JPS6246428B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for replacing the annular and bottom plate of a hazardous material storage tank, such as an oil tank.

Conventionally, the methods for replacing the annular and bottom plate of a hazardous materials storage tank include lifting the entire storage tank (jack-up method) and cutting off the lower part of the side plate over a width of about 50 mm without lifting the storage tank. The method used is to replace the annulus and bottom plate through this 50mm wide space (piece construction method). When comparing the above two construction methods, it can be said that the piece construction method is superior from an economical point of view since the jack-up construction method involves large-scale construction, but the piece construction method has the following advantages. It is possible to point out problems.

In other words, in the case of the piece construction method, a piece is attached to the side plate in advance, and the annular and bottom plate are replaced while supporting the side plate of the tank, which has been cut out to a width of 50 mm, with the same piece. Yes, after replacing the annular and bottom plate, cut out the above piece in small pieces, lower the main body side by the cut amount, join the upper and lower cut edges, and weld the same part. However, by cutting the side plate over a width of 50 mm, welding lines for doubling manholes etc. can be made. Since a part of the side plate is cut out, the width of the cut is inevitably limited to a maximum of about 50 mm, but in a space of about 50 mm, it is extremely difficult to replace the annular and bottom plate. And again
A space of about 50 mm will significantly impede finishing and beveling work on both the upper and lower cut edges. The tank capacity will decrease after replacing the annulus and bottom plate.

There are problems such as: And, conventionally, nuts are installed at regular intervals inside the tank side plate,
Screw the support bolt into the same nut, separate the side plate and the bottom plate with the tip of the support bolt in contact with the bottom plate, lift the separated side plate from the bottom plate through the screwing of the support bolt, and separate the side plate and the bottom plate. A method of inserting and removing the annular and bottom plate from the gap formed between them (Japanese Patent Application Laid-Open No. 55-29459)
However, with this construction method, when replacing the bottom plate where the tip of the support bolt touches, the support bolt must be pulled up from the state where it is in contact with the bottom plate each time, and However, there is a problem in that the guide plate must be removed, which is cumbersome, that is, the work efficiency is low.

The present invention is an attempt to improve the conventional situation as described above, and an object of the present invention is to provide a replacement method that is excellent in workability and economy.

That is, the present invention involves a process of cutting the lower edge of the tank side plate, a process of jacking up the tank to create a space of about 150 to 200 mm between it and the bottom plate, and replacing the bottom plate through the same space. The gist is that the annular and bottom plate can be replaced by a step of jacking down the tank and welding the cut portion.

Specific embodiments of the present invention will be described below with reference to illustrative drawings.

As a first work step, as shown in FIG. 3, a perfect circle holder 3 is attached over the inner circumferential wall surface of the side plate 2 constituting the tank body 1. The method for attaching the perfect circle holder 3 is to first weld plate-shaped attachment pieces 4 to the inner circumferential wall surface at regular intervals, and then weld ring material 5 between each attachment piece 4.
This is done by extending them endlessly and fixing them through wedges 6 between each mounting piece 4 and the ring material 5.

As described above, the tank body 1 to which the perfect circle holder 3 is attached to the inner circumferential wall surface of the side plate 2 is cut off at the lower edge portion of the side plate 2. In FIG. 4, 7 indicates the cut portion.

As shown in FIG. 4, the tank body 1 with the lower edge of the side plate 2 cut off is provided with jacking mechanisms 8 attached at regular intervals to the outer peripheral wall of the side plate 2. 1 and 2 are drawings showing the state in which the jacking mechanism 8 is attached to the tank body 1, and in both drawings, 9 is a jig welded to a position near the lower edge of the side plate 2. The mounting piece 10 is a plate-shaped mounting piece that is welded directly above the piece 9 in correspondence with the mounting piece 9.

11 is a jacking jig which is fixed to the side plate 2 side via the piece 9 and the mounting piece 10, and 12 is a jacking jig whose lower end is connected to the piece 9 via a reamer bolt 13, and whose lower end is connected to the piece 9 via a reamer bolt 13. A vertical rod whose upper end is engaged with the mounting piece 10 and fixed via the reamer bolt 13, 14 is a horizontal rod extending along the diametrical direction of the tank body 1 from an intermediate position of the vertical rod 12, and 15 is the same horizontal rod. A reinforcing rod diagonally connects the tip of the rod 14 and the lower end of the vertical rod, and 16 indicates a jack up post which is vertically installed from the horizontal rod 14 through an appropriate number of mounting holes so that its mounting position can be adjusted. . And 17... indicates a hydraulic jack. The hydraulic jack 17 connects the cradle 18' provided at the tip of the ram 18 to the jack up post 16.
It is arranged so that it can come into contact with the lower end of the. After sufficient compaction work has been carried out on the ground where the hydraulic jacks 17... are installed, each hydraulic jack 17... is operated in the direction in which the ram 18 rises, thereby placing the hydraulic jacks 17... on the asphalt sand. Bottom plate 19
The upper portion of the tank body 1 is lifted up from the cut portion 7 while leaving . Then, as shown in FIG. 7, a space 20 of about 150 to 200 mm is provided in the cut portion 7 through this jack.

With the space 20 of approximately 150 mm to 200 mm provided in the cut portion of the tank body 1 in this manner, each hydraulic jack 17...
After replacing ... with the journal jack 21 ..., the annualr and the bottom plate 19 are carried out of the tank through the space 20, and the foundation repair work (Fig. 10) at the bottom of the tank is carried out.
A new annulus and bottom plate 19 are carried into the tank and laid at the bottom of the tank. Then, after beveling the cut edge on the side plate 2 side, the journal jack 21... is replaced again with the hydraulic jack 17...
By jacking down the tank body 1, the tank body 1 is lowered. When the tank body 1 is lowered, a clearance 22 of about 3 mm is provided between the lower edge of the side plate 2 and the bottom plate 19, as shown in FIG. Then, temporary welding is performed between the lower edge of the side plate 2 and the bottom plate 19, and then main welding is performed, while the jacking jig 11, piece, and mounting piece 10 are removed from the outer peripheral wall surface of the side plate 2. All replacement work is completed after wall repairs, water tests, and other inspections.

The present invention is constructed as described above, and includes:
By cutting the lower edge of the side plate 2 as described above and jacking up the tank body 1 side, the bottom plate 19
A space 20 of about 150 to 200 mm is provided between the annulus and the bottom plate 19, and the annular and bottom plate 19 can be replaced through the space 20, thereby achieving excellent workability and economical efficiency. I was able to do something.

That is, in the present invention, by cutting the lower edge of the side plate 2 so that only the side of the tank body 1 can be jacked up, the raised width is 150 mm to 200 mm.
Coupled with the fact that it is about millimeters in size, it has become possible to jack up the storage tank much more easily than the conventional jack up method, which involves lifting the entire storage tank. In the present invention, by attaching the ring material 5 endlessly to the inner circumferential wall surface of the side plate 2, the tank side plate 2 can be constructed with a simpler structure than the conventional back ring correction jig. Since the ring material 5 maintains the perfect circle state, it is possible to jack up via the jacking mechanism 8, which is structurally simple.

On the other hand, in the case of the present invention, since the up width of the tank body 1 is approximately 150 mm to 200 mm, the danger during work is extremely small and the safety can be increased. Between,
By being able to obtain a wide space 20 of about 150 mm to 200 mm, it has become possible to significantly improve the work efficiency of replacing the annulus and bottom plate 19 compared to the conventional piece construction method. In particular, in the present invention, only the perfect circle holder 3 is attached to the inner circumferential wall of the side plate 2, and the jacking mechanism 8 is attached to the outer circumferential wall of the side plate 2, so that a nut can be attached to the inside of the conventional tank. By attaching a support bolt and screwing the support bolt into the same nut, the work efficiency of replacing the annular and bottom plate was significantly improved compared to the method of lifting the tank side plate.

Furthermore, foundation modification and compaction work on the bottom plate part can be easily performed, and welding work from beveling and tack welding to main welding on the lower edge of the side plate 2 can be easily performed. As a result, it has become possible to obtain a tank that is completely satisfactory in terms of quality compared to the tank before the repair, without reducing the tank capacity.

[Brief explanation of the drawing]

Fig. 1 is an overall view showing the state in which the tank body is jacked up using the replacement method according to the present invention, Fig. 2 is an enlarged sectional view of the main parts, and Figs. 3 to 13 are the replacement method according to the present invention. FIG. 3 is a drawing showing the process of attaching a perfect circle holder to the inner wall surface of the side plate, FIG. 4 is a drawing showing the process of cutting the lower edge of the side plate, Figure 5 is a drawing showing the process of attaching the jacking jig and hydraulic jack to the side plate;
The figure shows the process of compacting the ground where the hydraulic jack is installed, Fig. 7 shows the process of jacking up the jack, Fig. 8 shows the process of replacing the hydraulic jack with a journal jack, and Fig. 9 shows the process of replacing the hydraulic jack with a journal jack. and a drawing showing the process of transporting the bottom plate,
Figure 10 is a drawing showing the process of repairing the foundation;
Fig. 11 is a drawing showing the process of bringing in a new annular and bottom plate, Fig. 12 is a drawing showing the process of replacing the journal jack with a hydraulic jack,
FIG. 13 is a diagram showing a process for performing jacking down. 1...Tank body, 2...Side plate, 3...Perfect circle holder,
4... Mounting piece, 5... Ring material, 6... Wedge, 7... Cutting part, 8... Jacking mechanism, 9... Piece, 10... Mounting piece, 10'... Wedge, 11... Jacking jig, 12
...Vertical rod, 13...Reamer bolt, 14...Horizontal rod, 1
5... Reinforcement rod, 16... Jack up post, 17
...hydraulic jack, 18...ram, 18'...cradle, 1
9...Bottom plate, 20...Space, 21...Journal jack, 22...Clearance.

Claims (1)

[Claims] 1. A process of attaching ring material in an endless manner to the inner circumferential wall of the tank side plate to maintain a perfect circle; a process of attaching a jacking mechanism at regular intervals to the outer circumferential wall of the tank side plate; and a process of attaching the jacking mechanism to the outer circumferential wall of the tank side plate, and the lower end of the tank side plate. In the process of cutting the edges, the tank side plate is jacked up using the jacking mechanism described above, and there is a gap of 150 mm between the tank side plate and the bottom plate.
The annuller and bottom plate of a hazardous materials storage tank consists of a process of creating a space of about 200 mm, a process of replacing the annuller and bottom plate through the same space, and a process of jacking down the tank side plate and welding the cut part. Replacement method.