JPH083911A - Bridge finger joint - Google Patents

Abstract

PURPOSE:To make it possible to inhibit horizontal deformation and enhance a lateral buckling resistant force and respond to a large amount of expansion without increasing a clearance generated between finger members by improving rigidity in the axial and vertical and horizontal directions. CONSTITUTION:In bridge finger joints which engage movably each of beams 3 and 4 of finger members made of comb-like hardware, which are opposed to each other, in the longitudinal direction of a bridge, projected parts 6, which are continuous in the axial direction, are installed to a lateral surface of one beam 3 of adjacent beams while recessed parts 7, which are substantially similar to the projected parts in shape and continuous in the longitudinal direction, are installed to the lateral surface of the other beams 4, thereby producing a fitted state between the projected parts 6 and the recessed parts 7 with a specified clearance 6 clamped in between. This construction makes it possible to enhance the rigidity of the members in the axial and vertical and horizontal directions without increasing a clearance produced between the finger members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a finger joint as an expansion joint device such as a connecting portion with an abutment at an end of a bridge and a connecting portion between adjacent bridges on a pier.

[0002]

2. Description of the Related Art An expansion joint device for a bridge is designed so that a vehicle passing therethrough can pass without any hindrance while the bridge end is mainly expanded or contracted in the bridge axis direction due to a change in the bridge length caused by a temperature change or the like. In order to do this, it is a device that makes the bridge surface continuous. There are various types of expansion joint devices of this type, and a typical example is a finger joint structure.

The finger joint uses a comb-shaped metal object composed of a mounting portion and a large number of beam portions in the bridge axial direction as a finger member, and the finger member is connected to the end portion of the connecting member mounted on the abutment or pier to form a pair. The beam portions of the finger member are engaged with each other with a gap therebetween, and the relative displacement in the bridge axis direction generated between the connecting members can be absorbed by the change in the length of the engaged portions.

When the length of the bridge is small and the amount of expansion and contraction is small, since the length of the beam portion constituting the finger member is small, the finger member is fixed to the end portion of the connecting member.
Sufficient proof stress can be obtained with a cantilever structure overhanging the meshing part, but the required adjustment amount of relative displacement is 50 for long bridges.
If it exceeds 0 mm, the beam section of the finger member becomes very large in a cantilever structure, which is practically impossible.

[0005] It was proposed in Japanese Examined Patent Publication No. 52-32 that such a metal member for supporting a finger member corresponding to a large amount of expansion and contraction is proposed.
This is the invention described in Japanese Patent No. 175. Japanese Examined Japanese Patent Publication No. 52-3217
According to the invention described in Japanese Patent Publication No. 5, the beam portion that constitutes the finger member slides on the receiving metal fitting, and the beam portion of the finger member is supported at multiple points with respect to the loading load acting in the vertical direction.

Therefore, even if the length of the beam portion becomes large,
The cross-sectional force of the beam portion due to the applied load does not increase, and the cross-section can be reduced.

[0007]

In the case where the beam member of the finger member has a generally rectangular cross-sectional shape in the related art, if the width is increased, the interval between the beam members of the finger member is increased, and the beam of the opposing finger member is increased. In a region other than the section where the parts are meshed with each other, there is a risk that the tire of a vehicle passing through becomes large and gets into the gap between the beam parts.

For example, the minimum tire width of a motorcycle is about 58 mm.
It is said that when the gap between the beam parts that mesh with each other between the opposing finger members is 5 mm, a gap occurs (corresponding to the space between the adjacent beam parts of the finger member on one side).
The width of the beam portion is limited to 48 mm or less in order to reduce the width to 58 mm or less. Further, in the case of a bicycle, the minimum tire width is about 28 mm, and in order to make the gap less than this, the width of the beam portion of the finger member must be 18 mm or less.

Therefore, the conventional rectangular cross section has a limit in increasing the rigidity of the beam portion of the finger member in the direction perpendicular to the bridge axis.

The beam portion of the finger member in the invention described in Japanese Patent Publication No. 52-32175 described above is supported at multiple points in the vertical direction, but only the base portion in the horizontal direction perpendicular to the bridge axis. Since it is a cantilever structure that is supported, the generated cross-sectional force is large with respect to the load in the horizontal direction perpendicular to the bridge axis.

In the case of an ordinary finger joint, since the load acting is predominant in the vertical direction, the small rigidity in the horizontal direction perpendicular to the bridge axis does not pose a problem. However, for example, when the expansion / contraction amount exceeding 1 m is required, the length of the beam portion of the finger member becomes large, and a relatively large displacement occurs due to the horizontal load perpendicular to the bridge axis that acts when braking or changing the direction of the traveling vehicle. May occur and the gap between the beam portions of the finger member may not be maintained, and the function as the expansion joint device may not be achieved.

If the rigidity in the horizontal direction at right angles to the bridge axis is small, sideways buckling is likely to occur and the yield strength may be reduced even with respect to a vertical load.

The present invention is intended to solve the above-mentioned problems, and suppresses horizontal displacement by increasing the rigidity in the horizontal direction perpendicular to the bridge axis without increasing the gap generated in the finger member, thereby suppressing sideways buckling. It is an object of the present invention to provide a finger joint for a bridge, which has improved yield strength and can cope with a large amount of expansion and contraction.

[0014]

DISCLOSURE OF THE INVENTION The invention of the present application is a bridge expansion / contraction device in which opposing finger members each composed of a mounting portion and a large number of beam portions in the bridge axis direction are movably engaged in the bridge axis direction. In a finger joint, for adjacent beam parts in a state where the finger members are meshed with each other, a convex part that is continuous in the axial direction is provided on the side surface of one beam part, and a similar shape to this convex part on the side surface of the other beam part. Is characterized in that a concave portion continuous in the axial direction is provided so that the convex portion and the concave portion are in a fitted state with a predetermined gap therebetween.

The cross-sectional shapes of the convex portion and the concave portion are square,
The shape is not particularly limited to a semicircle, a triangle, and the like, and as an extension of the triangle, for example, one in which the entire beam portion has a V-shaped cross-sectional shape may be used.

[0016]

According to the present invention, the rigidity in the horizontal direction perpendicular to the bridge axis is increased without increasing the gap generated in the finger member.

That is, by providing a convex portion on one side surface of the beam portion constituting the finger member, the rigidity in the horizontal direction perpendicular to the bridge axis can be increased, and the other side surface has a similar shape to the convex portion. By providing the concave portion, the convex portion and the concave portion are in a fitted state in a state where the finger members are meshed with each other, and a gap generated in the finger member does not increase.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings while comparing it with a conventional example.

4 (a) and 4 (b) show an example of a link type expansion joint device as an example of a structure to which the finger joint for bridge of the present invention can be applied.

In this example, as shown in FIG. 4 (a), the opposing finger members 1 and 2 are connected to the transverse beam 20 at the bridge girder end of the bridge, respectively, and are placed on the central transverse beam 22 supported by the link mechanism 21. By sliding in opposite directions, the amount of expansion and contraction is absorbed.

FIG. 4 (b) shows an example of the planar arrangement of the finger members 1, 2 corresponding to FIG. 4 (a). The finger member 1 (or 2) is a comb-shaped metal object composed of a mounting portion connected to the lateral beam 20 at the end of the bridge girder and a large number of beam portions 3 (or 4) extending in the bridge axial direction. , 2 are engaged with each other with a gap 5 therebetween.

In FIG. 4 (b), the finger members 1 and 2 are
By moving in the left-right direction, the amount of expansion and contraction is absorbed, and the direction of expansion and contraction matches the axial direction of the bridge.

FIGS. 5 (a) and 5 (b) show a cross section of the meshing portion of the rectangular beam sections 3 and 4 in the conventional finger joint as a comparative example. FIG. 5 (a) is shown in FIG.
5B corresponds to the section taken along the line AA of FIG. 4B, and FIG. 5B corresponds to the section taken along the line BB of FIG. 4B.

That is, the beam portions 3 and 4 having a rectangular cross section are meshed with each other while holding the gap 5, and the width of the gap 5 between the beam portions 3 and 4 of the finger members in the mutually meshed state is a, When the width of the beam portions 3 and 4 is b (see FIG. 5 (a)), the maximum clearance 12 in the finger joint in the direction perpendicular to the bridge axis is 2a + b (see FIG. 5 (b)).

FIGS. 1 (a) and 1 (b) show the cross-sectional shapes of the beam portions 3 and 4 in an embodiment of the finger joint according to the present invention. FIG. 1 (a) shows the cross section of FIG. 4 (b). The cross section taken along the line AA in FIG. 1B corresponds to the cross section taken along the line BB in FIG. 4B.

In this embodiment, the beam portions 3 and 4 constituting the finger member of the finger joint are provided with the quadrangular convex portion 6 and the concave portion 7 which are continuous in the bridge axis direction. Here, the beam portion 3 constitutes one finger member 1 as a whole,
The beam portion 4 constitutes the other finger member 2 (see FIG. 4).
(See (a) and (b)).

As shown in FIG. 1A, the convex portion 6 and the concave portion 7 are in a state of being fitted with each other with a gap 5 therebetween. Here, the gap 5 is usually about 5 mm.

On the other hand, as shown in FIG. 1 (b), by adopting such a structure, the finger member 1 (or 2)
Even when the maximum clearance 12 on the upper surface of the bridge is the same as the clearance in the conventional rectangular cross section (2a + b), the rigidity in the horizontal direction perpendicular to the bridge axis is increased.

As a result, the displacement due to the load in the horizontal direction at right angles to the bridge axis can be made smaller than the width of the gap 5 between the beam portions 3 and 4, and sideways buckling can also be caused for the vertical load. It is possible to improve the yield strength, and for example, it is possible to realize a finger joint for a large expansion / contraction amount of 500 mm or more.

Since the material of the finger member is usually cast steel, a member having such a shape can be manufactured relatively easily.

FIG. 2 shows the meshing state of the beam portions 3 and 4 in another embodiment. In this embodiment, the convex portion 8 and the concave portion 9 which are fitted with each other with the gap 5 interposed therebetween have a triangular sectional shape. There is.

FIG. 3 shows a beam portion 3 according to still another embodiment.
4 shows the meshed state, and in this embodiment, as an extension of the embodiment of FIG. 2, the cross sections of the beam portions 3 and 4 in the direction perpendicular to the bridge axis have a dogleg shape.

[0033]

EFFECTS OF THE INVENTION A convex portion and a concave portion are provided on the side surface of a beam portion of a finger member, and they are fitted with each other with a predetermined gap therebetween, and the rigidity in the horizontal direction perpendicular to the bridge axis is increased without increasing the gap generated in the finger member. Can be increased.

Therefore, even when the length of the beam portion of the finger member is large, the displacement in the horizontal direction perpendicular to the bridge axis can be made smaller than the gap between the beam portions of the opposing finger members,
The lateral buckling resistance is improved even with respect to the load applied in the vertical direction.

As described above, an expansion joint device for a bridge having a large expansion / contraction amount can be realized.

[Brief description of drawings]

FIG. 1 shows a cross-sectional shape of a beam portion in an embodiment of a finger joint according to the present invention, in which (a) is a cross-sectional view taken along the line AA of FIG. 4 (b), and FIG. ) Of B
FIG. 6 is a cross-sectional view corresponding to a cross section taken along line B.

FIG. 2 is a cross-sectional view showing a meshing state of beam portions in another embodiment, and is a cross-sectional view corresponding to a cross section taken along the line AA of FIG. 4 (b).

FIG. 3 is a cross-sectional view showing a meshing state of beam portions according to still another embodiment, which is a cross-sectional view corresponding to a cross section taken along the line AA of FIG. 4 (b).

FIG. 4 shows an example of a link type expansion joint device as an example of a structure to which the finger joint for a bridge of the present invention can be applied, (a) is a side view of the expansion joint device, and (b) is a finger joint. It is a top view of a part.

FIG. 5 shows a cross section of a meshing portion of a beam section having a rectangular cross section in a conventional finger joint as a comparative example, and (a) is a cross-sectional view corresponding to the cross section taken along the line AA of FIG. 4 (b), FIG. 2 is a cross-sectional view corresponding to the cross section taken along the line BB of FIG.

[Explanation of symbols]

1, 2 ... finger member, 3, 4 ... beam part, 5 ... gap, 6
... convex portion, 7 ... concave portion, 8 ... convex portion, 9 ... concave portion, 12 ... maximum gap, 20 ... lateral beam at both ends, 21 ... link mechanism, 22 ... central lateral beam

Claims (2)

[Claims] 1. In a finger joint as a bridge expansion and contraction device, wherein finger members, which are opposed to each other and which are composed of a mounting portion and a large number of beam portions in the bridge axis direction, are movably meshed with each other in the bridge axis direction. Regarding the adjacent beam portions in the meshed state, a convex portion that is continuous in the axial direction is provided on the side surface of one beam portion, and a concave portion that is substantially similar to the convex portion and continuous in the axial direction is provided on the side surface of the other beam portion. Provided,
A finger joint for a bridge, wherein the convex portion and the concave portion are in a fitted state with a predetermined gap therebetween. 2. The finger joint for a bridge according to claim 1, wherein the cross section of the beam portion in the direction perpendicular to the bridge axis is a dogleg shape.