JPS5826444B2 - How to build super large structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing very large structures such as offshore oil field platforms.

Docks have traditionally been used to construct offshore work platforms.

Furthermore, in the case of large structures, attempts have been made to construct a lower structure and an upper structure separately, and then to join them together later.

However, in the case of extremely large structures such as offshore oil field work platforms,
The height and width of the substructure are too large to fit into a normal dock, and the lifting height of the crane is insufficient, making it impossible to use normal construction methods.

The present invention proposes a method that solves the above problems and enables construction using the dock when the width of the lower structure is slightly smaller than the dock width. The explanation will be based on.

1 and 2 show an example of a structure to which the method of the present invention is applied.

The structure 1 is constructed as a workbench for an offshore oil field, and consists of a lower structure 2 and an upper structure 3.

The lower structure 2 is composed of four main body pillars 4a to 4d forming a mud mat, and an intermediate member 5 arranged between these main body pillars 4a to 4d.

The intermediate member 5 consists of a plurality of columns 6 and horizontal and inclined beams 7 connected between each of the main body columns 4a to 4d and the columns 6.

The main body columns 4a to 4d are composed of a large number of unit columns 8, a connecting member 9, and an outer shell member.

The upper structure 3 includes a plurality of columns 10 connected to the main body columns 4a to 4d and columns 6 of the lower structure 2, and beams 11 in horizontal and inclined directions.

Next, the construction method will be explained with reference to FIG.

First, the lower structure 2 is constructed in an upright position on the bottom surface of the dock 10.

At this time, the outer portions 11 of the main body columns 1c and 1d on one side of the dock 10 are left unbuilt, and only the portion that fits within the dock width l is constructed.

Note that the intermediate member 5 can also be transported into the dock 10 in a state where it has been assembled to some extent elsewhere.

Since the construction is performed within the dock 10 in this manner, compared to the case where the construction is performed on the side upper surface 10a of the dock 10, the lifting height of the crane can be lowered by a height equivalent to the depth of the dock.

This partially unbuilt lower structure 2 is moved to the sea using a barge or the like, and rotated by 90 degrees on the sea as shown in FIGS. 3C to 3E, so that the unbuilt portion 11 faces downward.

Then, the lower structure 2 is lifted upward using the diving barge 12 (FIG. 3F).

G), and further installed across the upper surface 10a of both sides of the dock 10 (FIG. 3H).

After this, the unbuilt portions 11 of the main body columns 1c and 1d are completed.

At this time, since the unbuilt portion 11 is located at the lowest part of the lower structure 2, the lifting height of the crane is sufficient.

The superstructure 3 was completed using normal construction methods elsewhere,
Load it onto the barge 15 from another dock 13 as shown in Figure 3.

This barge 15 is moved to the dock 10 of the lower structure 2, and is aligned and joined to the lower structure 2 (Fig. 3 J).
.

Vertical positioning at this time is performed by adjusting the ballast of the barge 15.

The parts necessary for joining will be loaded by crane.

In this way, the super large structure 1 is completed.

The present invention can be implemented as described above, and according to this, a part of the main body column of the lower structure is left unbuilt, and the attitude of the lower structure is changed to position the unbuilt part at the bottom. Since the unbuilt part is completed after the construction, even if the lower structure is slightly wider than the dock width, most of it can be built inside the dock, and the unbuilt part can also be built at a lower position later. Therefore, it can be successfully constructed using existing cranes without the problem of insufficient lifting height.

Furthermore, since the attitude of the lower structure is changed on or in the water outside the dock, it can be easily changed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a front view of a super large structure, Fig. 2 is a bottom view of a main body column, and Fig. 3 A-J are explanatory drawings of the construction process. 1... Ultra-large structure, 2... Lower structure, 3... Upper structure, 4a to 4d...
- Main body column, 5... Intermediate member, 8... Unit column, 9... Connecting material, 10... Dock, 11... Unbuilt part, 12...diving barge, 15...barge, l...dock width.

Claims (1)

[Claims] 1. A construction method for a super large structure consisting of an upper structure and a lower structure, where the lower structure is composed of multiple main columns and intermediate members, in which the outer part of the main column on the dock side in a dock. Build the lower structure in an upright position except for A method for constructing a super-large structure, which comprises arranging the body to straddle the upper surfaces of both sides of a dock, constructing the traffic construction part of the body, and then joining the upper structure to the lower structure.