JPS5941507A - Assembly of leg for high-level landing type vertically movable working platform - Google Patents

Abstract

PURPOSE:To make easier the aseembling of long and large vertically movable legs for deep water depths by a method in which an unit leg is inserted from the upside of a working platform on a block, the working platform is raised and supported by struts, and the second unit leg is jointed with the lower part of the unit leg which has been raised. CONSTITUTION:The first process in which a working platform 11 having an elevator 12 is set on blocks 14 laid in a dock D, the second process in which the first unit legs 13 to make up the uppermost part of the legs 13 are lifted up by a crane, etc. and joined from above in the elevator 12 of the working platform 11, the third process in which the working platform 11 is raised along the first unit legs 13 by the elevator 12, the fourth and fifth processes in which the working platform 11 is set on the upside of a strut 16 erected on the downside of the working platform 11, and the sixth process in which the first unit legs 13 are raised and the second unit legs 19 are joined with the lower part of the first unit legs 13 are repeatedly performed. The vertically movable legs of the working platform 11 which are used in deep water can be thus be assembled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for assembling legs of a landing-type lifting workbench having a high lift, and more specifically, a method for assembling legs of a landing-type lifting workbench having a high lift, and more specifically, a method for assembling legs of a landing-type lifting workbench having a lifting device. The present invention relates to a method of assembling legs of a so-called landing type elevating workbench in which the workbench is raised to a use position by the elevating device.

In recent years, due to the depletion of existing petroleum resources, the development of these resources has been actively carried out on the continental shelf, etc., but in the case of 9, offshore work platforms are used. Various types of offshore work platforms have been developed, one of which is a landing type elevating work platform in which a plurality of legs are placed on the ground and the work platform is raised and lowered along the waist legs.

By the way, such a workbench is generally a heavy item with a leg length of 80 m or more and a weight of 7,000 tons, so there are various problems in manufacturing it, one of which is the method of assembling the legs. There is.

In other words, this type of workbench generally has a workbench with a lifting device and legs that are manufactured separately, and then the waist legs are loosely fitted into the lifting device, but as mentioned above, these legs can extend over 80 m. Therefore, a lifting machine with a lifting height of 100 m or more is required for loose fitting. However, installing such a new lifting machine would require a huge amount of cost, so the method is to manufacture the legs as unit legs of about 5 to 20 m depending on the capacity of the existing lifting machine, and then assemble the legs by adding the unit legs. Generally adopted.

An example of this will be explained based on FIG. 1. After a workbench 1 having a lifting device 2 is supported in a dock A by a board 6, a first unit leg 5-1 having a footing 4 at the lower end is installed. is loosely fitted into the lifting device 2, the second unit leg 5-2 is lifted up by a lifting machine 6 provided on the prefecture side, and the first and second unit legs are joined. The fourth unit leg is added upward, and when the height of the leg reaches the limit of the lifting height of the lifting machine A, the work platform is moved to a place with sufficient water depth, the leg is lowered, and the offshore crane There is a method of assembling the remaining upper unit legs using, etc.

However, in such an assembly method, the unit legs must be joined at a relatively high level within the dock, which poses problems in terms of work safety, increased construction time due to scaffolding, etc., and increased costs. 2. Furthermore, when joining the upper unit legs at sea, it is first necessary to select a sea area with sufficient water depth, and there is a danger of stepping on the seabed, so it is necessary to investigate the bedrock of the seabed. This was dependent on sea conditions, and transporting equipment and personnel to the site was complicated. In particular, recently, such offshore work platforms tend to be used in relatively deep waters, and the height of the legs has become 80 m or more. Improving the method of assembling the legs of a stand has become an important topic in the industry.

For this reason, the present applicant previously proposed a method of assembling the legs by introducing each unit leg from the lower part of the workbench, joining them, and sequentially moving them upward.

By the way, in this method of assembling the legs, the weight of the workbench was supported using boards or purges, but in the former case, the workbench cannot be supported at a relatively high place, so the unit legs are As a result, it took a long time to assemble the legs. On the other hand, in the latter case, although it is possible to support the workbench at a relatively high place, there is a problem that the purge becomes large and the equipment cost increases.

The present invention has been made in view of these points, and includes a first step of arranging a workbench having a lifting device on a board laid in a dock, and a first unit leg of the workbench. a second step of arranging the workbench so as to fit into the lifting device from above; a third step of raising the workbench to the top of the first unit leg and removing the board; and a third step of raising the workbench to the top of the first unit leg and removing the board; a fourth step of arranging at least one support on the lower surface of the unit and near where the first unit leg is provided;
a fifth step of lowering the workbench and supporting the weight of the workbench with the support; and a fifth step of raising the first unit leg by the lifting device and then moving the second unit leg to the first unit leg. It is an object of the present invention to provide a method for assembling legs of a high-lift landing type elevating workbench, which comprises a sixth step of introducing the legs under the unit legs and joining the first and twentieth unit legs.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

First, a workbench 11 having a lifting device 12 and a first unit leg 16 are manufactured separately, and the workbench 11 is placed on a board 14 laid in a dock, and then lifted by a lifting machine (not shown). The first unit leg 13 is suspended from above into the lifting device 12 and loosely fitted therein, and its lower end is positioned on the support stand 15 (FIG. 2(a)). Next, the lifting device 12 is operated to raise the workbench 11 to the upper part of the first unit leg 16, and after removing the board 14, the support 16 is placed (FIG. 2(b)). To be more specific, this support 16 has receiving portions 17, 17' at both upper and lower ends, as shown in FIG.
The cylindrical member 18 has a length l sufficient to support the workbench 11 at a relatively high location. This support 16 has a receiving part 17 at its upper end that is connected to the workbench 1.
At least one is disposed on the lower surface of the unit leg 1 and near where the first unit leg 16 is provided.

By the way, this support 16 has a cross section of a mouth shape (FIG. 5(a)) or a ■ shape (FIG. 5(b)), as shown in FIGS. 5(a) to (C), FIG. )), or a combination of multiple relatively small diameter pillars (Fig. 5 (C)), a combination of multiple pillars 16 (Fig. 6), and A conceivable structure is one in which flanges are provided at both ends of the unit struts 16' and a plurality of unit struts 16' are connected together (FIG. 7).

Of course, the workbench 11 is provided with at least three first unit legs 13, but one of the supports 16 may be used alternately, or three or more may be appropriately arranged. .

When the support columns 16 are arranged in such a state, the workbench 11
is lowered and its weight is supported by the support column 16 (FIG. 2(C)). Thereafter, the lifting device 12 is operated to raise the first unit leg 16 (FIG. 2(d)). Then, the second unit leg 19 is placed on the trolley 20 and the first unit leg 1 is placed on the trolley 20.
3, and the lower end of this first unit leg 16 and the second
Weld the upper ends of the unit legs 19 (FIG. 2(e)). If a leg of the required length cannot be formed only by joining the first unit leg 16 and the second unit leg 19, then the sixth
The third and fourth unit legs may be joined by repeating the steps in sequence. Finally, as shown in FIG. 3, a unit leg body 22 having a footing 21 at the lower end is joined, and a support part 26 made of a layer of powder such as sand is arranged.

Each of the above steps explained the procedure for assembling one leg, but what about the force? Since such a workbench 11 requires at least three legs, it goes without saying that in actual assembly, each step is performed simultaneously or alternately on each leg. After completing the assembly of the legs 24 in this way, the lifting device 1
2, the legs 24 are lowered, the weight of the workbench 110 is supported by the legs 24, and then the support 16 is removed.
As described above, according to the present invention, the workbench 11 can be supported at a relatively high place, and each unit leg can be configured to be long, so the time for assembling the legs can be shortened. It has advantages such as relatively low equipment cost.

Of course, the present invention is not limited to the above embodiments.

The important point of the present invention lies in the technical concept of supporting the workbench at a high position using columns and joining the unit legs at the bottom. Therefore, the structure of the support column 16 can be prepared in various ways.
It is also obvious that changes and additions can be made, such as attaching a scaffold to the support column 16 to facilitate the work of joining the unit legs.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the assembly situation of a conventional landing type lifting work platform.
Figure 2 (a) t (b) t (C) t Cd)
t(e), FIG. 3 is a process explanatory diagram of the method for assembling the legs of a landing type lifting work platform according to the present invention, FIG. 4 is a perspective view showing an example of a support used in carrying out the present invention, and FIG. a) ~ (C)
, FIG. 6 and FIG. 7 are explanatory diagrams of other embodiments of the strut, respectively. 1.11...Workbench, 2.12 River lifting device, 6°14
... Board, 4,21 ... Footing, 5-1.16
...First unit leg, Er-2,19...Second unit leg, 15...Support stand, 16...Strut, 1
7, 17'... Receiving part, 18... Cylindrical member, 20...
- Trolley, 23... Support part, 24... Legs. Agent: Patent Attorney Makoto Ogawa − Patent Attorney: Ken Noguchi Patent Attorney: Kazuhiko Saishita

Claims (1)

[Claims] A first step of arranging a workbench having a lifting device on a board laid in a dock, and a second step of arranging a first unit leg so as to fit into the lifting device from the upper part of the workbench. 2
a third step of raising the workbench to the top of the first unit leg and removing the board; and a third step of raising the workbench to the top of the first unit leg and removing the board; a fourth step of arranging at least one support in the vicinity of the first support; a fifth step of lowering the workbench to support the weight of the workbench by the support; a sixth step of raising the unit leg body, and then introducing a second unit leg body under the first unit leg body and joining the first and second unit leg bodies. A method for assembling legs of a high-lift landing type elevating work platform.