JP5223701B2 - Construction method of side wall of underground tank structure - Google Patents

Description

  The present invention relates to a method for constructing a side wall of an underground tank structure in which a lower part is buried in the ground.

  Conventionally, as a storage tank for liquefied gas such as LPG, LNG, etc., it consists of a bottom plate, a side wall constructed along the periphery of the bottom plate, and a roof covering the top of the side wall, and at least the lower part is buried in the ground. An underground tank constructed like this is used. Such underground tanks build a cylindrical underground continuous wall in the ground, excavate the underground continuous wall, build a bottom slab inside the underground continuous wall, and place it on the inner periphery of the underground continuous wall. It can be constructed by building a side wall along the top and connecting a roof to the top of the side wall.

  Further, for example, in Patent Document 1, as a method of improving the workability of the construction work of the side wall of such an underground tank, a temporary support column is erected on the bottom plate and is suspended from the upper part of the temporary support column. In addition, a method is described in which a side wall is constructed while raising the formwork support device using a formwork support device that takes a reaction force on the temporary support column and supports the formwork at a position corresponding to the inner peripheral surface of the side wall. Yes.

JP 2003-119806 A

  Here, normally, when a hardware is embedded so as to be exposed on the surface of the concrete member, the hardware is attached to the inner surface of the mold. However, in the method of raising the mold support apparatus as described above, the mold rises together with the mold support apparatus, so that a hardware cannot be attached to the inner surface of the mold.

  In addition, since the concrete placement operation or the like is performed while raising the formwork support device, there is a problem that the surface of the concrete is rubbed because the formwork is not sufficiently cured.

  The present invention has been made in view of the above problems, and its object is to expose the surface of the concrete while sliding up while maintaining the basic shape of the formwork when constructing the side wall of the underground tank. It is possible to embed hardware and provide a method for finishing the concrete surface beautifully.

The method for constructing a side wall of an underground tank structure according to the present invention comprises a reinforced concrete tank comprising a bottom slab, a side wall constructed along an outer peripheral edge of the bottom slab, and a roof constructed on the top of the side wall, A method for constructing a side wall of an underground tank structure in which a side wall and a bottom plate are buried in the ground,
In advance, at the ground level, a part of the roof is constructed, a cylindrical underground wall is constructed at a position corresponding to the outer periphery of the side wall, and the roof part is supported by the underground wall. Connecting a part of the roof to the underground wall, excavating the interior of the underground wall,
In a state where the formwork panels arranged along the surface of the side wall and connected to the upper and lower stages are supported by an annular formwork support device suspended on a part of the roof,
A step of placing concrete between the formwork panel and the underground wall, a step of raising the formwork support device, and a lowermost formwork of the formwork panels connected to the upper and lower stages. The side wall is constructed along the inside of the excavated underground wall by repeating the step of removing the panel and the step of connecting the formwork panel in an annular shape above the uppermost formwork panel. It is characterized by that.
In addition, the order of these repeated processes is not ask | required.

  In the above construction method of the underground tank structure, in parallel with the side wall construction step, the work for attaching the cold insulation material or the membrane lining work may be performed in the part where the construction of the side wall is completed.

  According to the present invention, since the slide is raised while maintaining the basic shape of the side wall mold, the assembly / disassembly work of the mold can be greatly reduced. In addition, the scaffold can be reduced by suspending the scaffold and the formwork, and the formwork panel will remain even if the formwork support device is raised, so hardware should be attached to the inner surface of the formwork panel. Thus, the hardware can be embedded so as to be exposed on the surface of the side wall, and the side wall surface can be beautifully finished.

It is a vertical sectional view showing an underground tank structure constructed by the construction method of the present embodiment. It is FIG. (1) for demonstrating the construction method of the underground tank structure in the case of constructing | assembling a roof ahead. It is FIG. (2) for demonstrating the construction method of the underground tank structure in the case of constructing | assembling a roof ahead. It is FIG. (3) for demonstrating the construction method of the underground tank structure in the case of constructing | assembling a roof ahead. It is FIG. (4) for demonstrating the construction method of the underground tank structure in the case of constructing a roof ahead. It is a top view which shows a formwork support apparatus. It is a vertical sectional view showing a formwork support device. It is an enlarged view of the C section in FIG. It is FIG. (1) for demonstrating the method of constructing | assembling a side wall using a formwork support apparatus. It is FIG. (2) for demonstrating the method of constructing | assembling a side wall using a formwork support apparatus. It is FIG. (3) for demonstrating the method of constructing | assembling a side wall using a formwork support apparatus. It is FIG. (4) for demonstrating the method to construct | assemble a side wall using a formwork support apparatus. It is FIG. (5) for demonstrating the method to construct | assemble a side wall using a formwork support apparatus. It is FIG. (6) for demonstrating the method to construct | assemble a side wall using a formwork support apparatus. It is FIG. (7) for demonstrating the method to construct | assemble a side wall using a formwork support apparatus. It is a figure (the 1) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and constructing | assembling a side wall using the formwork support apparatus suspended by a bracket. It is FIG. (2) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in a underground continuous wall and constructing a side wall using the formwork support apparatus suspended by a bracket. It is a figure (the 3) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and constructing | assembling a side wall using the formwork support apparatus suspended by a bracket. It is FIG. (4) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and building a side wall using the formwork support apparatus suspended by a bracket. It is a figure (the 5) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and building a side wall using the formwork support apparatus suspended by a bracket. It is a figure (the 6) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and constructing | assembling a side wall using the formwork support apparatus suspended by a bracket. It is FIG. (7) for demonstrating the construction method of an underground tank structure in the case of providing a bracket in an underground continuous wall and building a side wall using the formwork support apparatus suspended by a bracket.

Hereinafter, an embodiment of a method for constructing a side wall of an underground tank structure according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a vertical sectional view showing an underground tank structure 10. The underground tank structure 10 is for storing liquefied gas such as LPG and LNG. As shown in the figure, the underground continuous wall 30 formed in a cylindrical shape on the ground, and the underground continuous wall 30 An underground tank body 20 constructed so as to be integrated with the underground continuous wall 30 inside.

The underground tank body 20 is integrally formed with a reinforced concrete bottom plate 22, a reinforced concrete side wall 21 that is constructed along the periphery of the bottom plate 22 and adjacent to the underground continuous wall 30, and a top portion of the side wall 21. And a reinforced concrete roof 23 constructed in a dome shape.
A cold insulating material and a membrane are attached to the inner peripheral surface of the underground tank body 20 so that the cold heat of the liquefied gas stored in the underground tank body 20 does not propagate to the outside.

  Hereinafter, the construction method of the side wall 21 of the underground tank structure having such a configuration will be described with reference to FIGS. 2A to 2D. In addition, since the underground tank structure of this embodiment has symmetry in a vertical cross section, only the vertical cross section on the left side of the central axis is shown in FIGS.

  In constructing the side wall 21, first, as shown in FIG. 2A, the underground continuous wall 30 is constructed on the outer periphery of the side wall 22, and the underground continuous wall 30 is supported via the support portion 50 so as to be underground. A portion (hereinafter referred to as a central portion 23A) excluding the outer peripheral portion having a width of about 1 to 2 m from the inner peripheral surface of the side wall 21 in the roof 23 of the tank body 20 is constructed. Then, the portion of the ground surrounded by the underground continuous wall 30 is excavated, and the bottom plate 22 is constructed at the bottom. In addition, as a method of constructing the roof 23 ahead of the side wall 21 in this way, a method described in Japanese Patent No. 3888564 (particularly, paragraphs [0018] to [0024]) may be used.

  Next, as shown in FIG. 2B, the hanging material 110 is suspended from the central portion 23 </ b> A of the roof 23, and the side wall 21 is constructed by using the formwork support device 100 that can move up and down by taking a reaction force on the hanging material 110. .

  3 to 5 show the configuration of the mold support apparatus 100, FIG. 3 is a plan view, FIG. 4 is a vertical sectional view, and FIG. 5 is an enlarged view of a portion C in FIG. As shown in the figure, the formwork support apparatus 100 is a mold comprising an annular part 140 made of a truss frame assembled in an annular shape, a cross beam 152 attached to the outer periphery of the annular part 140, and a sliding bearing 151. A frame support 150, a jack 130 for raising the suspension member 110 by taking a reaction force, a support 120 attached to the annular part so as to extend vertically, and work provided on the upper and lower parts of the support 120 Work floors 160 and 162 on which an operator can work, and a plurality of spokes 170 made of a steel material attached so as to pass through the center of the annular portion 140 and connect opposing portions.

Hereinafter, the flow of constructing the side wall 21 using the mold support device 100 will be described with reference to FIGS. 6A to 6G.
First, as shown in FIG. 6A, the lower end 21A of the side wall 21 is constructed. That is, the reinforcing bar unit 180 is arranged along the underground continuous wall 30 and the formwork panel 200 is connected in a circular shape in the horizontal direction at a position corresponding to the surface of the side wall 21 and installed in a plurality of stages in the vertical direction. Then, concrete 181 is placed between the underground continuous wall 30 and the formwork panel 200.

  Next, as shown in FIG. 6B, the formwork support device 100 that is disassembled and carried on the bottom plate 22 is assembled, a jack 130 is attached to the hanging material 110 that hangs down from the roof 23, and the formwork is attached to the formwork panel 200. The support part 150 is brought into contact.

  Next, as shown in FIG. 6C, the mold support device 100 is raised by the jack 130. At this time, the formwork panel 200 is supported by the formwork support unit 150 of the formwork support apparatus 100, and when the formwork support apparatus 100 is lifted, the sliding support 151 attached to the formwork support apparatus 100 is used as the formwork panel. By sliding with respect to 200, the formwork support apparatus 100 can be raised while keeping the installed position without moving the formwork panel 200. Moreover, since the cast concrete 181 is hardened, the formwork support apparatus 100 is raised along the hardened concrete, and the positional accuracy of the formwork support apparatus 100 can be ensured.

  Next, as shown in FIG. 6D, the reinforcing bar unit 180 is newly connected to the upper part of the reinforcing bar unit 180 embedded in the lower end 21 </ b> A on the upper work floor 160. Then, the formwork panel 200 is connected in a ring shape above the uppermost formwork panel 200 already installed.

  Next, as shown in FIG. 6E, concrete 181 is placed between the underground continuous wall 30 and the formwork panel 200 on the upper work floor 160. At this time, the casting pressure of the concrete 181 acts on the formwork panel 200, but the shape of the formwork panel 200 is maintained in order to resist this by the ring compression effect of the annular part 140 and the thrust tension of the spokes 170. be able to. Before placing the concrete 181, it is preferable to perform a joining process on the joining surface of the concrete 181 that has already been placed.

  Next, as shown in FIG. 6F, the lowermost formwork panel 200 is removed on the lower work floor 162. When the embedded hardware is attached to the formwork panel 200, the embedded hardware is exposed on the surface of the concrete 181 constituting the side wall 21. At this time, of the concrete 181 placed between the underground continuous wall 30 and the formwork panel 200, the height corresponding to the lowermost formwork panel 200 is sufficiently hardened. And Moreover, the removed formwork panel 200 moves to the uppermost stage and can be used repeatedly.

  Next, as shown in FIG. 6G, the formwork support device 100 is raised by the jack 130. Then, on the upper work floor 160, the rebar unit 180 is newly connected to the upper part of the rebar unit 180 embedded in the lower end 21 </ b> A on the upper work floor 160. Then, the formwork panel 200 is connected in a ring shape above the uppermost formwork panel 200 already installed.

  And the side wall 21 can be constructed | assembled as shown to FIG. 2C by repeating the process of FIGS. 6E-6G demonstrated above. The steps described with reference to FIGS. 6D to 6G are not in any order. For example, after the work of connecting the formwork panel 200 to the uppermost stage is performed, the formwork support apparatus 100 is raised, and the order is different. You may go on. Further, in parallel with the construction work of the side wall 21 described above, it is possible to perform the work of attaching the cold insulation material on the part where the construction of the side wall 21 is completed or the bottom plate 22 and the work of lining the membrane.

  Next, as shown in FIG. 2D, a mold frame is installed at a position corresponding to a connection portion between the side wall 21 and the roof 23, a reinforcing bar is placed in the mold frame, concrete is placed, and the side wall 21 is placed. And the central portion 23A are connected. Thereby, the roof 23 and the side wall 21 are connected, and the construction of the underground tank body 20 is completed.

  As described above, according to the present embodiment, the support for supporting the formwork panel 200 by supporting the formwork panel 200 by the formwork support apparatus 100 while raising the formwork support apparatus 100. In addition, since the labor for installing and removing the work scaffold can be saved, the construction period can be shortened. Furthermore, since the work for attaching the cold insulation material and the work for lining the membrane in the part where the construction of the roof 23, the bottom plate 22 and the side wall 21 is completed can be performed in parallel, the construction period can be further shortened.

  Further, even when the formwork supporting apparatus 100 is raised, the formwork panel 200 is left in the installed position. That is, it does not move with respect to the concrete before the formwork panel 200 is hardened unlike the slip form method. For this reason, by attaching the embedded hardware to the inner surface side of the mold panel 200, the hardware can be embedded so as to be exposed on the surface of the side wall 21.

  Moreover, since the formwork panel 200 is left as mentioned above, the concrete surface which comprises the side wall 21 can be finished beautifully. Moreover, since it is possible to leave the formwork panel 200, the formwork panel 200 can be arrange | positioned for a sufficient period until concrete hardens | cures, and the deterioration of the quality by early demolding can be prevented.

  In the above embodiment, the case where the roof 23 is constructed prior to the construction work of the side wall 21 has been described. It is.

7A to 7G are views for explaining a construction method of the underground tank structure 10 when the construction work of the roof 23 is performed after the construction work of the side wall 21.
First, as shown in FIG. 7A, the underground continuous wall 30 is constructed at a position corresponding to the outer periphery of the side wall 21 of the underground tank body 20. Then, as shown in the figure, the bracket 33 is integrated with the upper part of the underground continuous wall 30 so as to protrude from the underground continuous wall 30 toward the center of the underground tank body 20 with an appropriate interval in the circumferential direction. To build.

  Next, as shown in FIG. 7B, after excavating the portion of the ground surrounded by the underground continuous wall 30 using the backhoe 71, the earth and sand bucket 72, etc., and reaching the planned depth, as shown in FIG. 7C The bottom plate 22 made of reinforced concrete is constructed at the bottom of the excavation hole 70 inside the underground continuous wall 30.

  Next, as shown in FIG. 7D, similarly to the above embodiment, the suspension member 110 is suspended from the bracket 33, and the mold holding device 100 is used to follow the inner periphery of the underground continuous wall 30. A side wall 21 of the underground tank body 20 is constructed adjacent to the underground continuous wall 30. At this time, in parallel with the construction work of the side wall 21, it is possible to perform the work of attaching the cold insulation material on the part where the construction of the side wall 21 is completed or the bottom plate 22 and the work of lining the membrane. In addition, after the construction work of the side wall 21 is completed, the bracket 33 is removed.

Next, as shown in FIG. 7E, a roof 23 is constructed on the bottom slab 22, and as shown in FIG. 7F, the roof 23 is lifted up to a ground level by a lift-up device, and as shown in FIG. The roof 23 and the side wall 21 are connected.
Also by the method described above, the same effect as the above-described embodiment can be obtained.

  In each of the above embodiments, the shape of the formwork panel 200 is maintained by resisting the casting pressure of the concrete 181 by the ring compression effect of the annular portion 140 and the protruding tension of the spokes 180. However, the present invention is not limited to this, and a separator may be provided between the underground continuous wall 30 and the formwork panel 200 to hold the formwork panel 200.

DESCRIPTION OF SYMBOLS 10 Underground tank structure 20 Underground tank main body 21 Side wall 22 Bottom plate 23 Roof 23A Center part 30 Underground continuous wall 50 Support part 60 Suspension scaffold 70 Excavation hole 71 Excavation heavy machine 72 Bucket 100 Formwork support apparatus 110 Suspension material 120 Prop 130 Jack 140 Annular part 150 Formwork support part 151 Sliding support 152 Cross girder 160 Upper work floor 162 Lower work floor 170 Spoke 180 Reinforcement unit 181 Concrete 200 Formwork panel

Claims (2)

An underground tank structure comprising a bottom slab, a side wall constructed along the outer periphery of the bottom slab, and a reinforced concrete tank comprising a roof constructed on the top of the side wall, and at least the side wall and the bottom slab are buried in the ground A side wall construction method,
In advance, at the ground level, a part of the roof is constructed, a cylindrical underground wall is constructed at a position corresponding to the outer periphery of the side wall, and the roof part is supported by the underground wall. Connecting a part of the roof to the underground wall, excavating the interior of the underground wall,
In a state where the formwork panels arranged along the surface of the side wall and connected to the upper and lower stages are supported by an annular formwork support device suspended on a part of the roof,
A step of placing concrete between the formwork panel and the underground wall, a step of raising the formwork support device, and a lowermost formwork of the formwork panels connected to the upper and lower stages. The side wall is constructed along the inside of the excavated underground wall by repeating the step of removing the panel and the step of connecting the formwork panel in an annular shape above the uppermost formwork panel. A method for constructing a side wall of an underground tank structure characterized by the above. A method of constructing the side wall of the underground tank structure according to claim 1 Symbol placement,
In parallel with the construction of the side wall,
A method for constructing a side wall of an underground tank structure, wherein a work for attaching a cold insulation material or a membrane lining work is performed in a portion where the construction of the side wall is completed.

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