JPS5953438B2 - 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.

This concrete structure is transported from a factory to a construction site, where it is prefabricated and assembled to construct subway tunnels, water supply and sewage systems, etc.

Incidentally, conventionally, this type of concrete structure has been 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 welding embedded legs 6 to both sides 5 of a flange portion 4 having bolt insertion holes 3. The legs 6 are 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 portion 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 flange portion of the joint fittings is When stress concentrates on the bolted part 7 at the center, the flange part 4 curves and the bolted central part bulges outward as shown in Figure 4, which causes the joint end surfaces of both concrete structures to bulge out. There was a risk that they would be separated from each other.

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

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 acts 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 a joint fitting buried in an object is 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 cylindrical reinforcing bar connecting part 13, which is shorter than the bolt attachment part 11, is provided at the end of the support part 12.

The joint fitting 9 has ribs 14 continuously extending from the bolt attachment part 12 to the support part 12 and the reinforcing bar connection part 13 on its outer peripheral surface.
are provided and integrally formed by casting.

The ends of the reinforcing bars 15 constituting the frame of the concrete structure 8 are fixed in the hollow portion of the reinforcing bar connecting portion 13 by a cast-in when the joint fitting 9 is integrally formed by casting.

As described above, the joint fitting 9 has its reinforcing bar connecting part 13 fixed to the end of the reinforcing bar 14, and as shown in FIGS.
The concrete structure 8 is buried so that its outer end surface coincides with the end surface of the concrete structure 8.

In addition, 16 in the figure is the joint fitting 9 of the concrete structure 8.
The inner end surface of the bolt attachment part 11 is exposed on the inner wall surface 16a of the opening for bolt fastening operation provided near the buried position.

Therefore, the concrete structure 8 constructed as described above
To connect the two pieces, as shown in Figure 7, the end faces 17 and 17 of the concrete structures 8 and 8 are brought into contact with each other so that the positions of the bolt attachment parts 11 and 11 match, and then tightened. The bolt 18 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, and the nut 20 is screwed and tightened via the fastening washer 19.

After the bolt fastening operation, the opening 16 is filled with a filling material such as non-shrinkage mortar.

In the above-mentioned embodiment, the joint fitting 9 has three supporting parts 12 on the outer periphery of the bolt attachment part 11, as shown in FIG.
Although the configuration is shown in which two supporting parts 12 are arranged, as shown in FIG. The number is not limited to three as in the above embodiment.

As shown in the above embodiment, if continuous ribs 14 are provided on the outer peripheral surface of the joint fitting 9 from the bolt attachment part 11 to the support part 12 and the reinforcing bar connection part 13, the wall thickness of the joint fitting 9 can be reduced. It is configurable and lightweight.

In addition, this rib 14 has a joint fitting 9 that is connected to a concrete structure 8.
It has the function □ to prevent it from slipping out.

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

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 has a cylindrical shape (lip configuration), the tension between the two connected concrete structures is Even when a force is applied, the bolt attachment part does not bulge outward like the flange part of a joint fitting buried in a conventional concrete structure, so the joint end surfaces of both concrete structures are pulled apart from each other. It never happens.

In addition, since the support part provided to extend radially around the outer periphery of the above-mentioned attachment part is fixed to the reinforcing steel that constitutes the framework of the concrete structure by cast-in, there is no risk of the fitting fitting coming off from the concrete structure. The strength of concrete structures is also improved, and the supporting parts can be firmly fixed to the reinforcing bars.

Furthermore, since the joint fitting consisting of the attachment part and the support part 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 9 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 structure, 9...Joint fittings, 10...Bolt insertion hole, 11...
... Bolt mounting part, 12... Support part, 15...
...Reinforced steel.

Claims (1)

[Claims] 1. When integrally casting a cylindrical bolt attachment part with a bolt insertion hole and a support part extending radially from its outer periphery, the support part and the reinforcing bars that constitute the frame of the concrete structure are cast-in. A concrete structure characterized in that a fixed joint fitting is buried in concrete such that a bolt insertion hole of the bolt attachment part opens at an end face of the concrete structure.