body unit, so that the welding strength is lowered. It is possible to obtain a high quality welding quality without causing it. Further, since the water blocking member 9 at the joint end portion of the floating body unit is deformable and is welded from the inside of the floating body unit with the backing plate 10 using the joint plate 15,
The positioning accuracy of the joining end 8 is poor, and there is a positional deviation,
Work can be done easily and reliably even during shaking. Further, since all joining work is performed from the inside of the floating body unit, it is possible to eliminate a dangerous long-time diver work, and it is possible to perform work safely and efficiently.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a floating body unit joint portion according to the present invention.

FIG. 2 is a joining diagram when the positioning accuracy of the joining end in FIG. 1 is poor.

3A, 3B, and 3C are cross-sectional views of an example of a water blocking member.

FIG. 4 is a divided view of a floating body unit according to the present invention.

FIG. 5 is an installation diagram of a large-scale floating structure according to the present invention.

FIG. 6 is a structural diagram of a floating body unit according to the present invention.

7 (a), (b) and (c) are views showing the procedure for joining the floating body units.

FIG. 8 is a drawing of a floating body unit according to the present invention.

[Explanation of symbols]

 1 Large-scale floating structure 2 Floating body unit 3 Top plate 4 Bottom plate 5 Partition wall 6 Joint part 7 Manhole 8 Joint end 9 Water stop member 10 Back plate 11 Long hole 12 Washer 13 Bolt 14 Nut 15 Joint plate 16 Talap 17 Submersible pump 18 Packing 30 Eye plate 31 Wire rope 32 Winch 33 Jack 34 Guide 35 Breakwater 36 Mooring equipment

Claims (1)

[Claims] 1. The side plate of the submerged portion of the floating body unit 2 or the outer surface of the joint end 8 of the partition wall 5 and the bottom plate 4 has a strength to withstand a water pressure higher than that of diffusing water and is deformable and connectable from the inside of the floating body unit 2. The water blocking member 9 and the backing metal 10 are provided, the floating body unit 2 is towed to a construction site, and then the floating body unit 2 is temporarily fixed by being attracted to an existing floating body on the sea.
The water blocking member 9 is connected from the inside of the joint portion 6 of
Large-scale, characterized in that after draining water from the inside, the backing plate 10 provided on the joining ends 8 of both floating bodies is bridged with the joining plate 15 and one-sided back welding is performed from the inside of the joining part 6 in the air. Offshore joining method for floating units.