JPS5953436B2 - concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to concrete structures used in constructing subway tunnels, water and sewerage systems, and water storage tanks.

Recently, when constructing subway tunnels, water supply and sewerage systems, and water storage tanks,
For the purpose of shortening the construction period and reducing the space at the construction site, arc plate-shaped concrete structures that are standardized and manufactured in advance at a factory are used.

These concrete structures are transported from factories to construction sites, where they are prefabricated and assembled to construct subway tunnels and water and sewage systems.

Incidentally, conventionally, this type of concrete structure was constructed as shown in FIG.

That is, a plurality of joint fittings 2 are buried in the end face of the arc plate-shaped concrete structure 1, and the connection between adjacent concrete structures is made by aligning the end faces of the concrete structures 1 and providing them on the end faces. This is done by bolting the fittings 2 together.

As shown in FIGS. 2 and 3, this joint fitting 2 is constructed by fixing embedded legs 6 by welding to both sides 5 of a flange portion 4 having bolt insertion holes 3. 6 is embedded in the concrete structure 1, and the flange portion 4 is exposed at the end face of the concrete structure 1.

However, according to conventional concrete structures, the flange part of the joint fitting is made of a thin steel plate, so when a strong tensile force acts in a direction that pulls the joint end surfaces of both concrete structures apart from each other, the central part of the joined flange part When stress concentrates on the bolted part 7 of the concrete structure, the flange part 4 curves and the bolted central part bulges outward as shown in Fig. 4, causing the joint end surfaces of both concrete structures to pull against each other. There was a risk of leaving.

This is extremely important for water supply, sewage, and water storage tanks where watertightness is an absolute requirement, and is also extremely important in that the structure of the water, sewage, and water storage tanks themselves is weakened.

Therefore, various proposals have been made to reinforce the flange portion of the joint fitting, but none of them have been able to sufficiently eliminate the above-mentioned drawbacks.

Furthermore, according to conventional concrete structures, both sides of the joint fittings and the embedded legs are simply buried in the concrete structure, so a strong tensile force acts in the direction of separating the joint end surfaces of both concrete structures from each other. In such a case, there was a risk that the joint fittings would come off from the concrete structure.

The present invention has been made in view of the above circumstances, and its purpose is to prevent the joined end surfaces of the concrete structures from being separated from each other even if a tensile force is applied between the two connected concrete structures, and to prevent the concrete structures from being separated from each other. To provide a concrete structure in which joint fittings buried in the structure are prevented from coming off from the concrete structure.

FIG. 5 shows an embodiment of the present invention, in which a concrete structure 8 is constructed in the shape of a circular arc plate, and a plurality of joint fittings 9 are buried in the end face thereof at appropriate intervals.

As shown in FIG. 6, this joint fitting 9 has three rectangular support parts 12 extending radially at equal intervals in the circumferential direction on the outer periphery of a cylindrical bolt attachment part 11 having a bolt insertion hole 10. It is located in

A reinforcing bar connecting part 14 having a cylindrical shape and shorter than the bolt attachment part 11 having a reinforcing bar insertion hole 13 is provided at the end of the supporting part 12 .

The joint fitting 9 has continuous ribs 1 on its outer peripheral surface from the bolt attachment part 11 to the support part 12 and the reinforcing bar connection part 14.
5 is provided and integrally formed by casting.

On the other hand, as shown in FIG. 7, a part of the reinforcing bars 16 constituting the frame of the concrete structure 8 has a male threaded portion 16a formed on the outer circumferential surface of the end thereof.

The reinforcing bar connecting part 14 is inserted into the reinforcing bar 16 formed with the male screw part 16a, and the end of the reinforcing bar 16 is inserted into the reinforcing bar insertion hole 13, and the reinforcing bar 16 protrudes from the reinforcing bar insertion hole 13.
A nut 17 is screwed into the male threaded portion 16a of the holder.

The joint fitting 9 connects its reinforcing bar connecting part 14 to the reinforcing bar 16 as described above, and as shown in FIGS. It is buried so as to coincide with the end surface of the structure 8.

In addition, 18 in the figure is an opening for bolt fastening operation provided near the position where the joint fitting 9 of e78 is buried in the concrete structure, and the inner end surface of the bolt attachment part 11 is exposed on the inner wall surface 18a. ing.

In order to connect the structures 8 to the concrete 1 constructed as described above, the end surfaces 19, 19 of the concrete structures 8, 8 must be connected to each bolt attachment portion 11, as shown in FIG. 11 so that they are in contact with each other,
The tightening bolt 20 is inserted from the bolt insertion hole 10 of one bolt attachment part 11 to the bolt insertion hole 10 of the other bolt attachment part 11.
The nut 22 is screwed and tightened through the fastening washer 21.

After the bolt fastening operation, the opening 18 is filled with a filling material such as non-shrinkage mortar.

In the above-mentioned embodiment, the joint fitting 9 was constructed by disposing three supporting parts 12 around the outer periphery of the bolt attachment part 11 as shown in FIG. 6, but as shown in FIG. Alternatively, two supporting portions 12 may be provided on the outer periphery of the bolt attachment portion 11, and the number of supporting portions 12 may be three as in the above embodiment.
It is not limited to individuals.

In addition, in order to connect the support part 12 to the reinforcing bar 16, the support part 12
A reinforcing bar connecting part 14 having a reinforcing bar insertion hole 13 □ is provided at the end of the reinforcing bar 16 , and a male thread 16 a is formed on the outer peripheral surface of the end of the reinforcing bar 16 . Although the case where the nut 17 is screwed into the male threaded portion 16a of the reinforcing bar 16 is shown, a female threaded portion may be formed on the inner peripheral surface of the reinforcing bar insertion hole 13 and the male threaded portion 16a of the reinforcing bar 16 may be directly screwed into the nut 17. Alternatively, instead of forming the male threaded portion 16a on the outer circumferential surface of the end of the reinforcing bar 16, a retaining portion may be formed by crushing the end of the reinforcing bar 16 to prevent it from coming out from the reinforcing bar insertion hole 13.

□ In addition, as shown in the above embodiment, the bolt attachment part 11 to the support part 12 and the reinforcing bar connection part 14 are connected to the outer peripheral surface of the joint fitting 9.
If continuous ribs 15 are provided throughout, the thickness of the joint fitting 9 can be made thinner and the weight can be reduced.

In addition, this rib 15 has a joint fitting 9 that is connected to a concrete structure 8.
It has the effect of preventing it from slipping out.

FIG. 10 shows another embodiment of the present invention, in which a rib 15a is provided on the front surface of the support portion 12 of the joint fitting 9, which slopes upward from the reinforcing bar connection portion 14 toward the bolt attachment portion 11. There is.

As explained above, according to the concrete structure of the present invention, since the bolt attachment part of the joint fitting buried in the concrete structure is configured in a cylindrical shape, a tensile force is exerted between the two connected concrete structures. Even if this happens, the bolt attachment part does not bulge outward like the flange part of a joint fitting buried in a conventional concrete structure, and therefore the joint end surfaces of both concrete structures are pulled apart from each other. There is no.

In addition, since a support part is provided on the outer periphery of the bolt attachment part and this support part is connected to the reinforcing bars that make up the frame of the concrete structure, there is no risk of the joint fittings coming off the concrete structure, and the concrete The strength of the structure is also improved.

Further, since the support portion is provided to extend radially around the outer periphery of the bolt attachment portion, it is easy to connect the support portion to the reinforcing steel.

Further, since the joint fitting having the mounting portion and the support portion is integrally formed by casting, it has the advantage that it is easy to manufacture and can be provided at low cost.

[Brief explanation of drawings]

Figures 1 to 4 show conventional examples. Figure 1 is a perspective view of a concrete structure, Figure 2 is a perspective view of a joint fitting, and Figure 3 is a buried joint fitting of a concrete structure. 4 is a sectional view showing a state in which the joint surfaces of the concrete structure are separated by tensile force; FIGS. 5 to 9 show an embodiment of the present invention; FIG. Figure 5 is a perspective view of the concrete structure, Figures 6 and 9 are perspective views of the joint fittings, Figure 7 is a partial longitudinal sectional view showing the concrete structure connected, and Figure 8 is the concrete structure. The side view and FIG. 10 are partial cross-sectional views showing another embodiment of the present invention. 8...Concrete IJ-to structure, 9...Joint fittings, 10...Bolt insertion hole, 11...
・Bolt mounting part, 12... Support part, 16...
...Reinforced steel.

Claims (1)

[Claims] 1 A joint fitting having a cylindrical bolt attachment part with a bolt insertion hole and a support part extending radially from the outer periphery is integrally formed by casting, and the support part is connected to the reinforcing bars that constitute the frame of the concrete structure. A concrete structure characterized in that the joint fitting is buried in concrete so that the bolt insertion hole of the bolt attachment portion opens at an end face of the concrete structure.