JP2996606B2 - Precast slab joint structure of bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a precast slab for constructing a bridge, for example.

[0002]

2. Description of the Related Art Conventionally, it is common practice to cast concrete on a bridge floor slab after setting a reinforcing bar. However, the work is easy to be soiled, it is heavy labor and is dangerous, and it is necessary to work at a high place. There's a problem. Therefore, recently, a method of precasting the slabs, laying the precast slabs, connecting the slabs with bolts, and connecting adjacent precast slabs has been frequently used.

If the precast slabs are not joined at that time, as shown in FIGS. 11A and 11B, the shear δs between the adjacent precast slabs 40 and 41 due to shearing.
And a shift δt due to torsional deformation occurs. If there are such shifts δs, δt, the wheels 42 collide with the precast slab 40, and the deterioration of the precast slab 40 is promoted.

In order to prevent the deviations δs and δt,
As shown in FIG. 11C, the shear key 43 and the shaft member 44 may be arranged at the boundary, and as a result, as shown in FIG. 11D, the moment M acting on the boundary surface, the axial force N, And the shear force Q can be transmitted, the deviations δs and δt disappear, and problems such as collision of the wheels 42 do not occur.

[0005] Conventional joining of precast slabs is described in A. As shown in FIG. 12, sheaths 45 and 46 are formed in advance on precast slabs 40 and 41, and after precast slabs 40 and 41 are laid side by side, PC steel material 47 extends between sheaths 45 and 46. Insert and join.

B. As shown in Fig. 13, loop joints at joints
48 is overhanging and concrete 49 is cast and combined. C. As shown in FIG. 14, concrete 49 is cast and connected by using overhanging reinforcing bars 50, 51 from the precast floor slabs 40, 41.

D. As shown in FIG. 15, the PC steel material 47 is inserted and joined to the joint material using a non-shrink mortar 52 or the like. And so on.

[0008]

However, the connection using the PC steel 47 of the above-mentioned item A has a problem that it is difficult to introduce prestress to the entire PC panel on site. Further, in the joining using the loop reinforcing bar 48 of the section B and the joining using the overhanging reinforcing bars 50 and 51 of the section C, there is a problem that the step of placing the concrete 49 on site cannot be omitted. Further, in the connection using the loop reinforcing bar 48 in the section B, the connection using the overhanging reinforcing bars 50 and 51 in the section C, and the connection using the non-shrink mortar 52 in the section D, sufficient bonding strength cannot be expected.

[0009] The object of the present invention is to firmly join precast slabs without casting concrete on site and without using difficult-to-manage construction methods such as PC steel. It is another object of the present invention to provide a joint structure of a precast floor slab which can easily perform the above.

[0010]

In order to achieve the above object, a joint structure of a precast slab of a bridge according to the present invention is provided by disposing a corner reinforcing material at a lower corner portion of a joint side end of the precast slab. , On the joint surface side of this corner reinforcement,
Forming at least one of a convex portion and a concave portion that can be fitted to each other, forming a quarter-circle through hole from the upper surface of the precast floor slab to the joint surface of the corner reinforcing material, and arranging a pair of precast floor slabs When a semicircular bolt body is provided between the communicating through holes, a threaded plate at both ends of the semicircular bolt body is inserted and disposed between the upper surfaces of both precast floor slabs. And a nut body that can be screwed into a screw portion exposed from the transfer plate.

[0011]

According to the construction of the present invention described above, the precast floor slab before joining has a corner reinforcing material integrated at the joining end thereof and a through hole formed therein. After such precast floor slabs are laid on the girder side,
The spar is connected to the spar by bolts, and the adjacent precast slabs are joined to each other.

[0012] At this time, the joining is performed by first bringing the joining surfaces of the two precast slabs into contact with each other or making them close to each other so that the convex portions and the concave portions are fitted to each other, and the open portions on the lower side of the through holes are joined to each other. Communicate. Next, a bridge plate is disposed between the upper surfaces of the two precast slabs. Then, the semicircular bolt body is inserted into the through holes that are communicated with each other by pushing the semicircular bolt body in an arc shape. At this time, since the two quarter-circle through holes are semicircular due to the communication, the semicircular bolts are semicircular. The insertion of the circular bolt body can be performed smoothly without any trouble. Next, by screwing the nut body to the threaded portions at both ends exposed on the transfer board, the two precast floor slabs can be joined by the tightening operation.

In the above-described joining state, when a bending moment acting in a direction of pushing down the joining portion acts on the joining portion, the steel section of the central portion of the semicircular bolt body shares the tensile force on the lower tension side. On the upper compression side, the portion forming the joint surface of both precast slabs shares the compression force. Further, the shearing force acting on the joint can be borne by the convex and concave portions fitted to each other.

When the precast slab is partially damaged, the nut body is first unscrewed and the semi-circular bolt body is pulled out in an arc shape at both joint ends of the corresponding precast slab. A precast slab may be separated from an adjacent precast slab. Then, after the corresponding precast slab is removed, a new precast slab is fitted into the removed mark, and the joining operation as described above is performed, thereby completing the replacement of the precast slab.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, lower corner reinforcing members 11, 21 each formed of an angle are provided at lower joint portions of the pair of precast floor slabs 10, 20 at the joint side ends. On one joint surface side of the lower corner reinforcing member 11, a convex portion (convex shear key) is formed from a plurality of portions in the width direction.
12 is formed to project and the other lower corner reinforcement 21
In the joint surface side, the convex portion is provided at a plurality of locations in the width direction.
A concave portion (concave shear key) 22 which can be fitted to the concave portion 12 is formed in a hole shape.

Further, at the joint side ends of the two precast floor slabs 10 and 20, steps 14 and 24 are formed on the upper surfaces 13 and 23, and an upper corner formed by the free ends of the steps 14 and 24. Are provided with upper corner reinforcement members 15 and 25 each formed of an angle. Here, a plurality of main reinforcing bars 16, 26 extending in the radial direction respectively are provided continuously from the inner side surfaces of the upper corner reinforcing members 15, 25 and from a plurality of locations in the width direction of the precast slabs 10, 20, and at each location, The intermediate portions of the main reinforcing bars 16 and 26 are connected by belt reinforcing bars 17 and 27.

At the joint side ends of the two precast slabs 10 and 20 and at a plurality of locations in the width direction of the precast slabs 10 and 20, the lower corner reinforcing members 11 and For example, quadrangular through holes 19 and 29 are formed by embedding sheaths 18 and 28 over the joint surface of 21, and these through holes 19 and 29
When the units 10 and 20 are arranged, the open portions on the lower corner reinforcing members 11 and 21 are configured to communicate with each other.

Using the steps 14 and 24, a bridge 1 is provided between the upper surfaces 13 and 23 of the two precast slabs 10 and 20. Through holes 19, 29
A through-hole 2 is formed in the open portion on the upper surface 13 or 23 side of the upper surface. A plurality of semicircular bolts 3 are provided to be inserted between the through hole 2 and the through holes 19 and 29 which are communicated with each other, and both ends of these semicircular bolts 3 are formed in screw portions 3A. A large number of nut bodies 4 are provided which can be screwed into the threaded portions 3A exposed from the passing plate 1 through the through holes 2.

Hereinafter, the joining operation in the above embodiment will be described. As shown in FIG. 3, for example, the precast floor slabs 10 and 20 before joining have lower corner reinforcing members 11 and 21 and upper corner reinforcing members 15 and 25 integrated at their joint side ends. Reinforcing bars 16 and 26, belt reinforcing bars 17 and 27, sheaths 18 and 28
Are arranged by embedding. Both precast floor slabs
10 and 20 are laid side by side on the girder side, then bolted to the girder, and
0 and 20 are joined together.

At this time, the joining is first performed as shown in FIG.
The joint surfaces of both precast floor slabs 10 and 20 are brought into contact with or close to each other, so that the convex portions 12 and the concave portions 22 are fitted to each other, and the lower open portions of the through holes 19 and 29 communicate with each other. . Next, as shown in FIG. 5, using the steps 14, 24, the bridge plate 1 is disposed between the upper surfaces 13, 23 of the precast floor slabs 10, 20, and the through holes 19, 29 are formed. Upper surface 13, 23
The through-hole 2 communicates with the opening on the side.

The semicircular bolt 3 is inserted between the through-hole 2 and the through-holes 19 and 29 which are communicated with each other by pushing the semi-circular bolt 3 in an arc shape. The semicircular bolt body 3 can be smoothly inserted without any trouble since the semicircular bolt body 3 is formed by the communication. Next, the nut body 4 is screwed into the screw portions 3A at both ends exposed on the handover plate 1 by the above-described insertion, so that FIGS.
As shown in (1), joining between the two precast slabs 10 and 20 can be performed by the tightening operation.

In the above-described joining state, for example, as shown in FIG. 7, when a bending moment Ms acting in a direction of pushing down the joining portion acts on the joining portion, the center of the semicircular bolt body 3 on the lower pulling side is actuated. The steel section of the part 3a shares the tensile force Ts, and both precast slabs on the upper compression side
Concrete parts 10a, 20a forming the joint surface of 10, 20
Share the compression force Ps. Further, the shearing force Qs acting on the joint can be borne by the convex portion 12 and the concave portion 22 fitted to each other.

When the shear force Qs is strong, for example, as shown in FIG. 8, cracks may occur between the portion surrounded by the semicircular bolt body 3 and the main bodies of the precast slabs 10 and 20. However, the occurrence of the cracks can be prevented by the main reinforcing bars 16, 26 provided continuously from the upper corner reinforcing members 15, 25.

When the precast slabs 10 and 20 are partially damaged, the nut body 4 is first unscrewed at both joint ends of the corresponding precast slabs 10 and 20, and the semicircular bolt body 3 is removed. By drawing out in an arc shape, the corresponding precast slabs 10 and 20 are separated from the adjacent precast slabs 10 and 20. And the corresponding precast slabs 10, 20
Is removed, and a new precast slab is placed on the removal mark.
After the fitting of the precast floor slabs 10, 20, the replacement of the precast floor slabs 10, 20 is completed.

FIGS. 9 and 10 show another embodiment of the present invention.
That is, the corner reinforcing member 30 is formed integrally with the upper corner and the lower corner by using the channel type steel, and is precast between the free ends of the reinforcing bars 31 which are connected diagonally downward from the upper inner surface of the corner reinforcing member 30. A fixing steel plate 32 exposed on the lower surface side of the floor slab 20 is provided. 33 shows a stephna.

According to this alternative embodiment, the end structure on the joint side of the precast slabs 10 and 20 can be further simplified. In the embodiment described above, the convex portion 12 is formed on one lower corner reinforcing material 11 and the concave portion 22 is formed on the other lower corner reinforcing material 21. Department
Forming both 12 and recess 22 and the other lower corner reinforcement
The structure may be such that both the concave portion 22 and the convex portion 12 are formed on the convex portion 21 so as to be fitted and opposed to the convex portion 12 and the concave portion 22.

[0027]

According to the present invention having the above-described structure, the joining between the ends of the precast slab can be easily performed without placing concrete on site and using a difficult-to-manage construction method such as a PC steel material. In addition, the bonding can be performed with sufficient bonding strength. Moreover, the replacement of the precast floor slab can be easily performed only by the screwing operation of the nut body and the inserting / removing operation of the semicircular bolt body.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a longitudinal sectional front view at the time of joining in a joining structure of a precast floor slab of a bridge.

FIG. 2 is an exploded perspective view of various members used for a joint structure of a precast floor slab of the bridge.

FIG. 3 is a longitudinal sectional front view before joining in a joining structure of a precast floor slab of the bridge.

FIG. 4 is a longitudinal sectional front view at the time of contact in the joint structure of the precast floor slab of the bridge.

FIG. 5 is a vertical cross-sectional front view of a connecting structure of a precast floor slab of the bridge at the time of disposing a bridge plate.

FIG. 6 is a partially cutaway perspective view at the time of joining in the joining structure of the precast floor slab of the bridge.

FIG. 7 is an explanatory diagram of an operation at the time of joining in a joining structure of a precast floor slab of the bridge.

FIG. 8 is an explanatory view of cracks in the joint structure of the precast floor slab of the bridge.

FIG. 9 shows another embodiment of the present invention, and is a longitudinal sectional front view before joining in a joining structure of a precast floor slab of a bridge.

FIG. 10 is a perspective view of a main part of a corner reinforcing member in the joint structure of the precast floor slab of the bridge.

FIG. 11 is an explanatory diagram showing the principle of displacement.

FIG. 12 shows a conventional example and is a schematic perspective view of a joining structure using a PC steel material.

FIG. 13 is a schematic perspective view of a joining structure using a loop reinforcing bar, showing a conventional example.

FIG. 14 shows a conventional example and is a schematic perspective view of a joining structure using an overhanging reinforcing bar.

FIG. 15 is a schematic perspective view of a joining structure using a non-shrink mortar, showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crossing board 2 Through-hole 3 Semi-circular bolt body 3A screw part 4 Nut body 10, 20 Precast floor slab 11, 21 Lower corner reinforcing material 12 Convex part 22 Recessed part 13, 23 Upper surface 18, 28 Sheath 19, 29 Through hole 30 Corner reinforcement

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Tanaka 5-28, Nishikujo, Konohana-ku, Osaka-shi, Osaka Hitachi Zosen Corporation (58) Field surveyed (Int.Cl. ⁷ , DB name) E01D 19/12

Claims (1)

(57) [Claims] At a joint side end of a precast floor slab, a corner reinforcing member is disposed at a lower corner portion thereof, and a joint portion of the corner reinforcing member is formed of a convex portion and a concave portion which can be fitted to each other. At least one is formed, a quarter-circle through hole is formed from the upper surface of the precast floor slab to the joint surface of the corner reinforcing material, and when a pair of precast floor slabs are arranged, they are passed between the communicating through holes. A semicircular bolt body is provided, and a crossover plate is provided between the upper surfaces of both precast floor slabs, through which both end thread portions of the semicircular bolt body are inserted. A joint structure of precast floor slabs for bridges, characterized by a freely adjustable nut body.