JPS6236798Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an assembled underground water storage tank, and more specifically, the end faces of cylindrical divided boxes are joined to each other, and these divided boxes are arranged in the longitudinal direction of the divided boxes. The present invention relates to a split box for an assembled underground water tank that is integrated with multiple prestressing steel materials.

The one shown in Figure 1 has been proposed as one of the assembled underground water tanks. This is the top plate part 1a,
The end faces 1d of the divided box 1 formed into a cylindrical shape by the bottom plate part 1b and the side plate parts 1c are joined to each other, and the opening is covered with the end plate 2, and the divided box body 1 and the end plate 2 are divided. A plurality of prestressing steel members 3 arranged in the longitudinal direction of the box 1 are integrated.

By the way, the divided box 1 is usually made up of a formwork 6 consisting of an outer formwork 4 and an inner formwork 5 as shown in FIG. 2, for example.
Since it is formed by pouring concrete inside, there is an unevenness of ±2 to 5 mm on the end face on the pouring side, that is, one of the end faces to be joined. Therefore, even if prestress is introduced into the divided box 1, the surface precision of the mutually joined end surfaces 1d of the divided box 1 is poor.
There was a problem that the introduction prestress was uneven in some parts of the end face 1d and was not uniform, resulting in poor introduction accuracy.

On the other hand, the end surfaces 1d and 1 of the adjacent divided boxes 1
In order to ensure watertightness between d and d, methods such as installing a packing 7 as shown in Fig. 1 have been implemented. As a result, the gasket 7 tends to deteriorate over time and lose its elasticity, which causes problems such as the watertightness of the gasket 7 being impaired and the tension force being impaired.

This idea was proposed in view of the above circumstances, and it can improve the surface accuracy of the joint between the end faces, improve the precision of introducing prestress, and further improve watertightness. The purpose of the present invention is to provide a divided box for a prefabricated underground water storage tank.

In order to achieve this purpose, this invention has a structure in which a bearing plate is embedded in the end face opposite to the end face finished by form molding, parallel to this end face and whose surface protrudes from the end face.

Hereinafter, one embodiment of this invention will be described based on the drawings.
As shown in the figures to FIG. 5, its basic structure is similar to the conventional one, and is formed into a cylindrical shape by a top plate part 10a, a bottom plate part 10b, and both side plate parts 10c, 10c, and the top plate part 10a is It is formed in an upwardly curved arc shape.

This divided box 10 has only one end face 10d (on the right side in FIG. 4) finished by molding, and the upper and lower parts of the both side plates 10c and 10c are provided with a divided box. A through hole 11 for inserting a PC steel material is formed along the axial direction of the steel member 10 .
Further, in the other (left side in FIG. 4) end surface 10e of the divided box 10, a square bearing plate 12 with the through hole 11 opened in the center is buried parallel to the end surface,
In addition, the surface 12a of this bearing plate 12 is similar to the end surface 10.
It protrudes from e by a protrusion length t (see Fig. 5). In the embodiment, the bearing plate 12 has a rectangular shape, is located on the axis of the through hole 11, and is embedded in the end surface 10e, but is not limited to this embodiment. A surface 1 parallel to the end surface 10e of the box 10 and parallel to the end surface 10e.
2a may be configured to protrude from one end surface 10e, and its shape and buried position are arbitrary.

Next, a method for burying the bearing pressure plate 12 will be explained with reference to FIG. 6. Before pouring concrete into the formwork 6, the bridge 13 with the bearing pressure plate 12 attached is placed between the inner formwork 4 and the outer formwork. The liner plate 14 is placed between the upper surface of the frame 5 and the end surface 10e of the divided box 10 formed by the form 6 after concrete is poured into the form 6. The bearing pressure plate 12 is made to protrude by the thickness. The bridge 13 has a pin 16 protruding from the center of the base plate 15. The pin 16 is inserted into the opening of the pressure plate 12, and the bolt 17 is inserted from the top surface of the base plate 15 into the bolt insertion hole of the pressure plate 12. The bearing pressure plate 12 is attached by inserting it into the inside of the bearing plate 12b and screwing it onto the embedded nut 18. Further, the pin 16 of the bridge 13 is inserted into a sheath 19 forming the through hole 11 to support the sheath 19.

After pouring concrete into the formwork 6 to form the split box 10, when the bolts 17 are loosened and the bridge 13 is removed from the form 6, the bearing plate 12 is placed on the end face 10e of the split box 10. Surface 12a
It is buried with a protruding part.

Therefore, the divided box 10 configured in this way
, the surface 12b of the bearing plate 12 is the end surface 10
As shown in FIGS. 7 and 8, the divided box 10 is joined so that the bearing plate 12 and the end surface 10d formed by the mold are in surface contact with each other, and the PC steel material 3 When tension is applied to the bearing plate 1
Prestress is introduced via 2, and thus,
The prestress can be uniformly introduced without being affected by the surface precision of the other end surface 10e of the divided box 10, and the precision of the introduction can be improved.

That is, the support plate 12 embedded in the end surface 10e
Since the support plate 12 is embedded and supported on the upper surface of the formwork 6 via the bridge 13, the position of the support plate 12 can be accurately determined, and the surface precision of the support plate 12 can be improved.

Note that since the end face on the side opposite to the pouring side is formed by molding, it goes without saying that the surface accuracy is good.

Also, if necessary, the end face 1 of the side to be formed by the formwork
A bearing pressure plate that is in surface contact with the bearing pressure plate 12 may be buried in 0d.

Furthermore, as shown in FIG. 8, a gap G is created between the end faces 10d of the divided box 10 by the protruding length t of the bearing plate 12, so that the packing 7 provided at the joint of the end faces 10d is free from prestress. Even when introduced, the gap G is not compressed, so its elastic force can be maintained for a long period of time, preventing deterioration of the packing 7 and improving watertightness.

As explained above, this invention is a split box for an assembled underground water tank in which only one end face is finished by molding, and the other end face is parallel to this end face and the surface protrudes from the end face. By burying the bearing pressure plate, it is possible to improve the precision of introducing prestress while increasing the surface accuracy in a very limited area. It is possible to prevent deterioration of the seal in the gap between the holes and improve the water-stopping effect, and by using bridges, the bearing plate can be easily protruded from the end face and buried, so it is easy to install. It has excellent effects such as good performance.

[Brief explanation of the drawing]

Figures 1 and 2 are shown to explain a conventional example. Figure 1 is a schematic perspective view of a prefabricated underground water tank, Figure 2 is a schematic perspective view of the formwork, and Figures 3 to 2 are diagrams. Figure 8 shows an embodiment of this invention, Figure 3 is a front view of a divided box, Figure 4 is a side view of the divided box, Figure 5 is an enlarged side view of the portion shown in Figure 4, FIG. 6 is a sectional view for explaining the method of burying the bearing plate, FIG. 7 is a side view of the prefabricated underground water tank, and FIG. 8 is an enlarged sectional view of the circular portion in FIG. 7. 3...PC steel material, 4...Outer formwork, 5...Inner formwork, 6...Formwork, 10...Divided box, 10a...
Top plate part, 10b...bottom plate part, 10c...side plate part,
10d, 10e... End face, 12... Bearing plate, 12
a...Surface, 13...Bridge.

Claims (1)

[Scope of utility model registration request] In a split box for a prefabricated underground water tank, which is formed into a cylindrical shape by a top plate, a bottom plate, and both side plates, and where only one end face is finished by molding, the other end face has this end face and A split box for an assembled underground water storage tank characterized by having buried bearing plates that are parallel and whose surfaces protrude from the end faces.