JP2000073385A - Execution method for underground tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a large truss by applying a banking process to a surface shape along the inside of a roof on a planned construction site of an underground tank, arranging a form for molding the roof on the banking, and placing concrete by using the form. SOLUTION: A water stop underground continuous wall 3 is buried in the ground, a recess is formed on the underground continuous wall 3, then a concrete reception frame 14 is integrally provided at the upper end of the underground continuous wall 3. A banking process is applied to the ground to form a banking section 1b protruded in a circular arc shape. A lattice-like support frame 21 extending in the radial direction from a disk-like support plate 20 installed at the center of the banking section 1b is provided. Air bag jacks 22 and height detecting means 23 are provided on the support frame 21, a concrete form 26 is installed on them, concrete 27 is placed on the form 26 in a dome shape to form a roof. A materiel such a heavy machine is introduced from the opening section of the roof, and an underground tank is constructed, thereby no large truss is required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a roof of a large underground tank for storing low-temperature liquefied gas (LNG) and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a relatively large underground tank 2 formed in a ground 1 comprises an underground continuous wall 3 forming a cylindrical body provided in the ground 1, and Middle continuous wall 3
A bottom slab 4 laid on the bottom of the slab, a cylindrical side wall 5 provided on the inner surface of the underground continuous wall 3, a segment 5a stretched inside the side wall 5, and a cold insulator 5b provided on the surface of the bottom slab 4. A dome-shaped roof 6 covering the upper part of the underground tank 2. A crushed stone layer 4a is provided on the lower surface of the bottom plate 4. Although the roof 6 is mainly made of concrete, a steel roof 6A is also known as shown in FIG. 10, and is a semi-underground type. In constructing the roof 6 shown in FIG. 9, as shown in FIG. 11, the underground continuous wall 3 is buried and the inside thereof is excavated, and then the bottom plate 4 and the side wall 5 are provided. The gantry 7 and the dome-shaped truss 9 whose center is supported by the gantry 7 are installed, and after passing through the top of the side wall 5 and the PC primary tensioning work, a concrete mold is mounted on the upper surface of the truss 9 as shown in FIG. The roof 6 is built by laying a frame, arranging reinforcement on the frame, and then pouring and pouring concrete.

[0003] Next, the truss 9 is lowered as shown in FIG. 13, and after a step of secondary tensioning of the PC, as shown in FIG. 14, the roof 6 provided on the upper part of the underground tank 2 with high strength is removed. A truss 9 disassembled as a support structure is hung down on the bottom slab 4 so as to be suspended, or a work hole 8 provided in advance on the roof 6 is used. The underground tank 2 is completed by carrying out, covering the roof 6 with the soil covering layer 11 on the roof 6 and leveling the ground as shown in FIG.

However, according to the roof construction process shown in FIGS. 11 to 15, the large gantry 7 and the truss 9 must be assembled and installed above the underground tank. Disassembly and unloading operations have become large-scale, and have the disadvantage that the construction period until the roof is completed is lengthened.

Therefore, as shown in FIG. 16, the underground continuous wall 3, the side wall 5, and the cooling material are provided, and after the tank 2 is completed, the small truss 10 is constructed on the bottom plate 4, and The roof formwork steel plate 19 is completed. Next, as shown in FIG. 17, the blower 13 operated by the generator 12 blows air into the inside of the relatively lightweight roof formwork steel sheet 19 using the blower tube 14 to reduce the roof formwork steel sheet 19 to 0. After pushing up from below with an air pressure of about 0.02 kgf / cm ² and fixing the roof formwork steel plate 19 at the height of the specified position as shown in FIG.
By pouring concrete on the surface, the roof 6 is completed as shown in FIG.

[0006] However, according to such a method, although no truss is required, the air is fed by pressure and the roof form steel plate 19
Since it is necessary to obtain sufficient air pressure to lift the roof formwork steel plate 19, it takes a long time to lift the roof formwork steel plate 19 to a predetermined portion, and also in this case, not only the construction period is delayed,
It has a disadvantage that it takes a long time to release air.
The underground tank 2 provided with the steel roof 6A shown in FIG.
According to this, the roof 6A exposed to the outside has a disadvantage that it is easily corroded, has poor durability, and impairs the appearance.

By the way, according to the conventional example of Japanese Patent Application Laid-Open No. 6-346621, the construction period of the underground tank is excavated and the construction period is shortened simultaneously with the construction of the roof. However, according to this, the excavation proceeds with the truss provided as a temporary structure for assembling the roof at the upper opening side of the underground tank, so there is a risk that the truss may collapse with this excavation Can be

[0008]

Conventionally, however, a large dome-shaped truss must be erected, which not only lengthens the construction period but also increases the cost, and also uses air pressure to build a roof. However, there was a disadvantage that the construction period was long.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and does not require a large truss and shortens the construction period.

[0010]

According to the first aspect of the present invention, an embankment treatment is performed on the planned underground tank ground so as to have a surface shape along the inside of the roof. Is provided, and concrete is cast using the formwork to manufacture a roof.

According to the second aspect of the present invention, after the roof is manufactured, the underground tank is constructed by excavating the planned underground tank inside the roof and then performing inner surface treatment.

According to the third aspect of the present invention, each formwork is supported on the embankment via a jack and is arranged.

According to the fourth aspect of the present invention, each formwork is supported by a frame arranged along the embankment.

According to the invention of claim 5, instead of the embankment,
A plurality of columns having a height such that the upper end is along the inside of the roof are arranged on the planned underground tank, and the columns support a formwork for concrete molding of the roof.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 to 7
9 is a simplified process diagram showing an embodiment of a method for constructing an underground tank according to the present invention, and the same components as those in FIGS. 9 to 19 are denoted by the same reference numerals. In the first embodiment, first, as shown in FIG.
The underground continuous wall 3 for stopping water is buried by a known method. In the upper part of the underground continuous wall 3, a recess 15 is formed and a concrete receiving frame 14 is integrally provided at the upper end of the underground continuous wall 3.

Next, as shown in FIG. 2, an embankment process is performed on the ground 1a in the planned underground tank site to form an embankment portion 1b projecting in an arc shape. At this time, the recess 15 is filled up, and a work start hole 1c is formed at the corner of the embankment 1b. The surface of the embankment portion 1b has a shape along the inner surface of a dome-shaped roof 6 described later, and is compacted by a compaction load roller or the like to form a relatively hard layer.

Next, as shown in FIG. 3 and FIG.
A lattice-like support frame 21 extending in the radial direction is provided from above the disk-like support plate 20 installed at the center of b. The tip of the support frame 21 is placed on the receiving frame 14. On the support frame 21, an air back jack 22 and a height detecting means 2 such as a pore water pressure gauge or a subsidence gauge are provided.
3 are distributed almost uniformly.

As shown in FIG. 4, the signal from the height detecting means 23 is supplied to a control unit 24, which is provided for each jack 22 or provided for each jack 22 in a plurality of block areas. The driven compressor 25 is driven to adjust the height of each jack 22 to a target height. A plurality of plate-shaped concrete forms 26 are laid on each of the jacks 22 and the height detecting means 23. The formwork 26 is substantially fan-shaped, and concrete 27 is cast on the formwork 26 in a layered state having a certain thickness. An opening 28 is provided in the formwork 26 and the concrete 27 corresponding to the hole 1c. The fan-shaped concrete 27 is developed so as to form a dome, and the dome-shaped roof 6 is completed.

After the construction of the roof 6, the frame 21, the jack 22 and the like are removed, and as shown in FIG.
Carry more heavy equipment and materials for excavation into the hole 1c
(See FIG. 2). After excavating the planned underground tank starting from the starting point, as shown in FIG.
Alternatively, an internal treatment is performed by providing a cold insulator, a membrane, or the like (not shown). This internal processing is performed by loading and unloading materials from the outside through the opening 28, and an underground tank as shown in FIG. 7 can be constructed.

Next, as shown in FIG. 7, the roof 6 is covered with a soil covering layer 11 to complete the underground tank 2 with a roof.

In the above configuration, the concrete form is supported by the embankment portion by the embankment treatment. However, the present invention is not limited to this, and as shown in FIG. Flat ground 1
A large number of struts 40 having a height such that the upper end is along the dome-shaped roof are distributed on the struts. On the struts 40, the concrete form 26 is supported, and concrete is cast on the form 26. You may make it. According to this, the embankment processing becomes unnecessary, and the construction period can be further shortened.

[0022]

According to the first aspect of the present invention, an embankment treatment having a surface shape extending along the inside of the roof is performed on the planned underground tank ground, and a formwork for concrete molding of the roof is formed on the embankment. Since the roof is manufactured by arranging and casting concrete using the formwork, it is not necessary to construct a large-sized dome-shaped truss, so that the cost can be reduced and the construction period can be shortened.

According to the second aspect of the present invention, after the roof is manufactured, the underground tank inside the roof is excavated and then the inner surface is treated to construct the underground tank, so that the excavation site can be protected from rainwater and wind and snow. Excavation work can proceed smoothly.

According to the third aspect of the present invention, since each mold is supported on the embankment via the jack, the level of each mold can be adjusted, and a roof having an accurate shape can be built.

According to the fourth aspect of the present invention, each mold is supported by the frame disposed along the embankment, so that the shape of the embankment can be prevented from being deformed.

According to the invention of claim 5, in place of the embankment,
A plurality of pillars with a height such that the upper end is along the inside of the roof are arranged on the planned underground tank, and the formwork for concrete molding of the roof is supported with these pillars, so embankment processing can be omitted and the construction period is shorter. Can be shortened.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a method for constructing an underground tank according to the present invention.

FIG. 2 is a cross-sectional view illustrating an embodiment of the method for constructing an underground tank according to the present invention.

FIG. 3 is a cross-sectional view illustrating an embodiment of the method for constructing an underground tank according to the present invention.

FIG. 4 is a plan view showing one embodiment of a method for constructing an underground tank according to the present invention.

FIG. 5 is a cross-sectional view showing an embodiment of the method for constructing an underground tank according to the present invention.

FIG. 6 is a cross-sectional view showing an embodiment of the method for constructing an underground tank according to the present invention.

FIG. 7 is a cross-sectional view showing an embodiment of the method for constructing an underground tank according to the present invention.

FIG. 8 is a cross-sectional view showing another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 10 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 11 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 12 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 13 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 14 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 15 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 16 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 17 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 18 is a cross-sectional view showing a conventional underground tank construction example.

FIG. 19 is a cross-sectional view showing a conventional underground tank construction example.

[Explanation of symbols]

1 Ground, 1a embankment, 3 underground continuous wall, 4 bottom slab,
5 side wall, 15 depression, 20 support plate, 21 support frame, 22 air back jack, 23 height detection means, 24 control unit, 25 compressor, 26 formwork.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kenji Yoshimatsu 2-1 Tsukudocho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo Head Office (72) Inventor Hiroshi Ito 2-1 Tsukudocho, Shinjuku-ku, Tokyo Kumagai Gumi Tokyo Head Office (72) Inventor Tomoo Mimura 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo Head Office (72) Inventor Kazuhiro Nishigaki 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Co., Ltd. Gumi Tokyo Main Office (72) Inventor Shigehide Sakurai 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo Main Office (72) Inventor Koichi Fujiki 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo Head Office F-term (reference) 2D047 AB02

Claims (5)

[Claims] In a method of constructing an underground tank having a concrete roof, an embankment treatment is performed on the planned underground tank ground so as to have a surface shape along the inside of the roof. A method for constructing an underground tank, comprising laying out a formwork, and casting a concrete using the formwork to build a roof. 2. The method for constructing an underground tank according to claim 1, wherein the underground tank is constructed by excavating a planned underground tank under the roof after the construction of the roof and then performing an inner surface treatment. 3. The method for constructing an underground tank according to claim 1, wherein each of the forms is supported on the embankment via a jack. 4. The underground tank construction method according to claim 1, wherein each form is supported by a frame arranged along the embankment. 5. A claim in which a plurality of pillars having a height such that the upper end thereof is along the inside of the roof are arranged on the planned underground tank instead of the embankment, and the pillars support a formwork for concrete molding of the roof. Item 6. The method for constructing an underground tank according to Item 1.