WO2015108103A1

WO2015108103A1 - Metal slab for overpass

Info

Publication number: WO2015108103A1
Application number: PCT/JP2015/050933
Authority: WO
Inventors: 英一郎佐伯
Original assignee: 日之出水道機器株式会社
Priority date: 2014-01-16
Filing date: 2015-01-15
Publication date: 2015-07-23
Also published as: JP6387020B2; JPWO2015108103A1

Abstract

A slab (14, 48, 54, 57, 60, 62) is supported on the upper surface of a main beam (4) which extends in the bridge-axis direction of an overpass (1), wherein a deck plate (18) and reinforcement ribs (20) formed on the bottom surface (18b) of the deck plate are provided. The deck plate and the reinforcement ribs are integrally formed by casting.

Description

Road deck metal floor version

The present invention relates to a metal floor slab of a road bridge.

In recent years, a number of road bridges constructed in and after Japan's high-growth period have reached their useful lives, and maintenance costs and workloads have become enormous, and rebuilding work is also increasing.
The floor slabs of road bridges are roughly divided into concrete floor slabs, composite floors of steel and concrete, and steel floor slabs. For example, as disclosed in Patent Document 1, a conventional steel floor slab has a structure in which a reinforcing rib is joined to a long deck plate such as a steel plate by welding, and compared to a concrete floor slab or a synthetic floor slab. It is lightweight. In addition, there is no concrete work after erection, and the construction period can be shortened.

The steel floor plate disclosed in Patent Document 1 includes a long deck plate such as a steel plate directly supporting a load of a vehicle, and a reinforcing rib such as a U-shaped steel provided on the lower surface in the longitudinal direction of the deck plate. It is supported by at least one of the main girder extending in the axial direction (the traveling direction of the vehicle) and the transverse girder extending in the direction orthogonal to the main girder.

Japanese Patent Application Laid-Open No. 63-89705

Although the reinforcing rib of the steel floor slab disclosed in the above Patent Document 1 is constituted by a longitudinal rib extending in the bridge axial direction, in the conventional steel floor slab, a transverse rib extending in a direction orthogonal to the longitudinal rib additionally The longitudinal ribs are welded to the deck plate, and the transverse ribs to the longitudinal ribs and the main girder by welding. In this case, the longitudinal rib extending in the bridge axial direction functions as a main rib to reinforce the deck plate against the load applied to the steel floor plate by the passing of the vehicle, and the horizontal rib has a function to transmit the load to the main girder The main girder, the longitudinal rib and the transverse rib respectively bear the load applied to the steel floor slab by the weight of the steel floor slab and the passage of the vehicle.

However, conventional steel floor slabs are joined by welding, and these welds are subjected to live load directly, and the welds have severe fatigue performance due to deterioration of fatigue performance, which has become a serious social problem in recent years ing.
This invention is made in view of such a subject, and the place made into the purpose is the metal floor plate of the road bridge which has the strength and rigidity equivalent to the conventional steel floor slab or more, and is high in fatigue performance. To provide. At the same time, the construction of the road bridge will be improved, and the cost reduction will be achieved by shortening the construction period and reducing the weight.

In order to achieve the above object, the metal floor plate of the road bridge of the present invention is a floor plate supported on the upper surface of the main girder extending in the axial direction of the road bridge, and is provided on the deck plate and the lower surface of the deck plate. And a formed reinforcing rib, wherein the deck plate and the reinforcing rib are integrally formed by casting.
Preferably, the deck plate has legs for transmitting the weight of the floor slab and the vertical load applied to the floor slab to the upper surface of the main girder, and joining means for joining the floor slab to the upper surface of the main girder .

Preferably, the joining means comprises a bolt mounting portion through which a bolt can be inserted from the upper surface of the deck plate, and the bolt mounting portion and the upper surface of the main girder are fastened by a bolt and a nut.
Preferably, the connecting means comprises a bolt mounting portion in which a nut can be inserted from the upper surface of the deck plate and a bolt can be inserted from below, and the bolt mounting portion and the upper surface of the main girder are fastened by the bolt and the nut.
Preferably, the bolt mounting portion is formed in connection with the reinforcing rib.
Preferably, the leg portion has a plurality of notches cut in the vertical direction along the bridge axis direction.

Preferably, the reinforcing rib comprises a main rib extending in a direction orthogonal to the bridge axial direction.
Alternatively, the reinforcing rib includes a main rib extending in a direction orthogonal to the bridge axial direction, and a secondary rib connected between the adjacent main ribs and transmitting a load applied to the floor plate to the main rib.
Preferably, the reinforcing rib is a flat rib vertically projecting from the lower surface of the deck plate.
Preferably, the deck plate is formed in a top view trapezoid.

According to the metal floor plate of the road bridge of the present invention, the deck plate and the reinforcing rib are integrally formed by casting to form the floor plate, so that the reinforcing rib for the deck plate needed in the conventional steel floor plate is No need for welding. Therefore, there is no joint by welding, and fatigue cracking (fatigue damage) of the welded part does not occur, so that the fatigue performance of the floor slab can be remarkably improved. Moreover, it is possible to freely set dimensions such as the shape, thickness, height, etc. of the reinforcing rib by casting, and the R surface can be smoothly applied easily to the corner portion (corner portion) of the proximal end of the reinforcing rib, It becomes possible to equalize the stress generated in the floor slab and reduce the stress concentration, and it is possible to realize improvement in fatigue durability.

It is a perspective view showing a part of road bridge in one example of the present invention. It is a top view which shows the state which laid the metal floor slab which concerns on Example 1 of this invention on the main girder of a road bridge, and a cross girder. It is the perspective view which looked at the metal floor slab concerning Example 1 of this invention from the upper surface. It is the perspective view which looked at the metal floor slab of FIG. 3 from the lower surface. (A) A side view of the metal floor slab of FIG. 3 as viewed from the direction A, (b) a plan view of a part of the metal floor slab of FIG. 3 as viewed from the bottom, (c) the metal floor slab of FIG. It is the side view which looked at a part of from the B direction. It is the fragmentary sectional view which showed the part which the metal floor slab which concerns on Example 1 of this invention which adjoins the Y direction contact | abuts on the main girder. It is the side view which showed the site | part to which metal decks which concern on Example 1 of this invention which adjoins the X direction are connected. It is the perspective view which looked at the metal floor slab which concerns on Example 2 of this invention from the lower surface. It is the perspective view which looked at the metal floor slab which concerns on Example 3 of this invention from the lower surface. It is the side view which showed the state in which the metal floor slab which concerns on Example 4 of this invention is installed in the main girder. It is the figure which looked at the metal floor slab concerning Example 5 of this invention from the upper surface. It is the figure which showed an example of the arrangement | positioning state in the bridge shaft direction of the metal floor slab of FIG. It is the figure which showed the other example of the arrangement | positioning state in the bridge shaft direction of the metal floor slab of FIG. It is the perspective view which looked at the metal floor slab which concerns on Example 6 of this invention which formed the convex part in the upper surface of the deck plate from the upper surface. FIG. 7 is a partial cross-sectional view showing another embodiment of joining the metal floor slab of FIG. 6 and a main girder.

Hereinafter, embodiments of the present invention will be described based on the drawings.
Example 1
FIG. 1 is a perspective view showing a part of a road bridge. FIG. 2 is a top view showing a state in which the metal floor slab according to the present embodiment is laid on the main girder and the cross girder of the road bridge. FIG. 3 is a perspective view of the metal floor slab according to the present embodiment as viewed from above. FIG. 4 is a perspective view of the metal floor plate of FIG. 3 as viewed from below. 5 (a) is a side view of the metal floor slab of FIG. 3 as viewed from direction A, and FIG. 5 (b) is a plan view of a part of the metal floor slab of FIG. (C) is the side view which looked at a part of metal floor slab of FIG. 3 from the B direction.

As shown in FIG. 1, the road bridge 1 of this embodiment includes a main girder 4 extending in the bridge axis direction (vehicle passing direction) X and a transverse girder 6 extending in a direction Y orthogonal to the main girder 4 (see FIG. 2). And a plurality of floor slabs 14 and a road surface 16 constructed by paving such as asphalt on the upper surface of the floor slab 14). The main girder 4 and the cross girder 6 are formed of an H-shaped steel having an upper flange 8, a lower flange 10 and a web 12.

The floor slab 14 is supported on the upper surface of the upper flange 8 of the main girder 4 and transmits to the main girder 4 the weight of the floor slab 14 and the weight of the road surface 16 applied to the floor slab 14 and the load generated by the passing of vehicles. There is. FIG. 1 shows a state in which two floor slabs 14 are supported by three main girder 4 as a part of road bridge 1.
As shown in FIG. 2, the floor slab 14 has a size that covers one of the grid divisions divided by the main girder 4 and the cross girder 6, and the plurality of floor slabs 14 are the upper surfaces of the main girder 4. And the upper surfaces of the cross beams 6 are closely spaced with one another.

As shown in FIGS. 3 and 4, the floor slab 14 includes a deck plate 18 and reinforcing ribs 20. The deck plate 18 is formed in a rectangular plate shape, and the road surface 16 is constructed on the upper surface 18 a side of the deck plate 18 by paving such as asphalt, and the reinforcing rib 20 is formed on the lower surface 18 b of the deck plate 18.

The floor slab 14 is formed by integrally casting the deck plate 18 and the reinforcing rib 20 with a spheroidal graphite cast iron (FCD) material, so that the floor slab 14 does not have warpage or internal defects, and a predetermined performance is ensured. The mold shape of the floor slab 14 and the cooling time in the casting process of the floor slab 14 are considered in advance. The floor slab 14 is not limited to the spheroidal graphite cast iron (FCD) material, and may be made of another kind of cast iron, cast steel, or a dissimilar metal such as aluminum alloy.

The reinforcing rib 20 includes a main rib 22 extending in a direction Y orthogonal to the bridge axial direction X, and a sub rib 24 extending in the bridge axial direction X. Each of the main rib 22 and the sub rib 24 is a so-called flat rib projecting in a plate shape in the vertical direction Z from the lower surface 18 b of the deck plate 18 and forms a reinforcing rib 20 in a grid shape in plan view as a whole There is.
As shown in FIGS. 5 (a) to 5 (c), the deck plate 18 is provided with legs 26 and bolt mounting portions (joining means). The legs 26 project from the lower surface 18b of the deck plate 18 in the vertical direction Z at both ends of the deck plate 18 in the direction Y, and the main ribs 22 are connected.

The main rib 22 is formed by connecting a bolt mounting portion 28 which is thicker than the thickness t1 of the main rib 22 with a distance D3 in the vicinity of the leg portion 26. The bolt mounting portion 28 has a shape capable of inserting and holding a bolt (joining means) 32 described later from the upper surface 18 a of the deck plate 18. The shape of the head of the bolt 32 used in the present invention is not limited to a polygonal one such as a hexagon, and may be a circular one.
The main rib 22 is formed to have a thickness t1 and a height H1 in the vertical direction Z, extends between the opposing legs 26 so as to be connected to each leg 26, and the lower surface of the deck plate 18 A plurality of rib spacings (pitches) P1 are provided in the bridge axis direction X of 18b.

The auxiliary rib 24 is formed between the adjacent main ribs 22 so as to be continuous with the main rib 22 and extends over the entire area of the lower surface 18b of the deck plate 18 in the bridge axial direction X. The load generated on the plate 14 is transmitted to the main rib 22. The auxiliary rib 24 is formed of a long rib 24a and a short rib 24b. The long rib 24a is formed to have a thickness t2 and H2 whose height in the vertical direction Z is substantially the same as the main rib 22. In this embodiment, the direction Y orthogonal to the bridge axis direction X of the lower surface 18b of the deck plate 18 Only one is placed at the center of the.

The short rib 24b is formed to have a thickness t3 and H3 having a height in the vertical direction Z shorter than that of the long rib 24a, parallel to the long rib 24a, and orthogonal to the bridge axis direction X of the lower surface 18b of the deck plate 18. A plurality of rib spacings P2 are provided in the direction Y to be arranged.
Four bolt holes 34 are bored in parallel in the vertical direction Z at both ends of the long rib 24 a in the bridge axis direction X, respectively. Further, two bolt holes 34 are bored in parallel in the vertical direction Z at both ends of the short rib 24 b in the bridge axis direction X, respectively.

Below, the specifications of the road bridge 1 and the floor slab 14 are illustrated.
The specifications of the road bridge 1 are shown below (see FIG. 2).
Road surface width Wr: 10 m,
-Center distance D1 of the main girder 4: 2.5 m,
-Center distance D2 of transverse beam 6: 5.0 m

The specifications of the floor slab 14 are shown below (see FIG. 4).
-Size of deck plate 18 (longitudinal L1 × width W1): 5.0 m × 2.5 m,
-Thickness t of the deck plate 18: 12 mm,
・ H of main rib 22 H 1: 215 mm,
・ Thickness t1: 15 mm of main rib 22,
-Rib spacing (pitch) P1: 320 mm of the main rib 22,
The number of main ribs 22: 16,
The height H2 of the long rib 24a (sub rib 24): 215 mm,
The number of long ribs 24a: 1,
The height H3 of the short rib 24b (sub rib 24): 100 mm,
The number of short ribs 24b: 6,
・ Thickness t2 of secondary rib 24: 15 mm

The thickness, height, rib interval (pitch) of the main rib 22 and the sub rib 24, the thickness of the deck plate 18, etc. are not limited to the above specifications, and may be determined according to the result of the stress analysis simulation in advance. For example, the thickness of a portion of the main rib 22 may be increased or increased, or the thickness of the tip and the root of the main rib 22 may be appropriately optimized so that stress concentration does not occur in the floor plate 14. .

FIG. 6 is a partial cross-sectional view showing a portion where a metal floor slab according to a different example 1 of the present invention adjacent in the Y direction abuts on a main girder. FIG. 7: is the side view which showed the site | part with which metal floor slabs which concern on Example 1 of this invention which mutually adjoins in the X direction are connected.
As shown in FIG. 6, on the upper surface of the upper flange 8 of the main girder 4, the legs 26 of the deck plates 18 of the floor slabs 14 adjacent in the direction Y orthogonal to the bridge axial direction X abut. . The load generated on the floor plate 14 due to the passage of the vehicle is transmitted from the main rib 22 to the leg 26 or from the sub rib 24 to the leg 26 via the main rib 22, and is indicated by an arrow from right above the main girder 4. It is transmitted to the main girder 4 in the vertical direction C shown.

Further, the floor plate 14 and the upper flange 8 of the main girder 4 are frictionally joined by the bolt 32 and the nut (joining means) 36 at the bolt mounting portion 28 in which the bolt holes 38 are bored. Specifically, the bolt holes 38 are composed of an upper hole 38a communicating with each other and a lower hole 38b smaller in diameter than the upper hole 38a. The upper hole 38a has such a depth that the head 32a of the bolt 32 can be sunk from the upper surface 18a of the deck plate 18 when the bolt 32 is inserted from the upper surface 18a of the deck plate 18, and the upper hole 38a and the lower hole 38b The head 32 a is locked by the step and can hold the bolt 32.

Thus, the length of the bolt 32 can be shortened by making the head portion 32 a of the bolt 32 engagable from the upper surface 18 a of the deck plate 18. The upper hole 38a may be formed into a polygon having the same shape as the head 32a of the bolt 32 and with substantially the same size as the head 32a of the bolt 32. With such a configuration, it is possible to realize the rotation prevention of the bolt 32 when the nut 36 is screwed to the bolt 32.

The upper flange 8 of the main girder 4 is also formed with a through hole 40 consistent with the bolt hole 38, and the floor plate 14 and the main girder are engaged by screwing the nut 36 to the bolt 32 projecting downward from the through hole 40. 4 are frictionally joined by the bolt 32 and the nut 36. Further, it is preferable to cover the opening of the upper hole 38a with a cap (not shown) to protect the bolt 32. In the present embodiment, the floor plate 14 is not joined to the cross beam 6 by the bolt and the nut.

As shown in FIG. 7, the floor slabs 14 adjacent in the bridge axial direction X are connected to each other by a connecting plate 42.
Bolt holes 44 are drilled in the connection plate 42 at positions corresponding to the bolt holes 34 drilled in the sub ribs 24 of the adjacent floor slabs 14. Adjacent floor slabs 14 are connected to each other by the connection plate 42 by inserting the bolt 46 into the consistent bolt holes 34 and 44 and fastening them with a nut (not shown). Although only the connection in the short rib 24b is shown in FIG. 7, the connection by the bolt 46 using the same connection plate 42 is performed also in the long rib 24a.

In this embodiment, by integrally forming the deck plate 18 and the reinforcing rib 20 by casting to form the floor plate 14, welding of the reinforcing rib to the deck plate, which is required in the conventional steel floor plate, becomes unnecessary. Therefore, there is no joint by welding, and fatigue crack (fatigue damage) of the weld does not occur, so that the fatigue performance of the floor slab 14 can be significantly improved. Moreover, since it is not necessary to perform welding work on the site, significant efficiency improvement of construction of the road bridge 1 can be achieved.

Furthermore, dimensions such as the shape, thickness, height and the like of the reinforcing rib 20 can be freely set by casting, and waste materials can be omitted, and weight reduction can be achieved. In addition, since the R surface can be easily applied to the corners (corners) of the floor slab 14 with a mold, it is easy to equalize stress generated in the floor slab 14, reduce stress concentration, and improve fatigue durability. It can be realized.
According to a stress analysis simulation performed on the floor slab 14 using a material having a fatigue limit of 300 MPa, a proof stress of 400 MPa, an allowable stress of 235 MPa (safety factor of 1.7), a Young's modulus of 170 GPa and a Poisson's ratio of 0.28. Under the condition that the maximum stress of the same size is generated, it is possible to reduce the weight of the slab itself in the casting of the present embodiment than the steel slab of the conventional structure, or It has been found that the floor plate of comparable weight can reduce the maximum stress occurring on the floor plate.

Further, in the conventional steel floor slab, the longitudinal rib extending in the bridge axial direction X functions as a main rib to reinforce the deck plate against the load generated on the steel floor slab by the passage of the vehicle, and is orthogonal to the bridge axial direction X The transverse rib extending in the direction Y has a function of transmitting the load to the main girder, and the main girder, the longitudinal rib and the transverse rib respectively bear the load generated on the steel floor slab by the passing of the vehicle.
On the other hand, the floor slab 14 of the present embodiment can easily realize an optimal shape design according to the generated stress. Further, the main rib 22 having a rib height higher than at least the short rib 24b of the sub rib 24 is extended in the direction Y orthogonal to the main girder 4, and the load generated on the floor slab 14 by the passing of the vehicle is It is transmitted to the main girder 4 from directly above via the leg portion 26 or from the auxiliary rib 24 to the main girder 4 via the main rib 22 and the leg portion 26. Therefore, as compared with the case of the conventional steel floor slab in which the longitudinal rib (main rib) is disposed parallel to the main girder, the load generated on the floor slab 14 by the passage of the vehicle is efficiently dispersed to the main girder 4 And the rigidity of the road bridge 1 can be improved as compared with the prior art.

Also, by making the main rib 22 and the auxiliary rib 24 into flat ribs with a simple shape, a floor that improves the strength, rigidity, and fatigue performance of the floor slab 14 while reducing the stress acting on the floor slab 14 The mold of the plate 14 can be manufactured relatively easily.
Also, the floor slab 14 has a size that covers one of the grid divisions divided by the main girder 4 and the cross girder 6, and supports the floor slab 14 in contact with the upper flange 8 of the main girder 4 Because it is a "simple beam" support method, one steel floor plate has a size that spans multiple main girders like a conventional steel floor plate, and one steel floor is supported by multiple main girders. Compared with the supporting method by “continuous beam”, a large moment is not generated at the end of the main rib 22, and the joint between the floor plate 14 and the main girder 4 can be made into a simple structure.

Further, as in the present embodiment, the leg portion for transmitting the vertical load is disposed by arranging the bolt mounting portion 28 as a separate part from the leg portion 26 and separating the portion for transmitting the vertical load and the horizontal load to the main girder 4. The position 26 can be as close to the web 12 of the main girder 4 as possible, and the eccentric moment generated on the upper flange 8 of the main girder 4 can be reduced.
Further, by forming the bolt mounting portion 28 so as to be connected to the main rib 22, even if a moment acts on the bolt mounting portion 28, the strength of the bolt mounting portion 28 can be secured by the rigidity of the main rib 22.

Further, as shown in FIG. 6, the upper flange 8 of the main girder 4 and the adjacent floor slab 14 are friction-joined together by means of the bolts 32 and the nuts 36 to form a composite of the main girder 4 and the floor slab 14 The effects can be exhibited, and the rigidity and strength of the road bridge 1 can be improved.
Also, by using a structure in which the main girder 4 and the floor plate 14 are fastened by the bolt 32 and the nut 36, compared to the case where a conventional steel floor plate is welded to the main girder and / or the transverse girder, Construction becomes easy, and construction period shortening and cost reduction can be realized.

In addition, since the reinforcing rib 20 of this embodiment is a flat rib and has a rib shape of an open cross section, the torsional rigidity is small, and even if there is an uneven part on the surface of the upper flange 8 of the existing main girder 4. As it is easy to attach, the floor plate 14 can be easily attached.
The present invention is not limited to the form of this embodiment, and various different embodiments are possible.

For example, in the present embodiment, as shown in FIG. 6, the bolt 32 is inserted from the upper surface 18a of the deck plate 18, but as shown in FIG. It may be.
Specifically, the bolt 32 is inserted from below the through hole 40 formed in the upper flange 8 of the main girder 4 into the bolt hole 38 drilled in the bolt mounting portion 28, and the nut 36 is bolted from the upper surface 18 a of the deck plate 18 The floor plate 14 and the main girder 4 are inserted into the upper holes 38a of the bolt holes 38 drilled at 38 and held by the step between the upper holes 38a and the lower holes 38b, and the nut 36 is screwed to the bolt 32. Are frictionally joined by the bolt 32 and the nut 36.

When the bolt 32 having a polygonal head shape is used, the upper hole 38a may be a polygon having the same shape as that of the nut 36 and may have substantially the same size as the nut 36. With such a configuration, it is possible to realize the rotation prevention of the nut 36 at the time of screwing the bolt 32 to the nut 36. In addition, it is preferable to cover the opening of the upper hole 38a with a cap (not shown) to protect the nut 36.

Further, in the present embodiment, the floor slab 14 is supported by being brought into contact with the main girder 4, but the floor slab 14 is made to abut against both the main girder 4 and the transverse girder 6 or the transverse girder 6. In this case, the bolt mounting portion 28 may be formed to be connected to the sub rib 24 and the floor plate 14 and the cross beam 6 may be fastened by a bolt and a nut.
In addition, the bolt mounting portion 28 may be formed in another portion without being connected to the reinforcing rib 20 (the main rib 22 or the sub rib 24).

Further, in the present embodiment, although the reinforcing rib 20 is formed of the main rib 22 and the sub rib 24, the sub rib 24 is not essential, and the reinforcing rib 20 may be formed of only the main rib 22.
Further, the heights of the main rib 22 and the sub rib 24 may be formed to be the same height.

(Example 2)
FIG. 8 is a bottom perspective view of a metal floor slab according to another embodiment of the present invention.
In this embodiment, the floor slabs 14 of the first embodiment are divided into four in the bridge axial direction X so that the floor slabs 14 have the same size.

The specifications of the floor slab 48 of a size obtained by dividing the floor slab 14 of Example 1 into four in the bridge axial direction X will be exemplified below. Description of the same configuration as that of the first embodiment will be omitted.
-Size of deck plate 18 (longitudinal length L2 × lateral width W2): 1.25 m × 2.5 m,
The number of main ribs 22: 4
The floor slab 48 having a size obtained by dividing the floor slab 14 of Example 1 into four in the bridge axial direction X is smaller and lighter than the floor slab 14 of Example 1. Therefore, since one floor plate 48 can be transported by a small car and construction with a small crane becomes possible, the workability in construction of the road bridge 1 can be improved and the cost can be reduced. Further, by dividing, even if there is a landless portion on the surface of the upper flange 8 of the main girder 4, the floor plate 48 can be easily attached.

In the case of using the floor slabs 48 of this embodiment, the floor slabs 48 adjacent in the bridge axial direction X are connected by bolting each other via the connection plate 42 shown in Example 1, Example 1 Form a connected slab version having the same size as the floor slab 14 of

(Example 3)
FIG. 9 is a bottom perspective view of a metal floor slab according to still another embodiment of the present invention.
In this embodiment, the floor slabs 48 are extended in the direction Y orthogonal to the bridge axial direction X, and the floor slabs 54 of the expanded size are connected. Description of the same configuration as that of the first embodiment and the second embodiment will be omitted.

Below, the specification of the floor slab 54 which has the extended overhang | projection part 56 is illustrated.
-Size of the deck plate 18 (vertical length L2 × horizontal width W3): 1.25 m × 3.5 m
In the case of the floor slab 54 having a size in which the floor slab 48 is expanded in the direction Y orthogonal to the bridge axial direction X as in this embodiment, the road surface width Wr is increased by 1.0 m than in the case of the first embodiment. The road bridge 1 can be constructed and used for the outside lanes where installation of a column or the like is required.

Also in the case of using the floor slab 54, as in the case of the second embodiment, the floor slabs 54 adjacent to each other in the bridge axial direction X are connected by bolting each other via the connection plate 42, Form

(Example 4)
FIG. 10 is a side view showing a metal floor slab according to still another embodiment of the present invention installed on a main girder. In this embodiment, the leg portion 26 of the floor slab 57 is formed with a notch 26 a cut out in the vertical direction Z. The notches 26a have, for example, a substantially isosceles triangle shape with the upper direction as a vertex, and a plurality of notches 26a are arranged at equal intervals along the bridge axis direction X of the leg 26. Each notch 26a is positioned in the leg 26 substantially in the middle between the positions where the main ribs 22 are connected.

Conventionally, the main girder 4 has a bow shape that is slightly convex upward in the bridge axis direction X in consideration of the weight of the floor slab and pavement such as asphalt so as to become horizontal when the road bridge 1 is constructed. Pre-designed, so-called camber processing is applied.
Therefore, when the floor plate 57 and the main girder 4 are joined by forming the notches 26 a in the leg portion 26, the floor plate 57 can be easily placed following the main girder 4 of the upwardly convex bow shape. It is possible. Further, since the leg portion 26 and the floor plate 57 are allowed to be deformed, the main girder 4 and the floor plate 57 can be joined in a state of being familiar with each other.

(Example 5)
FIG. 11 is a top view of a metal floor plate 62 according to still another embodiment of the present invention. FIG. 12 is a view showing an example of the arrangement of the metal floor slab 62 in the bridge axis direction X. As shown in FIG. FIG. 13 is a view showing another example of the arrangement of the metal floor slab 62 in the bridge axis direction X. As shown in FIG. In this embodiment, a floor plate 62 in which the deck plate 18 of the floor plate 48 of the second embodiment (the floor plate 48 of the size obtained by dividing the floor plate 14 of the first embodiment in four in the bridge axial direction X) is formed trapezoidally in top view You are using

More specifically, the deck plate 18 of the present embodiment is formed in an isosceles trapezoid in top view, extends in the bridge axis direction X, and is a pair of opposite

long sides

64a and 64b parallel to each other, and a bridge axis It extends in a direction Y orthogonal to the direction X, and is composed of another pair of opposite sides of

equal length legs

66a, 66b. The

legs

66a and 66b are inclined at an angle of θ from the direction Y as viewed in FIG. 11 so that the base angles formed with the long bottom 64a and the short bottom 64b are equal.

As shown in FIG. 12, by connecting a plurality of floor slabs 62 at

adjacent legs

66a and 66b in a direction in which the long bottom 64a and the short bottom 64b of the deck plate 18 are on the same side, one floor slab 62 is obtained. A curve having a radius of curvature R1 based on the inclination angle 2θ formed in the

legs

66a and 66b and the number n of floor slabs 62 can be formed in the bridge axial direction X of the road bridge 1.
Further, as shown in FIG. 13, the floor slabs 62 connected in the bridge axial direction X may be arranged, for example, in a direction opposite to that of FIG. By combining them, it is also possible to form a curve of a radius of curvature R2 which is gentler than in the case of FIG.

The road bridge 1 may have not only straight lines but also curves, and it is only necessary to use the floor plate 62 in which the deck plate 18 is formed in a trapezoidal shape in the top view with an angle of θ as in this embodiment. The road bridge 1 having a curve of a desired radius of curvature can be formed by variously changing the arrangement method.

(Example 6)
FIG. 14 is a top perspective view of a metal floor slab according to still another embodiment of the present invention. In this embodiment, for example, a floor slab 60 having a large number of convex portions 58 in which a plurality of convex portions in a plan view hexagonal shape having different sizes overlap each other on the upper surface 18a of the deck plate 18 is formed. In this case, when constructing the road surface 16, it is possible to improve the bondability of the pavement material such as asphalt to the upper surface 18a of the deck plate 18, which is preferable.

Moreover, when the convex part 58 has the slip resistance performance of a vehicle, since it can be used without paving the road bridge 1, the further weight reduction of the road bridge 1 is attained.

1 Road bridge 4 Main girder 8 Upper flange 14 Floor version (metal floor version)
18 deck plate 18a upper surface 18b of deck plate lower surface of deck plate 20 reinforcing rib 22 main rib 24 sub rib 26 leg 26a notch 28 bolt mounting portion (joining means)
32 bolt (joining method)
36 Nut (joining means)
48 floor version (metal floor version)
54 floor version (metal floor version)
57 floor version (metal floor version)
60 floor version (metal floor version)
62 Floor version (metal floor version)

Claims

A floor slab supported on the upper surface of a main girder extending in the axial direction of the road bridge,
Deck plate,
And a reinforcing rib formed on the lower surface of the deck plate,
A metal floor plate of a road bridge, wherein the deck plate and the reinforcing rib are integrally formed by casting.
The deck plate is
A leg that transmits the weight of the floor slab and the vertical load applied to the floor slab to the upper surface of the main girder;
2. A metal floor slab of a road bridge according to claim 1, further comprising joining means for joining the floor slab and the upper surface of the main girder.
The jointing means according to claim 2, further comprising: a bolt mounting portion through which a bolt can be inserted from the upper surface of the deck plate, and fastening the bolt mounting portion and the upper surface of the main girder with the bolt and nut. A metal floor version of the described road bridge.
The joining means comprises a bolt mounting portion capable of inserting a nut from the upper surface of the deck plate and inserting a bolt from below, and fastening the bolt mounting portion and the upper surface of the main girder with the bolt and the nut The metal floor plate of the road bridge according to claim 2 characterized by the above.
The metal floor plate of a road bridge according to claim 3 or 4, wherein the bolt mounting portion is formed by being connected to the reinforcing rib.
The metal floor plate of the road bridge according to any one of claims 2 to 5, wherein a plurality of notches cut in the vertical direction are provided in the leg portion along the bridge axial direction. .
The metal floor slab of a road bridge according to any one of claims 1 to 6, wherein the reinforcing rib comprises a main rib extending in a direction orthogonal to the bridge axial direction.
The reinforcing rib is
A main rib extending in a direction orthogonal to the bridge axis direction;
The road bridge according to any one of claims 1 to 6, further comprising: a secondary rib connected between the adjacent main ribs to transmit a load applied to the floor plate to the main rib. Metal floor version.
The metal floor slab of the road bridge according to any one of claims 1 to 8, wherein the reinforcing rib is a flat rib vertically provided in a plate shape from the lower surface of the deck plate.
The deck plate is
The metal floor slab of the road bridge according to any one of claims 1 to 9, which is formed in a trapezoidal shape in top view.