JPH04141B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a connection structure for composite structural members, and more specifically, for example, when forming a composite structure of concrete slabs and steel girders, the connection structure between concrete slabs,
and a structure for connecting and fixing concrete slabs and steel girders to integrate them.

BACKGROUND ART A typical prior art is shown in FIG. steel girder 1
Concrete slabs 3a and 3b are installed on the upper flange 2 so that their end faces face each other. In the space 5 where the concrete slabs 3a and 3b face each other, reinforcing bars 6a buried in the concrete slab 3a and reinforcing bars 6b buried in the concrete slab 3b are in a wrapped state. Concrete is placed in the space 5 in this state. This connects the concrete slabs 3a and 3b. In such prior art, the reinforcing bars 6a,
Since the reinforcing bars 6b are relatively roughly arranged and buried within the concrete slabs 3a and 3b, the tips of the reinforcing bars 6a and 6b come into contact with each other within the space 5, making it difficult to wrap them properly. To solve this problem, the worker may wrap the reinforcing bars 6a and 6b, but such an operation requires a lot of effort and is poor in operability.

Another problem with the prior art is that cast-in-place concrete is not suitable for concrete slabs 3a and 3b.
Peeling from the cast-in-place concrete is likely to occur near the interface between the two, and cracks may also occur, causing problems in terms of strength. Furthermore, it is also inferior in fatigue durability.

In other prior art, concrete slabs with a rectangular cross section spanning between steel girders are installed on the steel girders so that their end faces face each other, and mortar is injected between the end faces to integrate the concrete slabs. There is. In such prior art, the strength of the connection is also problematic, and inherent cracks in the cast-in-place concrete occur, and separation of the concrete slab and the cast-in-place concrete is likely to occur.

Problems to be solved by the invention In summary, the above prior art has poor workability;
Moreover, the strength transmission at the connection between the concrete slabs is unstable, and the fatigue durability is also poor.

The purpose of the present invention is to solve the above-mentioned technical problems,
An object of the present invention is to provide a connection structure for synthetic structural members that guarantees strength transmission between auxiliary members and improves workability and fatigue durability.

Means for Solving the Problems The present invention provides a plurality of steel girders 14 extending in the axial direction A of the bridge.
A plurality of concrete slabs 17 are placed adjacent to each other in the direction perpendicular to the bridge axis, and an upper flange of the steel girder 14 is attached to each end of each concrete slab 17 facing each other on the steel girder 14. A mounting recess 26 into which the upright anti-slip member 21 is inserted, a fixing hole 25 provided adjacent to the mounting recess 26 and partitioned by the mounting recess 26 and a partition 29, and a fixing hole. 25 and a buried hole 27 communicating with the mounting recess 26 are formed, and the mounting recess 26, the fixing hole 25, and the buried hole 27 have a depth at least equal to or longer than the length in the short side direction, and are opposed to each other. Distribution bars 50 are embedded in the concrete slab 17 between each anchoring hole 25.
A joining member 28 positioned by a is provided, and both ends 33a, 33b of this joining member 28;
4a, 34b are supported by fixing plates 31, 32 arranged in the fixing hole 25, and these fixing plates 31, 32 are supported by the partition part 29, and in this state, the fixing holes 26 and the fixing holes 25 and Buried hole 27
This is a connection structure for synthetic structural members, which is characterized in that a bonding agent is filled in and cured.

Effect According to the present invention, each of the mutually opposing ends of the plurality of concrete slabs 17 arranged between the plurality of steel girders 14 extending in the bridge axis direction A has the mounting recess 26 and the fixing hole 25. and a buried hole 27 are formed, respectively. A joining member 28 is provided between adjacent buried holes 27, and both ends of this joining member 28 are arranged within the fixing hole 25, respectively.
In this state, the mounting recess 26 and the fixing hole 2
5 and the embedded hole 27 are filled with a fixing agent and hardened. In this way, concrete slabs 17 adjacent in the direction perpendicular to the bridge axis are joined to each other.

Both ends of the joining member 28 are supported by fixing plates 31 and 32 arranged in the fixing hole 25, and the fixing plates 31 and 32 have a partition portion 29 that partitions the fixing hole 25 and the buried hole 27. As a result, a compressive force acts on the fixing agent disposed between each fixing plate 31 and 32, thereby reducing the tensile force generated when a load is applied to the concrete slab 17. It is possible to prevent cracks from occurring by reducing stress as much as possible. Furthermore, the anti-slip member 21 erected on the steel girder 14 is inserted into the mounting recess 26 and fixed with the adhesive, so the steel girder 14 and the concrete slab 17 are joined with great strength. can do.

Embodiment FIG. 1 is a plan view of a bridge in which a connection structure according to the present invention is used. The bridge 11 is supported by abutments 12 and 13 at both ends thereof. Bridge 11 is
The bridge is composed of a frame structure including a plurality of steel girders 14 having an I-shaped cross section extending in the axial direction A of the bridge, and cross beams or counter-tilt structures supported by these steel girders 14. A bridge deck slab 16 is installed on the steel girder 14. In addition, in FIG. 1, for ease of explanation, the concrete slab 17 that constitutes the bridge deck slab 16 is shown in the left half.
The right half omits this.

FIG. 2 is a simplified perspective view showing the state in which the concrete slab 17 is attached to the steel girder 14. The steel girder 14 extending in the bridge axial direction A has an upper flange 18
, a lower flange 19 , and a web 20 connecting the upper flange 18 and the lower flange 19 . A slip prevention member 21 is provided on the upper surface of the upper flange 18 to prevent the concrete slab 17 from slipping. This anti-slip member 21 is, for example, a dowel, and is made up of a plurality of rod-shaped protrusions 22, and is welded to the upper surface of the upper flange 18 to stand upright. A plurality of these anti-slip members 21 are arranged on the upper surface of the upper flange 18 at intervals.

A plurality of mounting holes 23 are formed in the concrete slab 17 at intervals along the bridge axis direction A.
At the end of the central girder 14a of this concrete slab 17, as shown in FIG. is formed. This notch 2
4 includes a mounting recess 26 into which the anti-slip member 21 is fitted, and a burying hole 27 into which a joining member 28 (see FIG. 4) connecting between the concrete slabs 17 is buried. The anti-slip member 2 is installed in the mounting recess 26.
1 is inserted. The attachment recess 26 and the fixing hole 25 are separated by a partition portion 29. The upper surface 29a of this partition portion 29 is formed to be recessed downward by a distance d1 from the upper surface 17a of the concrete slab 17. Further, the lower surface 29b of this partition portion 29 is formed to be flush with the lower surface 17b of the concrete slab 17.

The fixing hole 25 is formed in a generally rectangular shape with an upward opening. The fixing hole 25 is located outside the side portion 18a of the upper flange 18 of the steel girder 14a. The depth d2 of the fixing hole 25 is selected to be greater than or equal to the sum of the short side distance B1 of the fixing hole 25 and the depth d1 of the buried hole 27. Therefore, the effective depth of the fixing hole 25 from the upper surface 29a of the buried hole 27 is the distance B1 in the short side direction, and the depth is set to be sufficiently large with respect to the surface area of the adhesive filled in the fixing hole 25. As a result, the occurrence of cracks in the adhesive can be minimized, and even if cracks occur, the adhesive can be prevented from peeling off. Further, the depth d1 of the buried hole 27 is
The buried width B2 is selected to be larger than the buried width B2. Therefore, the depth can be made sufficiently large relative to the surface area of the adhesive filled in the buried hole 27, and thereby the occurrence of cracks can be minimized. It is possible to prevent the adhesive from peeling off even if the adhesive is removed.

In each concrete slab 17, a plurality of such attachment holes 23, notches 24, and fixing holes 25 are formed at intervals along the bridge axis direction A.

Further, distribution bars 50 are buried in the concrete slab 17 in parallel to the bridge axis direction A, and main reinforcing bars 60 are buried in a direction perpendicular to the bridge axis direction A.

FIG. 4 is a plan view of the concrete slab 17 installed between the steel girders 14 and connected by the connecting members 28, and FIG. 5 is a cross-sectional view taken from the cutting plane line - in FIG. FIG. 6 is a perspective view of the joining member 28. The joining member 28 is
A pair of fixing plates 31 and 32 that come into contact with the front wall 25a of the fixing hole 25, threaded rods 33 and 34 that pass through between the fixing plates 31 and 32, and a nut 35 that presses the fixing plates 31 and 32 against the front wall 25a. including. Threaded rod 3
3 and 34 are parallel, and each end has a threaded portion 33.
a, 33b, 34a, and 34b. Threaded part 3
3a, 33b, 34a, and 34b are bent such that their free ends are slightly separated from the bottom wall 25b of the fixing hole 25.

The assembled state of the joining member 28 having such a configuration is shown in FIG. That is, the fixing plate 31 has insertion holes 31e and 31f formed in advance. The interval l1 between the insertion holes 31e and 31f is
The distance is selected to be approximately the same as the buried width B2 of No.7. Further, the distance l2 from the lower end of the fixing plate 31 is
The horizontal parts 33c and 34c of 3 and 34 are the upper distribution bars 5
It is selected to be located near the bottom of 0a. The other fixing plate 32 has the same configuration as the fixing plate 31, and has insertion holes 32e and 32f. The fixing plates 31 and 32 have sufficient strength and rigidity to tolerate stress generated in the fixing plates 31 and 32 when the nut 35 is tightened.

Next, the process of laying the concrete slab 17 on the steel girder 14 to form the bridge deck slab 16 will be described below. First, a plurality of concrete slabs 17 are mounted on the steel girder 14 so that the recesses 26 face each other and are arranged in parallel along the bridge axis direction A. Mounting recesses 26 on the sides of the concrete slabs 17 facing each other in the direction perpendicular to the bridge axis
Adhesive is pre-applied to the remaining sides of the concrete slabs 17, so that rainwater and dirt do not enter between the adjacent concrete slabs 17, and the strength is strong enough to prevent them from easily shifting under the slightest load. It is glued with.

Next, adhesive is applied to the surfaces of the fixing plates 31 and 32 facing the front wall 25a, and the threaded rod 3 is inserted into the fixing hole 25.
Insert both ends of 3 and 34, respectively. As a result, the horizontal portions 33c, 34c of the threaded rods 33, 34
is in a state where it straddles between the fixing holes 25. After the fixing plates 31 and 32 are fixed to the front wall 25a of the fixing hole 25, the nut 35 is tightened to a required torque. This ensures the connection between the concrete slabs 17. After that, the mounting recess 26, the buried hole 27, the fixing hole 25, and the mounting hole 2
3. Inject a fixing agent such as mortar or cement. After curing for a certain period of time, the concrete slabs 17 are integrated, and furthermore, these concrete slabs 17 and the steel girder 14 are integrated. In this way, the bridge deck slab 16 is formed.

Next, the reason why the strength of the connection between the concrete slab 17 and the steel girder 14 and the joint between the concrete slabs 17 is improved by the above connection structure will be explained.

(1) Generally, negative bending moments occur on steel girders, and when concrete slabs are connected using conventional lap joints, cracks are likely to occur on the surface. That is, the reinforcing bars are supported by the adhesive force with the adhesive, and the adhesive is supported by the adhesive force with the concrete slab. However, if the adhesive filling process is rough, as is often the case in on-site construction, the adhesive between the parts that should support the reinforcing bars and the concrete slabs will not be secured, resulting in cracks and peeling of the adhesive. To prevent such peeling of the adhesive, either fill the adhesive deeply so that it exceeds the crack occurrence depth to ensure an effective adhesion area, or allow cracks but remove the adhesive. The depth at which it is difficult for the adhesive to protrude, that is, the occurrence of cracks, is simply due to tensile stress occurring near the surface of the adhesive and compressive stress occurring inside the adhesive, so the interior is compressed. Although the adhesive tends to be pushed out toward the surface, it is generally considered that the adhesive is filled deep enough to prevent the adhesive from extruding. In the present invention, the latter method is adopted and the ratio of the depth d2-d1 of the fixing hole 25 to the width B1 is set to be 1 or more, so even if the adhesive is peeled off from the inner wall of the fixing hole 25, The fixing agent does not protrude from the fixing hole 25, and therefore both ends of the threaded rods 33 and 34 can be securely fixed.

(2) In the present invention, on the premise that the degree of adhesion between the adhesive and the concrete slab 17 joint cannot be expected,
The fixing plate 3 is tightened with a nut 35 via the threaded rods 33, 34 and the fixing plates 31, 32.
The structure is such that it is supported by the bearing pressure of concrete according to Nos. 1 and 32. As a result, the threaded rods 33, 3
The tensile force acting on
acts as a compressive force on the adhesive within the notch 24, thereby generating compressive stress in the adhesive within the notch 24. Therefore, without relying on the adhesion force between the adhesive and the inner surface of the notch 24, the adhesive is held between the inner surfaces, so to speak, to prevent cracking and peeling of the adhesive between the fixing plates 31 and 32, The connection between the concrete slabs 17 becomes reliable.

(3) Also, fix the fixing hole 25 on the upper flange 18 of the steel girder 14.
Since it is provided outside the side portion 18a of the flange, it is set at a position where a negative bending moment (generally changing in a quadratic curve) occurs, which is much smaller than the negative bending moment that occurs directly above the flange. As a result, fixing hole 2
It is possible to prevent cracks by reducing the tensile stress generated in the adhesive in the container 5 and the surrounding concrete.

(4) Furthermore, so that there is no need to expect that the fixing agent will fill the lower part of the fixing hole 25 and the degree of fixation will not be high.
Both ends of the threaded rods 33 and 34 are bent so as to extend to the vicinity of the bottom wall 25b of the fixing hole 25. As a result, even if a slight play occurs in the fixing plates 31, 32, the front wall 25a and the fixing plates 31, 32
The adhesive surrounded by is in a triaxially compressed state, sufficiently restraining the horizontal parts 33c, 34c of the threaded rods 33, 34, and bending parts 33a, 33b; 34a, 34.
b and the adhesive that adheres to them can be prevented from being pulled out, and the adhesive that adheres to these bent portions is also compressed by the surrounding concrete and adheres tightly, thereby preventing extraction.

(5) When a load is applied to the concrete slab 17, the fixing agent filled in the fixing hole 23 becomes in a triaxially compressed state like the fixing agent in the fixing hole 25,
The anti-slip member 21 can be securely fixed.

(6) The fixing agent filled in the holes in the horizontal parts 33c and 34c of the threaded rods 33 and 34, whose both ends are sufficiently fixed as described above, is such that the depth _d1 of the hole is
Since it has a depth of 0a lower surface, the distribution bar 50
a and the horizontal parts 33c, 34c of the threaded rods 33, 34
It is securely fixed by

In this way, between the concrete slab 17 and the steel girder 14
and the concrete slab 17 can be reliably fixed. Therefore, it is possible to design the concrete slab 17 as a continuous slab, and it is possible to reduce the material cost by more than 10% compared to the conventional concrete slab, which is designed as a simple plate because the connection cannot be guaranteed. .

FIG. 8 is a perspective view of another embodiment of the joining member.

This embodiment is similar to the previous embodiment, and corresponding parts are provided with the same reference numerals. It should be noted that
In this embodiment, the insertion holes 31 of the fixing plates 31 and 32
e, 31f; instead of 32e, 32f, fixing plate 3
Notches 81e and 81 opened in the upper end surfaces of 1 and 32
f; 82e and 82f are formed. With such a configuration, the screw rods 33 and 34 are connected to the fixing plates 31 and 32.
This makes it easier to install.

In the above embodiment, both ends of the threaded rods 33 and 34 are bent, but they may be straight.

Although the above-described embodiments have been described with respect to concrete slabs constituting the bridge surfaces of bridges, the present invention can also be suitably implemented with respect to connection structures of synthetic structural members constituting floor slabs of buildings and the like.

Effects As described above, according to the present invention, the mounting recess 26
Since the fixing hole 25 and the embedding hole 27 have a depth at least equal to or greater than the length in each short side direction, cracking and peeling of the adhesive can be prevented.

Furthermore, since the joining member is supported by the fixing plates 31 and 32, even if a tensile force is applied to the joining member, a compressive force is applied to the adhesive present between the fixing plates 31 and 32. This makes it possible to prevent the occurrence of cracks and peeling, and also to increase the frictional force with the concrete without relying on the adhesion force with the concrete slab 17 to prevent pull-out.

Furthermore, since the joint member is positioned by the distribution reinforcement 50a buried in the concrete slab 17, there is no need to separately provide a sink reinforcement or the like.
The joining member can be positioned accurately and reliably. This is important in order to fill the entire circumference of the joining member with the adhesive and obtain reliable fixing. Each concrete slab 1 is thus placed across a plurality of steel girders 14 extending in the axial direction of the bridge.
7 in the direction perpendicular to the bridge axis, that is, in the direction of the main reinforcing bars, can be achieved with great strength.

[Brief explanation of drawings]

FIG. 1 is a plan view of a bridge using the connection structure according to the present invention, FIG. 2 is a simplified perspective view of the concrete slab 17 attached to the steel girder 14, and FIG. 3 is one end of the concrete slab 17. Figure 4 is an enlarged perspective view of the section where the concrete slab 17 is replaced by the steel girder 14.
5 is a sectional view taken from the cutting plane line - of FIG. 4, FIG. 6 is a perspective view of the joining member 28, and FIG. 7 is an exploded perspective view of the joining member 28, FIG. 8 is a perspective view of another embodiment of the joining member, and FIG. 9 is a perspective view showing a typical prior art. 11... Bridge, 14... Steel girder, 16... Bridge deck slab, 17... Concrete slab, 24... Notch,
25...Fixing hole, 26...Mounting recess, 27...
Buried hole, 28...Joining member, 29...Partition part, 3
1, 32... Fixing plate, 33, 34... Threaded rod, 3
5...Natsuto, 33a, 33b, 34a, 34b
... Threaded portion, d1 ... Depth of buried hole 27, d2...
... Depth of the fixing hole 25, B1...Short side of the fixing hole 25, B2... Width of the buried hole 27.

Claims (1)

[Claims] 1. A plurality of concrete slabs 17 are placed adjacent to each other in a direction perpendicular to the bridge axis between a plurality of steel girders 14 extending in the bridge axis direction A, and each concrete slab 17 is placed on the steel girder 14 of each concrete slab 17. At each end facing each other, there is a mounting recess 26 into which the anti-slip member 21 erected on the upper flange of the steel girder 14 is inserted; A fixing hole 25 partitioned by a partition 26 and a partition part 29, and a buried hole 27 communicating with the fixing hole 25 and the mounting recess 26 are formed. A distribution bar 50 having a depth equal to or greater than the length of each short side and buried in the concrete slab 17 between the mutually opposing fixing holes 25.
A joining member 28 positioned by a is provided, and both ends 33a, 33b of this joining member 28;
4a, 34b are supported by fixing plates 31, 32 arranged in the fixing hole 25, and these fixing plates 31, 32 are supported by the partition part 29, and in this state, the fixing holes 26 and the fixing holes 25 and Buried hole 27
A connecting structure for synthetic structural members, characterized by filling a bonding agent into the material and curing the bonding agent.