JP2000120093A - Manufacture of water reservoir and segment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrate steel and concrete and highly densify concrete to strengthen the peripheral wall of the water reservoir and make it thin. SOLUTION: Circumferential ribs 17 and axial ribs 18 are attached onto the inner peripheral face of a nearly cylindrical skin plate 16. Nearly annular plate-shaped joint flanges 19 are fitted to both axial ends of the skin plate 16 so as to project from the outer peripheral face of the skin plate 16. Concrete is placed so as to cover the inner peripheral face of the skin plate 16 and the inside face of the circumferential and axial ribs 17, 18 and the joint flanges 19 while rotating the skin plate 16 around the central axial line O to manufacture a segment 12. A plurality of segments 12 are axially connected and the joint flanges 19 mutually butted against each other are fixed with bolts to construct the peripheral wall 11 of the water reservoir 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a water tank such as an underground water tank buried in the ground and a water tank segment for constructing a peripheral wall of the water tank.

[0002]

2. Description of the Related Art Conventionally, as a water storage tank having a cylindrical peripheral wall, for example, a water storage tank segment formed into a circular plate shape, that is, a plate shape curved so as to form a part of the outer peripheral surface of a cylinder, is used.
BACKGROUND ART A structure in which a cylindrical peripheral wall is constructed by connecting a plurality of members in a circumferential direction and an axial direction is known. Hereinafter, an example of the above-described related art will be described with reference to FIGS. FIG. 13 is a perspective view showing a peripheral wall of a conventional water storage tank, and FIG. 14 is a perspective view of a water tank segment forming the peripheral wall of the water storage tank shown in FIG. The peripheral wall 1 of the substantially cylindrical water tank has a substantially arc-shaped water tank segment 2.
Are connected in the circumferential and axial directions. The water tank segment 2 includes a pair of main girders 3,
3 and joint plates 4 and 4, a skin plate 5, a bolt box 6, and an arc-shaped concrete portion 7 as main components. The portion of the water tank segment 2 excluding the arc-shaped concrete portion 7 is made of, for example, steel.

The main girder plate 3 is formed in an arc plate shape, and the joint plate 4 is formed in a rectangular plate shape. A pair of main girder plates 3, 3 and the joint plates 4, 4 are formed in substantially rectangular frame shapes on opposite sides. In each of the four corners, a substantially box-shaped bolt box 6 is installed so as to open to the outer peripheral side of the arc. Bolt insertion holes 3a, 3b are inserted in the vicinity of both ends of the main girder plate 3 and the joint plate 4 so as to be inserted into the respective bolt boxes 6.
3a and 4a, 4a are respectively penetrated. Two bolt insertion holes 3b, 3b are provided in the center of the main girder plate 3 so as to be spaced apart therefrom, and a fastener such as an insert nut is provided so as to communicate with these. Water tank segment 2
On the outer peripheral side of each of the bolts 6, an arc plate-shaped skin plate 5 is installed so as not to block the opening of each bolt box 6, and each pair of main beam plates 3, 3 and joint plates 4, 4 and skin plate Concrete is cast in a space surrounded by 5 and a bolt box 6 so as to be integrated with them, and an arc-shaped concrete portion 7 is provided.

In the portion where the adjacent water storage tank segments 2 and 2 are connected in the circumferential direction, the bolt insertion holes 4a and 4a of the joint plates 4 and 4 that are abutted with each other are bolted to be adjacent to each other. In the portion where the water tank segments 2 and 2 are connected in the axial direction, the water tank segments 2 and 2
2 are shifted from each other in the circumferential direction, and the bolt insertion holes 3a of the one water tank segment 2 communicate with the bolt insertion holes 3b of the other water tank segment 2 and are bolted.

When the arc-shaped concrete portion 7 is cast in the manufacture of the water tank segment 2, each pair of the main girder plates 3, 3 and the joint plates 4, 4, the skin plate 5, the bolt box 6, The concrete is poured into the space surrounded by and solidified. At this time, air or the like in the concrete is released to the outside by, for example, applying vibration.

[0006]

On the peripheral wall 1 of the water tank having the above-described structure, there are circumferentially and axially joined portions of the adjacent water tank segments 2 and 2. In this joint portion, since the adjacent water storage tank segments 2 and 2 are not integrated by concrete, there is a problem that the strength of the peripheral wall 1 is reduced. In addition, water tank segment 2
Is provided with a bolt box 6 for connecting the adjacent water storage tank segments 2, 2, so that the space in which concrete is poured is reduced, and the strength of the water storage tank segment 2 is reduced. Brought.

Further, in the method of manufacturing the water tank segment 2 described above, vibration is applied to the water tank segment 2 when the concrete is poured in order to escape the air and the like mixed in the concrete to the outside. Tedious work had to be performed, which required a great deal of labor.

The present invention has been made in view of the above circumstances, and in a segment for constructing a peripheral wall of a water storage tank, a portion made of a metal such as steel is integrated with concrete, and air and the like in the concrete are removed. A method for manufacturing a water tank segment that can be made high density and high strength, and a water tank capable of reducing the weight of the peripheral wall by thinning the concrete portion of the peripheral wall of the water tank. The purpose is to provide.

[0009]

In order to solve the above-mentioned problems and achieve the object, a water storage tank according to the present invention has a substantially cylindrical peripheral wall. A water tank having both ends sealed by end plates, wherein the peripheral wall is constructed by a plurality of segments connected in the axial direction, the segments are formed in a substantially cylindrical shape, and the outer peripheral surface is formed of metal. The skin plate is provided with reinforcing ribs on the inner peripheral surface of the skin plate, and concrete is coated on the inner peripheral surface of the skin plate and the reinforcing ribs so as to be integrated therewith. It is characterized by being cast.

[0010] In the water tank having the above-described structure, the joint between the segments exists only in the axial direction, and is not provided in the circumferential direction. Here, in the peripheral wall of the water storage tank buried in the soil, the external force that crushes the peripheral wall and the internal water pressure that expands the peripheral wall radially outward maintain the shape of the peripheral wall particularly in the peripheral direction. Although it may be damaged, by eliminating the joint in the circumferential direction of the peripheral wall, the durability against external pressure and internal water pressure can be improved, and the strength of the water storage tank can be increased.

Further, in the water storage tank according to the present invention, a joint flange is provided at both ends of the segment so as to protrude in a radial direction of the peripheral wall, and the segment connected in the axial direction is provided. The end plates are joined by fastening members at the joint flanges located at both ends of the peripheral wall, respectively.

In the water tank having the above structure, for example, there is no need to provide a bolt box or the like for inserting a bolt and a nut or other joining members inside the peripheral wall and the end plate.
Therefore, it is possible to prevent the space in which the concrete is poured from being reduced inside the segments and the end plates forming the peripheral wall, and to improve the strength of the water storage tank. Also,
Since the segments are joined to each other and the segment and the end plate are formed on the outer peripheral side of the peripheral wall, the joining operation is facilitated, and the efficiency of assembling the water storage tank can be improved. Since there is no restriction on the thickness, it is possible to make the peripheral wall as thin as possible to reduce the weight. Thereby, the labor of the assembling work when constructing the peripheral wall can be reduced.

According to a third aspect of the present invention, there is provided a method for manufacturing a water tank segment for constructing a peripheral wall of a substantially cylindrical water tank by itself or by connecting to each other. A metal skin plate is provided on the inner peripheral surface of the substantially cylindrical formwork, reinforcing ribs are provided on the inner peripheral surface of the skin plate, and the skin is provided at both ends in the axial direction of the skin plate. A joint flange is provided so as to protrude radially from the plate, and the skin plate is sandwiched from both sides in the axial direction. After forming the installation space, concrete is placed in the casting space so as to cover the inner peripheral surface of the skin plate and the reinforcing ribs while rotating the formwork around the axis. It is characterized in that pouring.

In the method for manufacturing the water tank segment described above, the concrete is pressed against the inner peripheral surface of the skin plate and the reinforcing ribs under the centrifugal force, and the concrete itself is compressed. For this reason, no air or the like enters between the concrete and the inner peripheral surface of the skin plate and the reinforcing ribs to form a gap, and the concrete is firmly fixed and the mutual integration is made strong. Further, since the air and the like mixed in the concrete are expelled to the outside, pores and the like are not formed after the concrete is solidified, and the density of the concrete can be increased. This makes it possible to increase the strength of the water tank segment, that is, the peripheral wall, and to reduce the weight by reducing the thickness.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water storage tank according to the present invention will be described below with reference to FIGS. FIG.
FIG. 2 is a perspective view of an embodiment of a water storage tank according to the present invention, in which a part of a peripheral wall and an end plate is removed and cut away. FIG. FIG. 3 is an enlarged cross-sectional view of an essential part showing a joint part between segments, and FIG. 4 is an enlarged sectional view showing a joint part between a peripheral wall of a water storage tank and an end plate. FIG. 5 is an enlarged cross-sectional view of a main part, showing a joining portion of a manhole installed on a peripheral wall.

The water storage tank 10 according to the present embodiment includes a peripheral wall 1.
1 is made of, for example, steel and has a so-called hybrid water tank in which concrete is poured into the inner circumference thereof so as to be integrated with the steel.
And a manhole 14 and a drainage pit 15. The segment 12 is formed in a substantially cylindrical shape having a central axis O, and the plurality of, for example, three-piece segments 12 are connected in the axial direction to form a substantially cylindrical peripheral wall 11.
The segment 12 includes the skin plate 16 and the circumferential rib 1.
7 and axial rib 18 (reinforcing rib) and joint flange 1
9 and a concrete part 20.

The skin plate 16 is made of, for example, steel.
The outer peripheral surface of the substantially cylindrical segment 12 is formed. On the inner peripheral surface of the skin plate 16, circumferential and axial ribs 17, 18 made of, for example, steel are attached in a lattice shape by welding or the like. The circumferential ribs 17 are formed in a substantially annular plate shape, have an appropriate inner diameter in the radial direction, and are arranged at predetermined intervals in the axial direction. An axial rib 18 is provided between the adjacent circumferential ribs 17 and 17, and has an inner diameter equal to that of the circumferential rib 17, and a plurality of axial ribs are arranged at predetermined intervals in the circumferential direction. At both ends in the axial direction of the skin plate 16, a pair of substantially annular plate-like joint flanges 19, 19 made of, for example, steel are provided. The outer diameter of the joint flange 19 is larger than the outer diameter of the skin plate 16, and the inner diameter is smaller than the inner diameter of the skin plate 16. Therefore, the joint flange 19
Is formed by a flange outer peripheral portion 19a protruding radially outward from the outer peripheral surface of the skin plate 16, and a flange inner peripheral portion 19b protruding radially inward from the inner peripheral surface of the skin plate 16. A substantially triangular plate-like flange reinforcing plate 21 made of, for example, steel is attached between the flange outer peripheral portion 19a and the outer peripheral surface of the skin plate 16 so as to be in contact with both. In addition, flange outer peripheral portion 19
a has a flange joining hole 23 into which the fastening bolt 22 is inserted.
Are provided in the axial direction. Of the two surfaces of the joint flange 19, the flange contact surface 24 that faces the outside of the segment 12 in the axial direction is coaxial with the joint flange 19 at a position on the outer peripheral side of the flange joint hole 23, and has a substantially annular shape. One seal groove 25 is provided.

The concrete portion 20 is formed in a substantially cylindrical shape, and covers the inner peripheral surface of the skin plate 16, the circumferential and axial ribs 17, 18 and the inner surface of the flange inner peripheral portion 19b. It is cast so as to be integrated with. The inside diameter of the concrete portion 20 is smaller than the inside diameters of the circumferential and axial ribs 17 and 18, and the positions of the concrete contact surfaces 26 at both ends in the axial direction coincide with the flange contact surfaces 24. The end surfaces of the segment 12 are formed by the contact surfaces 24 and 26. The concrete contact surface 26 has a substantially annular second seal groove 2.
7 is provided coaxially with the concrete part 20. A circumferential and axial rib 1 is provided inside the concrete part 20.
The reinforcing bar 28 is arranged at a position where it does not interfere with the concrete bars 7 and 18, and the outer circumferential bar and the axial vertical bar are assembled in a lattice shape to form a substantially cylindrical appearance, and are coaxial with the concrete portion 20. .

As shown in FIG. 3, adjacent segments 1
At the portion where the connecting bolts 2 and 12 are connected in the axial direction, the fastening bolt 22 is inserted from one of the flange connection holes 23 and 23 that are connected to each other, and the fastening bolt 2 protruding from the other.
By screwing the nut 29 to the tip of the second 2, the segments 12, 12 are joined to each other. here,
The first seal recesses 25, 25 of the flange contact surfaces 24, 24, which face each other, define first seal holes 30, and the second seal recesses 27, 27 of the concrete contact surfaces 26, 26. Are opposed to each other to define a second seal hole 31,
Sealing materials 30a, 31a are mounted in the first and second sealing holes 30, 31, respectively.

At both ends of the peripheral wall 11, as shown in FIG.
The inside diameter of the concrete portion 20 is increased from the inside of the water storage tank 10 to the outside in the axial direction, and a tapered concrete end face 32 is formed. The concrete end face 32 intersects the flange contact face 24 at a substantially obtuse angle, and the end plate 13 is attached so as to contact the flange contact face 24 and the concrete end face 32. End plate 13
Is composed of an end plate skin plate 33, an end plate rib 34, and an end plate concrete portion 35. The end plate skin plate 33 is made of, for example, steel and is formed in a substantially disk shape, and has an outer diameter equal to the outer diameter of the joint flange 19. Further, the end plate skin plate 33 has skin plate joining holes 3 communicating with the flange joining holes 23 of the joint flange 19.
6 are provided. A substantially annular plate-shaped end plate rib 34 made of, for example, steel is mounted coaxially with the end plate skin plate 33 on an inner surface facing the inside of the water tank 10 in the axial direction on both surfaces of the end plate skin plate 33. ing. The end plate concrete portion 35 covers the inner surface of the end plate skin plate 33 and the end plate ribs 34 and is cast so as to be integrated therewith. The end plate concrete portion 35 has a tapered outer peripheral surface so as to contact the tapered concrete end surface 32, and an outer diameter on the surface of the end plate skin plate 33 is made equal to an inner diameter of the joint flange 19, The outer diameter of the inner surface facing the inside of the water tank 10 in the axial direction is equal to the inner diameter of the concrete portion 20. Sealing grooves 32a and 35a are formed in portions where the concrete end face 32 and the outer peripheral surface of the end plate concrete portion 35 are in contact with each other. 32 and the outer peripheral surface of the end plate concrete portion 35 are sealed.

On the outer surface of the end plate 13, a substantially annular plate-like joining auxiliary plate 37 made of, for example, steel is installed.
Has an outer diameter equal to the outer diameter of the end plate skin plate 33, and an inner diameter smaller than the inner diameter of the joint flange 19,
A fastening bolt hole 38 having the same diameter and the same diameter as the skin plate joining hole 36 of the end plate skin plate 33 is provided therethrough. The flange connecting hole 23 of the joint flange 19, the skin plate connecting hole 36 of the end plate skin plate 33, and the bonding auxiliary plate 3
7 are connected to the fastening bolt holes 38, respectively, and these flange connection holes 23 and skin plate connection holes 36
The segment 12 and the end plate 13 are joined by fastening the nut 29 to the fastening bolt 22 inserted through the fastening bolt hole 38.

In either one of the segments 12 located at both ends of the peripheral wall 11, a manhole 14 and a drain pit 15 are respectively installed on opposite sides of the outer peripheral surface with the central axis O interposed therebetween. The manhole 14 has a substantially cylindrical shape made of, for example, concrete, and includes a manhole protrusion 39 protruding from the outer peripheral surface of the segment 12 and a segment 1.
2 and a manhole fitting portion 40 attached to the inside of the housing 2. The manhole projecting portion 39 is formed in a substantially cylindrical shape, and the manhole fitting portion 40 coaxial with the manhole projecting portion 39 has a tapered outer peripheral surface whose diameter is reduced from the outer peripheral surface of the segment 12 toward the central axis O. have. The inner diameters of the manhole projecting portion 39 and the manhole fitting portion 40 are made equal. A manhole joint 41 made of, for example, steel is provided between the manhole protruding portion 39 and the manhole fitting portion 40.
A manhole joint hole 42 is provided, which is mounted so as to protrude radially outward from the outer peripheral surface of the joint hole and into which the fastening bolt 22 is inserted.

Segment 1 in which manhole 14 is installed
2, a manhole mounting hole 43 is provided through the outer peripheral surface toward the central axis O. The manhole mounting hole 43 is
The segment 12 has a tapered inner peripheral surface whose diameter decreases from the outer peripheral surface of the segment 12 toward the central axis O so as to contact the tapered outer peripheral surface of the manhole fitting portion 40. In addition, seal grooves 43a and 40a are formed at portions where the inner peripheral surface of the manhole mounting hole 43 and the outer peripheral surface of the manhole fitting portion 40 are in contact with each other.
The inner peripheral surface of the manhole mounting hole 43 and the outer peripheral surface of the manhole fitting portion 40 are sealed by the sealing material 14a provided in the a and 40a. In the vicinity of the manhole mounting hole 43, a bolt hole 44 is provided through the skin plate 16, and the cap nut 4 is connected so as to face the bolt hole 44 and communicate therewith.
5 is mounted on the inner peripheral surface of the skin plate 16. The fastening bolt 22 is inserted into the bolt hole 44 from the manhole joint hole 42 and screwed to the cap nut 45.
The drain pit 15 has, for example, the same structure as the manhole 14, and the same reference numerals are assigned to the same portions as the manhole 14, and description thereof will be omitted.

The water tank 10 according to the present embodiment has the above-described configuration. Next, an example of a method of manufacturing the segment 12 for constructing the peripheral wall 11 of the water tank 10 will be described with reference to FIGS. I do. 6 is a cross-sectional view taken along the axis orthogonal to the manufacturing apparatus of the segment 12 viewed from the axial direction, FIG. 7 is a cross-sectional view taken along the line XX in FIG. 6, and FIG.
4 and segment 1 to which drainage pit 15 is attached
2 is an axially orthogonal cross-sectional view of the inside of the mold when viewed from the axial direction when manufacturing No. 2.

For manufacturing the segment 12, so-called centrifugal molding is used. For example, a substantially cylindrical mold 46 is
The outer peripheral surface of the form 46 is supported by the two rotating wheels 47, 47 so as to sandwich the outer peripheral surface from both sides, and the form 46 is rotated by rotating the two rotating wheels 47, 47 in the same direction. , 47 in the opposite direction. Here, a substantially cylindrical skin plate 16 is fitted so as to be in contact with the inner peripheral surface of the formwork 46, and circumferential and axial ribs 17, 18 are welded on the inner peripheral surface of the skin plate 16 by welding or the like. Attach. Further, a reinforcing bar 28 is installed coaxially with the skin plate 16 so as not to interfere with the circumferential and axial ribs 17 and 18 at a position on the inner peripheral side of the circumferential and axial ribs 17 and 18. After the joint flange 19 is attached to both ends in the axial direction of the skin plate 16 by welding or the like, a substantially annular plate having at least an outer diameter larger than the inner diameter of the joint flange 19 and an inner diameter smaller than the inner diameter of the concrete portion 20. The frame plate 48 is mounted in contact with the flange contact surface 24. On the inner surface of the frame plate 48, the concrete contact surface 2
In order to form the second gasket fixing groove 27 in 6, a substantially annular gasket groove forming frame 49 is mounted coaxially with the frame plate 48. Thus, the casting space 50 for placing concrete is formed.

Next, concrete is poured into the casting space 50 while rotating the formwork 46, and is solidified sequentially to increase the radial thickness of the concrete portion 20. At this time, the concrete is pressed against the inner peripheral surface of the skin plate 16 and the circumferential and axial ribs 17 and 18 under the centrifugal force, and the concrete itself is compressed. And axial rib 1
7, 18 and each of the reinforcing steel bar 28 and the joint flange 19,
No gap is formed between the concrete portion 20 and the concrete portion 20 is firmly integrated and firmly integrated. At the same time, the air in the concrete is expelled, and the density of the concrete portion 20 is reduced. Enhanced. Thus, concrete is poured until the concrete portion 20 has a predetermined thickness in the radial direction.

The manhole 14 and the drain pit 1
5 is installed in the segment 12 where the skin plate 1
A manhole hole 51 having a diameter equal to the outer diameter of the manhole projecting portion 39 is formed in the outer peripheral surface of 6. A manhole forming form 52 having the same shape as the manhole fitting portion 40 is fitted in the manhole hole 51. By casting concrete in this state, the manhole mounting hole 43 is formed in the segment 12.

According to the water storage tank 10 according to the present embodiment,
There is no joint between the segments 12 in the circumferential direction of the peripheral wall 11, and the inner peripheral surface of the skin plate 16, the circumferential and axial ribs 17, 18, the portion made of steel of the joint flange 19, and the concrete portion 20 are integrated. Therefore, the durability against the external pressure and the internal water pressure applied to the peripheral wall 11 can be improved, and the strength of the water storage tank 10 can be increased. Furthermore, since the adjacent segments 12 and 12 and the segment 12 and the end plate 13 are joined by bolting on the outer peripheral side of the peripheral wall 11, for example, a space for inserting the fastening bolt 22 is formed in the segment 12 and the end plate 13. It is not necessary to form inside, and it is possible to prevent a decrease in the strength of the water storage tank 10 without reducing the space for placing concrete. In addition, in this joining method, there is no restriction on the thickness of the peripheral wall 11, so that the thickness of the peripheral wall 11 can be made as thin as possible to reduce the weight. Thereby, the labor of the assembly operation when constructing the peripheral wall 11 can be reduced.

Further, according to the method of manufacturing the water storage tank 10 according to the present embodiment, the concrete receives the centrifugal force and the inner peripheral surface of the skin plate 16 and the circumferential and axial ribs 17, 17.
18 and the concrete itself is compressed. Therefore, a gap is not formed due to air or the like entering between the concrete and the inner peripheral surface of the skin plate 16 and the circumferential and axial ribs 17 and 18.
When the concrete is securely set, mutual integration is made strong. Further, since the air and the like mixed in the concrete are expelled to the outside, the concrete portion 20 can be densified without forming pores or the like after the concrete is solidified. Thus, the strength of the segment 12, that is, the peripheral wall 11, can be increased, and the weight can be reduced by reducing the thickness.

The joint flange 19 of the segment 12
In the joint portion between the end plate 13 and the end plate 13, the joining auxiliary plate 37 may be omitted by thickening the end plate skin plate 33 of the end plate 13 in the axial direction. Further, as shown in a sectional view of a main part of a joining portion between the peripheral wall 11 and the end plate 13 shown in FIG. 9, the end plate 13 may be formed of concrete, for example. In this case, as shown by a broken line in FIG. 9, a groove 53 having an appropriate shape is provided on the outer surface of the end plate 13, that is, the surface facing the outside in the axial direction of the water storage tank 10, to reduce the weight of the end plate 13. You may. Furthermore, both ends of the peripheral wall 11 may be constituted by a flange contact surface 24 and a concrete contact surface 26 as shown in a sectional view of a main part of a joint portion between the peripheral wall 11 and the end plate 13 shown in FIG. In this case, the end plate 13 may be made of concrete, for example, and may be formed in a substantially disk shape.

Regarding the configuration of the manhole 14 (or the drain pit 15), the manhole joint 41 is formed of, for example, concrete, as shown in the sectional view of the main part of the joint between the peripheral wall 11 and the manhole 14 shown in FIG. You may. Further, as shown in the cross-sectional view of the main part of the joining portion between the peripheral wall 11 and the manhole 14 shown in FIG. A plate-shaped manhole rib 55 is provided in the circumferential direction, and a substantially cylindrical concrete inner wall 56 is cast so as to cover the inner peripheral surface of the manhole peripheral wall 54 and the manhole rib 55 so as to be integrated therewith. Is also good. Here, the inner peripheral surface of the manhole fitting portion 40 is formed substantially parallel to the outer peripheral surface, and the inner diameter thereof is
The diameter is reduced from the outer peripheral surface toward the central axis O. An approximately triangular plate-like joint reinforcing plate 57 made of, for example, steel is attached between the manhole joint 41 and the outer peripheral surface of the manhole peripheral wall 54.

In this embodiment, the water tank 1 is formed by connecting a plurality of segments 12 in the axial direction.
Although it is assumed that the peripheral wall 11 of 0 is constructed, it is not limited to this.
The segment 12 may be a single unit. Further, in the present embodiment, the manhole 14 and the drainage pit 15 are attached to the segment 12 at one end in the axial direction of the water tank 10, but the present invention is not limited to this. May be attached to the segment 12. Further, the manhole 14 and the drain pit 15 may be attached to different segments 12, respectively. In short, it suffices if they are attached to the opposite sides of the outer peripheral surface of the segment 12 with the center axis O interposed therebetween.

In this embodiment, the segment 1
2 is manufactured, the formwork 46 comprises two rotating wheels 4
Although it is described that it is supported so as to be sandwiched from both sides by 7, 47, it is not limited to this, and it may be supported by more than two rotating wheels 47. Further, instead of being driven by the rotating wheel 47, the formwork 46 may rotate on its own. Further, the rotating shaft of the formwork 46 may be rotated in the vertical direction instead of in the horizontal direction. In this embodiment, the substantially cylindrical segment 12 is manufactured using the substantially cylindrical mold 46. However, the present invention is not limited to this. For example, the inner peripheral surface of the mold 46 may be appropriately partitioned. As a result, arc-shaped or other shaped segments may be manufactured. In short, a centrifugal force acts when the concrete is poured, and the concrete and the portion made of steel, such as the inner peripheral surface of the skin plate 16 and the circumferential and axial ribs 17, 18 and the joint flange 19, are integrated. do it.

[0034]

As described above, according to the water tank of the first aspect of the present invention, the peripheral wall of the water tank is constructed by connecting the segments in the axial direction, and the metal on the outer peripheral side of the segments is formed. And the concrete cast on the inner peripheral side thereof are integrated, so that the durability against external pressure and internal water pressure acting on the peripheral wall can be improved, and the strength of the water storage tank can be increased.

Further, according to the water tank of the present invention, since the segments are joined to each other and the segment and the end plate are joined on the outer peripheral side of the water tank, the joining operation becomes easy and the assembling efficiency can be improved. At the same time, there is no need to arrange joining members such as fastening bolts inside the segments and the end plates, and it is possible to prevent a decrease in the strength of the water storage tank without reducing the space for placing concrete.

According to the method for manufacturing a water tank segment according to the third aspect of the present invention, the concrete is pressed against the inner peripheral surface of the skin plate and the reinforcing ribs by the centrifugal force, and the concrete itself is compressed. Air does not enter between the concrete and the inner peripheral surface of the skin plate and the reinforcing ribs to form a gap,
When the concrete is securely set, mutual integration is made strong. In addition, since air and the like mixed in the concrete are expelled to the outside, the density of the concrete can be increased, and the strength of the segment, that is, the peripheral wall can be improved, and the thickness can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of a water storage tank according to the present invention, in which a part of a peripheral wall and an end plate are removed and cut away.

FIG. 2 is an axially orthogonal cross-sectional view of a segment forming a peripheral wall of the water storage tank shown in FIG. 1 viewed from an axial direction.

FIG. 3 is an enlarged cross-sectional view of a main part showing a joint between segments of the water storage tank shown in FIG. 1;

FIG. 4 is an enlarged cross-sectional view of a main part showing a joint between a peripheral wall and an end plate of the water storage tank shown in FIG. 1;

FIG. 5 is an enlarged cross-sectional view of a main part showing a joint portion of a manhole installed on a peripheral wall of the water storage tank shown in FIG.

FIG. 6 is an axial cross-sectional view of the segment manufacturing apparatus as viewed from the axial direction.

FIG. 7 is a sectional view taken along line XX in FIG.

FIG. 8 is an axially orthogonal cross-sectional view of the inside of the mold when viewed from the axial direction when manufacturing a segment to which a manhole and a drainage pit are attached.

FIG. 9 is a cross-sectional view of an essential part showing, as a first modified example of the water storage tank according to the present embodiment, a joining portion between a peripheral wall of the water storage tank and an end plate in an enlarged manner.

FIG. 10 is a cross-sectional view of a main part, in which a joining portion between a peripheral wall of the water storage tank and an end plate is enlarged as a second modification of the water storage tank according to the present embodiment.

FIG. 11 is an enlarged cross-sectional view of a main part showing, as a third modified example of the water storage tank according to the present embodiment, a joint portion of a manhole installed on a peripheral wall of the water storage tank.

FIG. 12 is a cross-sectional view of an essential part showing, as a fourth modified example of the water storage tank according to the present embodiment, a joined portion of a manhole installed on a peripheral wall of the water storage tank in an enlarged manner.

FIG. 13 is a perspective view showing a peripheral wall of a conventional water storage tank.

14 is a perspective view of a water tank segment that forms the peripheral wall of the water tank shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 water storage tank 11 peripheral wall 12 segment 13 end plate 14 manhole 15 drain pit 16 skin plate 17 circumferential rib 18 axial rib 19 joint flange 20 concrete part 28 reinforcing bar 46 formwork 47 rotating wheel 48 frame plate O center axis

Claims (3)

[Claims] 1. A water storage tank having a substantially cylindrical peripheral wall, both ends of which are sealed by end plates, wherein the peripheral wall is constructed by a plurality of segments connected in an axial direction. The segment is formed in a substantially cylindrical shape, its outer peripheral surface is made of a metal skin plate, and a reinforcing rib is provided on the inner peripheral surface of the skin plate. A water tank, wherein concrete is cast so as to cover the surface and the reinforcing ribs and integrate them. 2. A joint flange is provided at both ends of the segment so as to protrude in a radial direction of the peripheral wall. In the joint flange in which the segments connected in the axial direction abut each other, The water tank according to claim 1, wherein the end plates are joined by fastening members at the joint flanges located at both ends of the peripheral wall. 3. A method of manufacturing a water tank segment for constructing a peripheral wall of a substantially cylindrical water tank by itself or by connecting to each other, wherein a metal tube is formed on an inner peripheral surface of the substantially cylindrical mold. The skin plate is installed, reinforcing ribs are provided on the inner peripheral surface of the skin plate, and joint flanges are provided at both ends in the axial direction of the skin plate so as to project radially from the skin plate, After the skin plate is sandwiched from both sides in the axial direction, and a frame plate is placed in contact with each joint flange to form a casting space in which concrete is cast, and then the mold is rotated around the axis. Wherein the concrete is poured into the casting space so as to cover the inner peripheral surface of the skin plate and the reinforcing ribs. Law.