JPS61122090A - Construction method of large steel structure on the sea - Google Patents

Abstract

PURPOSE:To enable a large structure to be constructed without utilizing a large dock by floating, on the sea, each block, built on land, and welding in the air a part which is in the air and performing underwater welding, for a part submerged in the sea, through pressing a joining plate against the submerged part. CONSTITUTION:A block 8 is formed by welding, on land, two side plates 4, with respective notch parts 2 in the lower part, to a bottom plate 6. After floating each block 8 on the sea for alignment, welding is performed for a boundary part 10 staying in the air. Then, a joining plate 12 is pressed on a submerged part and a boundary part 14 between the joining plate 12 and the block 8 is welded in the water. Thus, construction work of a large structure can be simply performed without requirement for a construction dock for said work.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an offshore construction method for assembling large steel structures on the ocean.

[Conventional technology]

Conventionally, methods for constructing large steel structures such as ships include a berth or dock construction method and an offshore construction method.

The former type of dock or dock construction method involves constructing ships, etc. within a dock or dock set up on land, but it requires a large dock depending on the size of the structure, and it takes a long time during the docking period. It also took a long time.

The latter offshore construction method, as shown in Section 5 (8), is a method for constructing large ships that cannot be accommodated in docks.

In this method, the front hull 102 and the rear hull 104 are built in advance in a ship, and the front hull 104 is installed at sea.
Then, the hull 108 is constructed by welding the hull rear part 104 and the joint part 106.

6 is a cross-sectional view taken along line AA in FIG. 5, and FIG. 7 is a cross-sectional view taken along line B-H in FIG. 6.

In order to weld the joint 106 in the offshore construction method, normal welding is performed in the atmospheric part, but in the submerged part, the welded part is covered with a waterproof shelter 110 shown in FIGS. 6 and 7, and the inside of the waterproof shelter 110 is welded. After draining water to form a space 112, the joint 5106 and the rear hull 104 (or the front hull 102
) is to be welded to the boundary 114. Note that 116 indicates the ocean. However, if welding is performed after installing the waterproof shelter 110 in this way, the number of work steps will increase, which will lengthen the construction period, and there will be problems such as high equipment and material costs. .

〔the purpose〕

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned problems, an object of the present invention is to provide an offshore construction method for large steel structures that does not require a large construction dock, has a short construction period, and is low in construction cost.

[Means for solving the invention]

In order to achieve the above object, the present invention constructs a large steel structure on the ground that is divided into a plurality of large steel structures, floats the plurality of structures on the ocean, and places them in the atmosphere of adjacent structures. Welding is performed in the atmosphere on the part located in the atmosphere, a joint plate is brought into contact with the submerged part of the adjacent block, and the blocks and the joint plate are welded underwater to join a plurality of blocks. It is characterized by

[Example] Hereinafter, examples of the present invention will be described in detail based on the drawings, taking a floating dock as an example of a large steel structure.

Figure 1 shows the offshore construction method for a floating boat. First, as shown in Figure 1-), the floating boat has a notch s2 at the bottom.
By welding the two side plates 4 and the bottom plate 6,
A block 8 is formed as shown in FIG.

Next, as shown in the same figure (C), after arranging a plurality of protrusions 8 on the ocean, as shown in the same figure @), the boundary parts 10 of the adjacent protrusions 8 in the atmosphere are welded.

The joint plate 12 is brought into contact with the submerged portion of the adjacent block 8 (
The same figure ←)) After that, the boundary 14 between the joint plate 12 and the block 8 is underwater welded, and each professional
Join them and construct floating dome 16.

Other methods for joining the submerged parts include the methods shown in FIGS. 2 and 3.

In Fig. 2(a), the block 8' which does not have the notch 2 (Fig. 1(a)) and the joint plate 12 are welded together. Show what you do.

3 and 4 show a method of joining blocks using an auxiliary plate and a chill plate, and FIG. 4 is a sectional view taken along line CC in FIG. 3. As shown in the figure, an auxiliary plate 20 is provided in the space 18 formed by the notch 2 of the block 8 having the notch 2, and a chill plate 22 is applied to the auxiliary plate 20 and the side plate 4 of the block 8 from the inside. It is welded and joined.

Fu Mukaimoto The explanation was given using a floating dock as an example, but it goes without saying that the present invention can also be applied to ships and the like.

〔Effect of the invention〕

As described above in detail and concretely, according to the present invention, there is no need for a large construction dock, and since underwater welding can be performed, there is no need to provide a waterproof shelter or an atmospheric space at the joints of the hull. As the number of steps is reduced, the construction period is shortened and equipment and material costs are also reduced, resulting in cost reduction.

[Brief explanation of the drawing]

Figure 1 shows 1 of the present invention! #! This is a diagram showing the offshore construction method of a floating dock according to an example, where (-) and (b) are perspective views of the block, and (C) and (d) are side views of the block placed on the ocean. Figure, (e) is an enlarged view of part E of the same figure @),
Figure (f) is a side view of the floating dock. Figures 2 and 3 show other examples of the block joining method, and correspond to Figure 1(e), and Figure 4 is C in Figure 3.
-C is a sectional view. FIG. 5 is a side view of a hull according to a conventional offshore construction method, FIG. 6 is a sectional view taken along FIG. 7 AA, and FIG. 7 is a sectional view taken along FIG. 6 B-H. 8...Block, 14...Joining board, 16...Floating do, ri. ＝Uノ
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ν N-Figure 2 (a) (b) Figure 5, A Figure 7 +12 110

Claims (1)

[Claims] (1) A large steel structure to be constructed is divided into multiple blocks and built on the ground, then the multiple blocks are floated on the ocean, the parts of the adjacent blocks that are in the atmosphere are welded in the atmosphere, and the adjacent blocks are welded in the atmosphere. 1. A method for constructing a large steel structure offshore, characterized in that a plurality of blocks are joined by abutting a joint plate on the submerged portion of the block, and underwater welding the block and the joint plate.