JP6951961B2 - How to build a ground tank and a ground tank - Google Patents

Description

The present invention relates to a above-ground tank and a method for constructing the above-ground tank.

Ground tanks are sometimes used as equipment for storing low-temperature liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas).

FIG. 11 shows an example of an LNG tank 100 that stores LNG as a ground tank. The LNG tank 100 is a tank frame in which a liquid barrier 6 is fixed on a bottom slab 5 supported by piles 4 in the ground 7, and an inner tank 3a and an outer tank steel plate 3b made of steel plates or the like are provided inside the tank skeleton. be. LNG is stored in the inner tank 3a, and the heat insulating material 8 is arranged between the inner tank 3a and the outer tank steel plate 3b to keep it cool. The outer tank steel plate 3b is integrally formed with the liquid barrier 6. Reinforcing reinforcing bars and heater pipes (not shown) are also provided in the bottom plate 5.

The liquid barrier 6 is a concrete side wall provided to prevent liquid leakage from the LNG to the outside when the inner tank 3a is damaged, and is usually cylindrical. The liquid barrier 6 needs to have a structure that can withstand the hydraulic pressure of LNG. Therefore, it is rigidly coupled to the bottom slab 5, and is not shown. A tension force (prestress) due to the tension material of the concrete is introduced to generate a predetermined compressive stress in the concrete.

When the tension material is tensioned in the circumferential direction with the liquid barrier 6 rigidly connected to the bottom slab 5, the bending moment in the vertical plane that tries to bend the liquid barrier 6 inside the tank (bending moment of tension on the outside of the liquid barrier). ) Is generated at the bottom of the liquid barrier 6, so it is necessary to dispose an amount of vertical tension material necessary for canceling the liquid barrier 6.

On the other hand, as one of the construction methods of the above-ground tank, there is a method of rigidly connecting the liquid barrier and the bottom slab after tensioning the tension material in the circumferential direction while the bottom of the liquid barrier is free. When the tension material in the circumferential direction is strained after the liquid barrier and the bottom slab are rigidly bonded, the introduction of the tension force in the circumferential direction to the liquid barrier is hindered by the bottom slab, and the bending moment in the vertical plane is generated. Since such a situation does not occur in the above method, the amount of the tension material in the circumferential direction can be reduced, and the amount of the tension material in the vertical direction can also be reduced.

For example, in Patent Document 1, the bottom slab is constructed by dividing it into an outer peripheral portion and a central portion, and a gap is provided between them. The outer peripheral part of the bottom slab is only placed on the foundation pile, and a liquid barrier is constructed integrally with the outer peripheral part, and the tension material in the circumferential direction is strained when the liquid barrier is almost completed. After that, the gap between the outer circumference and the center of the bottom slab is filled with padded concrete, the radial tension material of the bottom slab is strained to attract the outer circumference of the bottom slab toward the center, and the outer circumference of the bottom slab and the foundation pile are integrated. To become.

Japanese Unexamined Patent Publication No. 2014-167244

In the method of Patent Document 1, the outer peripheral portion of the bottom slab integrated with the liquid barrier is a thick annular shape, so that the rigidity is high. Therefore, the amount of tension material required for introducing the tension force in the circumferential direction increases, and it is necessary to dispose the tension material in the circumferential direction not only on the liquid barrier but also on the outer peripheral portion of the bottom slab.

Further, in the method of Patent Document 1, the unstable state in which the liquid barrier is constructed on the outer peripheral portion of the bottom slab placed on the foundation pile in a free state continues for a long time, and finally the outer peripheral portion of the bottom slab. The work of fixing the to the foundation pile is also quite difficult. Further, a tension material in the tank radial direction is required to integrate the outer peripheral portion of the bottom slab with the central portion, and it is also necessary to connect a reinforcing bar or a heater tube between the outer peripheral portion and the central portion of the bottom slab.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a ground tank or the like which can reduce the amount of tension material in the circumferential direction of the tank and is easy to construct.

The first invention for solving the above-mentioned problems has a tank skeleton including a bottom slab and a side wall, and the bottom portion of the side wall is formed with a gap from the bottom slab to fill the gap. A tension force in the circumferential direction of the tank is introduced into the tank, and an overhanging portion extending laterally from the side wall is extended in the circumferential direction of the tank at the bottom of the side wall, and the overhanging portion is divided in the circumferential direction of the tank by a slit. The slit is a above-ground tank characterized in that the slit is provided only in the portion of the side wall excluding the overhanging portion and the overhanging portion of the overhanging portion.

In the present invention, since the side wall having the overhanging portion at the bottom is arranged on the bottom slab, the construction of the side wall is stable, and the bottom slab may be fixed on the pile from the beginning. Further, in the present invention, since the bottom slab is not divided into the inside and the outside, the above-mentioned tension material in the tank radial direction is unnecessary, and the connecting work such as the reinforcing bar and the heater pipe is also unnecessary. Further, by providing the above slit in the overhanging portion, the rigidity of the bottom portion of the side wall is reduced, and the tension force of the tension material in the circumferential direction of the tank is received in the portion excluding the overhanging portion of the side wall. Further, in the present invention, the tension force in the circumferential direction of the tank does not act on the bottom slab. As a result, the amount of the tension material in the circumferential direction of the tank can be reduced, and the tension material in the circumferential direction, which is arranged in the outer peripheral portion of the bottom slab described above, is also unnecessary.

It is desirable that a step portion in which the position of the upper surface is lowered in a stepped manner is formed on the outer peripheral portion of the bottom slab, and the bottom portion of the side wall is arranged in the step portion.
By arranging the bottom portion of the side wall having the overhanging portion in the above-mentioned step portion, the overall shape of the tank skeleton can be accommodated in the conventional shape, which is rational in terms of structure and construction.

It is desirable that the overhanging portion extends to the inside and the outside of the side wall, and both the overhanging portion extending to the inside and the outside are divided in the tank circumferential direction by a slit.
As a result, the stability of the side wall during construction can be improved, and the amount of tension material in the circumferential direction can be suppressed by providing the above slit.

It is desirable that the overhanging portion extends to the outside of the side wall, and the overhanging portion extending to the outside includes a haunch portion of the side wall.
In this case, the side wall can be reinforced by the haunch portion, and the amount of tension material in the circumferential direction can be suppressed by providing the slit.

Further, it is desirable that the overhanging portion extends to the outside of the side wall, and a slit material is arranged in the slit of the overhanging portion extending to the outside.
In the present invention, the slit can be suitably formed by the slit material at the time of placing the concrete, and the slit can be secured by the slit material after the concrete is placed.

A second invention is a method for constructing a ground tank having a tank skeleton including a bottom slab and a side wall, wherein a side wall is formed on the bottom slab and a tension force in the tank circumferential direction is introduced into the side wall. , And the bottom of the side wall is formed with a gap from the bottom slab, and the gap is filled after introducing a tension force in the tank circumferential direction into the side wall, and the bottom of the side wall is lateral to the side wall. The overhanging portion extends in the tank circumferential direction, and the overhanging portion is divided in the tank circumferential direction by a slit, and the slit is a portion of the side wall excluding the overhanging portion and the overhanging portion. It is a method of constructing a above-ground tank characterized in that it is provided only by the overhanging portion.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a ground tank or the like which can reduce the amount of tension material in the circumferential direction of the tank and is easy to construct.

The figure which shows the LNG tank 1. The figure which shows the liquid barrier 2. The figure which shows the cross section in the thickness direction of the bottom of the liquid barrier 2. The figure which shows the sealing material 24. The figure which shows the H-section steel 31 and the head bar bar 33. The figure which shows the construction method of the LNG tank 1. The figure which shows the hoop muscle 35. The figure which shows the anchor bolt 37a, 37b. The figure which shows the haunch part 21a. The figure which shows the liquid barrier 2', 2 ". The figure which shows the LNG tank 100.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(1. LNG tank 1)
FIG. 1 is a diagram showing an LNG tank 1 which is a above-ground tank according to an embodiment of the present invention.

The LNG tank 1 is a ground tank having a size of about 200,000 KL for storing LNG (low temperature liquid) inside, and like the LNG tank 100 described with reference to FIG. 11, a bottom slab supported by a pile 4 in the ground 7. The liquid barrier 2 is fixed on the 5 to form a tank skeleton, and an inner tank 3a and an outer tank steel plate 3b are provided inside the tank skeleton. The liquid barrier 2 is a cylindrical side wall rigidly coupled to the bottom slab 5 and is provided to prevent liquid leakage from the LNG to the outside when the inner tank 3a is damaged. The liquid barrier 2 is constructed of concrete having a predetermined tensile strength, and the inner diameter of the tank frame is about 80 m and the height is about 40 m.

The LNG tank 1 is a PC (prestressed concrete) tank, and a tensioning force due to a tensioning material in the circumferential direction of the tank and a tensioning material in the vertical direction is introduced into the liquid barrier 2 as described later.

At the bottom of the liquid barrier 2, overhanging portions 2a and 2c overhanging the side of the liquid barrier 2 are provided. The overhanging portion 2a overhangs the outside of the liquid barrier 2 and has a haunch portion 21 and a plate-shaped portion 22.

The haunch portion 21 is a right-angled triangular cross-sectional portion that is widened outward with respect to an equal-thickness portion 2b having a constant thickness (for example, about 0.6 m) above the haunch portion 21. The outer surface of the haunch portion 21 is inclined linearly with respect to the vertical direction so as to go outward as it goes downward, and at the lower end of the haunch portion 21, the thickness of the liquid barrier 2 including the haunch portion 21 is about 1.2 m. It becomes. Here, "outside" means the outside of the tank, and "inside" means the inside of the tank. The height range in which the haunch portion 21 is provided varies depending on the design, but for example, the height of the haunch portion 21 from the plate-shaped portion 22 is set to about 5.0 m.

The plate-shaped portion 22 is formed below the haunch portion 21. The outer surface of the plate-shaped portion 22 is formed along the vertical direction, and in the example of FIG. 1, the plane position of the outer surface is substantially the same as the lower end of the haunch portion 21, but it may protrude outward.

The overhanging portion 2c is a plate-shaped overhanging portion inside the liquid barrier 2, and the height of the upper surface of the overhanging portion 2c is substantially equal to the height of the upper end of the plate-shaped portion 22 described above. The height of the bottom surface of the overhanging portion 2c is also substantially equal to the height of the bottom surface of the plate-shaped portion 22, and the bottom end portion of the liquid barrier 2 including the overhanging portion 2c and the plate-shaped portion 22 supports the liquid barrier 2. It constitutes the support plate part to be used.

The height of the overhanging portion 2c and the plate-shaped portion 22 is about 0.6 m, and the length of the bottom surface of the liquid barrier 2 including the overhanging portion 2c and the plate-shaped portion 22 in the tank radial direction is, for example, about 3.0 m. .. The tank radial direction corresponds to the left-right direction in FIG.

FIG. 2A is a view of the liquid barrier 2 from the outside. As shown in FIG. 2A, the overhanging portion 2a extends along the circumferential direction of the tank on the outer surface of the liquid barrier 2. However, the overhanging portion 2a is provided with slits 20 at predetermined intervals in the tank circumferential direction, and the overhanging portion 2a is divided in the tank circumferential direction by the slits 20. The slit 20 is provided so as to be continuous between the haunch portion 21 and the plate-shaped portion 22, and the above interval is set to, for example, 2.5 m, which is equal to or less than the combined height of the haunch portion 21 and the plate-shaped portion 22.

FIG. 2B is a diagram showing a part of the inside of the liquid barrier 2. In the present embodiment, the overhanging portion 2c is also provided with slits 25 at predetermined intervals in the tank circumferential direction, and the overhanging portion 2c is divided in the tank circumferential direction by the slits 25. The position of the slit 25 in the tank circumferential direction corresponds to the position of the slit 20 in the tank circumferential direction. However, the positions of the slits 20 and 25 in the tank circumferential direction may be different.

These slits 20 and 25 are provided only by the overhanging portions 2a and 2c, and no slit is provided in the main body portion of the liquid barrier 2 (the portion excluding the overhanging portions 2a and 2c). The slits 20 and 25 are provided in the vertical direction and are orthogonal to the outer or inner surface of the liquid barrier 2 and the upper surface of the bottom slab 5. The width of the slits 20 and 25 is smaller than the installation interval of the slits 20 and 25 described above, for example, about 20 mm.

3 (a) and 3 (b) are views showing a cross section of the bottom of the liquid barrier 2 in the thickness direction, and FIG. 3 (a) shows positions without slits 20 and 25 (slits 20, 25 and slits 20). 25), FIG. 3B shows the cross section at the positions of the slits 20 and 25.

As shown in the figure, a stepped portion 51 having a stepped upper surface position is formed on the outer peripheral portion of the bottom slab 5. The bottom portion of the liquid barrier 2 is separated from the bottom slab 5 and formed as a separate body, and the bottom portion is arranged on the step portion 51.

The step of the step 51 is about 0.7 m, the length in the tank radial direction is about 3.1 m, and a gap is formed between the bottom of the liquid barrier 2 and the step 51. That is, there is a gap of about 0.1 m between the bottom surface of the liquid barrier 2 and the upper surface of the step 51, and between the inner peripheral surface of the overhanging portion 2c at the bottom of the liquid barrier 2 and the wall surface of the step 51. .. The gap is filled with a filler 30 such as mortar, whereby the gap is filled. Further, the upper surface of the bottom plate 5 in the inner portion of the step portion 51 and the upper surface of the overhanging portion 2c are at the same height.

In the liquid barrier 2, a circumferential PC steel material 11 which is a tension material in the tank circumferential direction and a vertical PC steel material 13 which is a vertical tension material are provided.

A plurality of PC steel materials 11 in the circumferential direction are provided at intervals at the top and bottom, and are arranged over almost the entire height from the bottom to the top of the liquid barrier 2. The circumferential PC steel 11 is arranged along the vertical PC steel 13.

The vertical PC steel material 13 is provided in the vertical direction inside the circumferential PC steel material 11. The vertical PC steel material 13 is arranged from the top of the liquid barrier 2 to the bottom slab 5, and is arranged at a position substantially in the center of the equal thickness portion 2b in the thickness direction.

The amount, placement and tension of these PC steels are determined by the design. Further, each PC steel material is arranged in a sheath (not shown) embedded in the concrete of the liquid barrier 2 and the bottom slab 5, and mortar is filled between the sheath and the PC steel material after tensioning. Reinforcing bars (not shown) in the circumferential direction of the tank are also embedded in the overhanging portions 2a and 2c for reinforcement, but these reinforcing bars do not penetrate the slits 20 and 25. However, with respect to the inner overhanging portion 2c, the reinforcing bar in the circumferential direction of the tank may penetrate the slit 25.

A plate-shaped slit material 23 is arranged in the slit 20 of the overhanging portion 2a, and the slit 20 is filled with the slit material 23. The material of the slit material 23 is not particularly limited, but an elastic body such as a hard rubber plate, polyurethane foam, or styrofoam can be used in addition to a wooden plate such as plywood. On the other hand, the slit 25 of the overhanging portion 2c is filled with the filler 30.

By arranging the slit material 23 at the position of the slit 20 in advance and placing the concrete at the bottom of the liquid barrier 2 in the state where the slit material similar to the slit material 23 is arranged in advance at the position of the slit 25, the slit 20 , 25 can be preferably formed. These slit materials can also be attached to and arranged in a buried formwork (not shown) at the time of placing concrete at the bottom of the liquid barrier 2.

By leaving the slit material 23 arranged at the position of the slit 20 as it is, the slit 20 can be secured by the slit material 23 after the concrete is placed. On the other hand, the slit material arranged at the position of the slit 25 is removed after the concrete is placed.

FIG. 4 is a diagram showing a cross section taken along line AA of FIG. 3 (b). As shown in FIG. 4, at the open end on the outside of the slit 20, a sealing material 24 is provided on the outside of the slit material 23, and the slit 20 (slit material 23) is protected from the outside world. At this open end, the concrete of the overhanging portion 2a is chamfered to form the chamfered portion 28 when the sealing material 24 is installed.

FIG. 5A is a diagram showing a gap between the bottom portion of the liquid barrier 2 and the step portion 51 of the bottom slab 5, omitting the filler 30 and the PC steel material. 5 (b) is a view of the gap seen from the direction indicated by the arrow a of FIG. 5 (a), and FIG. 5 (c) is a view of the gap viewed from the direction indicated by the arrow b of FIG. 5 (a). be.

In the present embodiment, the H-shaped steel 31 in the tank radial direction (corresponding to the left-right direction in FIG. 5A) is in the tank circumferential direction (FIG. 5 (FIG. 5)) between the bottom surface of the liquid barrier 2 and the upper surface of the stepped portion 51. A plurality of c) are provided at intervals (corresponding to the left-right direction). The H-shaped steel 31 has a function as a receiving material that movably supports the liquid barrier 2 during construction.

Between the bottom surface of the liquid barrier 2 and the upper surface of the step 51, the inner peripheral surface of the overhanging portion 2c and the wall surface of the step 51, the head bar bar 33 (reinforcing bar) is formed from both the bottom of the liquid barrier 2 and the bottom slab 5. Is protruding. The tip of the head bar bar 33 protruding from the bottom slab 5 is arranged closer to the liquid barrier 2 than the tip of the head bar bar 33 protruding from the bottom of the liquid barrier 2. These head bar bars 33 are arranged so as not to interfere with the H-shaped steel 31.

When constructing the LNG tank 1, after constructing the bottom slab 5 having the stepped portion 51, an H-shaped steel 31 is arranged on the upper surface of the stepped portion 51 as shown in FIG. 2 is formed at a partial height (for example, a height of 10 m or more) or the entire height.

After that, by introducing the tension force by the circumferential PC steel material 11, the liquid barrier 2 moves slightly (about 1.0 to 2.5 cm) inward on the H-shaped steel 31 as shown by the arrow B. After that, the filler 30 is filled in the gap between the bottom of the liquid barrier 2 and the step 51 as shown in FIG. 6 (b).

In the present embodiment, the filler 30 and the head bar bar 33 embedded therein rigidly connect the liquid barrier 2 and the bottom slab 5 without connecting reinforcing bars or the like, and finally prevent tension due to the vertical PC steel material 13. It is introduced into the liquid bank 2. Hereinafter, the LNG tank 1 is constructed by performing installation work on the inner tank 3a, the outer tank steel plate 3b, and the like.

In the present embodiment described above, since the liquid barrier 2 having the overhanging portions 2a and 2c at the bottom is arranged on the bottom slab 5, the construction of the liquid barrier 2 is stable, and the bottom slab 5 is also piled up. 4 It may be fixed on the top from the beginning. Further, in the present embodiment, since the bottom slab 5 is not divided into the inside and the outside, the above-mentioned tension material in the tank radial direction is unnecessary, and the connecting work such as the reinforcing bar and the heater pipe is also unnecessary.

By providing the slits 20 and 25 in the overhanging portions 2a and 2c, the rigidity is reduced, and the tension force in the circumferential direction of the tank is received by the portion of the liquid barrier 2 excluding the overhanging portions 2a and 2c. Further, in the present embodiment, the tension force in the circumferential direction of the tank does not act on the bottom slab 5. As a result, the amount of the circumferential PC steel material 11 can be reduced, and the circumferential tension material that is arranged in the outer peripheral portion of the bottom slab is also unnecessary.

Further, in the present embodiment, by arranging the bottom portion of the liquid barrier 2 having the overhanging portions 2a and 2c on the step portion 51 of the bottom slab 5, the overall shape of the tank skeleton can be accommodated in the conventional shape, and the structural surface and It will be rational in terms of construction. A gap is provided between the bottom of the liquid barrier 2 and the step 51 so that the liquid barrier 2 can be moved when the PC steel material 11 in the circumferential direction is tense. The gap is filled with the filler 30. , The integrity of the liquid barrier 2 and the bottom slab 5 can be enhanced.

Further, in the present embodiment, since the overhanging portions 2a and 2c overhang inside and outside the liquid barrier 2, the stability of the liquid barrier 2 during construction can be improved, and both the overhanging portions 2a and 2c are slits. Since the tank is divided in the circumferential direction by 20 and 25, the amount of the PC steel 11 in the circumferential direction can be suppressed.

Further, in the present embodiment, the haunch portion 21 can be provided on the overhanging portion 2a to reinforce the liquid barrier 2, and the slit 20 is continuously provided on the haunch portion 21 and the plate-shaped portion 22 in the circumferential direction. The amount of PC steel 11 can also be suppressed.

Further, the slit material 23 is arranged in the slit 20, and the slit 20 can be suitably formed by the slit material 23 at the time of placing concrete, and the slit 20 can be secured by the slit material 23 after placing concrete.

However, the present invention is not limited to this. For example, the slit may be provided only in either of the overhanging portions 2a and 2c.

Further, instead of the head bar muscle 33, a hoop muscle 35 can be provided as shown in FIG. Also in this case, the tip of the hoop bar 35 protruding from the bottom slab 5 is arranged closer to the liquid barrier 2 than the tip of the hoop bar 35 protruding from the bottom of the liquid barrier 2.

Further, as shown in FIG. 8, the overhanging portions 2a and 2c and the bottom slab 5 may be integrated by anchor bolts 37a and 37b. In this example, the anchor bolt 37a is provided on the overhanging portion 2a, and the anchor bolt 37b is provided on the overhanging portion 2c. PC steel may be used instead of the anchor bolts 37a and 37b.

The lower ends of the anchor bolts 37a and 37b are embedded in the bottom slab 5, and the upper ends of the anchor bolts 37a are fixed in the bolt box 26a which is a recess formed by punching out the overhanging portion 2a. Similarly, the upper end of the anchor bolt 37b is fixed in the bolt box 26b, which is a recess formed by punching out the upper surface of the overhanging portion 2c. These bolt boxes 26a and 26b are filled with a filler 27 such as mortar after the anchor bolts 37a and 37b are provided.

Further, by providing an edge cutting material such as a sheet between the haunch portion 21 and the plate-shaped portion 22, the edge of the haunch portion 21 and the plate-shaped portion 22 is cut, and the rigidity is further reduced to reduce the amount of the circumferential PC steel material 11. It is also possible to reduce it.

Further, although the haunch portion 21 of the present embodiment has a right-angled triangular shape, the shape thereof is not particularly limited, and the haunch portion 21a may be rectangular as shown in the overhanging portion 2a'of FIG. Further, in the present embodiment, the vertical PC steel material is not required in the haunch portion, but it is also possible to arrange the vertical PC steel material in the vertical direction or the direction inclined with respect to the vertical direction in the haunch portion. In some cases, the haunch portion can be provided on the overhanging portion 2c inside the liquid barrier 2.

Further, it is possible to omit the overhanging portion 2a as shown in the liquid barrier 2'in FIG. 10 (a), or the overhanging portion 2c as shown in the liquid barrier 2 "in FIG. 10 (b). May be omitted.

In addition, the present invention is not limited to LNG tank 1, and can be applied to so-called PC tanks that introduce tension in the circumferential direction of the tank. It may be water or water.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea disclosed in the present application, and these also naturally belong to the technical scope of the present invention. Understood.

1,100: LNG tank 2, 2'2 ", 6: Liquid barrier 2a, 2a', 2c: Overhanging part 2b: Equal thickness part 3a: Inner tank 3b: Outer tank steel plate 4: Pile 5: Bottom slab 7 : Ground 8: Insulation material 11: Circumferential PC steel material 13: Vertical PC steel material 20, 25: Slit 21, 21a: Hunch portion 22: Plate-shaped portion 23: Slit material 24: Sealing material 26a, 26b: Bolt box 28: Chamfered portions 27, 30: Filling material 31: H-shaped steel 33: Head bar reinforcement 35: Hoop reinforcement 37a, 37b: Anchor bolt 51: Step portion

Claims (6)

It has a tank skeleton including a bottom slab and side walls,
The bottom of the side wall is formed with a gap from the bottom slab, and the gap is filled.
A tension force in the circumferential direction of the tank is introduced into the side wall,
At the bottom of the side wall, an overhanging portion extending laterally from the side wall extends in the circumferential direction of the tank.
The above-ground tank is characterized in that the overhanging portion is divided by a slit in the circumferential direction of the tank , and the slit is provided only in the portion of the side wall excluding the overhanging portion and the overhanging portion of the overhanging portion. .. On the outer peripheral portion of the bottom slab, a step portion in which the position of the upper surface is lowered in a stepped manner is formed.
The above-ground tank according to claim 1, wherein the bottom portion of the side wall is arranged on the step portion. The overhanging portion extends to the inside and outside of the side wall.
The above-ground tank according to claim 1 or 2, wherein both the overhanging portion extending to the inside and the overhanging portion to the outside are divided in the circumferential direction of the tank by a slit. The overhanging portion extends to the outside of the side wall,
The above-ground tank according to any one of claims 1 to 3, wherein the overhanging portion extending outward includes a haunch portion of the side wall. The overhanging portion extends to the outside of the side wall,
The above-ground tank according to any one of claims 1 to 4, wherein a slit material is arranged in the slit of the overhanging portion that overhangs to the outside. A method of constructing a ground tank having a tank skeleton including a bottom slab and a side wall.
The step of forming a side wall on the bottom slab and
The process of introducing a tension force in the circumferential direction of the tank into the side wall, and
Have,
The bottom of the side wall is formed with a gap from the bottom plate.
The gap is filled after introducing a tension force in the circumferential direction of the tank into the side wall.
At the bottom of the side wall, an overhanging portion extending laterally from the side wall extends in the circumferential direction of the tank, the overhanging portion is divided in the circumferential direction of the tank by a slit, and the slit is the overhanging portion of the side wall. A method for constructing a above-ground tank, characterized in that it is provided only in the overhanging portion of the portion excluding the portion and the overhanging portion.

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