JP3250632B2 - How to assemble large steel structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling a large steel structure in a case where a large steel structure is assembled into a large block and mounted at an installation position.

[0002]

2. Description of the Related Art As an example of assembling a large steel structure, a reactor containment vessel used in a nuclear power plant will be described as an example. The reactor is housed in a reactor pressure vessel (RPV), and the reactor containment vessel houses the reactor pressure vessel and piping connected thereto. The reactor containment vessel is composed of a steel plate only, or a reactor vessel having a lining plate made of steel plate on the inner surface and made of reinforced concrete.

FIG. 2 is a view showing an example of a reinforced concrete containment container (RCCV) using a steel plate lining plate on the inner surface and a main structure inside the container. The RCCV is composed of a cylinder as a whole. The height direction is divided into upper and lower parts by a diaphragm floor 4, and a cylindrical pedestal 12 is provided at the center of the lower part. The upper part is an upper dry well 1, the lower part is a suppression chamber 2, The inside of the pedestal 12 is a lower dry well 3. The upper dry well 1 and the lower dry well 3 are in communication.

The top of the upper dry well 1 is composed of a top slab 5 using a steel plate lining plate on the inner surface and a steel plate openable and closable top head 10 provided at the center. The bottom of the suppression chamber 2 is a reinforced concrete structure with a steel plate lining plate on the inside,
The pedestal 12 is made of a steel plate, and is filled with concrete. In addition, a vent pipe 8 for guiding the vapor generated in the upper dry well 1 and the lower dry well 3 into the suppression chamber 2 is embedded in the pedestal 12. An access tunnel 7 is provided in the suppression chamber 2 for traffic between the outside and the lower drywell 3.

[0005] The reactor pressure vessel 11 is mounted on a pedestal 12, and a cylindrical reactor shielding wall (RSW) 6 is provided around the diaphragm floor 4. An RPV stabilizer 14 is provided at a section of the reactor shield wall 6 to support a horizontal force applied to an upper portion of the reactor pressure vessel 11. An upper reactor shield wall 13 slightly thinner than the reactor shield wall 6 is provided above the reactor shield wall 6. A pipe whip structure 9 composed of steel columns and beams in a hierarchical structure is provided around the reactor shield wall 6 and supports piping and equipment connected to the reactor pressure vessel 11.

In the construction of such a reinforced concrete containment container, first, reinforced concrete at the bottom is cast, and the bottom lining plate 20 of the suppression chamber 2 is placed thereon.
And attach the surrounding lining plate 21 in parallel with this. Reinforcing bars are arranged around the lining plate 21 in parallel with the
I will put in. When the installation of the lining plate 21 of the suppression chamber 2 is completed, the lining plate 22 of the upper drywell 1 is subsequently installed, followed by the installation of the reinforcing steel and the concrete casting, thereby constructing the reinforced concrete containment vessel. . At the same time, the internal pedestal 12, the diaphragm floor 4, the reactor shield wall 6, the upper reactor shield wall 13, and the pipe whip structure 9 are also mounted. After most of the members and equipment to be installed in the reinforced concrete containment vessel are mounted, reinforced concrete work is performed on the lining plate of the top slab 5.

[0007] The construction period of the reinforced concrete containment vessel directly affects the construction period of the nuclear power plant, so it is necessary to construct the container as short as possible. For this purpose, an assembling table is provided near the installation position of the reinforced concrete containment vessel. The assembling table is used to assemble the suppression chamber 2 and the lining plates 21 and 22 on the peripheral wall of the upper drywell 1 into a cylindrical shape, and install this with a crane. A method of mounting at a position and installing it is adopted. Since the work of assembling into a cylindrical shape takes time, a plurality of surface plates are provided, and the assembly is performed in parallel. The lining plate assembled in a cylindrical shape is lifted by a crane,
Although it is mounted at the installation position, it has to be lifted by using a substantially circular hanging tool (called a balance) because the rigidity for maintaining the cylindrical shape is small.

[0008]

The diameter of the lining plate assembled in a cylindrical shape as described above is about 30 m or more. For this reason, the diameter of the balance is almost the same as this. The frequency of use of this balance is very small because it is used only when mounting the lining plate assembled in a cylindrical shape. However, when the balance is used, it is necessary to lift the balance with a crane, so that it is necessary to place the balance within the lifting range (reach) of the crane. By the way, there are a plurality of bases described above in the reach of the crane, and in addition, an area for temporarily placing objects to be suspended by the crane is required. For this reason, in many cases, it is not possible to secure an area for placing a balance that is used less frequently in the crane reach. In such a case,
It is necessary to temporarily place the balance at a position outside the crane reach, and to use a lifting machine and a transport vehicle inside the crane reach to carry the balance. In addition, work on the surface plate is an outdoor work, so the working environment is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made to improve the working environment of the assembling platen by installing the cover above the large steel structure assembling platen.
In addition, an object of the present invention is to provide a method for assembling a large-scale steel structure in which a place for placing a balance is secured by giving the cover a function of a balance.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of platens of substantially the same size for assembling a large steel structure into a predetermined shape, and a large steel plate assembled around the platen. A support that can be raised according to the height of the structure is arranged, and on this support, a removable cover that can cover the large steel structure being assembled with this surface plate and also serves as a lifting jig The cover is provided so that it can be placed on any of the supports of the platen.

[0011]

A column is provided around each surface plate so that it can be raised as the height of the large steel structure to be assembled increases. Since a cover having the function of a lifting jig can be set on the support, this serves as a roof, and a working environment for assembling a large steel structure under the roof is improved. When taking in a member or the like of a large steel structure, the cover is placed on a column of another surface plate, the height of the column is increased according to the height of the member to be taken in, and then the cover is attached again. Further, since this cover is a lifting jig, there is no need to provide a separate lifting jig area in the crane reach. In addition, a work scaffold can be provided between the support and the large steel structure.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Although the present embodiment is described using a lining plate of a reinforced concrete containment vessel as an example of a large steel structure, the present invention is not limited to this and can be applied to other large steel structures. FIG. 1 shows the configuration of the present embodiment, in which (a)
Shows a side view, and (b) shows a plan view. The surface plate 30 is made of concrete and has strength and rigidity enough to withstand the load at the time of assembling the lining plate. This figure shows a case where two base plates 30 are provided, but three or four base plates are provided as necessary. The shape of the cylinder to be assembled is written on the surface plate 30, and the block transported from the factory is assembled into a cylinder according to this shape. A fixed support 31 is embedded and fixed in the surface plate 30 around the cylindrical writing position. The number of the fixed columns 31 is four or more around the cylinder, and the fixed columns 31 between two adjacent stools 30 are shared.

An assembling column 33 is provided on the upper portion of the fixed column 31 by a sleeve-type plug-in joint 32, and can be connected according to the height of the lining plate to be assembled. A receiving support 34 is provided at the top of the fixed support 31 or the assembly support 33 so that the cover 36 also serving as a balance can be supported. The cover 36 has, for example, a truncated conical shape, has sufficient strength to lift the assembled cylindrical lining plates 21 and 22, and is configured to cover with a canvas or the like to function as a roof. When the cylindrical lining plate is lifted, the receiving column 34 is rotated so as not to hinder the lifting. A temporary scaffold 35 for assembling work is provided between the cylindrical lining plate being assembled and the fixed strut 31, the assembling strut 33, and the receiving strut 34. Also cover
36 can be moved to a surface plate requiring a roof at a desired time, so that the environment can be improved and work efficiency can be improved.

[0014]

As is clear from the above description, a plurality of surface plates for assembling a large steel structure are provided, and each surface plate is provided with a supporting column which is raised in accordance with the assembly height. Since a large-sized steel structure being assembled can be covered on this support and a detachable cover having a function of a lifting jig can be installed, an area for installing a lifting jig is not required. To improve the environment of the work area
Improvement of work efficiency and quality can be expected.

[Brief description of the drawings]

1A and 1B are diagrams illustrating an embodiment of the present invention, wherein FIG. 1A is a side view and FIG. 1B is a plan view.

FIG. 2 is a view showing a reinforced concrete containment vessel and an internal configuration thereof.

[Explanation of symbols]

 21,22 Lining plate 30 Surface plate 31 Fixed column 32 Sleeve-type plug-in joint 33 Assembly column 34 Receiving column 36 Cover

Claims (1)

(57) [Claims] 1. A strut which is provided with a plurality of base plates having substantially the same size for assembling a large steel structure into a predetermined shape, and which can be raised in accordance with the height of the large steel structure assembled around the base plate. Is disposed on the support, and a detachable cover that can cover the large steel structure being assembled with the surface plate and also serves as a lifting jig is provided, and the cover is provided on any of the supports of the surface plate. A method for assembling a large-scale steel structure, characterized in that it can also be placed.