JPS5953435B2 - 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, arc plate-shaped concrete structures that have been standardized and produced in advance at factories are being used to shorten construction periods and reduce construction site space. ing.

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 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 has embedded legs 6 on both sides of a flange portion 4 having bolt insertion holes 3.
are fixed by welding, the both side parts 5 and the embedded legs 6 are embedded in the concrete structure 1, and the flange part 4 is exposed at the end surface 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 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 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 a joint fitting buried in the structure 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.

This joint fitting 9 has a bolt insertion hole 10 as shown in FIG.
Three rectangular support parts 12 made of steel plates are disposed at equal intervals in the circumferential direction on the outer periphery of a cylindrical bolt attachment part 11 made of a steel pipe.

The support portion 12 has a base portion welded to the outer circumference of the bolt attachment portion 11 by welding 13 so as to extend radially from the outer circumference of the bolt attachment portion 11 .

Moreover, the end of this support part 12 is attached to the concrete structure 8.
It is fixed by welding 15 to the ends of reinforcing bars 14 that constitute the frame of the frame.

The joint fitting 9 connects the end of the support portion 12 to the reinforcing bar 1 as described above.
4 by welding 15, and as shown in FIGS. 7 and 8, the bolt attachment portion 11 is buried in a concrete structure 8 such that the outer end surface thereof is aligned with the end surface of the concrete structure 8.

In addition, 18 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 v0 configured as described above
To connect the 8 comrades, connect the end faces 17 of the concrete structure vIJ8 to each bolt attachment part 11. as shown in FIG.
11 are brought into contact with each other in the same position, and the tightening 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 washer 19 for fastening is inserted. The nut 20 is screwed and tightened through.

After the bolt tightening operation, the opening 16 is filled with, for example, non-shrinkage mortar.

Fill it with filler such as

In the above-mentioned embodiment, the joint fitting 9 was constructed by arranging three supporting parts 12 around the outer periphery of the bolt attachment part 11 as shown in FIG. 6, but as shown in FIG. Two supporting parts 1 and 2 may be arranged around the outer periphery of the attachment part 11, and the number of supporting parts 12 is not limited to three as in the above embodiment.

FIG. 10 shows another embodiment of the present invention, in which a rib 21 is provided on the front surface of the support portion 12 of the joint fitting 9, which 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 is configured in a cylindrical shape, tensile force is generated between the two connected concrete structures. Even when the bolt attachment part is in contact with the concrete structure, 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 separated from each other. Never.

In addition, since the joint fittings are constructed by fixing the support parts extending radially around the outer periphery of the bolt attachment part by welding, it is easy to manufacture the joint fittings. Since it is fixed by welding to the reinforcing bars that make up the joint, there is no risk of the joint fittings coming off the concrete structure, the strength of the concrete structure is improved, and the support part can be firmly fixed to the reinforcing bars.

Further, since the support part is provided to extend radially around the outer periphery of the bolt attachment part, there is an advantage that the end part of the support part can be easily welded to the reinforcing bar.

[Brief explanation of drawings]

Figures 1 to 4 show conventional examples, where 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 part of a concrete structure where the joint fitting is buried. FIG. 4 is a partial sectional view showing a state in which the joint surfaces of a concrete structure subjected to tensile force are separated; FIGS. 5 to 9 show an embodiment of the present invention; FIG. is a perspective view of the concrete structure, Figures 8 and 9 are perspective views of the joint fittings, Figure 7 is a partial longitudinal sectional view showing the state in which the concrete structures are connected, and Figure 8 is a side view of the concrete structure. , FIG. 10 is a partial cross-sectional view showing another embodiment. 8...Concrete structure, 9...Joint fittings, 10...Bolt insertion hole, 11...
... Bolt mounting part, 12... Support part, 14...
...Reinforcing bars, 13.15...Welding.

Claims (1)

[Claims] 1 A radially extending support part is fixed by welding to the outer periphery of a cylindrical bolt attachment part having a bolt insertion hole to form a joint fitting, and the end of the support part is attached to the reinforcing steel that constitutes the frame of the concrete structure. A concrete structure, characterized in that the joint fitting is fixed by welding and buried in concrete so that the bolt insertion hole of the attachment part opens at an end face of the concrete structure.