JPS6352192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing a roof portion of a double shell tank.

In general, a double shell tank is a cylindrical flat-bottomed dome roof type with an inner tank made of low-temperature steel, such as nickel steel or aluminum-killed steel, and an inner tank made of ordinary steel, such as general carbon steel or PS concrete. It consists of an outer tank, and the space between the outer tank and the inner tank is a cold insulation wall structure filled with a cold insulation material such as perlite as a space for cold insulation. The roof also has a double wall structure.

Conventionally, the method of constructing the roof of such a double shell tank is to assemble the outer tank side plates after laying the outer tank bottom plate, and then construct the roof inside the inner tank once it has been assembled to a predetermined height. Or, in parallel with the assembly of the outer tank side panels, a double-walled roof is fabricated by assembling the inner and outer tank roofs together, and the roof is assembled at the bottom of the inner tank after the inner and outer tank side panels are completed. The roof edge of the inner tank is fixed to the upper end of the inner tank side plate by lifting it with a large crane or floating to a specified height using air pressure, and the outer tank periphery is supplemented and fixed to the upper end of the outer tank side plate. There are construction methods.

According to the above-mentioned conventional method, in the former case, the assembly work of the upper part of the side panels and the roof must be done at heights, especially in the case of large tanks, which can reach up to 30 to 40 meters above the ground. Excessive equipment was required to ensure the safety of the work at the site, and due to the danger of the work, a decline in welding quality was unavoidable.
In addition, there were drawbacks such as the need for heavy cranes with large capacity to lift and lower materials.

In the latter case, pressurized air equipment (fan) is required to float the assembled roof, which requires even more advanced construction technology.

This invention relates to a method for constructing a double shell tank in which the outer tank is made of prestressed concrete and the inner tank is made of metal, from the above-mentioned viewpoint. It is a combination of

The feature of this method is that in parallel with the construction of the outer tank with prestressed concrete, the lowermost peripheral wall of the metal inner tank is assembled inside the outer tank, and then the uppermost peripheral wall is assembled using rollers. The parts are assembled onto the lowermost peripheral wall part so as to be able to be pushed up by rotating in a spiral pattern, and then the inner tank roof and the outer tank roof are placed on top of the uppermost peripheral wall part. The inner tank roof, the outer tank roof, and the uppermost peripheral wall are integrally rotated spirally and pushed up to form a double roof structure, and the middle part of the inner tank peripheral wall is raised to the uppermost stage. The rollers are joined to the peripheral wall portions in sequence, and after the intermediate peripheral wall portion has been assembled, the rollers are removed, the inner tank peripheral wall is integrally joined, and the outer periphery of the outer tank roof is attached to the upper end of the outer tank. This is what I did.

Next, the construction method of the present invention will be specifically explained based on example diagrams showing the construction steps in order.

First of all, Figure 1 shows the foundation concrete 1 of the outer tank OS constructed in a floating bed type, and 2 shows this foundation concrete 1.
It is a support pile that supports the

3 is the outer tank laid on this foundation concrete 1
The bottom of the OS is made of prestressed concrete.

5 is ring concrete 4 which is the base of the inner tank IS
With the annual plate of the inner tank IS installed on top of the
6 is the inner tank IS placed on top of this annular plate.
This is the lowest peripheral wall part of the . In addition, its upper edge 7
is spirally inclined along the upper edge 7.

FIG. 2 shows that the uppermost circumferential wall portion 9 of the inner tank IS is assembled on the lowermost circumferential wall portion 6 via rollers 8.
Furthermore, the roof 10 of the inner tank IS is shown assembled thereon.

The rollers 8 are set at regular intervals on the spiral upper edge 7 of the lowermost peripheral wall portion 6, and the uppermost peripheral wall portion 9 is placed on the rollers 8 so that it can gradually rise while rotating. In other words, it is assembled so that it can be rotated in a screw-like manner.

Figure 3 shows the process progressing to the point where the roof 11 of the outer tank OS is further assembled on the roof 10 of the inner tank IS, creating a double roof structure. .

FIG. 4 shows the uppermost peripheral wall portion 9 of the inner tank IS in the state shown in FIG.
This figure shows the process of assembling the intermediate portion of the inner tank peripheral wall using the gap 12 created between the inner tank and the inner tank. That is, the side plate member 13 is applied to the gap 12 and joined to the uppermost peripheral wall portion, and the following steps are performed.
The turning step of spirally rotating the side plate member 13
The inner tank IS itself is assembled to a predetermined height by sequentially repeating the joining steps, and then the rollers 8 are removed and the inner tank uppermost peripheral wall portion 9 and the inner tank lowermost peripheral wall portion 6 are integrally joined.

Figure 5 shows that the outer tank OS is constructed in parallel with the assembly of the inner tank IS, and then the outer tank roof 11 is finally assembled.
This figure shows the state in which the main assembly process has been completed, with the main assembly process completed.

As explained at the beginning, the outer tank OS has a prestressed concrete structure, so the inner tank IS
In parallel with the assembly using the helical construction method, the building was constructed through a series of operations such as reinforcing sheathed wire and steel bars, assembling formwork, pouring concrete, and pre-stretching. Not even.

As can be understood from the above explanation, the construction method of the present invention adopts the helical construction method for assembling the inner tank IS, so there is less work at high places, and as a result, the completeness of the work is increased. Since welding, which is the main work in tank IS assembly, can be done at a fixed and low location (the side plate member assembly position), higher quality inner tank assembly is possible.

Furthermore, the biggest advantage of this method is that the roofs of the inner and outer tanks
and 11 at the initial stage of inner tank assembly, i.e.
The assembly is carried out at the point shown in FIG. 3, and the assembly work is carried out at a position as low as possible to maintain safety and quality as described above.

Therefore, as explained at the beginning, compared to the conventional construction method in which the roof is erected after the peripheral walls of the inner and outer tanks have been assembled, the work is not only safer, but the quality of the finished product is significantly improved, and the construction period is also reduced. However, it has the advantage of being able to shorten the construction period compared to conventional methods.

[Brief explanation of the drawing]

FIGS. 1 to 5 are flowcharts showing the construction method of the present invention in the order of construction steps. IS...Inner tank, OS...Outer tank, 1...Basic concrete,
2...Support pile, 3...Outer tank bottom plate, 4...Ring concrete, 5...Annual plate of inner tank, 6...Inner tank lowermost circumferential wall part, 7...Same mouth rim, 8...Roller, 9
...Inner tank uppermost peripheral wall part, 10...Roof of inner tank, 11
...Outer tank roof, 12...Gap, 13...Side plate member.

Claims (1)

[Claims] 1. In parallel with the construction of the outer tank with breast-stressed concrete, the lowermost circumferential wall of the metal inner tank is assembled inside the outer tank, and then the uppermost circumferential wall is attached to the lowermost circumferential wall using rollers. Assemble it so that it can be pushed up by rotating it spirally, and then assemble the inner tank roof and the outer tank roof on top of that uppermost peripheral wall part to form a double roof structure. Then, the inner tank roof, the outer tank roof, and the uppermost peripheral wall portion are integrally rotated spirally and pushed up, and the intermediate portion of the inner tank peripheral wall is successively joined to the uppermost peripheral wall portion, and the intermediate peripheral wall portion is After completing the assembly, the rollers are removed, the inner tank peripheral wall is integrally joined, and the outer periphery of the outer tank roof is attached to the upper end of the outer tank.