JP6754219B2 - Floor slab joint structure and floor slab renewal method - Google Patents

Description

The present invention relates to a floor slab joint structure and a floor slab renewal method.

As a floor slab renewal work, after removing an old floor slab from a steel girder, a new floor slab may be installed on the steel girder (see, for example, Patent Document 1).
To renew (replace) the floor slab, it is common to crush the existing concrete floor slab to divide it into small pieces and remove it, and then place the new floor slab on the steel girder. However, it takes time and effort to crush the floor slab. In addition, noise and vibration generated during crushing may affect the neighborhood.
Therefore, as a method of updating the floor slab, the floor slab may be removed relatively easily and early by cutting the joint between the existing floor slab and the steel girder. At this time, the joining girder (stud girder, etc.) projecting from the upper surface of the steel girder as a joining member between the floor slab and the steel girder is cut together with the concrete of the existing floor slab. Therefore, when a new floor slab is installed, a new joining gibber is welded to the upper surface of the existing steel girder, and the new floor slab is installed with the joining gibber wound around.
Further, in Patent Document 2, after removing the upper part of the steel girder together with the existing floor slab by cutting the upper part of the web of the steel girder, a new floor slab provided with the upper part of the steel girder is already installed. A method of renewing a plate slab to be joined to the lower part of a steel girder is disclosed.

Japanese Unexamined Patent Publication No. 2005-256430 JP-A-2007-239365

In order to newly install a joining gibber on the upper surface of the steel girder, it is necessary to clean and remove the concrete remaining on the upper surface of the steel girder, which is troublesome. In addition, it takes time and effort to weld the joining gibber.
Further, in the method of cutting the steel girder on the web, it is necessary to join the steel girder with the joint surfaces of the lower web and the upper web abutting each other, which is troublesome. In addition, since it is necessary to form a large number of bolt holes along the girder shaft at the joint between the webs, the work is also troublesome. Further, since the proof stress of the steel girder is lowered by removing the upper flange of the steel girder, reinforcement work for increasing the proof stress of the steel girder is required.
From this point of view, it is an object of the present invention to propose a floor slab joint structure and a floor slab renewal method that can reduce the labor during construction in the floor slab renewal work and shorten the construction period. ..

The floor slab joining structure of the present invention for solving the above problems includes a steel girder, a floor slab placed on the upper surface of the steel girder, and a fixing member for joining the steel girder and the floor slab. The fixing member is fixed to the corners of the lower surface of the upper flange of the steel girder and the side surface of the web, and the fixing piece fixed to the side surface of the web of the steel girder and the web. It is provided with an upper piece extending in the intersecting direction and a joining girder erected on the upper surface of the upper piece, and the tip end portion of the upper piece protrudes from the side end of the flange. The joining girder is characterized in that it is fixed to the tip of the upper piece and inserted into the floor slab.
According to such a floor slab joining structure, since the steel girder and the floor slab are joined via a fixing member, it is not necessary to newly form a joining jib on the upper surface of the steel girder. Therefore, it is possible to omit the labor required for the work of cleaning the upper surface of the steel girder and the work of installing the joining gibber in the floor slab renewal work.
If the pair of fixing members are opposed to each other with the web of the steel girder sandwiched between them and the fixing pieces of the pair of fixing members are fixed by bolts penetrating the web, the fixing means for fixing the fixing member is obtained. The fixing member can be fixed without using the above separately.
Further, if the fixing member is a shaped steel that is continuous along the axial direction of the steel girder, the steel girder can be reinforced by the fixing member. Therefore, even when the force acting on the steel girder increases with the renewal of the floor slab, the desired proof stress can be exhibited.

Further, the floor slab renewal method of the present invention includes a removal step of removing the existing floor slab fixed to the upper surface of the steel girder and mounting of a fixing member for fixing the fixing member to the corner between the upper flange of the steel girder and the web. A floor slab renewal method including a step and a floor slab mounting step of mounting a new floor slab on the upper flange of the steel girder, wherein the fixing member is for joining that protrudes upward on the side of the upper flange. A gibber is provided, and the floor slab mounting step is characterized in that the joining gibber is inserted into a box punch formed on the new floor slab.
According to this plate renewal method, it is not necessary to newly form a joining gibber on the upper surface of the steel girder, so that the labor required for cleaning the upper surface of the steel girder and installing the joining girder after the removal process can be omitted. can do. Further, since the new floor slab may be arranged so that the joining gibber is inserted into the box punch, positioning is easy and workability is excellent.
In the fixing member attaching step, it is desirable to dispose a pair of the fixing members so as to face each other with the web sandwiched between them, and to fasten a nut to the pair of fixing members and a bolt penetrating the web.

According to the joint structure of the floor slab and the steel girder and the floor slab renewal method of the present invention, it is possible to reduce the labor at the time of construction in the floor slab renewal work and to shorten the construction period.

It is a perspective view which shows the floor slab joint structure which concerns on embodiment of this invention. (A) is a cross-sectional view showing the details of the floor slab joint structure shown in FIG. 1, and (b) is the same perspective view. (A)-(c) are sectional views which show each step of the floor slab renewal method which concerns on embodiment of this invention. It is a perspective view which shows the floor slab joint structure which concerns on other forms. It is a perspective view which shows the floor slab joint structure which concerns on other forms.

In the embodiment of the present invention, as a floor slab renewal work, a floor slab joint structure adopted when a new floor slab is installed on a steel girder after removing an old existing floor slab from a steel girder and using the same. This section describes how to update the floor slab.
As shown in FIG. 1, the floor slab joint structure 1 of the present embodiment includes a steel girder 2, a floor slab 3, and a fixing member 4.

The steel girder 2 is a main girder that supports the floor slab 3 in a road bridge, and is an existing member that is left as it is even after the existing floor slab is removed.
As shown in FIG. 2A, the steel girder 2 of the present embodiment has an I-shaped cross section due to the upper and lower flanges 21 and 22 and the web 23 provided between the flanges 21 and 22. .. The material constituting the steel girder 2 and the cross-sectional shape of the steel girder 2 are not limited.
As shown in FIG. 2B, ribs 24, 24, ... Are provided at predetermined intervals in the space formed by the upper and lower flanges 21 and 22 and the web 23. The rib 24 may be installed as needed.
As shown in FIG. 1, in the present embodiment, one floor slab 3 is supported by three steel girders 2. The number of steel girders 2 that support the floor slab 3 is not limited.

As shown in FIG. 1, the floor slab 3 is a concrete plate-shaped member placed on the upper surface of the steel girder 2. In this embodiment, a precast member produced in a factory or the like is adopted as the floor slab 3.
A plurality of box punches 31 are formed on the floor slab 3 corresponding to the positions of the steel girders 2. In the present embodiment, three box punches 31 along the girder shaft of the steel girder 2 are arranged side by side in two rows corresponding to the positions of the steel girders 2. The rows of the box punches 31 are formed on the outside of the upper flange 21 of the steel girder 2 (see FIG. 2A). That is, the box punches 31, 31 adjacent to each other in the direction intersecting the girder shaft are formed so as to face each other with the upper flange 21 interposed therebetween, as shown in FIG. 2A. The box punch 31 is an opening having a rectangular shape in a plan view, and penetrates the floor slab 3 vertically.
Further, in the floor slab 3, joint portions 32, 32, ... Are formed at joints with other adjacent floor slabs 3. The joint portion 32 is a concave portion formed on the edge of the floor slab 3, and is configured so that a rectangular concave portion (out of the box) in a plan view is formed when the floor slabs 3 are brought together. .. The configuration (shape, arrangement, etc.) of the joint portion 32 is not limited. Further, the joint portion 32 may be formed as needed.

The fixing member 4 is arranged at the joint between the steel girder 2 and the floor slab 3.
As shown in FIG. 2A, the fixing member 4 includes a fixing member main body 40 and a joining gibber 41.
The fixing member main body 40 of the present embodiment has a so-called chevron shape including a fixing piece 43 fixed to the side surface of the web 23 of the steel girder 2 and an upper piece 42 extending in a direction intersecting the fixing piece 43 (web 23). It is made of steel. The material constituting the fixing member main body 40 is not limited as long as it can be fixed to the corners (near the corners) of the upper flange 21 of the steel girder 2 and the web 23, and is not limited, for example, channel steel. It may be configured by.
In the present embodiment, a pair of fixing members 4 and 4 are arranged so as to face each other across the web 23, and the fixing pieces 43 of both fixing members 4 and 4 are fixed by bolts 44 penetrating the web 23. .. Further, the number and arrangement of the bolts 44 used for fixing the fixing member 4 are not limited.

The upper piece 42 extends from the end of the fixing piece 43 on the upper flange 21 side along the lower surface of the upper flange 21. The upper surface of the upper piece 42 may have a gap between it and the lower surface of the upper flange 21, or may be in contact with the lower surface of the upper flange 21.
The tip portion of the upper piece 42 projects outward from the side end of the upper flange 21 and is located below the box punch 31 of the floor slab 3.
The joining gibber 41 is erected on the upper surface of the tip end portion of the upper piece 42, and is inserted into the box punch 31. The joining gibber 41 of the present embodiment has a height of about 1/2 or more of the thickness of the floor slab 3, and the upper end thereof is located above the middle portion in the height direction of the floor slab 3. ..
In the present embodiment, as the joining gibber 41, a perforated steel plate gibber is adopted as shown in FIG. 2 (b). The shape and dimensions of the joining gibber 41 are not limited.

Next, a floor slab renewal method using the floor slab joint structure 1 of the present embodiment will be described.
The floor slab renewal method includes a removal step, a fixing member mounting step, and a floor slab placing step.
As shown in FIG. 3A, the removal step is a step of removing the existing floor slab 3a fixed to the upper surface of the steel girder 2.
In the present embodiment, the existing floor slab 3a is removed by crushing the existing floor slab 3a using the concrete breaker M. At this time, the joining gibber 4a projecting from the upper surface of the steel girder 2 is also removed together with the existing floor slab 3a. The method of removing the existing floor slab 3a is not limited. For example, it may be removed by dividing it into a plurality of pieces using a concrete cutter, or it may be removed by cutting the joint with the steel girder 2 with a wire saw or the like.

The fixing member attaching step is a step of fixing the fixing member 4 to the steel girder 2.
As shown in FIG. 3B, the fixing member 4 is fixed to the corner portion between the lower surface of the upper flange 21 of the steel girder 2 and the side surface of the web 22. That is, the fixing member 4 is fixed in a state where the upper piece 42 is arranged parallel to the lower surface of the upper flange 21 and the fixing piece 43 is in contact with the web 22.
A through hole for inserting the bolt 44 is formed in advance in the web 22.
In the present embodiment, a pair of fixing members 4 and 4 are attached so as to face each other with the web 22 interposed therebetween, and a nut 45 is fastened to a bolt 44 penetrating the fixing members 4 and 4 and the web 22. Then, the fixing members 4 and 4 are fixed to the steel girder 2.
When the fixing members 4 and 4 are fixed to the steel girder 2, as shown in FIG. 3C, the joining gibber 41 of each fixing member 4 is in a state of protruding upward on the side of the upper flange 21.

The floor slab mounting step is a step of mounting the floor slab 3 on the upper flange 21 of the steel girder 2.
As shown in FIG. 3C, the floor slab 3 is placed so that the joining gibber 41 is inserted into the box punch 31 that opens (penetrates the floor slab 3) on the lower surface.
After the floor slab 3 is placed, the packing material 5 is filled in the box punch 31 and the joint portion 32 (see FIG. 2A). The material constituting the filler is not limited as long as it is cured to exhibit a predetermined strength, but for example, mortar may be used.

According to the floor slab joining structure 1 and the floor slab renewal method of the present embodiment, since the steel girder 2 and the floor slab 3 are joined via the fixing members 4, 4, ..., They are newly joined to the upper surface of the steel girder 2. There is no need to form a gibber. Therefore, it is possible to omit the labor required for cleaning the upper surface of the steel girder 2 and installing the joining gibber after removing the existing floor slab.
Further, since the pair of fixing members 4 and 4 are bolted together with the web 23 sandwiched between them, it is not necessary to separately use the fixing means for fixing the fixing members 4 and 4. Therefore, it is possible to reduce the material cost and the labor during construction.
Further, since the floor slab 3 may be arranged so that the joining gibber 41, 41, ... Is inserted into the box punches 31, 31, ..., The floor slab 3 can be easily positioned and is excellent in workability. ..
A through hole for inserting a bolt 44 is formed in the web 23 of the steel girder 2, and the web 23 is reinforced by fixing pieces 43, 43 of fixing members 4, 4 arranged so as to be sandwiched from both sides. Has been done.

The embodiment according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and each of the above-mentioned components can be appropriately modified without departing from the spirit of the present invention.
For example, in the above embodiment, the case where a plurality of fixing members 4, 4, ... Are installed along the girder shaft of the steel girder 2 has been described, but as shown in FIG. 4, the fixing member 4 is attached to the girder shaft. It may be a continuous member along the line. That is, as the fixing member main body 40 of the fixing member 4, a shaped steel material continuous along the girder shaft may be used. According to the fixing member 4, it also functions as a reinforcing member for the steel girder 2 (upper flange 21). Therefore, even when the force acting on the steel girder 2 increases with the renewal of the floor slab 3, the desired proof stress can be exhibited.
Further, in the above-described embodiment, the perforated steel plate gibber is used as the joining gibber of the fixing member 4, but the material constituting the joining gibber is not limited. For example, as shown in FIG. 5, the stud It may be composed of a gibber.
The fixing member 4 may be manufactured by carrying in a factory-made one, or may be manufactured by welding a joining gibber 41 to a shaped steel material on site. The method of joining the joining gibber 41 and the fixing member main body 40 is not limited.
The box punch 31 of the floor slab 3 may have an opening on the lower side so that the joining gibber 41 can be inserted, and does not necessarily have to penetrate the floor slab 3.
If necessary, a padding material is provided between the steel girder 2 and the floor slab 3.

1 Floor slab joint structure 2 Steel girder 21 Upper flange (upper flange)
22 Lower flange 23 Web 3 Floor slab (new floor slab)
31 Box removal 4 Fixing member 41 Joining gibber 42 Upper piece 43 Fixing piece 44 Bolt 45 Nut

Claims (5)

With steel girders
The floor slab placed on the upper surface of the steel girder and
A floor slab joining structure including a fixing member for joining the steel girder and the floor slab.
The fixing member is fixed to the corner between the lower surface of the upper flange of the steel girder and the side surface of the web.
A fixed piece fixed to the side surface of the web of the steel girder,
An upper piece extending in the direction intersecting the web,
It is provided with a joining gibber erected on the upper surface of the upper piece.
The tip of the upper piece protrudes from the side end of the flange.
The floor slab joining structure is characterized in that the joining gibber is fixed to the tip end portion of the upper piece and inserted into the floor slab. The pair of fixing members face each other with the web of the steel girder sandwiched between them.
The floor slab joining structure according to claim 1, wherein the fixing pieces of the pair of fixing members are fixed to each other by bolts penetrating the web. The floor slab joint structure according to claim 1 or 2, wherein the fixing member is a shaped steel that is continuous along the axial direction of the steel girder. The removal process to remove the existing floor slab fixed to the upper surface of the steel girder,
The fixing member mounting process for fixing the fixing member to the corner between the upper flange of the steel girder and the web,
It is a floor slab renewal method including a floor slab mounting step of mounting a new floor slab on the upper flange of the steel girder.
The fixing member includes a joining gibber that projects upward on the side of the upper flange.
The floor slab renewal method, wherein the floor slab placing step is characterized in that the joining gibber is inserted into a box punch formed on the newly installed floor slab. The fixing member attaching step is characterized in that a pair of the fixing members are arranged so as to face each other across the web, and a nut is fastened to the pair of fixing members and a bolt penetrating the web. The floor slab updating method according to claim 4.

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