JP2000160871A - Waterproof structure of tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the waterproof structure of a tank capable of improving durability of the tank by preventing water from entering a base part and preventing the corrosion of the tank body. SOLUTION: An underground tank is set on a hole bottom dug in underground. Cobble stones 2 are laid on the hole bottom, and leveling concrete 3 is placed on the cobble stones 2. Base concrete 5 is placed in a waterproof sheet 4 on the leveling concrete 3, and asphalt mortar 6 is placed thereon. The bottom plate 12 of the tank body is mounted on the asphalt mortar 6, and an edge plate 10 is mounted and fixed through an anchor bolt 7 so as to surround the bottom plate 12. A side wall 13 is welded and fixed on the edge plate 10. A skirt part 23 is provided on the lower end of the outer face side of the side wall 13. The waterproof sheet 4 is provided up to a higher position than the skirt part 23, and the upper end is stuck on the outer peripheral face of the side wall 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure of a tank mainly used for storing substances to be stored such as tap water and chemicals.

[0002]

2. Description of the Related Art Conventionally, as a tank for storing fire-extinguishing water, for example, a concrete tank formed by casting concrete into a frame structure such as a bottom wall and a side wall has been used for many years. However, concrete tanks have cracks in the event of an earthquake or the like, so there is a problem in terms of tank durability. Therefore, in recent years, in order to improve the durability of the tank, a tank using a metal structural material for a bottom plate and a side wall, for example, a tank in which an iron bottom plate and an iron side wall are placed on a base concrete has become common. Was.

[0003]

However, when groundwater or the like penetrates into the base (concrete), as is particularly remarkable in an underground tank, a metal structural material for extending the life of the tank by the water is used. It will rust, which will shorten the life of the tank. In addition, it is clear that the tank has a shorter service life due to cracks in the base portion during an earthquake, which makes it easier for groundwater and the like to permeate.

On the other hand, in order to cope with such shortening of the service life of the tank, a tank having a structure in which asphalt mortar or oil sand is provided between a base portion and a bottom plate has been developed. However, even in a tank using asphalt mortar, there is a problem that it is difficult to maintain the durability of the tank due to cracks in the asphalt mortar during an earthquake. Further, even in a tank using an oil sand, the water resistance is not satisfactory in a long term, and as a result, there is a problem that it is difficult to maintain the durability of the tank.

An object of the present invention is to provide a waterproof structure for a tank, which can prevent water or the like from entering the base portion and prevent corrosion of the tank body, thereby improving the durability of the tank.

[0006]

In order to achieve the above object, according to the present invention, there is provided a waterproof structure for a tank in which a tank body for storing a substance to be stored is mounted and fixed on a base portion. The gist is that waterproof means is provided so as to surround the entire base portion on which the metal structural material of the tank body is placed. Therefore, in the invention of claim 1,
The waterproof means prevents water and the like from entering the base from the outside, and prevents corrosion of the metal structural material of the tank body.

According to a second aspect of the present invention, in the first aspect, the waterproofing means is constituted by a plurality of types of waterproofing means having different characteristics. Therefore, according to the second aspect of the invention, in addition to the operation of the first aspect of the invention, the respective waterproofing means complement each other with respect to waterproofing-related functions.

According to a third aspect of the present invention, in the invention of the second aspect, the first waterproofing means provided between the base portion and the tank main body, of the respective waterproofing means, is configured to connect another portion of the base portion. The gist of the invention is that the second waterproofing means is superior in mechanical strength to the covering. Therefore, in the invention of claim 3, in addition to the operation of the invention of claim 2,
When mounting and fixing the tank body on the base portion, the possibility that the waterproof function of the first waterproofing means is impaired by the tank body is reduced.

A fourth aspect of the present invention is based on the third aspect, wherein the second waterproofing means is more excellent in water resistance than the first waterproofing means. Therefore, in the invention of claim 4, in addition to the effect of the invention of claim 3, intrusion of water or the like from the outside into the base portion is reliably reduced.

[0010] The invention of claim 5 is the invention of claim 3 or claim 4.
In the invention described in (1), the gist is that the second waterproofing means is a sheet-like material having flexibility. Therefore,
According to the fifth aspect of the present invention, in addition to the function of the third or fourth aspect of the present invention, the base portion is covered by the second waterproofing means in accordance with the surface shape thereof. The intrusion of water or the like from the outside into the gap between the two is reliably reduced. Also, due to its flexibility, the waterproof function of the second waterproof means does not have to be impaired even during an earthquake or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention applied to an underground tank for storing fire extinguishing water will be described below with reference to the drawings.

As shown in FIG. 1, an underground tank 1 as a tank is installed at the bottom of a hole dug in the ground. Chestnut 2 is spread over the bottom of the hole, and concrete 3 is cast on the chestnut 2. The second on abandoned concrete 3
A base concrete 5 as a base portion is cast in a waterproof sheet 4 (for example, a thermoplastic resin sheet such as a vinyl sheet) as a sheet means having waterproofing means and flexibility. Is provided with asphalt mortar 6 as first waterproof means having water resistance.

The asphalt mortar 6 has better mechanical strength and heat resistance than the waterproof sheet 4. Further, the waterproof sheet 4 is more excellent in water resistance than the asphalt mortar 6. A positioning hole 9 is formed between the base concrete 5 and the asphalt mortar 6, and a concrete block 8 having an anchor bolt 7 is embedded in the positioning hole 9. In the present embodiment, the waterproofing means is constituted by the waterproof sheet 4 and the asphalt mortar 6.

On the asphalt mortar 6, a tank body 11 is installed. The tank body 11 is the edge plate 10
, A bottom plate 12, side walls 13 and a ceiling wall 14. A circular steel bottom plate 12 is placed and fixed on the asphalt mortar 6. The upper surface of the bottom plate 12 is covered with a first lining material 15. First lining material 1
Numeral 5 is made of a corrosion-resistant plate (stainless steel plate in the present embodiment), and reduces corrosion of the bottom plate 12 by water 16 for fire extinguishing as a stored substance.

The bottom plate 1 is placed on the asphalt mortar 6.
A ring-shaped steel edge plate 10 is mounted and fixed via the anchor bolt 7 so as to surround the frame 2. The edge plate 10 is called an annular plate. The thickness of the edge plate 10 is set larger than that of the bottom plate 12 in order to maintain the strength of the tank body 11. Although not shown, the edge plate 1
The surface of No. 0 is provided with anticorrosion coating using a urethane-based coating or the like. The lower end of the cylindrical side wall 13 made of steel is fixed to the edge plate 10 by welding. In the present embodiment, the edge plate 10 and the bottom plate 12 constitute a metal structural material.

The inner surface of the side wall 13 is covered with a second lining material 21. The second lining material 21 is made of a corrosion-resistant plate (stainless steel plate in the present embodiment), and reduces corrosion of the side wall 13 by the fire extinguishing water 16. Further, between the first lining material 15 and the second lining material 21, a third lining material 22 is fixed by welding. The third lining material 22 is made of a corrosion-resistant plate (stainless steel plate in this embodiment), and
Corrosion by the water 16 for fire extinguishing is reduced at the seam portion between the side walls 13 and between the edge plate 10 and the bottom plate 12.

The lower end of the side wall 13 on the outer surface side and the edge plate 1
A skirt 23 made of steel is welded and fixed along the periphery of the tank main body 11 between the peripheral portion of the tank body 11 and the periphery of the tank body 11. Side wall 1
An anticorrosion coating 24 is applied to the outer surfaces of the skirt portion 23 and the skirt portion 23. A material having corrosion resistance and insulation properties (for example, urethane paint or epoxy paint) is used for the anticorrosion coating 24 to reduce corrosion of the side wall 13 and the skirt portion 23 by rainwater or groundwater that has penetrated into the ground. At the same time, the corrosion of the side wall 13 and the skirt portion 23 (electrostray corrosion) is reduced. The waterproof sheet 4 is provided up to a position higher than the skirt 23, and the upper end thereof is attached to the outer peripheral surface of the side wall 13.

The steel ceiling wall 14 is formed in a substantially dome shape, and is fixed to the upper end of the side wall 13 by welding. The annular covering plate 27 is formed integrally with the outer periphery of the ceiling wall 14, and a flange portion 28 is bent downward at the outer peripheral edge thereof. When the ceiling wall 14 is fixed to the upper end edge of the side wall 13 by welding, the cover plate 27
3 is joined to the upper end. Further, in this state, the flange 28 of the cover plate 27 is hung down on the outer periphery of the side wall 13 so as to reduce rainwater or the like flowing down from the outer surface of the ceiling wall 14 from entering the tank body 11. .

Next, a method of manufacturing the underground tank 1 configured as described above will be described. First, as shown in FIG. 2 (a), after burrowing the chestnut stone 2 at the bottom of the hole dug in the ground, cast the discarded concrete 3 on the chestnut stone 2 and lay the waterproof sheet 4 on the discarded concrete 3. .

Next, a reinforcing bar and a reinforcing angle (both not shown) are placed on the waterproof sheet 4, and a formwork 30 is placed on the discarded concrete 3 so as to surround the reinforcing bar and the reinforcing angle. At this time, as shown in FIG. 2 (b), the waterproof sheet 4 is
The surplus part is taken out of the formwork 30. And the formwork 30
The base concrete 5 is cast therein, and after the base concrete 5 is solidified, the asphalt mortar 6 is cast on the base concrete 5. In addition, this base concrete 5
When the asphalt mortar 6 is cast, the positioning holes 9 are formed at the same time.

Next, after removing the mold 30, the bottom plate 12 is placed and fixed on the asphalt mortar 6, and
The edge plate 10 to which the side wall 13 is welded and fixed in advance is arranged on the asphalt mortar 6 so as to surround the positioning holes 9 so as to surround the positioning holes 9. In addition, the upper surface of the bottom plate 12 is coated with the first lining material 15 in advance. In addition, the inner side surface of the side wall 13 is coated with a second lining material 21 in advance. By the way, after the edge plate 10 is arranged in an annular shape, the bottom plate 1
2 may be arranged.

Then, the anchor bolt 7 is inserted into the insertion hole 10 a of the edge plate 10, and the anchor bolt 7 is set in the positioning hole 9. Thereafter, the edge plate 10 is tightened by screwing the nut 7 a to the anchor bolt 7, and placed and fixed on the asphalt mortar 6. Thereafter, when the concrete block 8 is formed by placing concrete in the positioning holes 9, the state shown in FIG.

Next, the space between the first lining material 15 and the second lining material 21 is covered with a third lining material 22 and
Then, the third lining member 22 is fixed to the second lining members 15 and 21 by welding. Further, the skirt 23 is fixed by welding between the lower end on the outer surface side of the side wall 13 and the peripheral edge of the edge plate 10.

Next, after the ceiling wall 14 is welded and fixed to the upper edge of the side wall 13, an anticorrosion coating 24 is applied to the outer surfaces of the side wall 13 and the skirt portion 23. Then, after the waterproof sheet 4 is made to extend along the outer surfaces of the base concrete 5, the asphalt mortar 6, the edge plate 10, and the skirt portion 23, and the upper end of the waterproof sheet 4 is attached to the outer peripheral surface of the side wall 13, FIG. The underground tank 1 shown is completed. After that, the outer periphery of the side wall 13 is backfilled with earth and sand.

Next, the underground tank 1 constructed as described above
The operation of will be described. Since the waterproof sheet 4 is provided between the discarded concrete 3 and the base concrete 5, it is possible to prevent rainwater, groundwater, and the like that have permeated into the ground from entering the base concrete 5. Also, the bottom plate 12
Since the asphalt mortar 6 is provided between the edge plate 10 and the base concrete 5, corrosion of the bottom plate 12 and the back surface of the edge plate 10 can be prevented.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, since the waterproof sheet 4 is provided between the discarded concrete 3 and the base concrete 5, it is possible to prevent infiltration of groundwater or the like into the base concrete 5, so that the tank body 11 (particularly, metal) Corrosion of the edge plate 10 and the bottom plate 12), which are structural materials, can be prevented, and the durability of the underground tank 1 can be improved.

(2) In the present embodiment, since the asphalt mortar 6 is provided between the base plate 5 and the bottom plate 12 and the edge plate 10, the back surface of the bottom plate 12 and the edge plate 10 can be prevented from being corroded. Thus, the durability of the underground tank 1 can be improved.

(3) In the present embodiment, the waterproof sheet 4 and the asphalt mortar 6 complement each other with the waterproof-related functions, thereby exhibiting a synergistic effect, and maximizing the waterproof-related functions for the base concrete 5. Can be Therefore, the durability of the tank body 11 can be maintained well, and as a result, the durability of the underground tank 1 can be improved.

That is, since the asphalt mortar 6 has a waterproof function and also has excellent mechanical strength, when the tank main body 11 is mounted and fixed on the asphalt mortar 6, the asphalt mortar 6 The possibility that the waterproof function is impaired can be reduced. On the other hand, although the waterproof sheet 4 is inferior in mechanical strength to the asphalt mortar 6, but excellent in water resistance, the waterproof sheet 4 is provided on the lower side and the side of the base concrete 5 where there is no possibility of being damaged when the tank body 11 is placed and fixed. It is possible to reliably prevent infiltration of groundwater or the like into the base concrete 5 by being provided. Therefore, the durability of the tank body 11 can be reliably maintained in terms of water resistance and earthquake resistance, and as a result, the durability of the underground tank 1 can be improved.

(4) In the present embodiment, the base concrete 5 is provided with the waterproof sheet 4 which is a sheet-like material having flexibility.
, The base concrete 5 is coated according to its surface shape. Also, because of its flexibility,
The waterproof function of the waterproof sheet 4 is not likely to be impaired even during an earthquake or the like. Therefore, since the possibility that groundwater or the like intrudes into the gap between the base concrete 5 and the waterproof sheet 4 is reduced, the corrosion of the tank body 11 is reduced, so that the durability of the underground tank 1 can be improved. .

(5) In this embodiment, since the asphalt mortar 6 has excellent heat resistance, the asphalt mortar 6 is heated by the heat generated when the third lining material 22 is welded or when the skirt portion 23 is welded. Damage is reduced. Therefore, the durability of the tank body 11 can be reliably maintained from the viewpoint of water resistance, and as a result, the durability of the underground tank 1 can be improved.

Further, the waterproof sheet 4 is used as a base concrete 5
The third lining member 22 and the skirt portion 23 were welded and fixed in a state where they were disposed below. Therefore, since the heat generated at the time of each welding is hardly transmitted to the waterproof sheet 4, the damage of the waterproof sheet 4 due to the heat is reduced. Therefore, the durability of the tank body 11 can be reliably maintained from the viewpoint of water resistance, and as a result, the durability of the underground tank 1 can be improved.

The above embodiment may be modified as follows. -In the said embodiment, although asphalt mortar 6 was used as 1st waterproofing means, oil sand may be used as 1st waterproofing means. Also in this case, the durability of the tank body 11 can be reliably maintained in terms of water resistance and earthquake resistance, and as a result, an effect of contributing to the improvement of the durability of the underground tank 1 is obtained.

In place of the asphalt mortar 6, a waterproof sheet similar to the waterproof sheet 4 may be used as the first waterproof means. In this case, since the waterproof sheet as the first waterproof means has excellent water resistance, it is possible to reliably prevent the back surface of the bottom plate 12 and the back surface of the edge plate 10 from being corroded, and to improve the durability of the underground tank 1. The effect of being able to contribute is obtained.

Next, technical ideas other than the inventions described in the claims, which can be understood from the above embodiment and other examples, will be described below together with their effects. (A) In the waterproof structure for a tank according to any one of claims 3 to 5, the second waterproof means is a thermoplastic resin sheet disposed below the base portion. Construction.

Therefore, according to the invention described in (A), when the tank body is fixed to the base portion by welding, the heat generated at the time of welding is difficult to be transmitted to the second waterproofing means. Damage due to the heat is reduced.
Therefore, the durability of the tank body can be reliably maintained from the viewpoint of water resistance, and as a result, an effect of contributing to the improvement of the tank durability can be obtained.

(B) In a method of manufacturing a tank in which a tank body for storing a substance to be stored is mounted and fixed on a base portion, a step of casting concrete on flexible sheet-like waterproof means. And a step of arranging another waterproofing means on the base portion formed in the step, and after mounting and fixing the tank body on the other waterproofing means, the sheet-shaped waterproofing means is attached to the outer periphery of the tank body. A method for manufacturing a tank comprising a step of attaching.

Therefore, according to the invention described in (b), the entire base portion is wrapped by the respective waterproofing means, and the intrusion of water or the like from the outside into the base portion is reduced. Can be improved in terms of water resistance,
As a result, the effect of contributing to the improvement of the durability of the tank is obtained.

[0039]

According to the first aspect of the invention, the penetration of water and the like from the outside into the base portion is reduced, and the corrosion of the metal structural material of the tank body is reduced. Can contribute to improvement.

According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, each waterproofing means exerts a synergistic effect to maximize the waterproof-related function for the base portion. As a result, the durability of the tank body can be maintained satisfactorily, and as a result, the durability of the tank can be improved.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, the durability of the tank body is improved by the waterproof function and mechanical strength of the first waterproof means. In addition, it can be reliably maintained in terms of earthquake resistance, and as a result, it can contribute to improving the durability of the tank.

According to the fourth aspect of the invention, in addition to the effect of the third aspect of the invention, the durability of the tank body can be reliably maintained in terms of water resistance by the second waterproof means. As a result, the durability of the tank can be improved.

According to the fifth aspect of the invention, in addition to the effect of the third or fourth aspect, water or the like is externally supplied to the gap between the base portion and the second waterproofing means. Since the risk of intrusion is reduced, the corrosion of the tank body is reduced, which can contribute to an improvement in the durability of the tank.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of one embodiment embodied in an underground tank.

FIGS. 2A to 2C are front cross-sectional views of a main part showing a method of manufacturing an underground tank.

FIG. 3 is a front sectional view of a main part showing a waterproof structure of an underground tank.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Underground tank as a tank, 4 ... Second waterproofing means constituting waterproofing means, and waterproof sheet as a sheet-like material, 5
... base concrete as a base part, 6 asphalt mortar as a first waterproofing means constituting a waterproofing means, 10 ... an edge plate constituting a metal structural material, 11 ... a tank body, 12 ... constituting a metallic structural material Bottom plate, 16: water for fire extinguishing as stored substance.

Claims (5)

[Claims] In a waterproof structure of a tank in which a tank body for storing a substance to be stored is mounted and fixed on a base portion, the tank body surrounds the entire base portion on which the metal structural material of the tank body is mounted. The waterproof structure of the tank provided with waterproof means. 2. The waterproof structure for a tank according to claim 1, wherein said waterproof means is constituted by a plurality of types of waterproof means having different characteristics. 3. The waterproofing means, wherein the first waterproofing means provided between the base portion and the tank body has a higher mechanical strength than the second waterproofing means covering the other part of the base portion. 3. The waterproof structure for a tank according to claim 2, wherein: 4. The tank waterproofing structure according to claim 3, wherein the second waterproofing means has better water resistance than the first waterproofing means. 5. The waterproof structure for a tank according to claim 3, wherein the second waterproofing means is a sheet-like material having flexibility.