JP5560768B2 - Composite floor slab, bridge using the same, and construction method thereof - Google Patents

Description

  The present invention relates to a composite floor slab obtained by combining a floor steel plate and concrete, a bridge using the composite floor slab, and a construction method thereof.

  Conventionally, synthetic floor slabs made of steel and concrete have been used as floor slabs for bridges such as road bridges, viaducts, and railway bridges. Synthetic floor slab is made by integrating floor steel plate and concrete by placing concrete on top of floor steel plate as a formwork. It can be made thinner than RC floor slab and has excellent durability. There is an advantage of being. The composite floor slab integrated with the hardened floor steel plate has sufficient strength. However, when constructing bridges using the composite floor slab, the shape of the floor steel plate during concrete placement should be maintained. For this purpose, reinforcing steel materials such as lateral ribs, three-dimensional trusses, and CT section steel are disposed on floor steel plates.

  For example, a bridge structure using a composite floor slab disclosed in Patent Document 1 is known as such a reinforcing steel material provided for shape retention. In this bridge structure, a composite floor slab is used in which a plurality of reinforcing steel materials made of I-shaped steel extending in a direction orthogonal to the bridge axis direction are arranged side by side in the bridge axis direction on the floor steel plate.

Japanese Patent Laid-Open No. 2008-231688, page 2-8, FIG. 1-10

  However, in the bridge structure using the conventional composite floor slab described above, a problem has been pointed out that cracks are generated in the concrete from the upper end of the reinforcing steel material and affect the fatigue life of the composite floor slab.

  The present invention provides a composite floor slab, a bridge using the composite slab, and a construction method therefor, in which fatigue cracks in concrete are unlikely to occur and manufacturing costs can be reduced in order to eliminate the above-described problems caused by the prior art. With the goal.

  In order to solve the above-described problems and achieve the object, a composite floor slab according to the present invention comprises a plurality of floor steel plates and concrete placed on the floor steel plates, and is installed at a bridge installation location. A horizontal slab attached to the floor steel plate, and a connecting member connected at one end to the horizontal rib and connected at the other end to a support that supports the floor steel plate when the concrete is placed. And the concrete is placed in a state where the floor steel plate is supported by the support work through the connecting member and the lateral rib.

  In the composite floor slab according to the present invention, the floor steel plate may be configured to have a plurality of vertical ribs extending in a direction orthogonal to the horizontal ribs and arranged in parallel in the extending direction of the horizontal ribs.

  Moreover, the said horizontal rib can be made into rigidity smaller than the rigidity required for shape maintenance of the said floor steel plate at the time of the placement of the said concrete.

  Further, the connecting member is made of a steel material whose vertical direction is a longitudinal direction capable of forming a space of a predetermined interval between the floor steel plate and the support work, and a connection portion with the support work is exposed on the upper surface of the concrete. It can be configured to have a length.

  Moreover, the said connection member can be comprised so that it may be connected by the said support work and bolting.

  In the composite floor slab according to the present invention, preferably, a reinforcing bar is installed on the floor steel plate, and the reinforcing bar is integrated with the vertical rib and the horizontal rib by the concrete. .

  The bridge using the composite floor slab according to the present invention includes a composite floor slab in which a plurality of floor steel plates and concrete placed on the floor steel plate are integrated, and a fitting material formed on the composite floor slab, The composite floor slab includes a horizontal rib attached to the floor steel plate, and a support that supports the floor steel plate when one end is attached to the horizontal rib and the other end is placed in the concrete. And the concrete is characterized in that the concrete is placed in a state in which the floor steel plate is supported by the support work via the connection member and the lateral rib.

  In the bridge using the composite floor slab according to the present invention, preferably, a reinforcing bar is installed on the floor steel plate, and the reinforcing bar is integrated with the vertical rib and the horizontal rib by the concrete. be able to.

  The bridge construction method using the composite floor slab according to the present invention includes a floor steel plate erection process for laying a plurality of floor steel plates with lateral ribs attached to a bridge installation location, and the lateral ribs are connected to a support work through a connecting member. And supporting and suspending supporting the plurality of floor steel plates by the support, and a concrete placing step of placing concrete on the plurality of floor steel plates supported by the support And a connecting member removing step of removing the connecting member from the support after the placed concrete is hardened, and a pavement step of piling the concrete with a paving material.

  In the construction method of the bridge using the composite floor slab according to the present invention, preferably, after the floor steel plate laying step, a rebar installation step of installing reinforcing bars on the plurality of floor steel plates is further provided. Can do.

  According to this invention, fatigue cracks in concrete are unlikely to occur, and the manufacturing cost can be reduced.

It is a top view which shows schematic structure of a part of bridge using the composite floor slab which concerns on one Embodiment of this invention. It is A-A 'sectional drawing of FIG. FIG. 3 is an enlarged view of an X part showing an enlarged X part of FIG. 2. FIG. 4 is a B-B ′ sectional view of FIG. 3. It is a flowchart which shows the construction process of the construction method of the bridge using the composite floor slab which concerns on one Embodiment of this invention. It is process drawing for demonstrating a part of construction process of the construction method. It is process drawing for demonstrating a part of construction process of the construction method. It is process drawing for demonstrating a part of construction process of the construction method. It is process drawing for demonstrating a part of construction process of the construction method. It is a figure for demonstrating the application example of the bridge using the composite floor slab which concerns on one Embodiment of this invention.

  Exemplary embodiments of a composite floor slab, a bridge using the same, and a construction method therefor according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view showing a schematic configuration of a part of a bridge using a composite floor slab according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. 3 is an enlarged view of a portion X showing the portion X of FIG. 2 in an enlarged manner, and FIG. 4 is a cross-sectional view taken along the line B-B ′ of FIG.

As shown in FIGS. 1 and 2, the bridge 100 according to this embodiment includes a plurality of main bridges extending in the bridge axis direction L and laid at a predetermined interval in the bridge axis orthogonal direction W orthogonal to the bridge axis direction L. A girder (beam) 1 and a composite floor slab 200 installed on the main girder 1 are provided. On the main girder 1, a support column 1a for supporting a supporting work 20 described later is disposed.
The composite floor slab 200 is, for example, a plurality of continuous floor steel plates 10 laid on the main girder 1 in the bridge axis direction L and the bridge axis orthogonal direction W and connected to each other with high-strength bolts, etc. The cast concrete 50 (FIG. 6) is integrated. The plurality of floor steel plates 10 are reinforced by horizontal ribs 12 and vertical ribs 11.

  The horizontal ribs 12 extend in the bridge axis orthogonal direction W, are arranged at a predetermined interval (for example, 2.5 m to 10 m) in the bridge axis direction L, and are a plurality of floor steel plates arranged in the bridge axis orthogonal direction W. 10 fixed by welding, or those previously welded to each floor steel plate 10 can be used. The lateral rib 12 has a rigidity smaller than the rigidity necessary for maintaining the shape of the floor steel plate 10 at the time of placing concrete, for example, when a plurality of floor steel plates 10 are laid on the main beam 1, at the arrangement interval of the connecting members 30. It suffices that the floor steel plate 10 has rigidity enough to prevent deformation due to its own weight. This is different from the reinforcing member that holds the weight of the conventional concrete.

Further, the vertical ribs 11 are previously attached to the floor steel plate 10 by welding, and a plurality of the longitudinal ribs 11 are arranged in parallel with a predetermined interval in the bridge axis orthogonal direction W extending in the bridge axis direction L. In addition, the vertical rib 11 functions also as a concrete gap stop simultaneously with reinforcement of the floor steel plate 10. For this reason, the construction cost can be reduced by omitting or greatly simplifying other misalignment prevention work such as a stat gibber.
In addition, although not shown, the reinforcing bars are appropriately disposed in the bridge axis direction L and the bridge axis orthogonal direction W.

  The floor steel plate 10 is made of a steel plate having a thickness of about 8 mm to 10 mm, for example, and includes a drain hole (not shown). Further, side wall portions 19 are erected at side end portions of the floor steel plate 10 at both ends in the bridge axis orthogonal direction W.

  In the above configuration, before the concrete is placed, the lateral ribs 12 attached to the connected floor steel plates 10 are connected to the connecting member 30 connected to the support work 20 extending in the bridge axis orthogonal direction W. Is done. The support 20 is made of a so-called truss beam or I-beam, extends in the direction orthogonal to the bridge axis W along the lateral rib 12, and is arranged in parallel in the bridge axis direction L so as to correspond to the position of the lateral rib 12. Is done. Further, when the lateral buckling strength of the support 20 becomes a problem, each support 20 is connected to each other via an axial floor slab support 40 extending in the bridge axis direction L. However, the support 20 is self-supporting. When it does, it does not need to be connected.

  For example, as shown in FIG. 3 and FIG. 4, the support work 20 has a reinforcing rib 21 made of L-shaped steel extending in the bridge axis orthogonal direction W on the lower end portion side. 51, the upper end of the connecting member 30 is screwed and connected. The connecting member 30 is made of, for example, a bar-shaped steel material (copper copper), the longitudinal direction thereof is arranged in the vertical direction, and the lower end portion thereof is screwed and fixed by a nut 52 fixed to the lateral rib 12 by welding. The connecting member 30 is set to such a length that a space with a predetermined interval can be formed between the support work 20 and the floor steel plate 10 so that a sufficient work space can be secured even after the concrete is placed, for example. Yes. The length of the space is such that the connecting portion between the reinforcing rib 21 and the connecting member 30 of the support work 20 is exposed from the concrete upper surface after the concrete is placed, and the worker can work on the upper surface of the concrete while avoiding the support work 20 at least. The length is set such that a space (for example, a space having a height of about 1.5 m) can be formed. In addition, the horizontal rib 12 may be joined by welding, for example, in addition to the connecting member 30 and the bolting described above.

  When the support 20 and the horizontal rib 12 are connected via the connecting member 30 in this way, the floor steel plate 10 is suspended via the support 20, the connecting member 30 and the horizontal rib 12 by lifting it with a crane or the like (not shown). It will be erected. Thereafter, the supporting work 20 is set and fixed to the support 1a on the main girder 1, and these are supported by the support 1a by removing the crane and the like. Thus, the concrete is placed on the floor steel plate 10 and hardened in a state in which the support of the support steel 20 enables the shape retention of the connected floor steel plates 10 during concrete placement. Thereafter, the nut 51 on the upper end side of the connecting member 30 exposed on the concrete is removed, the supporting work 20 is removed from the connecting member 30 and the column 1a, and the supporting work 20 is removed. Further, the connecting member 30 exposed on the upper surface of the concrete is removed. At this time, it removes in the state which the part which remained in the concrete inside of the connection member 30 after removal is not exposed to the concrete upper surface. In addition, after concrete hardening, since the floor steel plate 10, the vertical rib 11, the horizontal rib 12, a reinforcing bar, and concrete are integrated, sufficient intensity | strength is ensured.

  As described above, in the bridge 100 according to the present embodiment, the weight of the concrete applied to the floor steel plate 10 at the time of placing the concrete is not supported by the lateral ribs 12 but is supported by the support works 20, thereby reducing the weight of the lateral ribs 12. And miniaturization. Therefore, it is possible to omit or simplify the processing of the reinforcing steel material for maintaining the shape and the floor steel plate 10 as in the past, and to improve the fatigue life by suppressing the crack of the concrete at the upper end of the reinforcing steel material. it can. Further, it is possible to reduce the manufacturing cost by reducing the material cost and the number of work steps.

  In addition, by hanging and supporting the floor steel plate 10 via the connecting member 30 connected to the support work 20, a space of a predetermined interval can be formed between the support work 20 and the floor steel plate 10. For example, by using as a work space, construction work such as placing concrete can be easily performed. Furthermore, since the support work 20 can be used repeatedly or diverted to other works, the total manufacturing cost can be reduced.

  Next, an example of a bridge construction method using the composite floor slab according to this embodiment described above will be described. FIG. 5 is a flowchart showing a construction process of a bridge construction method using a composite floor slab according to an embodiment of the present invention, and FIGS. 6A to 6D are steps for explaining a part of the construction process of the construction method. FIG. For convenience of explanation, explanation will be made including in-factory work in addition to on-site work.

  First, the floor steel plate 10 is processed from the steel material in the factory (step S101), and the horizontal ribs 12 are attached to the floor steel plate 10 by welding along the bridge axis orthogonal direction W as described above (step S102). . Next, the floor steel plate 10 is transported from the factory to the site (step S103), and the floor steel plate 10 of the composite floor slab 200 is installed on the main girder 1 and installed (step S104). Note that the floor steel plate 10 is transported in a plurality of divided states when transported (conveyed) from the factory to the site. For example, the floor steel plate 10 is connected in the bridge axis direction L and then installed in the bridge axis direction L. Install with. Further, for example, vertical ribs 11 are fixed to the floor steel plate 10 by welding in advance in a factory.

  When the floor steel plate 10 is installed, reinforcing reinforcing bars are assembled and installed on the floor steel plate 10 as necessary (step S105). And while attaching the connection member 30 to the horizontal rib 12 of the floor steel plate 10, the support 20 is attached to the horizontal rib 12 via this connection member 30, and it moves with a crane etc. and installs on the support | pillar 1a (step S106). ). Note that the order of these steps S105 and S106 may be changed.

  The state of the bridge 100 when the support work 20 is installed in step S106 is, for example, as shown in FIG. 6A. Specifically, a plurality of floor steel plates 10 are installed on the main girder 1, the reinforcing bars 14 are arranged on the floor steel plates 10, and the support works 20 are connected to the lateral ribs 12 of the floor steel plates 10 via the connecting members 30. It is attached together with the reinforcing rib 21. Then, when the crane rope 41 attached to the axial floor slab support material 40 of the support 20 through the connection member 42 is removed, the support 20 is supported by the support 1a as shown in FIG. 6B.

  Thus, if the floor steel plate 10 is supported with the support work 20, as shown to FIG. 6B, the concrete 50 will be poured and hardened on the floor steel plate 10 (step S107), and the composite floor slab 200 of the bridge 100 will be comprised. To do. At this time, the thickness of the concrete 50 is such that the connecting member 30 is removed from the reinforcing rib 21 and a working space is secured between the support work 20 and the concrete 50, so that the connecting portion between the connecting member 30 and the reinforcing rib 21 is concrete. The dimension exposed to the upper surface of 50 is determined to be about 30 cm, for example.

  Thereafter, the connecting member 30 exposed on the concrete 50 is removed from the support work 20 and the connection member 30 is disassembled (step S108), and the support work 20 is removed from the synthetic floor slab 200. The state of the bridge 100 at this time is as shown in FIG. 6C. The removed support work 20 can be reused in the next construction.

  When the support member 20 is removed, if the exposed portion of the connecting member 30 is excessive, the exposed portion is cut and removed as necessary so as to ensure the so-called covering of the concrete 50. Do the work. That is, here, as shown in FIG. 6D, the removal is performed so that the unremoved portions of the support pillars 1 a and the connecting members 30 are not exposed from the upper surface of the concrete 50. Finally, a paving material such as asphalt is laid on the concrete 50 (step S109), a series of construction steps according to this flowchart is completed, and the bridge 100 is completed.

  As shown in FIG. 7A, the bridge 100 completed by the construction process as described above has a predetermined interval in the bridge axis orthogonal direction W extending on the floor steel plate 10 on the main girder 1 in the bridge axis direction L. The vertical ribs 11 arranged side by side, the horizontal ribs 12 extending in the bridge axis orthogonal direction W and arranged at a predetermined interval in the bridge axis direction L, and the composite floor slab 200 including the reinforcing bars 14, Although the traveling direction of the vehicle 50 is along the longitudinal direction of the main beam 1, it may be as shown in FIG.

  That is, the bridge 100A in this case uses an abutment 9 in place of the main girder 1, and the steel plate 10 extends on the abutment 9 in a direction orthogonal to the bridge axis W and is arranged in parallel with a predetermined interval in the bridge axis direction L. The vertical rib 11, the horizontal rib 12 extending in the bridge axis orthogonal direction W and arranged at a predetermined interval in the bridge axis direction W, and the composite floor slab 200A provided with the reinforcing bars 14 are provided. It differs from the previous bridge 100 in that the traveling direction is along the longitudinal direction of the bridge 100 </ b> A connecting the abutment 9.

  As described above, according to the present embodiment, the reinforcing steel material for maintaining the weight of the concrete, which has been conventionally required when placing concrete, is no longer necessary, and the crack of the concrete at the upper end of the reinforcing steel material is thereby eliminated. Can prevent and improve fatigue life.

  Further, since the rigidity required for the lateral rib is much smaller than before, it is possible to reduce the manufacturing cost by reducing the material cost and the number of work steps.

DESCRIPTION OF SYMBOLS 1 Main girder 10 Floor steel plate 11 Vertical rib 12 Horizontal rib 19 Side steel plate 20 Support work 21 Reinforcement rib 30 Connecting member 40 Axial floor slab support material 41 Crane rope 50 Concrete 100 Bridge 200 Composite floor slab

Claims (10)

A composite floor slab comprising a plurality of floor steel plates, and concrete cast on the floor steel plates, and installed at a bridge installation location,
Lateral ribs attached to the floor steel plate;
A connecting member connected at one end to the transverse rib and connected at the other end to a support that supports the floor steel plate when the concrete is placed;
The support is supported by a column installed on the main girder while maintaining the shape of the floor steel plate in a state where the floor steel plate is placed on the main girder,
The composite floor slab is characterized in that the concrete is placed with the floor steel plate supported by the support member via the connecting member and the lateral rib. The composite floor slab according to claim 1, wherein the floor steel plate has a plurality of vertical ribs extending in a direction orthogonal to the horizontal ribs and arranged in parallel in the extending direction of the horizontal ribs. The composite floor slab according to claim 1, wherein the lateral rib has a rigidity smaller than a rigidity necessary for maintaining a shape of the floor steel plate when the concrete is placed. The connecting member is made of a steel material whose vertical direction is a longitudinal direction capable of forming a space having a predetermined interval between the floor steel plate and the support work, and the connection portion with the support work is exposed to the upper surface of the concrete. The composite floor slab according to any one of claims 1 to 3, wherein the composite slab has a thickness. The composite floor slab according to claim 1, wherein the connecting member is connected to the support by bolting. Reinforcing bars are installed on the floor steel plate,
The said reinforcing bar is integrated with the said vertical rib and the said horizontal rib by the said concrete. The synthetic floor slab of any one of Claims 1-5 characterized by the above-mentioned. A bridge comprising a plurality of floor steel plates and a composite floor slab in which concrete placed on the floor steel plate is integrated, and a fitting material formed on the composite floor slab,
The synthetic floor slab is
Lateral ribs attached to the floor steel plate;
A connecting member connected at one end to the transverse rib and connected at the other end to a support that supports the floor steel plate when the concrete is placed;
The support is supported by a column installed on the main girder while maintaining the shape of the floor steel plate in a state where the floor steel plate is placed on the main girder,
A bridge using a composite floor slab, wherein the concrete is placed in a state where the floor steel plate is supported by the support member via the connecting member and the lateral rib. Reinforcing bars are installed on the floor steel plate,
The bridge using the composite floor slab according to claim 7, wherein the reinforcing bar is integrated with the vertical rib and the horizontal rib by the concrete. A floor steel plate erection process in which a plurality of floor steel plates with horizontal ribs are installed at a bridge installation location;
Said transverse ribs are connected via a connecting member to the shoring, the plurality of shaped floor steel plate in a state of being placed on the main beam I by the said shoring supported by the installed struts to the main girder A supporting connection suspension support process for supporting the suspension while holding ;
A concrete placing step of placing concrete on the plurality of floor steel plates supported by the support work;
After the placed concrete is cured, a connecting member removing step of removing the connecting member from the support,
A bridge construction method using a synthetic floor slab comprising a pavement process of piling the concrete with a pavement material. The construction method of the bridge using the composite floor slab according to claim 9, further comprising a reinforcing bar installation step of installing reinforcing bars on the plurality of floor steel plates after the floor steel plate laying step.

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