JP2001173263A - Constructing method for tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit an internal temporary scaffold in the construction of a concrete storage tank to attain the labor saving in a work field, shortening of the term of works, and the reduction in construction cost. SOLUTION: An anticorrosive FRP-made panel is set as an inner surface side placing form 2 on a reinforced concrete floor slab 1. An external scaffold 4, a reinforcement 6, an external form 5 and the like are constructed, and the inner part is filled with water 7. The internal placing form 2 is supported by this hydraulic pressure, and concrete 9 is placed therein. A floating scaffold 8 is made to float on the water surface and utilized as a working space or the like. This is repeated to continuously place concrete, and a roof is constructed to complete a tank of a prescribed height. According to this, conventional internal temporary scaffold, internal form support, and the like can be omitted, and this method can serve as water filling test. Therefore, the shortening of term of works, the reduction in construction cost, and the labor saving of work can be performed in the construction of a biologic reaction tank such as a tank for water, oil, chemical or the like, a digestion tank, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank construction method, and particularly to a water distribution tank for water supply, a storage tank for oil and chemicals, or a biological reaction tank such as a sludge treatment tank and a digestion tank. The present invention relates to a method for constructing a tank suitable for:

[0002]

2. Description of the Related Art In general, a water distribution tank or a tank for storing a chemical solution is composed of a flat disk-shaped bottom plate, a vertical cylindrical side wall thereon, and a dome-shaped roof. , Oil, chemicals, etc. Therefore, after the tank is completed, a water filling test is performed to check for water leakage.

[0003] The structure of the tank is such that the side walls are made of prestressed concrete (so-called PC: Prestressed concrete).
Concrete, and the roof and bottom plate are generally made of reinforced concrete. In the construction method, for example, when constructing a cylindrical side wall, an internal scaffold and an external scaffold are assembled, wall reinforcement is provided, an inner formwork and an outer formwork are installed, and wall concrete is poured.

[0004] These steps are repeated step by step, and concrete is spliced to construct a concrete wall having a predetermined height. As a construction method of this kind of tank, for example, there is a technique described in Japanese Patent Application Laid-Open No. 11-35094 by the present inventors.

In a sewage treatment plant, water and sludge are separated from the incoming sewage by sedimentation or the like, and the extracted sludge is removed by gasification of organic components by a biological reaction in a digestion tank at a predetermined temperature. The remaining sludge is dehydrated and dried for incineration. The extracted organic gas is burned and used as an energy source.

As such a digestion tank, there is a concrete tank having a longitudinal cross section of an egg shape, a turtle shape, a flat large-diameter cylindrical shape, or the like. The construction method is the same as that for the storage tank described above. For example, in the case of a tank wall, an internal scaffold and an external scaffold are assembled, reinforcing bars are laid, a formwork is installed inside and outside, concrete is placed, and Prestress is introduced by steel.

Further, a heat insulating material for keeping heat and an exterior material of an external finish are installed on the outer wall. In addition, a corrosion inhibitor is applied to the inner wall surface, and after that, mechanical equipment inside the tank,
It is normal to carry out construction such as piping. As a method of constructing this type of reaction tank, for example, Japanese Patent Application Laid-Open No.
There is a technique disclosed in Japanese Patent No. 6538.

The side walls of these PC tanks and tank walls such as digestion tanks are constructed of concrete.
m. For the construction, temporary scaffolding is assembled inside and outside along the wall to be constructed, wall reinforcement and inner and outer formwork are installed using this temporary scaffold, and support works to withstand the concrete casting pressure are implemented Then, concrete is poured to a certain height. It is common practice to repeat this procedure to construct a concrete wall of a predetermined height. In addition, the construction of the tank roof is usually performed using this internal scaffold.

[0009] In either case of a drinking water storage tank or a sludge treatment tank, the inner wall surface of the tank is subjected to a treatment such as painting according to each. Therefore, as described in the above publication, FRP (F
iber Reinforced Plastics)
For example, a method of manufacturing a driving form in advance with such a material and embedding it in concrete as a tank inner wall surface is also adopted.

[0010]

In the above prior art,
Temporary scaffolding on the inside was indispensable for constructing tall concrete walls.

[0011] Further, it is necessary to provide a supporter capable of withstanding the concrete placing pressure, and a considerable amount of these temporary scaffolding and temporary supporter-related materials alone is required. This was one of the major factors in construction costs, such as securing storage space and material costs. Further, these tanks had to be subjected to a water filling test as a final step to check for leakage of the liquid stored therein.

An object of the present invention is to solve the above-mentioned problems and to provide an internal temporary scaffold in a tank constructed as a biological reaction tank such as a water distribution tank, an oil or chemical solution tank, or a digestion tank for sludge treatment. By omitting, it is to realize labor saving of a construction site, shortening of a construction period, and reduction of a construction cost.

[0013]

In order to solve the above-mentioned problems, the present inventors have paid attention to the fact that most of the concrete casting pressure can be supported by water pressure, and have focused on a driving method that is embedded in the inner side of the tank side wall. A device was devised to support the formwork with the water pressure applied to the inside.

That is, in a construction method of a tank for storing water, oil, chemicals, etc., or a biological reaction tank such as a digestion tank for treating sewage, sewage, sludge, etc.
After installing the inner-side casting formwork for placing the side wall concrete, water is applied to the inside to support the inner-side casting form by water pressure and to support the concrete placing pressure. I made it.

That is, reinforcing bars and formwork are installed at predetermined heights, water is spread on the inside, and concrete is poured.
By repeating this, a concrete wall having a predetermined height can be constructed. This eliminates the need for a conventional supporter that supports the inner-side driving formwork, and also allows a floating buoyant body on the water surface to be used as a scaffold or material storage area, thereby omitting temporary scaffolding in the tank. it can.

In this case, the use of a punching mold having corrosion resistance on the surface on the inner side of the tank makes it possible to omit the anticorrosion coating on the inner wall of the tank, so that a scaffold for the inner wall anticorrosion work is also unnecessary. As such an inner wall material, a member having both a heat insulating material and an anticorrosive material, such as a composite material in which FRP or a plastic foam is reinforced with long glass fibers or the like, may be used as the driving mold.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
(A) A tank for storing water and the like, and (B) a biological reaction tank such as a sludge treatment tank will be described with reference to the drawings.

(A-1) Construction Method of Storage Tank Hereinafter, an embodiment in which the method of the present invention is applied to a water distribution tank for water supply or a tank for storing oil, chemicals, or the like will be described. This type of tank is made of PC
A corrosion-resistant material having corrosion resistance and strength resistance, for example, an inner wall material made of FRP is used as a driving form (also referred to as a buried form).

First, as shown in FIG. 1, an FRP panel constituting an inner wall is set as an inner-side driving form 2 on a reinforced concrete bottom slab 1 so that the tank has a cylindrical horizontal section. . Epoxy coating 3 is applied to the inner surface of the bottom plate 1. Of course, an anticorrosive material may be used to omit the painting.

Next, as shown in FIG. 2, an external scaffold 4 is constructed, a reinforcing bar 6 on the side wall of the tank and a PC steel wire (not shown) are laid, and an external formwork 5 is built. Next, water 7 is put in the installed inner surface driving formwork 2. By this water pressure, the concrete 9 is cast by supporting the inner-side driving formwork 2. The floating scaffold 8 is floated over almost the entire surface of the water and used as a work space. Floating scaffold 8
Can be replaced with a raft or rubber boat.

By repeating this procedure, concrete is spliced to complete the cylindrical PC wall 10. Since the inner-side driving form 2 made of FRP has corrosion resistance, it can be formed on the inner wall of the tank without performing anticorrosion coating. As such an inner wall material, a member having both heat insulation performance and anticorrosion performance, such as a composite material in which a plastic foam is reinforced with long glass fibers or the like, may be used as the driving mold.

As shown in FIG. 3, when the side wall 10 is completed, the FRP using the floating scaffold 8 on the water surface is used.
Assemble the roof dome 11 such as a panel. Next, the external scaffold 4 is dismantled to complete the tank. In addition, since the water filling test can be performed as it is with the water 7 filled in the tank, there is no need to perform the water filling test again.

According to the tank construction method of the present invention described above, the following effects are obtained. (1) The floating scaffold,
By floating a raft, boat, etc., it can be used for work space and material storage. Therefore, the conventional internal scaffold can be omitted, and the construction period can be shortened and the construction cost can be reduced.

(2) By utilizing the water pressure applied to the inside of the tank, it is possible to omit a conventional support work for supporting the internal formwork. Therefore, it is possible to greatly reduce labor of materials and labor.

(3) This type of tank is subjected to a water filling test in the final step. However, since the tank is filled with water from an early stage of construction, the tank can be substituted for the water filling test, and the conventional water filling test in the final step can be omitted.

(A-2) Reference Example of Storage Tank A reference example of this type of tank construction method will be described with reference to FIGS. As shown in FIG. 4, first, a slab 21 made of reinforced concrete is constructed. Next, as shown in FIG. 5, the inner scaffold 22 and the outer scaffold 23 are assembled, the side walls are arranged, the inner driving formwork 24 and the outer formwork 25 are erected, and the concrete 26 is cast. This procedure is repeated until the concrete reaches a predetermined height.

Next, as shown in FIG. 6, when the side wall 27 is completed, the internal scaffold 22 is further assembled, and the roof dome 28 is constructed. After the roof dome is completed, as shown in FIG. 7, for example, an epoxy resin is painted as the anticorrosion work 29 on the inner wall, and the inner and outer scaffolds 22 and 23 are dismantled. Finally, as shown in FIG. 8, water 30 is filled, and a water filling test is performed to complete the tank.

As can be understood from the above description, according to the tank construction method which is an example of the present invention, compared with the reference example,
Since the internal scaffold can be omitted completely, the process can be significantly shortened, and the cost can be reduced, for example, by eliminating the need for the scaffold and related materials.

(B-1) Construction Method of Biological Reaction Tank Next, the method of the present invention is applied to a biological reaction tank such as a concentration tank, a digestion tank, an anaerobic sewage treatment tank, a sewage sludge treatment tank, or a denitrification tank. As an example, a case where the present invention is applied to a digestion tank will be described. In general, this type of digestion tank generally has a turtle-shaped vertical section.
In the following, the tank is also referred to as a tank.

First, as shown in FIG. 9, a ground 51 is excavated, reinforced concrete is cast, and a mortar-shaped lower conical portion 52 is constructed. F as a punching formwork on the inner surface of a mortar
If an anticorrosion material having strength and corrosion resistance, such as RP, is used, the inner anticorrosion can be omitted. Of course, an anticorrosive coating 53 such as epoxy may be applied to the inner surface of the mortar.

Next, as shown in FIG. 10, the cylindrical portion of the side wall of the tank is constructed. On the inner surface side of the tank (tank), a driving form 54 that also serves as an anticorrosive inner wall material is installed. Side wall reinforcement 5
5 is arranged, a normal external formwork 56 is installed, and a side wall concrete 57 is poured.

At this time, according to the present invention, the water 58
To support the inner side driving formwork 54 by water pressure. Thereby, the conventional internal scaffolding and support work can be omitted. Further, a floating scaffold 59 as a buoyant body is floated on water 58 stretched in the tank, and is used as a work space. Of course, floating scaffold 5
9 can be replaced by another buoyant body such as a raft or rubber boat.

As shown in FIG. 11, when the side wall work is completed, the upper conical portion is constructed. An anticorrosion-resistant upper inner wall material 61 is suspended and placed on the side wall cylindrical portion 60 where concrete has been cast. The upper inner wall material 61 may be the same as the lower conical inner wall material.

The upper inner wall material 61 is used as the inner driving formwork 61, the upper reinforcing bar 62 is arranged, the outer formwork 63 is installed, the upper concrete 64 is driven, and the outer formwork 63 and the outer scaffold 65 are dismantled. Then a digestion tank is constructed. At this time, the water pressure in the tank is used to support the inner-side driving formwork, and the floating scaffold floating on the water is used for a work space or a material storage space.

According to the above-described method, the following effects can be obtained. (1) The floating scaffold can be floated on the water in the tank, so that it can be used for work space and material storage. Therefore, the conventional internal temporary scaffolding can be omitted, so that the construction period is shortened and the construction cost is reduced.

(2) By utilizing the water pressure applied to the inside of the tank, a support work for supporting the internal form can be omitted. Therefore, it is possible to save labor of materials and labor and shorten the construction period.

(3) In this type of reaction tank, a water filling test is performed in the final step. However, since water is filled from an early stage of construction, it can be substituted for the water filling test, and the water filling test in the final step conventionally performed can be omitted. .

(B-2) Reference Example of Biological Reaction Tank Here, a reference example of a construction method for this type of reaction tank will be described. The same components as those in the above embodiment are denoted by the same reference numerals.

First, as shown in FIGS. 12 and 13, a ground 51 is excavated, a reinforced concrete 52 is poured, a lower conical portion is constructed, and an anticorrosion work 53 is performed on the inner surface. next,
Assemble the internal scaffold 70. The inner wall material 71 is assembled using the internal scaffold 70, and this is used as the internal driving formwork 71. On the outside, after assembling the external scaffold 65 and arranging the reinforcing bar 55,
A normal external formwork 56 is installed, and reinforced concrete 57 on the side wall is cast.

As shown in FIG. 14, the upper conical portion is further assembled with the inner scaffold 70 and the outer scaffold 65, and the upper inner wall material 6 is placed on the side wall cylindrical portion 60 in which concrete is cast.
1 is suspended and installed. The upper inner wall material 61 is used as an internal driving form, an upper reinforcing bar 62 is arranged, an external form 63 is installed, and an upper concrete 64 is driven.

Next, as shown in FIG.
Using 0, the anticorrosion coating 71 on the inner surface of the tank is performed. After that, as shown in FIG. 16, the internal scaffold 70 is disassembled, water 72 is filled in the tank, and a water filling test for confirming the presence or absence of water leakage is performed. On the other hand, as shown in FIG.
After carrying out the heat insulation cladding to install the heat insulating material 73 on the outer wall,
The external scaffold 65 is dismantled.

As can be seen from the above description, according to the method for constructing a reaction tank, which is an example of the present invention, the internal scaffold can be omitted completely as compared with the reference example, so that the process can be greatly shortened. Costs can be reduced, for example, by eliminating the need for scaffolding and related materials.

[0043]

According to the present invention, as described above, the present invention is constructed as a water distribution tank, a storage tank for oil or chemicals, LNG, LPG, or the like, or a biological reaction tank such as a digestion tank for sludge treatment. In the tank, the inner side driving formwork can be supported by filling the inside with water, and the concrete placing pressure can be supported by the water pressure, so that the internal temporary scaffolding and support work can be omitted. Therefore, labor saving at the construction site, shortening of the construction period, and reduction of the construction cost can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a bottom slab in one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a reinforced concrete side wall work in one embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing construction of a roof dome in one embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a bottom slab in a reference example.

FIG. 5 is a longitudinal sectional view showing a reinforced concrete side wall work in a reference example.

FIG. 6 is a longitudinal sectional view showing the construction of a concrete roof dome in a reference example.

FIG. 7 is a longitudinal sectional view showing an inner surface anticorrosion work in a reference example.

FIG. 8 is a longitudinal sectional view showing a water filling test in a reference example.

FIG. 9 is a longitudinal sectional view showing construction of a lower conical portion in another embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing a reinforced concrete side wall work according to another embodiment of the present invention.

FIG. 11 is a longitudinal sectional view showing construction of an upper conical portion in another embodiment of the present invention.

FIG. 12 is a longitudinal sectional view showing construction of a lower conical portion in another reference example.

FIG. 13 is a longitudinal sectional view showing a reinforced concrete side wall work in another reference example.

FIG. 14 is a longitudinal sectional view showing construction of an upper conical portion in another reference example.

FIG. 15 is a longitudinal sectional view showing an internal anticorrosion coating in another reference example.

FIG. 16 is a longitudinal sectional view showing a water filling test in another reference example.

FIG. 17 is a longitudinal sectional view showing a heat insulating cladding in another reference example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottom slab 2 Inner side driving formwork 4 External scaffolding 5 External formwork 6 Side wall reinforcement 7 Water 8 Floating scaffolding 9 Casting concrete 10 Concrete wall 11 Roof dome 22 Internal scaffolding 23 External scaffolding 52 Lower conical part 53 Anticorrosion coating 54 Inner side Driving form 55 Side wall reinforcement 56 External form 57 Side wall concrete 58 Water 59 Floating scaffold 60 Side wall cylindrical part 61 Corrosion-resistant upper inner wall material 62 Upper reinforcement 63 External form 64 Upper concrete 65 External scaffold 70 Internal scaffold

Claims (6)

[Claims] 1. An inner-side casting form is installed at a side wall concrete casting portion of a tank, and water is filled inside the inner-side forming form, and the inner-side driving is performed by a water pressure of the water. Construction method for tanks supporting formwork. 2. A tank for installing an inner surface driving form on a side wall concrete casting portion of a tank and then filling the inside of the inner surface driving form with a working buoyant body in the water. Construction method. 3. The tank construction method according to claim 2, wherein the work buoyant body is used for a work scaffold or a material storage space. 4. The construction method for a tank according to claim 1, wherein the inner surface side driving form has an inner surface having corrosion resistance. 5. The water tank, agricultural water, LN
The tank according to any one of claims 1 to 4, which is a tank for storing any one of G, LPG, oil, and a chemical solution, or a biological reaction tank for treating any one of sewage, sewage, and sludge. Construction method. 6. A tank constructed by the construction method according to claim 1.