JP2020128671A - Joint structure of concrete matter - Google Patents

Abstract

To provide a joint structure of concrete matter which is excellent at tolerance against errors and favorably improve operability in construction sites.SOLUTION: In a state where a locking part a in a joint fitting fixed to an end of a concrete matter faces a locking part b in the joint fitting fixed to an end of another concrete matter, a connecting fitting is mounted so as to surround the locking parts a and b, wedge-shaped members are inserted into each of the two wedge-shaped voids formed as a result, which are surrounded by the inclined surface of the connecting fitting and the inclined surfaces of the locking parts a, locking part b, and after bolts are inserted into each of the insertion holes in the wedge-shaped members, the bolts are screwed into the locking holes in the joint fittings and a joint structure is configured.SELECTED DRAWING: Figure 7

Description

The present invention relates to a joint structure of concrete slabs, and more particularly to a joint structure capable of advantageously connecting adjacent concrete slabs when laying the concrete slab for road surfaces such as bridges and pavement for airports and roads. Is.

Conventionally, a concrete precast plate (concrete plate) has been used as a structure for constructing road surfaces such as bridges and pavements for airports and roads. Concrete slabs that make up the road surface, etc., where it is necessary to connect adjacent slabs with a joint device, etc., as a type of such joint device, a cotter type that has been frequently used as a joint device for shield tunnel segments. It is widely known that what is called a joint device is applied as a joint for concrete slabs. In addition, the cotter type coupling device is configured such that a C-type coupling metal fitting is faced to each other, and a cotter having an H-shaped cross-section is inserted into a cavity (groove) having an H-shaped cross-section formed between the facing metal fittings. , To confront the metal fittings.

As such a cotter type coupling device, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 2001-214694), a device having the following structure is proposed. That is, the same patent document discloses a cotter-type joint device in which a C-type fitting having a groove with a lip groove in cross section is opposed to each other, and a cotter having an H-shaped cross section is inserted into and fastened to the H-shaped groove. In this case, a bolt hole is opened near the center of the left and right flanges of the cotter having the H-shaped cross section, and a bottom portion having a predetermined thickness is formed on the C-type joint fitting. There is disclosed a cotter type joint device, characterized in that a locking portion for a bolt to be inserted into the bolt hole is provided in the portion. It is specified in the patent document that the cotter type coupling device having such a configuration can surely prevent the cotter from loosening or coming off, and can advantageously enhance the fastening strength between the individual members.

However, the inventors of the present invention have made detailed studies on using the cotter joint device disclosed in Patent Document 1 when connecting concrete slabs. It was found that there is still room for improvement in terms of the ability to absorb placement errors (in other words, the tolerance for placement errors).

Specifically, when connecting the concrete slabs by using the cotter type joint device disclosed in Patent Document 1, the concrete slab with the C-shaped joint fitting fixed to the end is brought into the construction site, and the target ground is obtained. Etc., the concrete slabs are arranged so that the C-type joint fittings of the adjacent plates face each other, and then the facing C-type joint fittings are connected by using a cotter and a bolt having an H-shaped cross section. It will be.

Here, the fixing (embedding) of the C-type joint fitting to the concrete slab, the placement of the concrete slab on the ground, etc. are all carried out based on a predetermined plan. Mounting error of fittings, unevenness of the ground where concrete slabs are placed, joint spacing between adjacent concrete slabs, side profile error of concrete slabs, dimensional error of concrete slabs, warpage and bending due to aging of concrete slabs Due to such reasons, it is rare that the concrete slab (and the C-type joint fitting fixed to the end thereof) is placed at the planned position without error. Therefore, if the joint fitting or joint structure has a low absorption capacity for the above-mentioned error (hereinafter, collectively referred to as placement error) (in other words, the tolerance for placement error is poor), it will be a connection target at the construction site. There is a possibility that the concrete slab cannot be connected.

Then, when the inventors of the present invention have scrutinized the cotter type joint device disclosed in Patent Document 1 from the viewpoint of the tolerance to the placement error, in such a cotter type joint device, the horizontal direction (plane direction) of the concrete slab is shown. Although a certain degree of tolerance for the placement error in () is recognized, there is room for further improvement in view of the actual conditions at the construction site.

JP 2001-214694 A

Here, the present invention has been made in view of such circumstances, and the problem to be solved is that the concrete slab has excellent tolerance to errors and can advantageously improve workability at the construction site. It is to provide a joint structure.

Then, the present invention, in order to solve such a problem, a joint fitting fixed to an end of one concrete slab, and a joint fitting fixed to an end of another one concrete slab, a connecting fitting and a In a joint structure of a concrete slab that is connected by using a wedge-shaped member, 1) the joint fitting has a bottom surface portion having a substantially rectangular shape in which a bolt locking hole is provided, and the bottom surface portion A side wall portion having a U-shaped cross section is erected on the peripheral edges of the three sides, and a locking portion is provided apart from the side wall portion on one peripheral edge where the side wall portion is not provided. The surface of the engaging portion facing the side wall is an inclined surface that inclines toward the side wall from the upper side to the lower side. 2) Two sets of the connecting metal fittings are provided. A substantially rectangular tubular shape composed of opposing cylindrical wall portions, and the inner wall surface of the cylindrical wall portion in any one of the two sets inclines from the upper side to the lower side toward the facing inner wall surface. It is an inclined surface, 3) the bolt-shaped insertion hole is formed in the wedge-shaped member so as to penetrate in the vertical direction, and 4) the joint metal fitting is provided at the end of the one concrete slab. Is fixed so that the locking portion is located outside in the plane direction of the one concrete slab, and 5) the joint fitting is attached to the end of the other concrete slab. 6) is fixed so that the locking portion is located outside in the plane direction of the one concrete slab, and 6) the locking portion α of the joint fitting fixed to the end of the one concrete slab, The connecting metal fitting is attached so as to surround the locking portion α and the locking portion β in a state where the locking portion β of the joint metal fitting fixed to the end of the other concrete plate is confronted. And a wedge-shaped space formed by the mounting and surrounded by the inclined surface of the connecting fitting and the inclined surface of the locking portion α, and the inclined surface of the connecting fitting and the inclined surface of the locking portion β. The wedge-shaped member is inserted into each of the wedge-shaped cavities surrounded by, and the bolt inserted into each of the insertion holes of the wedge-shaped member is screwed into the locking hole of the joint fitting. The gist is a joint structure of a concrete slab, which is characterized by being confined.

In the joint structure of the concrete slab according to the present invention, preferably, the one concrete slab and the other concrete slab are provided on at least a part of the inner wall surface of the insertion hole of the wedge-shaped member. A female screw portion corresponding to the male screw of the threaded bar used to release the connection with is formed.

As described above, in the joint structure of the concrete slab according to the present invention, when two joint fittings each fixed to the concrete slab face each other and a connecting fitting having a predetermined structure is attached, the connecting fitting There are two wedge-shaped voids formed by the inner wall surface of the and the wall surface of the fitting. Then, with a wedge-shaped member attached to each of the wedge-shaped cavities, a bolt is inserted into the insertion hole of the wedge-shaped member, and the bolt is screwed into the locking hole provided on the bottom surface of the joint fitting. By the action, the two facing joint fittings (concrete plates) are moved toward each other. At this time, in the present invention, two wedge-shaped members are used, and since the action described above is effectively exhibited in each of the two wedge-shaped members, compared with the conventional cotter type joint device, In particular, it exhibits excellent tolerance to the placement error in the horizontal direction (plane direction) of the concrete slab.

It is a top view which shows an example of the joint structure of the concrete slab according to this invention. It is a front view which shows the joint metal fittings connected in the joint structure of FIG. It is a right view which shows the joint metal fittings connected in the joint structure of FIG. It is a top view which shows the state which removed the cover material of the joint metal fittings in the joint structure of FIG. It is sectional drawing of the AA surface in FIG. 1 of the joint metal fittings connected in the joint structure of FIG. FIG. 2 is a cross-sectional view taken along the line B-B in FIG. 1 of the joint fittings connected in the joint structure of FIG. 1. FIG. 6 is a cross-sectional view showing a state before and after bolt fastening in the joint structure of the concrete slab according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view related to an example of a joint structure for a concrete slab according to the present invention, and is a plan view showing a joint joint metal fitting and its periphery partially enlarged. 2 to 6 are explanatory views showing only the joint fittings in the connected state in the joint structure of FIG. 1, FIG. 2 is a front view, FIG. 3 is a right side view, and FIG. 4 is a lid. FIG. 5 is a plan view showing a state in which the material is removed, FIG. 5 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 6 is a cross-sectional view taken along the line BB in FIG. Further, FIG. 7 is a cross-sectional view showing a state before and after bolt fastening according to the joint structure of the concrete slab shown in FIG. 1 and a cross section taken along a plane corresponding to the AA plane in FIG. 1.

In the joint structure 10 for a concrete slab according to the present invention, the joint metal fitting 14 fixed to one concrete slab 12 and the joint metal fitting 14 fixed to another one concrete slab 12 are connected in a confronting state. It is connected by a metal fitting 16. As is clear from the comparison between FIG. 1 and FIG. 4, the upper portion of the fitting 14 is covered with the lid member 18. A through hole for a bolt 20 with a hole is provided in the lid member 18, and the bolt 20 with a hole inserted into the through hole is screwed into a screw hole 24 provided in the locking portion 22 of the joint fitting 14. The lid member 18 is fixed to the joint metal fitting 14 by being swaged.

First, the joint fitting 14 will be described in detail. As is clear from FIGS. 4 to 6, the joint fitting 14 has a bottom surface portion 30 in which a locking hole 28 for the bolt 26 is provided. A female screw corresponding to the male screw of the bolt 26 is formed on the inner surface of the locking hole 28. In addition, side walls 32 having a U-shaped cross section are erected on the three peripheral edges of the bottom surface portion 30, while on the peripheral edges where the side wall portions 32 are not provided, apart from the side wall portions 32, A locking portion 22 is provided.

Two screw bars 34, 34 are joined to the outer peripheral surface of the side wall portion 32 facing the locking portion 22. Since the two screw bars 34, 34 are fixed so as to be embedded in the concrete slab 12, the fitting part 14 of the joint fitting 14 has the locking portion 22 outward in the plane direction of the concrete slab 12 (in the horizontal direction of the concrete slab 12). It is fixed so that it is located outside). Further, each of the two outer peripheral surfaces of the side wall portion 32 to which the screw bar 34 is not joined is provided with a raised portion 36 having a substantially H shape in a plan view. The raised portion 36 is provided to assist in fixing the joint fitting 14 to the concrete slab 12.

Then, in the locking portion 22 of the joint fitting 14, the surface on the side facing the side wall portion 32 is an inclined surface 38 that inclines toward the side wall portion 32 from the upper side to the lower side ( See especially Figure 5).

On the other hand, as can be understood from FIGS. 4 to 6, the connecting fitting 16 has a substantially rectangular tubular shape as a whole, and the opposing long side tubular wall portions 40, 40 and the opposing short side tubular wall portion 42. , 42.

In the present embodiment, the inner wall surfaces of the short side tubular wall portions 42, 42 are inclined surfaces 44, 44 that incline toward the inner wall surfaces of the opposing short side tubular wall portions from the upper side to the lower side, respectively. (See Figure 5).

Further, as can be seen from FIG. 5, the wedge member 46 has a wedge shape. The wedge shape has an inclination in the engaging portion 22 of the joint fitting 14 when the connecting fitting 16 is mounted so as to surround the respective engaging portions 22 and 22 in a state where the two joint fittings 14 and 14 face each other. The shape corresponds to a wedge-shaped space formed by being surrounded by the surface 38 and the inclined surface 44 of the short side tubular wall portion 42 of the connecting fitting 16.

Further, the wedge-shaped member 46 is provided with an insertion hole 48 penetrating in the vertical direction. In this embodiment, the inner diameter of the insertion hole 48 is slightly larger than the outer diameter of the bolt 26. In addition, on a part of the inner wall surface of the insertion hole 48, a female screw portion 50 corresponding to the male screw of the threaded bar used for releasing the connection between the concrete slabs 12 is formed. The joint structure 10 according to the present invention also has an advantage that the connection between the concrete slabs 12 can be easily released by having the female screw portion 50.

In the present embodiment, the bolt 26 is introduced into the insertion hole 48 of the wedge-shaped member 46 via the spherical washer 52, and is screwed into the locking hole 28 provided in the bottom surface portion 30 of the joint fitting 14. There is.

Here, the material forming the joint fitting 14, the connecting fitting 16 and the wedge-shaped member 46 is not particularly limited, and they are connected due to the stress generated when tightening the bolt 26 described later and various factors. Any material can be used as long as it does not break or break due to an external force applied to the concrete slab 12. Specifically, a metal material such as cast iron can be exemplified.

If the tip angle of the wedge-shaped member 46 (θ in FIG. 5) is too large, a large torque is required when tightening the bolt 26, and the bolt 26 may be broken. On the other hand, if the tip angle (θ) is too small, excessive stress is generated in the joint fitting 14 and the connecting fitting 16 when the bolt 26 is tightened, and the joint fitting 14 and/or the connecting fitting 14 are damaged or broken. There is a risk of The tip angle (θ) of the wedge-shaped member 46 is appropriately determined according to the material forming the joint fitting 14 and the size thereof, and for example, a concrete slab of a general size is connected. At this time, the wedge-shaped member 46 whose tip angle (θ) is set to about 8 to 12° is advantageously used. The inclination angle of the inclined surface 38 of the locking portion 22 of the joint fitting 14 and the inclination angle of the inclined surface 44 of the short side tubular wall portion 42 of the connecting fitting 16 are both set as described above. By making the tip angle (θ) of 46 the same, the action of the wedge produced by tightening the bolt 26 becomes more effective.

Then, according to the present invention, when connecting the two concrete slabs 12, 12 each having the joint fitting 14 fixed to each end by using the connecting fitting 16 and the two wedge-shaped members 46, follow the present invention. In the joint structure, first, the two concrete slabs 12 and 12 (not shown in FIG. 7) are arranged so that the engaging portions 22 of the joint fitting 14 face each other. As shown in FIG. 7A, the wedge-shaped member 46 is inserted into the wedge-shaped space formed between the joint metal fitting 14 and the coupling metal fitting 16 and further inserted into the insertion hole 48 of the wedge-shaped member 46. After inserting the bolt 26, the concrete slab 12 is arranged so that the bolt 26 can be screwed into the locking hole 28.

Next, the connecting fitting 16 is attached so as to surround the two facing engaging portions 22, 22. Further, a wedge-shaped member 46 is attached to each of the two wedge-shaped voids formed by such attachment and surrounded by the inclined surface 44 of the coupling fitting 16 and the inclined surface 38 of the locking portion 22 of the joint fitting 14. In addition, the bolt 26 is inserted into the insertion hole 48 via the spherical washer 52 (see FIG. 7A for the above).

Then, when the bolt 26 is screwed into the locking hole 28, the joint metal fitting 14, the coupling metal fitting 16 and the two wedge-shaped members 46, 46 are firmly fixed by the action of the wedge (Fig. 7 ( See b)).

Further, as the bolt 26 is screwed into the locking hole 28, the distance between the two facing joint fittings 14 (in other words, the two concrete slabs 12) decreases. More specifically with reference to FIG. 7A, as the bolt 26 is screwed into the locking hole 28, the joint fitting 14 located on the left side of the drawing moves to the right side of the drawing. On the other hand, the joint fitting 14 located on the right side of the drawing in the figure moves to the left side of the drawing.

In the joint structure of the concrete slab according to the present invention, two wedge-shaped members are used, and when the bolt is screwed in, the wedge action is exerted in each wedge-shaped member, so that one conventional wedge-shaped member is used. The amount of change in the relative distance between the joint fittings is larger than that in a joint device or the like that uses the action of a single wedge. Therefore, in the concrete slab joint structure according to the present invention, excellent tolerance is exhibited particularly with respect to the placement error of the concrete slab in the horizontal direction (plane direction).

As described above, one of the typical embodiments of the present invention has been described in detail, but the present invention is not limited to the above specific mode.

For example, the number of screw bars joined to the joint fitting 16 used for fixing to the concrete slab is two in the above-described embodiment, but the present invention is not limited to this. .. Further, the screw bar may be integrated with the joint fitting.

In addition, the gap (joint) between the concrete slabs connected according to the present invention can be filled with a conventionally known joint material.

In addition, although not listed one by one, it is understood that various changes, modifications, improvements, etc. can be added to the present invention based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

DESCRIPTION OF SYMBOLS 10 Joint structure 12 Concrete plate 14 Joint metal fitting 16 Connection metal fitting 22 Locking part 26 Bolt 28 Locking hole 38 Sloping surface 42 Short side cylinder wall part 44 Sloping surface 46 Wedge-shaped member 48 Insertion hole

Claims (2)

A joint for a concrete slab, in which a joint fitting fixed to the end of one concrete slab and a joint fitting fixed to the end of another concrete slab are connected using a connecting fitting and a wedge-shaped member. In structure,
The joint fitting has a bottom surface having a substantially rectangular shape in which a bolt locking hole is provided, and side walls having a U-shaped cross section are erected on the peripheral edges of the bottom surface on three sides. On the other hand, on one peripheral edge where the side wall portion is not provided, a locking portion is provided apart from the side wall portion, and a side of the locking portion facing the side wall portion is provided. The surface is an inclined surface that inclines toward the side wall portion from above to below,
The connecting fitting has a substantially rectangular tubular shape composed of two sets of facing tubular wall portions, and the inner wall surfaces of the tubular wall portions in either one of the two sets face each other from the upper side to the lower side. It is an inclined surface that inclines toward the inner wall surface,
In the wedge-shaped member, the insertion hole for the bolt is formed in a form that penetrates in the vertical direction,
At the end of the one concrete slab, the joint fitting is fixed so that the locking portion is located outward in the plane direction of the one concrete slab,
At the end of the other concrete slab, the fitting is fixed so that the locking portion is located outward in the surface direction of the other concrete slab,
In a state where the engaging portion α of the joint metal fitting fixed to the end of the one concrete slab and the engaging portion β of the joint metal fitting fixed to the end of the other concrete slab face each other. , The fitting is mounted so as to surround the engaging portion α and the engaging portion β, and is surrounded by the inclined surface of the engaging fitting and the inclined surface of the engaging portion α formed by the attachment. The wedge-shaped member is inserted into and inserted into each of the wedge-shaped voids surrounded by the inclined surface of the connecting fitting and the inclined surface of the locking portion β, and the insertion of the wedge-shaped members. The bolt inserted into each of the holes is screwed into the locking hole in the joint fitting.
A concrete slab joint structure characterized in that A female screw corresponding to the male screw of the threaded joint reinforcing bar used to release the connection between the one concrete slab and the other concrete slab on at least a part of the inner wall surface of the insertion hole of the wedge-shaped member. The joint structure for a concrete slab according to claim 1, wherein the joint is formed.

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