JPH052598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a prefabricated storage tank suitable for use in the sludge concentration process of small-scale sewage treatment facilities, and a construction method thereof.

[Background Art] For example, in a sewage treatment facility, a sludge concentration storage tank is installed as equipment for further concentrating sludge produced in a settling tank. This type of sludge concentration storage tank has a box-shaped structure including a bottom plate, a peripheral wall formed continuously on the bottom plate, and a top wall provided at the upper end of the peripheral wall. Conventional sludge thickening and storage tanks are generally constructed using so-called cast-in-place concrete.

[Problems to be Solved by the Invention] However, in order to construct such a storage tank using cast-in-place concrete, large-scale form work and reinforcing work on the site are indispensable, which makes the work complicated. Therefore, there are problems in that it is difficult to shorten the construction period and reduce costs, and there are certain limits to quality control.

The present invention was made with the aim of solving these problems, and it is possible to construct a surrounding wall body that can easily accommodate various capacities using one type of U-shaped concrete block, and also,
Because prestressing is introduced around the entire circumference of the surrounding wall, it is possible to guarantee especially high quality and reduce complicated work on site. The purpose of the present invention is to provide a construction method that can be assembled without causing inconvenience or deterioration in the strength of the surrounding wall.

[Means for solving the problem] In order to achieve the object, the first invention has the following features:
The prefabricated storage tank consists of a bottom plate made of precast concrete blocks, a circumferential wall made of precast concrete blocks that is rectangular in plan view and placed in multiple stages on the bottom plate, and a lid attached to the opening at the top of the circumferential wall. A top plate made of a precast concrete block, and connecting means for connecting the bottom plate, the peripheral wall body, and the top plate, respectively, the peripheral wall body being connected to a pair of blocks having the same shape. The U-shaped concrete blocks are joined into a housing shape, and first and second PC steel rods are used to connect the two U-shaped concrete blocks.
Prestress is applied to the entire circumference of the surrounding wall by pre-buried PC steel rods in each of these U-shaped concrete blocks. And the first PC
A steel rod is housed within the peripheral wall of one U-shaped concrete block, and a second PC steel rod is housed within the peripheral wall of the other U-shaped concrete block, and these first and second PC steel bars It is characterized in that the rods are connected by a coupler at the joining position of both U-shaped concrete blocks.

In addition, in the second invention, when constructing such a storage tank, first, a bottom plate made of precast concrete blocks is laid, and a pair of U-shaped concrete blocks of the same shape are joined onto this bottom plate to form a housing. A plurality of sets of circumferential walls, each of which is approximately square in plan view, are arranged in a row in alternating directions horizontally by 90 degrees so that their joints do not coincide, and the upper ends of the circumferential walls are This is a construction method in which a top plate made of precast concrete blocks is installed as a cover, and when the pairs of U-shaped concrete blocks are butted together,
A first PC steel rod inserted into one U-shaped concrete block and a second PC steel rod inserted into the other U-shaped concrete block are connected via a coupler. , second
By applying a certain tension to the PC steel rods, the two U-shaped concrete blocks are joined together, and the first and second PC steel rods and the PC steel that had been buried in each of the U-shaped concrete blocks in advance are connected. It is characterized in that a prestress is applied to the entire circumference of the peripheral wall body by means of a rod.

[Function] With this kind of storage tank, all you need to do is to assemble the bottom plate, surrounding wall body, and top plate, which have been manufactured in advance at a factory, on site, so there is no need for complicated form work or reinforcing steel work on site. It can be omitted and a finished product can be obtained easily and quickly. This product can correspond to various storage capacity specifications by appropriately selecting the number of stacked stages of the peripheral wall body. This surrounding wall is square in plan view, and is constructed by stacking up the required number of stages of joined U-shaped concrete blocks of the same shape, so only one type of U-shaped concrete blocks can meet all requirements. can respond to Therefore, it is possible to prevent manufacturing and parts management from becoming complicated, and also to simplify on-site construction. Moreover, although the surrounding wall is made of U-shaped concrete blocks joined together,
Since the entire circumference is prestressed, it can exhibit high strength. Since the prestressing system effectively utilizes the PC steel rods used to join the U-shaped concrete blocks, it can be constructed with a small number of parts.

Furthermore, according to the storage tank construction method described above, the peripheral wall, which tends to be particularly bulky, can be delivered to the site in two parts, that is, in the form of a U-shaped concrete block, making transportation easier. It is possible to facilitate the Moreover, since the surrounding walls formed by joining the U-shaped concrete blocks into a housing shape are arranged in a row in alternating directions so that the joined parts do not match, the walls adjacent to each other above and below can Comrades will mutually reinforce the joints of the U-shaped concrete blocks. Therefore, in combination with the fact that prestress is applied to the entire circumference of each peripheral wall, it is possible to effectively suppress the disadvantage that the strength of each peripheral wall decreases due to the two-part structure. .

Furthermore, in the present invention, the PC steel rods that connect U-shaped concrete blocks are not made to be long enough to correspond to the length of the peripheral wall after connection, but can be accommodated in the portion corresponding to the peripheral wall of the concrete blocks before joining. Since it is divided into two parts, when joining U-shaped concrete blocks in an excavated hole, a long PC can be used around the outside of the concrete block.
There is no need to level the steel rod and insert it into the block. Therefore, there is no need to excavate the ground to a size twice the size of the tank, and the excavation and backfilling operations can be simplified.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 14.

FIG. 1 is a schematic plan view showing an assembled storage tank used for sludge concentration, etc., FIG. 2 is a front sectional view thereof, and FIG. 3 is a perspective view thereof. As shown in these drawings, this storage tank is
Bottom plate A made of precast concrete block
Surrounding walls B ₁ to _{B 3} made of precast concrete blocks and having a square shape in plan view are mounted on this bottom slab A in multiple stages, and tops are provided at the upper end openings of the surrounding walls B ₁ to _{B 3} . It is equipped with version C.

As shown in Fig. 4, the bottom plate A is made by joining a pair of flat concrete blocks 1 and 2 made of reinforced concrete, and the two flat concrete blocks 1 and 2 are joined together using high-tensile bolts 3. It is done using. More specifically, a metal connecting fitting 4 is embedded in the joint end of each of the flat concrete blocks 1 and 2.
As shown in FIG. 5, the connecting fitting 4 includes a thick plate-shaped base plate part 5 and a thin plate-shaped cover part 6 connected to the base plate part 5. Anchor bars 7 are fixed to the plate portion 5. The connecting fitting 4 has the base plate portion 5 exposed on the joint end surfaces 1a and 2a of the flat concrete blocks 1 and 2, and an opening on the upper surface of the concrete blocks 1 and 2. It is buried. A bolt hole 8 is bored in the base plate portion 5, and the two flat concrete blocks 1 and 2 are connected to each other by a high-tensile bolt 3 inserted through the bolt hole 8. After fixing the bolts, the connecting fittings 4 are filled with mortar (not shown).

On the other hand, the surrounding walls B ₁ to _{B 3} are formed by joining a pair of U-shaped concrete blocks 9 and 10 of the same shape into a housing shape, as shown in FIGS. 6 to 8. . U-shaped concrete blocks 9 and 10 are made of reinforcing bars (not shown) and PC steel rods 1.
It is a prestressed concrete structure with 2 and 2 inside, and both U-shaped concrete blocks 9 and 10.
As shown in Fig. 6, the comrade-to-joint joint is made of PC steel rod 1.
3,14. That is, with both U-shaped concrete blocks 9 and 10 brought together, the first PC steel rod 13 inserted into one block 9 and the second PC steel rod 14 inserted into the other block 10. are connected via a coupler 15, and with tension applied to these PC steel bars 13, 14, a nut 16 is fixed to the PC steel bar 14 to tightly connect both blocks 9, 10. . Therefore, this peripheral wall body B ₁ to _{B 3}
, a prestress is applied to the entire circumference by these PC steel bars 13, 14 and the pre-buried PC steel bar 12. FIG. 9 is an enlarged plan sectional view showing the joint portion of both blocks 9 and 10, in which 17 is a sealing material made of water-expandable rubber;
8 is a polyurethane resin joint, and 19 is a mortar joint.

Further, as shown in FIG. 1, the top plate C is formed by joining a pair of flat concrete blocks 21 and 22 made of reinforced concrete, and the joining of both flat concrete blocks 21 and 22 is as described above. As with bottom plate A, high tension bolts 3 are used.

Then, the bottom plate A and the lowermost peripheral wall body B ₁ are connected by the first connecting means 23, and the peripheral wall bodies B ₁ to _{B 3} are tightly joined together using the second connecting member 24, and then The upper peripheral wall body _B3 and the top plate C are connected by a third connecting means 25. The first connecting means 23 is shown in FIG.
As shown in FIG. 1, a pair of insert nuts 27 and 28 are buried adjacent to each other in the outer periphery of the bottom plate A and the lower end outer periphery of the peripheral wall B _1. A connecting iron plate 29 is attached to the opening end face, and bolts 31 and 32 passed through the connecting iron plate 29 are screwed into both the insert nuts 27 and 28. As shown in FIG. 3, a plurality of sets of the connecting means 23 are provided at required intervals in the lateral direction. Further, the second connecting means 24 connects each of the peripheral wall bodies B ₁ to _{B 3} as shown in FIGS. 3 and 6.
Connecting boxes 33 are buried in an open state on the inner surface of the four corners of the connecting box 33 and the connecting boxes 33 are buried within the wall thickness of the four corners of each of the peripheral walls _{B 1 to B 3} . An insertion hole 36 is provided to communicate the upper and lower end surfaces 34 and 35, and the lower end threaded portion 38 of the vertically tightened PC steel rod 37 inserted into the insertion hole 36 is used for connecting the lower peripheral wall body B ₁ or B ₂ . At the same time, by positioning the upper end screw portion 39 within the connecting box 33 of the upper peripheral wall body B ₂ or B ₃ and fixing the nut 41 to each of the screw portions 38 and 39, Peripheral wall body B ₁ adjacent to
, B ₂ and B ₃ are connected to each other. Furthermore, the third connecting means 24
As shown in the figure, recesses 42 are provided on the upper surface of the four corners of the top plate C, and these recesses 42 and the insertion holes 36 of the peripheral wall body B ₃ are communicated via through holes 43. 36 and through hole 43
Lower end screw part 45 of vertically tightened PC steel rod 44 inserted inside
is located in the connection box 33 of the uppermost peripheral wall member _B3 , and the upper end screw portion 46 is made to protrude into the recess 42, and both screw portions 45, 46
The nut 47 is fixed to the hole.
After fixing the nut, the connecting box 33 and the recess 42 are also filled with mortar (not shown).

In addition, FIG. 12 shows the joint part a of the flat concrete blocks 1 and 2 constituting the bottom slab A, and the flat concrete blocks 21 and 22 constituting the top slab C.
joint part e, joint part f between bottom plate A and peripheral wall body _B1 ,
It is an enlarged sectional view showing the joint g between the surrounding wall bodies B ₁ to _{B 3} and the joint h between the peripheral wall body B ₃ and the top plate C, in which 48, 49, 50, 51, and 52 are water-expandable rubber. 54, 55, 56, and 57 are polyurethane resin joints, and 58, 59, and 60 are mortar joints. In addition, 62 is a sloped floor made of cast-in-place concrete provided on the bottom slab A, 63 is an opening hole drilled in the top slab C for attaching a manhole cover, 64, 6
5 is a piping opening.

Next, a method of constructing this storage tank will be explained. First, precast flat concrete blocks 1, 2, 21, 22 and U-shaped concrete blocks 9, 10 manufactured in a factory or the like are carried to the site. At the site, first, the ground 70 is excavated, and foundation stone 71 and foundation concrete 72 are placed at the bottom. Then, a mortar 73 is laid on the foundation concrete 72, and the bottom slab A is laid in a predetermined position. Since the bottom plate A is divided into two parts as described above into a pair of flat concrete blocks 1 and 2, these blocks 1 and 2 are joined at predetermined positions with high-tensile bolts 3. Next, the first stage peripheral wall body _B1 is installed on the bottom plate A. Peripheral wall body B ₁
It is also divided into two U-shaped concrete blocks 9 and 10 that form a pair of identical shapes.
First, both the U-shaped concrete blocks 9, 1
0 is assembled on the bottom plate A into a housing shape. and,
At the joint part b of both blocks 9 and 10,
The first and second PC steel rods 13 in both blocks,
14 is connected with Katsupura 15, and the connected PC
The steel rods 13 and 14 are tensioned with a predetermined tension using a hydraulic jack or the like, and the nuts are fixed. After that,
The bottom plate A and this peripheral wall body B ₁ are connected by bolts 31, 3.
Connect by 2. Next, the second stage surrounding wall body B ₂ ,
It is assembled in the same manner as the surrounding wall body _B1 . Thereafter, the first-stage peripheral wall body B ₁ and the second-stage peripheral wall body B ₂ are fastened together using vertically tightened PC steel rods 37 with a predetermined tension. That is, as shown in FIG. 13, _the lower end threaded portion 38 and the upper end threaded portion 39 of the vertically tightened PC steel rod 37 inserted into the insertion holes 36 of both the surrounding wall bodies B 1 and B ₂ are connected to the respective surrounding wall bodies B _{1 , B 2} . , B ₂ connection box 3
3, and a nut 41 is provisionally screwed into the lower end threaded portion 38 and upper end threaded portion 39 via an anchor plate 40, respectively. After that, 2
The tension rod 74 inserted into the insertion hole 36 from the upper end side of the circumferential wall body B ₂ of the stage is connected to the upper end screw portion 39 of the vertically tightened PC steel rod 37 via a connector 75 . Then, the tension rod 74 is pulled upward with a predetermined force by the hydraulic jack 76, and in this state, the nut 41 screwed into the upper end screw portion 39 is tightened using a wrench or the like. Thereafter, the tension rod 74 and the connector 75 are removed, and the third stage surrounding wall body B ₃ is placed on this surrounding wall body B ₂ . The third-stage peripheral wall body _B3 is also assembled in the same manner as the second-stage peripheral wall body _B2 , and is tightly connected to the second-stage peripheral wall body _B2 . After assembling peripheral walls B ₁ to B ₃ , the top peripheral wall
Set the top plate C in the upper opening of _B3 . Top version C
, since it is divided into two pairs of flat concrete blocks 21 and 22, these blocks 21 and 22 are connected to high-tensile bolts 3 at predetermined positions.
Join at. Next, a longitudinally tightened PC steel rod 44 is inserted from the through hole 43 of the top plate C into the insertion hole 36 of the peripheral wall body _B3 .
is inserted, and a nut 47 is screwed into the lower end threaded portion 45 of the PC steel bar 44 via the anchor plate 40 in the connection box 33 of the peripheral wall body _B3 , and in the recess 42 of the top plate C. , A nut 47 is screwed into the upper end screw portion 46 of the PC steel bar 44 via the anchor plate 40. Then, this nut 47 is tightened with a wrench or the like to fix the top plate C on the peripheral wall body _B3 .

The surrounding walls B ₁ to _{B 3} are made of U-shaped concrete blocks 9 and 1, as shown in FIG.
The connecting portions b, c, and d of 0 are alternately arranged in different directions in the horizontal direction by 90 degrees so that they do not coincide with each other. In this embodiment, the bottom plate A and the peripheral wall body B ₁ are further oriented at 90 degrees with respect to each other so that the joint part a of the bottom plate A and the joint part b of the lowest peripheral wall body B ₁ do not match. At the same time, the top plate C and the peripheral wall body B ₃ are connected at 90 degrees to each other so that the joint part e of the top plate C and the joint part d of the uppermost peripheral wall body B ₃ do not match. They are installed in series in different directions.

With this kind of configuration, the finished product can be obtained by combining the bottom plate A, the plurality of peripheral walls B ₁ to B ₃ and the top plate C on site, so there is no need for large-scale on-site work. There is no need for formwork or reinforcing steel work, which greatly reduces the complexity of on-site work. Further, the bottom plate A, a plurality of peripheral wall bodies
_B1 to _B3 and top plate C can be manufactured using mass production methods during construction work, etc., so quality control can be adequately controlled, and they have high dimensional accuracy and are easy to reduce costs. It can provide a storage tank. Moreover, the peripheral wall bodies B ₁ to _{B 3}
By appropriately changing the number of stages, various tank capacities can be selected, and storage tanks of various capacities can be obtained without changing the design or remanufacturing formwork, etc. There is a convenience. Furthermore, the surrounding wall bodies _B1 to _B3 are square in plan view, and are made by stacking up a required number of stages by joining a pair of U-shaped concrete blocks 9, 10 of the same shape. Although the numbers are different, only one type of U-shaped concrete blocks 9 and 10 can meet all demands.

Moreover, according to the construction method of the storage tank as described above, the surrounding wall body B ₁ - which tends to be particularly bulky.
Since B ₃ can be delivered to the site in a divided state, that is, in the state of U-shaped concrete blocks 9 and 10, transportation can be facilitated. Furthermore, the surrounding walls B ₁ to _{B 3} are formed by joining the U-shaped concrete blocks 9 and 10 into a housing shape.
are arranged in a row with the directions alternately different by 90 degrees so that the joint parts b, c, and d do not match, so that the vertically adjacent surrounding walls B ₁ to _{B 3} form a U-shape. The joint parts b, c, and d of the concrete blocks 9 and 10 are mutually reinforced.
That is, by doing this, during assembly, the weight of the concrete blocks 9, 10 will cause the joints b, c, d of the lower concrete blocks 9, 10 to
The difference in height between the top and bottom disappears. Moreover, the joint parts b, c, and d are no longer concentrated in one place. Therefore, since each of the peripheral wall bodies B ₁ to B ₃ is made into a two-part type, it is possible to effectively suppress the inconvenience that the shape is disordered and the strength thereof is reduced.

Note that the number of stacked peripheral wall bodies is of course not limited to that shown in the illustrated example, and can be changed as appropriate depending on the required tank capacity.

Further, the connecting means for connecting the bottom plate, the peripheral wall body, and the top plate are not limited to those of the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

Furthermore, it goes without saying that the U-shaped concrete block referred to in the present invention is not limited to that of the embodiment described above, and for example, as shown in FIG. They may have different lengths. Therefore, when constructing the tank according to the first invention using the U-shaped concrete block 83 having such a shape, for example,
It is also possible to stack the stacks one after another by joining the odd-numbered rows as shown in FIG. 16a and the even-numbered rows as shown in FIG. 16b.

[Effects of the Invention] As detailed above, the storage tank according to the first invention has its bottom plate, peripheral wall, and top plate each made of precast concrete blocks, thereby eliminating the complexity of on-site work. It is possible to shorten the construction period and reduce costs. In addition, since the surrounding wall is made up of a plurality of surrounding wall bodies, it is possible to easily manufacture tanks with various capacities by appropriately selecting the number of stages in which the surrounding wall bodies are stacked. is obtained. Furthermore, although the surrounding wall body is made of U-shaped concrete blocks joined together, prestress is applied to the entire circumference, so that it can exhibit high overall strength. Therefore, there is no problem that there is a weak portion in a part of the peripheral wall, and the device has high reliability and durability. Furthermore, since the PC steel rods used to join the U-shaped concrete blocks are also used as a material for applying prestress, the number of parts can be reduced and implementation can be facilitated.

Furthermore, according to the construction method according to the second invention, at least the peripheral wall body can be delivered to the site in a state in which it is divided into two pairs of U-shaped concrete blocks, which makes it difficult to carry them together because they are precast. This problem can be effectively prevented. Furthermore, since the peripheral wall bodies are substantially square in plan view, it is possible to easily install them one after another with their orientations different in the horizontal direction by 90 degrees so that their joint portions do not coincide with each other. In this way, the vertically adjacent surrounding walls mutually reinforce the joints of the U-shaped concrete blocks. In particular, by making the orientations different by 90 degrees, there is no need to measure the mounting angle etc. of the U-shaped concrete blocks, which effectively prevents the complexity of construction. The joints of the body will be spaced apart most effectively, and each joint will have excellent reinforcement. Therefore, in combination with the fact that prestress is applied to the entire circumference of each peripheral wall, it is possible to effectively prevent the inconvenience of reducing the strength of each peripheral wall due to the two-part structure. It is possible to construct a high-strength storage tank.

Furthermore, in the present invention, the PC steel rod for connection and prestressing is made into a two-piece type that can be accommodated in each U-shaped concrete block, so the size of the excavated hole in which the storage tank is buried can be minimized. can be made into Therefore, the special effect of reducing the number of man-hours required for excavating and backfilling the ground and speeding up construction is achieved.

[Brief explanation of the drawing]

1 to 14 show an embodiment of the present invention, in which FIG. 1 is a schematic plan view, FIG. 2 is a front sectional view, FIG. 3 is a partially cutaway perspective view, and FIG. 5 is a schematic plan view showing the bottom plate, FIG. 5 is a plan cross-sectional view showing an enlarged joint part of the bottom plate, FIG. 6 is a partially omitted plan cross-sectional view showing the peripheral wall body, and FIG. 7 is a side view of the same. , 8th
Figure 9 is a front view of the same, Figure 9 is an enlarged plan sectional view showing the joint part of the U-shaped concrete blocks, Figure 10 is
The figure is an enlarged front view showing the connecting part between the bottom plate and the peripheral wall, FIG. 11 is a sectional view of the same side, and FIG. 12 is the bottom plate,
Cross-sectional view showing the joint part of the peripheral wall body and the top plate, 1st
FIG. 3 is an explanatory diagram for explaining the method of connecting the surrounding wall bodies, and FIG. 14 is an explanatory diagram for explaining the construction method. FIG. 15 and FIGS. 16a and 16b are explanatory views for explaining other embodiments of the present invention. A... Bottom plate, B ₁ to B ₃ ... Surrounding wall body, C... Top plate,
1, 2... Flat concrete block, 1a,
2a... Joint end surface, 3... High tensile strength bolt, 4...
Connecting fittings, 5...Base plate part, 6...Cover part,
7... Anchor bar, 8... Bolt hole, 9, 10...
... U-shaped concrete block, 12 ... PC rod, 13 ... 1st PC steel rod, 14 ... 2nd PC
Steel rod, 15...Katsupura, 16...Natsuto, 17
... Sealing material, 18 ... Polyurethane resin joint,
19... mortar joint, 21, 22... flat concrete block, 23... first connection means,
24... Second connecting means, 25... Third connecting means, 27, 28... Insert nut, 29...
Connecting iron plate, 31, 32... Bolt, 33... Connection box, 34... Upper end surface, 35... Lower end surface,
36...Insertion hole, 37...Vertical tightening PC steel bar, 38...
...lower end thread, 39...upper end thread, 40...anchor plate, 41...nut, 42...recess, 43...through hole, 44...vertically tightened PC steel bar, 4
5...Lower end threaded part, 46...Upper end threaded part, 47...
... Nut, 48-52 ... Seal material, 54-57
...Polyurethane resin joint, 58, 59, 60...
... Mortar joint, 62 ... Slanted floor, 63 ... Opening hole, 64, 65 ... Piping opening, 70 ... Ground,
71...Foundation chestnut stone, 72...Foundation concrete,
73...bed mortar, 74...tension bar, 75...
Connector, 76... Hydraulic jack, 81, 82...
Joint wall, 83... U-shaped concrete block.

Claims (1)

[Scope of Claims] 1. A bottom plate made of precast concrete block, a circumferential wall body made of precast concrete block having a rectangular shape in plan view and placed in multiple stages on the bottom plate, and a lid at the upper end opening of this circumferential wall body. A top plate made of a precast concrete block, and connecting means for connecting the bottom plate, the peripheral wall body, and the top plate, respectively, the peripheral wall body being connected to a pair of the same shape. U-shaped concrete blocks are joined into a housing shape, and first and second prestressed steel rods are used to connect both U-shaped concrete blocks, and pre-stressed prestressed steel rods are buried in each of the U-shaped concrete blocks in advance. Therefore, prestress is applied to the entire circumference of the peripheral wall body, and the first PC steel bar is housed within the peripheral wall of one U-shaped concrete block, and the second PC steel bar is housed within the peripheral wall of one U-shaped concrete block. is housed in the peripheral wall of the other U-shaped concrete block, and these first and second PC steel bars are connected by a coupler at the joining position of both U-shaped concrete blocks. tank. 2. A bottom plate made of precast concrete blocks is laid, and on this bottom plate, a plurality of sets of peripheral walls each having a substantially square shape in plan view are formed by joining pairs of U-shaped concrete blocks of the same shape into a housing shape. , are installed in a row with alternate horizontal orientations of 90 degrees so that the joints do not match,
This is a construction method in which a top plate made of precast concrete blocks is placed on the upper end of the surrounding wall body, and when the pairs of U-shaped concrete blocks are butted against each other, one of the U-shaped concrete blocks is The first PC steel rod that has been inserted through it and the second PC steel rod that has been inserted into the other U-shaped concrete block are connected via a coupler, and these first and second PC steel rods are connected to each other through a coupler. Both U-shaped concrete blocks are joined by applying a certain tension, and the first and second PC steel bars and the PC steel bars buried in each of the U-shaped concrete blocks in advance are used to connect the two U-shaped concrete blocks. , a construction method for a prefabricated storage tank characterized by applying prestress to the entire circumference of its peripheral wall.