JP6757834B1 - Plate structure and plate replacement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the work time required for replacing a slab from a concrete slab to a steel slab, and to reliably transmit a shear force in the bridge axis direction between the main girder and the steel slab. Provide a plate structure and a method for replacing a floor slab. SOLUTION: A part of a reinforced concrete floor slab supported by a main girder 11 of a bridge is removed in a concave shape, and a remaining reinforced concrete 21 is left on the upper surface side of a main girder upper flange 11b to form a pair of main girders. A slip prevention member 51 is provided on the horizontal and vertical ribs 32A, the steel plate 30 is arranged so as to cover the remaining reinforced concrete 21, and the slip prevention member 51 is arranged in the concrete removal area 2A provided around the remaining reinforced concrete 21. Provided is a floor slab replacement method in which a mortar 47 is filled between a pair of main girder horizontal and vertical ribs 32A and the remaining reinforced concrete 21 on the upper surface side of the main girder upper flange 11b. [Selection diagram] Fig. 4

Description

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

For bridges used on highways, etc., it may be necessary to replace the slabs of aging roads. Conventionally, when replacing the RC slab (reinforced concrete slab) of a bridge with a new slab, the existing reinforced concrete slab is first removed. Next, after completely smoothing the main girder upper flange of the main girder, re-strike the studs, or when replacing the RC floor slab with a steel slab, make a bolt hole in the main girder upper flange of the main girder. I try to do it.

However, the conventional construction method has the following problems. (1) It takes a lot of labor and time to remove the reinforced concrete slab with studs. (2) When removing concrete between studs, noise, vibration and dust problems may occur. (3) When the reinforced concrete slab is removed, the dead load of the bridge is reduced to less than half, so that the deflection of the girder is reduced and various dimensional adjustments are required to maintain the same planned height as the original. (4) If a new floor slab is installed according to the current standards, the weight will increase compared to the original structure. This requires reinforcement of girders, piers and, in some cases, piles (not only thickness but also width).

As an example of a bridge slab replacement method for solving such a problem, for example, the method described in Patent Document 1 is known. In the floor slab replacement method described in Patent Document 1, in order to replace the reinforced concrete floor slab supported and laid by the main girder of the bridge with the steel floor slab, the steel floor slab is arranged at the position where the reinforced concrete floor slab is removed. In the method of replacing the slab of a bridge, a slab support bracket is attached to the main girder at appropriate intervals below the reinforced concrete slab, and the reinforced concrete slab of the portion located on the upper flange of the main girder is attached. The other portion removed is removed to provide a residual portion on the upper flange portion of the main girder, and instead of the removed reinforced concrete slab, the lateral side of the steel slab having a lateral rib arranged so as to avoid the residual portion. The ribs are arranged, and the horizontal ribs are placed and attached to the floor slab support bracket.

Japanese Unexamined Patent Publication No. 2016-194215

However, the above-mentioned method for replacing the floor slab described in Patent Document 1 has the following problems.
Here, many of the bridges whose concrete slabs are damaged to the extent that they need to be replaced are cases of heavy traffic, and it was necessary to limit the traffic volume or stop the traffic when replacing the concrete slabs. Therefore, it is required that the time required for traffic restriction when replacing the concrete floor slab is short, and there is room for improvement in that respect.

Then, in Patent Document 1, a floor slab support bracket is attached to the web of the main girder by welding or the like. Therefore, it takes time and effort to attach the floor slab support bracket, and since the horizontal ribs of the steel floor slab are attached to the floor slab support bracket by welding or the like, it also takes time to attach to the horizontal ribs.
Further, the horizontal ribs of the steel floor slab are mounted on the floor slab support bracket and attached to the floor slab support bracket, but basically this floor slab support bracket is attached to the main girder as a cantilever. .. Therefore, the plate support bracket that supports the weight of the steel plate must have high strength.

Further, since it is attached to the main girder only via the floor slab support bracket, it is difficult to transmit the shear force in the bridge axial direction between the main girder and the steel slab. Therefore, it is difficult to form a bridge having an integrated structure of a steel plate and a main girder, and there is a risk that the strength of the bridge will be insufficient.

The present invention has been made in view of the above-mentioned problems, and it is possible to shorten the work time required for replacing the floor slab from the concrete slab to the steel slab, and between the main girder and the steel slab. It is an object of the present invention to provide a slab structure and a slab replacement method capable of reliably transmitting a shearing force in the direction of the bridge axis.

In order to achieve the above object, the floor slab structure according to the present invention is a floor slab structure supported by a main girder of a bridge, and includes reinforced concrete provided on the upper surface side of the main girder upper flange of the main girder and the above. A steel slab arranged so as to cover the reinforced concrete is provided, and the steel slab is composed of a deck plate arranged on the reinforced concrete and a main slab arranged in the bridge axis direction on the lower surface side of the deck plate. The girder has horizontal and vertical ribs, and the main girder upper flange of the main girder is arranged between a pair of the main girder horizontal and vertical ribs arranged adjacent to each other in the bridge width direction, and the pair of main girders. The horizontal and vertical ribs are provided with a slip-preventing member in a recess formed around the reinforced concrete, and on the upper surface side of the main girder upper flange, between the pair of main girder horizontal and vertical ribs and the reinforced concrete, the said It is characterized in that it is filled with an amorphous material that integrally embeds a slip stopper.

Further, the floor slab replacement method according to the present invention is a floor slab replacement method for replacing a part of the existing reinforced concrete floor slab supported and laid by the main girder of the bridge with a steel floor slab, and is the reinforced concrete. A step of removing a part of the floor slab and leaving reinforced concrete on the upper surface side of the main girder upper flange, a step of providing the slip prevention member on the pair of main girder horizontal and vertical ribs, and the step of providing the steel slab The step of arranging the member so as to cover the reinforced concrete and arranging the slip prevention member in the recess provided around the reinforced concrete, and the pair of main girder horizontal and vertical ribs and the said on the upper surface side of the main girder upper flange. It is characterized by having a step of filling the amorphous material between the reinforced concrete and the reinforced concrete.

In the present invention, an amorphous material is filled so as to integrally embed a slip-preventing member between the horizontal and vertical ribs of the main girder arranged in the bridge axis direction on the lower surface side of the deck plate in the steel deck slab and the reinforced concrete. Will be done. As a result, the steel deck slab and the upper flange of the main girder are joined, and the rigidity and strength of the bridge can be ensured. As a result, it is possible to reduce the structural weight as compared with the case where the conventional floor slab support bracket is used. At this time, since the reinforced concrete is left on the main girder, buckling of the upper flange of the main girder can be suppressed.
Further, in the present invention, it is possible to leave the concrete between the studs, which is difficult to remove among the reinforced concrete,, so that the labor and time required for the concrete removing work can be reduced.

Further, in the present invention, a slip stopper member embedded in the filled amorphous material is provided at a portion in contact with the filled amorphous material. Therefore, the slip-preventing member can reliably transmit the shearing force in the bridge axis direction from the main girder to the steel deck slab.

Further, in the present invention, since an amorphous material is filled between the steel slab, the upper flange of the main girder and the reinforced concrete, the reinforcing bars of the reinforced concrete, the lower surface of the steel slab exposed in the recesses around the reinforced concrete, and the upper of the main girder. Corrosion of the upper surface of the flange can be prevented.
It is not necessary to require a large strength for this amorphous material. In the first place, reinforced concrete is also concrete that was cast in an era when there was not enough construction technology, and since it was shared for a long time, it is difficult to guarantee the strength that can be reliably designed. , It is not necessary to require a large strength for the amorphous material to be filled therein. Furthermore, by using an amorphous material with high fluidity, even if the remaining concrete deteriorates and cracks occur, the amorphous material permeates and solidifies in the cracks, and a large recovery in strength can be expected. There are advantages.
Further, as described above, the structure leaves the reinforced concrete, and the amount of breaking the concrete of the reinforced concrete floor slab can be reduced, so that the generation of noise, vibration, and dust can be reduced.

Further, the floor slab structure according to the present invention may be characterized in that the slip prevention member is a protruding member protruding from the inner surfaces of the pair of main girder horizontal and vertical ribs facing each other.

In this case, for example, a protruding member such as a bolt or a stud can be easily fixed and projected on the inner surface of a pair of main girder horizontal and vertical ribs facing each other by a fixing means such as welding. Since the protruding member is embedded in the irregular material to be filled, the shearing force in the bridge axis direction can be reliably transmitted from the main girder to the steel deck slab.

Further, the floor slab structure according to the present invention may be characterized in that the slip prevention member is an uneven portion formed on the inner surfaces of the pair of main girder horizontal and vertical ribs facing each other.

In this case, for example, a checker plate having irregularities on the surface may be used to form the horizontal and vertical ribs of the main girder, the horizontal and vertical ribs of the main girder may be superposed on the inner surface, or the surface on the inner surface side may have irregularities. By adopting the formed main girder horizontal and vertical ribs, the slip prevention member can be easily provided. Since the uneven portion formed on the horizontal and vertical ribs of the main girder is embedded in the irregular material to be filled, the shearing force in the bridge axis direction can be reliably transmitted from the main girder to the steel deck slab.

Further, in the floor slab structure according to the present invention, the steel slab has through horizontal ribs arranged in the bridge width direction on the lower surface side of the deck plate, and the through horizontal ribs are the pair of main girders in the horizontal and vertical directions. The ribs are continuously provided through the bridge width direction, and the reinforced concrete is formed with a notch that opens upward and extends along the bridge width direction, and the through lateral rib is inserted into the notch from above. provided in a state, the displacement preventing member may be characterized in that the a portion interposed between the pair of main girder horizontal longitudinal ribs of the notch in the plugged in the through transverse ribs.

In this case, of the horizontal ribs on the steel plate, the through horizontal ribs are provided between the pair of main girder horizontal and vertical ribs, and the through horizontal ribs located between the pair of main girder horizontal and vertical ribs are displaced. It can be provided as a stop member. Since the through-horizontal ribs between the pair of main girder horizontal and vertical ribs are embedded in the irregular-shaped material to be filled, the main girder and the steel deck slab can reliably transmit the shear force in the bridge axis direction.
Further, in the present invention, since the through horizontal ribs are continuous between the horizontal ribs on the left and right sides of the main girder, the stress generated by the horizontal girder and the deck plate can be reduced.

Further, in the floor slab structure according to the present invention, it is preferable that the overlaid concrete on the upper part of the reinforced concrete is removed.

In this case, since it is only necessary to remove the overlaid concrete on the upper part of the remaining reinforced concrete, it is not necessary to remove the concrete between the studs erected on the upper flange of the main girder. Since it takes a lot of time and effort to remove the concrete between the studs, it is possible to significantly reduce the time and effort of the removal work by leaving the concrete. The purpose of removing the overlaid concrete at the upper part is to secure a space for adjusting the road surface height and to facilitate the removal of the asphalt portion existing on the steel plate slab.

Further, in the floor slab structure according to the present invention, it is preferable that a height adjusting bolt capable of adjusting the height of the steel slab is screwed into the steel slab so as to be in contact with the reinforced concrete.

In this case, the height of the steel slab can be adjusted by turning the height adjustment bolt, so the height of the steel slab is made equal to the target position, for example, the height of the reinforced concrete slab before replacement. be able to. That is, the planned road surface height can be adjusted at the site.

According to the floor slab structure and the floor slab replacement method of the present invention, the work time required for replacing the floor slab from the concrete floor slab to the steel floor slab can be shortened, and between the main girder and the steel floor slab. The shearing force can be reliably transmitted in the direction of the bridge axis.

This is for explaining the method of replacing the floor slab according to the first embodiment of the present invention, and is a perspective view of the bridge before the replacement of the floor slab as viewed from diagonally above. However, only one lane is shown. FIG. 5 is a perspective view of the bridge before the replacement of the floor slab shown in FIG. 1 as viewed from diagonally below. It shows the state where the steel deck slab is installed, (a) is a perspective view of the bridge viewed from diagonally below, and (b) is a front view of the bridge. It is a vertical cross-sectional view seen from the bridge axis direction which shows the structure of the joint part which joins a steel deck slab to a main girder. It is an enlarged vertical sectional view of the main part of the joint part shown in FIG. It is a work flowchart of the floor slab replacement method. It shows a state where the horizontal rib mounting member is mounted on the main girder web, (a) is a perspective view of the bridge viewed from diagonally below, and (b) is a cross-sectional view including the horizontal rib mounting member of the right main girder. .. The horizontal rib mounting member is shown, (a) is a perspective view of the horizontal rib mounting member, and (b) is a view taken along the arrow A in (a). It is sectional drawing of the main part which shows the state which the horizontal rib mounting member is attached to the main girder web. It shows a state where a part of the reinforced concrete slab is removed, and is a perspective view of the bridge viewed from diagonally above. It shows a state where a part of the reinforced concrete slab is removed, and is a perspective view of the bridge viewed from diagonally below. It is sectional drawing which shows the state which removed the upper part of the residual concrete. It shows the state where the steel deck is installed, (a) is a perspective view of the bridge seen from diagonally above, and (b) is a perspective view of the bridge showing the state where the temporary fixing plate is installed from diagonally above. .. The main part including the residual concrete is shown, (a) is a cross-sectional view, and (b) is a cross-sectional view showing a state in which an amorphous material is filled. It shows a state in which the lateral ribs are rigidly connected to the main girder web, (a) is a perspective view seen from diagonally below, and (b) is a side view. It is a perspective view of the main part in FIG. 3 (b). It is a plan sectional view of the main part in FIG. 15A. (A) is a cross-sectional view of a main part showing a steel slab and a reinforced concrete slab adjacent to it, and (b) is a temporary pavement by temporarily installing a temporary fixing plate between the steel slab and the reinforced concrete slab. It is sectional drawing of the main part which shows the state. It is sectional drawing which shows the main part of the structure of the bridge by 1st Embodiment. In the first embodiment, it is for demonstrating the method of installing the next steel plate slab, and is the perspective view seen from diagonally above which shows the state which provided the removal part. It is a perspective view seen from diagonally below which shows the state which provided the removal part. It is a perspective view seen from diagonally above which shows the state which the next steel plate is installed. It is a perspective view seen from diagonally below which shows the state which the next steel plate is installed. It is a regular cross-sectional view which shows the state which the steel deck slabs adjacent to each other in the bridge axis direction are joined by the inter-panel joint. It shows a state in which a part of the reinforced concrete slab in the other lane is removed, and is a perspective view of the bridge viewed from diagonally above. It shows a state in which a part of the reinforced concrete floor slab of the other lane is removed, and is a front sectional view of the removed portion. It shows a state in which a steel deck slab is installed on the lane side on the other side, and is a perspective view of the bridge viewed from diagonally above. It shows a state in which a steel slab is installed on the lane side on the other side, and is a front sectional view of the steel slab. It is a regular cross-sectional view which shows the state which the temporary fixing plate was temporarily installed between the steel slab and the reinforced concrete slab, and the temporary pavement was applied. This is for explaining the method of replacing the floor slab according to the second embodiment of the present invention, and is a perspective view of the bridge before the replacement of the floor slab as viewed from diagonally above. However, only one lane is shown. FIG. 30 is a perspective view of the bridge before the replacement of the floor slab shown in FIG. 30 as viewed from diagonally below.

Hereinafter, the plate structure and the plate replacement method according to the embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
As shown in FIGS. 1 and 2, in the slab structure according to the first embodiment, a part of the reinforced concrete slab 14 supported and laid by the main girder 11 of the bridge 10 is a steel slab 30 (FIG. 3). (A), (b), and FIG. 13 (a), (b)))). That is, in the first embodiment, the distance between the main girders 11 and 11 adjacent to each other in the bridge width direction X is about 3 m, and a part of the reinforced concrete slab 14 is cut in the bridge width direction X to form a new steel slab 30. Applies when replacing with.

1 and 2 show the bridge 10 before the replacement of the floor slab (however, only one lane (in the case of the one shown in the figure, two lanes on one side)), and FIG. 1 is a perspective view seen from diagonally above, FIG. Is a perspective view seen from diagonally below.
As shown in FIGS. 1 and 2, the bridge (bridge structure) 10 includes a main girder 11, a cross girder 12, an anti-tilt structure 13, and a reinforced concrete slab 14.

The main girder 11 is formed of H-shaped steel or I-shaped steel, and is provided extending in the bridge axis direction (Z direction in FIG. 1). In the case of the one shown in the figure, of the six main girders provided in total for both lanes, only three lanes on one side are shown. These main girders 11 are arranged at predetermined intervals in the bridge width direction (horizontal direction orthogonal to the bridge axis direction Z (so-called bridge axis orthogonal direction; X direction in FIG. 1)). The main girder 11 has a main girder web 11a, a main girder upper flange 11b, and a main girder lower flange 11c. The main girder 11 is erected between a bridge pier and a pier (not shown).

The cross girder 12 is formed of H-section steel or I-section steel, extends in the bridge width direction X, and is erected between adjacent main girders 11 and 11, and the end of the cross girder 12 is welded to the main girder web 11a. It is connected by bolting or bolting. Further, although a plurality of cross girders 12 are arranged at predetermined intervals in the bridge axis direction Z, since a part of the bridge 10 is shown in FIG. 2, two cross girders 12 extend coaxially in the bridge axis orthogonal direction. A cross girder 12 is provided.

The anti-tilt structure 13 is for resisting a lateral load such as a wind or an earthquake, and has a truss structure made of an upper chord member, a lower chord member, a vertical member, an oblique member, and the like. The anti-tilt structure 13 is erected between adjacent main girders 11 and 11 and is connected to the main girder 11 by a gusset or the like. Further, a plurality of anti-tilt structures 13 are arranged at predetermined intervals in the bridge axis direction Z, but since a part of the bridge 10 is shown in FIG. 2, two pairs extending coaxially in the bridge axis orthogonal direction. Tilt structures 13 are provided, and these anti-tilt structures 13 are provided at positions separated in the bridge axis direction Z and sandwiching the cross girder 12.

Reinforced concrete slab 14 has reinforcing bars arranged vertically and horizontally inside the reinforced concrete slab 14, and ridges (haunch portions) 14a protruding from the lower surface extend in the bridge axis direction Z on the lower surface of the reinforced concrete slab 14. In this embodiment, three ridges 14a are formed at predetermined intervals in the bridge width direction X. The three ridges 14a are located directly above the three main girders 11 and are installed and fixed to the main girder upper flange 11b. A plurality of studs (not shown) are erected on the upper surface 11e of the main girder upper flange 11b at predetermined intervals in the bridge width direction X and the bridge axial direction Z, respectively, and these studs are joined to the concrete of the reinforced concrete slab 14. Further, the reinforced concrete slab 14 is provided with ground coverings 14b at both ends in the bridge width direction X, and balustrades 14c are provided at one end. Further, a pavement portion 15 formed of asphalt or the like is constructed between the ground covers 14b and 14b on the upper surface of the reinforced concrete floor slab 14.

Next, the configuration of the newly installed steel plate 30 will be specifically described.
As shown in FIGS. 3A and 3B, the steel plate bridge 30 has a deck plate 31, a plurality of vertical ribs 32 joined to the lower surface of the deck plate 31 by welding or the like, and perpendicular to the vertical ribs 32. It is provided with an arranged horizontal rib 33. A pavement portion 34 is previously constructed on the upper surface of the deck plate 31. The outer peripheral edge portion 31a of the deck plate 31 projects outward from the outer peripheral edge portion 34a of the pavement portion 34.

The plurality of vertical ribs 32 extend in the bridge axis direction Z, respectively, and are provided in parallel at predetermined intervals in the bridge width direction X. As shown in FIG. 4, of the plurality of vertical ribs 32, the two vertical ribs 32 arranged so as to sandwich the main girder upper flange 11b in the bridge width direction X project downward from the other vertical ribs 32 and are newly installed. In a state where the deck plate 31 of the steel deck 30 is arranged at a predetermined position so as to cover the remaining reinforced concrete 21, the main girder horizontal and vertical ribs whose lower end extends sufficiently below the lower surface of the main girder upper flange 11b. It is 32A and 32A.
In the present embodiment, the main girder horizontal and vertical ribs 32A are provided so as to project sufficiently downward from the other vertical ribs 32, but they do not necessarily have to project with such a length. It may be lower than the upper surface 11e of the main girder upper flange 11b.

As shown in FIG. 4, the lateral ribs 33 are arranged substantially in the bridge width direction X on the lower surface side of the deck plate 31, and at least a part of one end surface or both end surfaces of the bridge width direction X is the nearest main girder. It is provided so as to face the web surface of the main girder web 11a of 11.
Specifically, two lateral ribs 33 (33A, 33B) extending in the bridge width direction X are joined to the lower surface of the deck plate 31 by welding or the like with the main girder 11 interposed therebetween.

Further, the horizontal rib 33A on the right side of the paper surface in the bridge width direction X in the steel deck 30 has a lower end formed in a substantially horizontal direction from the main girder 11 to a certain distance, and at a position further away from the main girder 11, this is As the distance from the main girder 11 increases, the lower end portion is formed in a plate shape inclined so as to gradually approach the deck plate 31 side (see FIG. 15A). This is because the required height for the joint to the main girder 11 is larger than the required height for the horizontal rib 33A. Therefore, the height near the joint may be uniform. A part of one end surface (that is, the end surface on the main girder 11 side) of the horizontal rib 33A in the bridge width direction X faces the web surface on the right side of the nearest (right side of the paper) main girder web 11a. A flange 33b is fixed to the lower end surface of the horizontal rib 33A.
The right side referred to below means the right side when facing the display surface of the present specification. The same applies to the left side.

Such horizontal ribs 33A are arranged substantially at the center of the short side of the deck plate 31 in the length direction (bridge axis direction Z), and the vertical ribs 32 are arranged orthogonally to the horizontal ribs 33A. The intersection is welded. In order to reduce the stress generated at the joint between the panels, it is also an effective means to arrange the deck plate 31 at a portion approximately 1/3 in the length direction. Further, in the main girder horizontal and vertical ribs 32A, the surface opposite to the main girder upper flange 11b faces one end surface of the horizontal ribs 33A, and the extending direction of the main girder horizontal and vertical ribs 32A and the extending of the horizontal ribs 33A. It is brought into contact with one end surface of the lateral rib 33A so as to be orthogonal to the current direction, and then joined to the lateral rib 33A by welding. Further, one end of the main girder horizontal and vertical ribs 32A extends downward from the lower surface of the main girder upper flange 11b, and is in a state of facing the web surface of the main girder web 11a.

As shown in FIG. 3B, the lateral ribs 33B on the left side of the steel deck 30 in the bridge width direction X are provided at both ends of the rectangular plate-shaped base portion and the bridge width direction X. It is formed in a plate shape integrally having a protruding portion 33c protruding downward from each of the above. The lower end side of the protruding portion 33c is formed in a plate shape that gradually protrudes downward toward both ends in the extending direction of the lateral rib 33B. Therefore, both ends of the lateral rib 33B and its vicinity have a shape in which the length in the vertical direction gradually increases toward both ends in the extending direction due to the protruding portions 33c.

Further, as shown in FIG. 4, both end portions 33d of the lateral rib 33B face each other with the web surface of the nearest main girder web 11a. Such a horizontal rib 33B is arranged at a substantially central portion in the length direction of the short side of the deck plate 31, that is, is arranged on an extension of the horizontal rib 33A, and the vertical rib 32 is arranged orthogonally to the horizontal rib 33B. And their intersections are welded.

Next, in the first embodiment, the slab structure for replacing the reinforced concrete slab 14 with the steel slab 30 will be described with reference to FIGS. 4 and 5.
Among the reinforced concrete floor slabs 14 shown in FIGS. 13 (a) and 13 (b), the floor slab structure includes a residual reinforced concrete 21 (reinforced concrete) provided on the upper surface side of the main girder upper flange 11b of the main girder 11 and a residual reinforced concrete 21. The steel plate 30 is provided so as to cover the steel plate 30. Here, the residual reinforced concrete 21 is a portion that is left when the reinforced concrete of the reinforced concrete floor slab 14 provided on the main girder 11 is removed.
In the present embodiment, the area where the reinforced concrete of the reinforced concrete plate 14 is removed is defined as the concrete removal area 2A (recess) in the area surrounded by the main girder upper flange 11b and the steel plate 30.

On the inner surfaces 32b of the pair of main girder horizontal and vertical ribs 32A and 32A facing each other, a slip prevention member 51 (protruding member) is provided in the concrete removal region 2A formed around the remaining reinforced concrete 21. The slip stopper 51 usually uses a stud with a head. Here, the main girder horizontal and vertical ribs 32A and 32A act as vertical ribs of the steel deck 30 as a mechanical action.

As shown in FIG. 5, the anti-slip member 51 is perpendicular to the opposing inner surfaces 32b of the main girder horizontal and vertical ribs 32A and 32A on both sides of the main girder 11. It is projected. In the slip prevention member 51, the head portion 51a is on the protruding tip side, and the base end portion 51c of the shaft portion 51b is fixed by butt welding or the like. A plurality of slip prevention members 51 are arranged symmetrically at predetermined intervals in the bridge axis direction Z with the main girder 11 interposed therebetween.

These slip prevention members 51 are integrally embedded in the mortar 47 (amorphous material) filled in the concrete removal region 2A between the main girder horizontal and vertical ribs 32A and 32A. The slip stopper 51 functions as a slip stopper between the steel deck 30 and the main girder 11 through the slip stopper 51, and has an action of transmitting a shearing force in the bridge axial direction Z.
Here, the concrete removal region 2A is an region surrounded by the main girder upper flange 11b of the main girder 11, the deck plate 31, and a pair of main girder horizontal and vertical ribs 32A and 32A, and mortar inside these. 47 is filled.

In the present embodiment, as shown in FIG. 4, the vertical length L1 of the main girder web 11a between the main girder upper flange 11b and the lateral rib mounting member 16 (described later) is 224 mm or more.
The length L1 is preferably 38 times or less the thickness of the main girder web 11a. This is because the stress generated in the welded portion between the main girder upper flange 11b and the main girder web 11a is sufficiently reduced to a level at which fatigue does not occur.
In addition, webs with a thick cross section are also manufactured. In this case, the minimum length L1 of the rib mounting member is 224 mm when the girder height is 1600 mm and the plate thickness is 9 mm. Set as the separation distance. Therefore, in order to reduce the stress between the main girder upper flange 11b and the main girder web 11a, it can be said that it is appropriate to secure a distance of 224 mm or more as the length L1.
Also, taking buckling into consideration, as described in the Road Bridge Specification, the maximum level of buckling resistance is not reduced when high-strength steel SBHS is used for the main girder web 11a. Setting 38 times the plate thickness as the non-buckling section width is an appropriate upper limit in terms of design.

Next, with reference to the construction flow of FIG. 6, a construction method for replacing a part of the reinforced concrete slab 14 laid supported by the main girder 11 of the bridge 10 having the above-described configuration with a new steel slab 30 This will be described in detail.
First, as a preparatory step (step S1 in FIG. 6), a full suspension scaffold (not shown) is installed under the bridge 10, and the full suspension scaffold interferes with the installation (replacement) of the new steel deck 30. Remove, improve, and finish parts (partially grinder work). If a full-scale scaffold is installed in advance for inspection or the like, the same work can be performed using the scaffold.

Next, as shown in FIGS. 7 (a) and 7 (b), and 8 (a) and 8 (b), the lateral rib mounting member 16 is bolted to the upper portion of the main girder web 11a with a high-strength bolt. In this case, work is performed on the lower surface side of the reinforced concrete floor slab 14, and the lateral rib mounting member 16 is bolted to the main girder web 11a (step S2).
7 (b) is a cross-sectional view of the right main girder 11 in FIG. 7 (a) including the horizontal rib mounting member 16.

As shown in FIGS. 8A and 8B, the lateral rib mounting member 16 is formed in a T-shaped cross section, and is fixed to a rectangular plate-shaped fixing plate 16a and a central portion of the fixing plate 16a in the width direction. It has a rectangular plate-shaped connecting plate 16b projecting from the plate surface of the plate 16a in a direction perpendicular to the plate surface. The lengths of the fixing plate 16a and the connecting plate 16b in the vertical direction are the same, and the protruding length of the connecting plate 16b from the fixing plate 16a is the tip of the connecting plate 16b on the end surface of the lateral rib 33 of the steel plate 30. The length is set so that the surfaces can come into contact with each other. The horizontal rib mounting member 16 is a member for connecting the horizontal rib 33 and the main girder web 11a, and is attached to the main girder web 11a by tension bolt joining, and the horizontal rib 33 of the steel plate 30 is It is connected by frictional joining of two-sided shear.
Further, the fixing plate 16a is provided with a plurality of bolt holes 16c, and the connecting plate 16b is provided with a plurality of bolt holes 16d.

The horizontal rib mounting member 16 is mounted by bringing the fixing plate 16a into contact with the web surface of the main girder web 11a located below the portion where the newly installed steel plate 30 is to be replaced and bolting the fixing plate 16a. In the present embodiment, a part of the reinforced concrete floor slab 14 is replaced with the steel floor slab 30 between the main girder 11 on the right side and the main girder 11 in the central portion in FIG. 7A. Therefore, as shown in FIG. The horizontal rib mounting members 16 are mounted substantially symmetrically on both web surfaces of the main girder web 11a of the main girder 11 on the right side with the central portion in the thickness direction of the main girder web 11a as a boundary, and the main girder 11 in the central portion is attached. The horizontal rib mounting member 16 is attached to the web surface of the main girder web 11a facing the right main girder 11 side.

In FIG. 9, the right side horizontal rib mounting member 16 is longer in the vertical direction than the left side horizontal rib mounting member 16, and the lower end of the right side horizontal rib mounting member 16 is the left side horizontal rib mounting member. It protrudes downward from the lower end of 16. This is because the vertical length of the end of the horizontal rib 33A on the main girder web 11a side is longer than the vertical length of the end of the horizontal rib 33B on the main girder web 11a side, and the lower end of the horizontal rib 33A. Is due to the fact that the lateral rib 33B protrudes downward from the lower end (see FIG. 3B). Therefore, when the vertical length of the end of the horizontal rib 33A on the main girder web 11a side and the vertical length of the end of the horizontal rib 33B on the main girder web 11a side are equal, the right horizontal rib mounting member 16 The vertical length of the left lateral rib mounting member 16 may be equal to the vertical length of the left lateral rib mounting member 16.

Further, when the lateral rib mounting member 16 is connected to the web surface of the main girder web 11a on the right side, the coating on the web surface is peeled off, and then the members are joined by ordinary friction stir welding with high-strength bolts 18. That is, as shown in FIG. 9, the main girder web 11a is provided with a bolt hole 11d at a position corresponding to the bolt hole 16c, and is brought into contact with both the bolt hole 11d and both web surfaces of the main girder web 11a. By inserting the high-strength bolts 18 into the bolt holes 16c and 16c of the fixing plates 16a of the horizontal rib mounting members 16 and 16 and screwing and tightening the nuts into the high-strength bolts 18, the web surface of the main girder web 11a The horizontal rib mounting member 16 is connected to.

At this time, the fixing plate 16a of the horizontal rib mounting member 16 is pre-drilled at the factory and provided with the bolt holes 16c, while the main girder web 11a is in the stage before the joining work is performed. The bolt hole 11d is not provided. The lateral rib mounting member 16 is temporarily installed at an appropriate position, and the bolt hole 16c is used as a template to drill holes in the main girder web 11a using an instrument such as a portable drilling machine (not shown). At the time of joining work, there is a possibility that misalignment may occur between the members, and it is necessary to adjust the position of the bolt hole 16c. However, by this method, the relative of the bolt holes between the horizontal rib mounting member 16 and the main girder web 11a Position adjustment is possible.

Further, the same applies when the lateral rib mounting member 16 is connected to the web surface of the main girder web 11a in the central portion.
Further, on the web surface on the opposite side (left side main girder 11 side) of the central main girder web 11a, a reinforced concrete floor slab supported by the central main girder 11 and the left main girder 11 is laid. When a part of 14 is replaced with a new steel plate 30, the horizontal rib mounting member 16 is mounted in the same manner.
After the horizontal rib mounting member 16 is attached to the main girder 11, as shown in FIG. 10, lane regulation of upper traffic is performed as necessary (step S3). When lane regulation is performed, temporary guards 17 are erected at predetermined intervals in the bridge axis direction Z at the center of the road surface in the width direction (bridge width direction X). FIG. 10 shows a regulation of one lane on the right side, in which the left side of the temporary guard 17 is the vehicle traffic zone and the right side is the construction zone.

Next, in the construction zone, as shown in FIGS. 4 and 5, a part of the reinforced concrete slab 14 is provided on the upper surface 11e side of the main girder upper flange 11b within a predetermined width in the bridge axis direction Z. By removing the region (concrete removal region 2A) where the remaining portion (remaining reinforced concrete 21) is left, the removal portion 20 is formed in a part of the reinforced concrete slab 14, and is left on the upper surface 11e side of the main girder upper flange 11b. Reinforced concrete 21 is left behind.

That is, as shown in FIGS. 10 and 11, the predetermined reinforced concrete slab 14 located between the main girder 11 located on the right side of the bridge width direction X and the main girder 11 located at the center in the bridge axial direction Z. The portion is cut and removed by a concrete cutter according to the plan view shape and size of the steel plate 30 (in the case of this embodiment, the plan view substantially rectangular shape) (step S4).
At this time, as described above, the reinforced concrete floor slab 14 is predetermined by removing the portion other than the portion provided on the upper surface 11e side of the main girder upper flange 11b (concrete removal region 2A shown in FIG. 5) to form a space. A removal portion 20 is provided at a portion (part). In this case, the remaining reinforced concrete 21 is left on the entire upper surface of the main girder upper flange 11b of the right main girder 11, and the remaining reinforced concrete 21 is left on the upper surface 11e of the main girder upper flange 11b of the main girder 11 in the central portion.

At this time, in the concrete removal region 2A, the portion of the reinforced concrete slab 14 adjacent to the removal portion 20 and the bridge width direction X is pavement shown in FIG. 12 on the upper surface 11e side of the main girder upper flange 11b of the main girder 11. A part of the portion 15 is removed along the bridge axis direction Z to expose the edge portion along the removing portion 20. Further, for the portion of the reinforced concrete slab 14 located between the main girders 11 and 11 and adjacent to the removal portion 20 in the bridge axial direction Z, the pavement portion 15 is removed along the bridge width direction X, and the removal portion 20 is used. Expose a pair of edges along.

In this way, the length of the rectangular removing portion 20 formed by cutting the predetermined portion of the reinforced concrete floor slab 14 into a substantially rectangular shape in a plan view is the length of the bridge axis direction Z in the plan view of the newly installed steel floor to be replaced. It is set slightly longer than the length in the bridge axis direction Z in the plan view of the plate 30. Further, as shown in FIG. 11, when a predetermined portion of the reinforced concrete floor slab 14 is cut into a substantially rectangular shape in a plan view, the ground cover 14b and the balustrade 14c on the right side are also cut, so that the bridge width direction X of the removing portion 20 The outside (right side) is open.

Further, in such a reinforced concrete plate removal step, as shown in FIG. 12, a hammer is applied to the overlaid concrete 22 on the upper part of the remaining reinforced concrete 21 and the pavement portion 15 on the upper part of the remaining reinforced concrete 21 on the main girder upper flange 11b of the right main girder 11. It is removed by manual work such as hitting (step S5). In this case, the overlaid concrete 22 above the upper reinforcing bar of the remaining reinforced concrete 21 is removed, but steel materials such as studs (not shown) and slab anchors (not shown) standing on the upper surface of the main girder upper flange 11b are left behind. ..

Next, as shown in FIG. 13A, the newly installed steel plate bridge 30 is arranged on the removal portion 20 so as to cover the remaining reinforced concrete 21, and is temporarily placed. In this case, the remaining reinforced concrete 21 is arranged so as to be sandwiched between the main girder horizontal and vertical ribs 32A and 32A shown in FIGS. 4 and 5 in the bridge width direction X, and the lower surface of the deck plate 31 is in contact with the upper surface of the remaining reinforced concrete 21. The steel deck slab 30 is temporarily placed by touching it (step S6).

Then, when arranging the newly installed steel deck 30 so as to cover the remaining reinforced concrete 21 on the rectangular removing portion 20 in a plan view, as shown in FIGS. 14 (a) and 14 (b), the side of the main girder The vertical ribs 32A and 32A are arranged so as to sandwich the main girder upper flange 11b of the main girder 11 in the bridge width direction X.
Since there is a gap between the end of the main girder upper flange 11b in the bridge width direction X and the surface of the main girder horizontal and vertical ribs 32A and 32A facing the end in the bridge width direction X, there is a gap. The sealing material 36 is fitted into this gap. Further, from the surface of the main girder horizontal and vertical ribs 32A, 32A facing the main girder upper flange 11b, to the lower surface of the sealing material 36 and the lower surface of the main girder upper flange 11b, a concrete formwork, waterproofing, and titanium foil for corrosion protection. Paste 37.

Further, as shown in FIGS. 14A and 14B, a height adjusting bolt 40 capable of adjusting the height of the steel plate 30 is screwed onto the steel plate 30 so as to be in contact with the remaining reinforced concrete 21. Has been done. That is, a screw hole 41 is provided in the portion of the deck plate 31 located above the remaining reinforced concrete 21 on the main girder upper flange 11b of the main girder 11 on the right side, and the height adjusting bolt 40 is provided in the screw hole 41. Is screwed, and the tip end portion (lower end portion) of the height adjusting bolt 40 is in contact with the upper surface 21a of the remaining reinforced concrete 21. A plurality of such height adjusting bolts 40 are provided at the edge of the deck plate 31 in the bridge axis direction Z and above the main girder 11. Then, after the steel plate slab arrangement step, the height adjusting bolt 40 is appropriately turned in the forward and reverse directions to raise and lower the steel plate 30 to adjust the height. That is, the height of the steel plate 30 is adjusted so that the upper surface of the pavement portion 34 of the steel plate 30 and the upper surface of the pavement 15 of the reinforced concrete plate 14 are substantially flush with each other (step S7).

Next, the lateral rib 33 of the steel deck 30 is rigidly coupled to the main girder web 11a closest to the end at the end of the lateral rib 33 in the bridge width direction X. As shown in FIGS. 15 (a), 15 (b), and 16, the lateral ribs 33A and 33B are formed, and one end surface of the end portion of the lateral ribs 33A and 33B in the bridge width direction X is used as the web of the main girder web 11a. The ends 33e, 33e of the lateral ribs 33A, 33B in the bridge width direction X are rigidly coupled to the nearest main girder webs 11a, 11a in a state of facing the surface. As a result, the stress generated due to the traffic load due to the slab action of the steel plate 30 can be reduced. That is, even with the horizontal ribs 33 having the same height, the stress generated in the steel plate bridge 30 is reduced by rigidly coupling to the main girder webs 11a and 11a, and it is possible to sufficiently secure the fatigue life.

Specifically, in the present embodiment, with respect to the lateral rib 33B, as shown in FIG. 17, in a state where one end 33d of the end 33e in the bridge width direction X faces the web surface of the main girder web 11a. , The end portion 33e and the connecting plate 16b are spliced from both sides thereof after being brought into contact with the tip surface of the connecting plate 16b of the lateral rib mounting member 16 fixed to the main girder web 11a of the main girder 11 in the central portion. It is sandwiched between the plates 42 and 42 and frictionally joined by the high-strength bolt 45 and the nut 45a. As a result, the lateral rib 33B is rigidly coupled to the main girder web 11a closest to the end 33e at the left end 33e of the lateral rib 33B in the bridge width direction X.

Similarly, the right end 33e of the horizontal rib 33B in the bridge width direction X is spliced to the tip of the connecting plate 16b of the horizontal rib mounting member 16 fixed to the main girder web 11a of the right main girder 11. Rigidly connect the plates 42, 42 and the high-strength bolt 45 with the nut 45a.

As shown in FIGS. 8A and 8B, a plurality of bolt holes 16d are formed in advance in the connecting plate 16b at a factory or the like, and the splice plate 42 is also formed in advance as shown in FIGS. 16 and 17. A plurality of bolt holes 42c are formed in a factory or the like.
Then, after inserting the high-strength bolts 45 into the bolt holes 42c, 16d, 42c and the bolt holes 42c, 33g, 42c arranged coaxially, respectively, the nut 45a is screwed into the high-strength bolts 45 and tightened. The lateral rib 33B is rigidly coupled to the nearest main girder web 11a at the end 33e of the lateral rib 33B in the bridge width direction X by friction welding. In FIG. 16, the high-strength bolt 45 is not shown.

Similarly, as shown in FIGS. 15A and 15B, for the lateral rib 33A, one end 33d of one end 33e in the bridge width direction X is made to face the web surface of the main girder web 11a. In the state, after contacting the tip surface of the connecting plate 16b of the lateral rib mounting member 16 fixed to the main girder web 11a of the main girder 11 on the right side, the end portions 33e and the connecting plate 16b are spliced from both sides thereof. By sandwiching it between 42 and 42 and fastening it with a high-strength bolt 45, the lateral rib 33B is rigidly coupled to the main girder web 11a closest to the end 33e at the end 33e of the lateral rib 33A.

Further, even in such a friction joining structure using high-strength bolts, the surface of the splice plate 42 to which the surface of the end portion 33e of the lateral rib 33A in the bridge width direction X is joined and the surface of the connecting plate 16b are joined to the splice plate. The surface of 42 is subjected to friction surface treatment by spraying a metal such as aluminum by a factory or the like.

Next, as shown in FIGS. 4 and 5, a slip stopper 5 is previously welded to the inner surfaces 32b of the pair of main girder horizontal and vertical ribs 32A and 32A so as to be arranged in the concrete removal area 2A. (Step S8).

Next, as shown in FIG. 14B, mortar 47 is filled between the steel plate bridge 30, the main girder upper flange 11b, and the remaining reinforced concrete 21. At this time, the height adjusting bolt 40 is not removed from the screw hole 41, and the main girder upper flange 11b and the remaining reinforced concrete 21 are housed from the filling hole (not shown) provided in advance in the deck plate 31. The space between the ribs 32A and 32A is filled with the mortar 47 (step S9). The height adjusting bolt 40 and the mortar 47 may be sufficiently cured before being removed, or may be buried in the mortar 47 and left behind.

As described above, the main girder horizontal and vertical ribs 32A and 32A are arranged so as to sandwich the main girder upper flange 11b in the bridge width direction X, and are filled between the main girder upper flange 11b and the main girder horizontal and vertical ribs 32A and 32A. The mortar 47 is formed in a space (concrete removal area 2A) surrounded by the deck plate 31 of the steel floor slab 30, the main girder upper flange 11b, the sealing material 36, and the main girder horizontal and vertical ribs 32A and 32A. It spreads all over and fills the gap. This makes it possible to prevent corrosion of the upper reinforcing bar of the remaining reinforced concrete 21, the lower surface of the deck plate 31, and the upper surface 11e of the main girder upper flange 11b.

In this embodiment, mortar 47 is used as the amorphous material, but other than mortar 47, non-shrinkable resin, rubber latex, or other material having rapid curability and fluidity can be used.
The filling operation of the mortar 47 may be performed after the steel plate bridge joining step described later. Further, in order to improve the overall work efficiency, the steel deck slabs 30 for several panels may be filled together after construction. This is because the dead load and live load (traffic load) acting on the steel plate 30 are, by design, transmitted to the main girder web 11a through the lateral rib 33.

In the present embodiment, as shown in FIG. 4, the main girder 11 and the steel deck 30 are connected to each other by a slip stopper 51 that transmits a shearing force in the bridge axis direction Z to steel from the main girder 11. Shear force in the bridge axis direction Z can be transmitted toward the floor slab 30.

Next, as shown in FIGS. 13 (b) and 18 (a) and 18 (b), the steel slab 30 and the reinforced concrete slab adjacent to the steel slab 30 in the bridge width direction X and the bridge axial direction Z are adjacent to each other. A temporary fixing plate 55 is bridged between the temporary fixing plate 55 and the temporary fixing plate 55, and a temporary paving portion 56 is provided on the upper surface of the steel deck 30 in advance on the paving portion 34 and the reinforced concrete floor slab 14. The construction is carried out almost flush with the pavement portion 15 (step S10). The temporary fixing plate 55 temporarily connects between the reinforced concrete slab 14 and the steel slab 30, or between adjacent steel slabs, thereby suppressing the depressed state of the road and enabling the passage of vehicles. It has a function.

That is, as shown in FIG. 18A, in the peripheral portion of the reinforced concrete slab 14 surrounding the removal portion 20 where the steel slab 30 is arranged by the above-mentioned reinforced concrete slab removing step, the bridge width direction X In the portion adjacent to the main girder 11, a part of the pavement portion 15 is removed on the upper surface 11e side of the main girder upper flange 11b of the main girder 11, and the edge portion adjacent to the removed portion 20 in the bridge width direction X of the reinforced concrete slab 14 is removed. It is in an exposed state. Further, in the reinforced concrete slab 14 located between the main girders 11 and 11 and adjacent to the bridge axis direction Z, a part of the pavement portion 15 is removed along the bridge width direction X, and the reinforced concrete slab 14 The edge portion adjacent to the removal portion 20 is exposed in the bridge axis direction Z.

On the other hand, the outer peripheral edge portion 31a of the deck plate 31 of the steel plate 30 projects outward from the outer peripheral edge portion of the pavement portion 34, and a plurality of bolt holes 31b are provided in the protruding outer peripheral edge portion 31a.
Further, in the bridge width direction X and the bridge axial direction Z, between the outer peripheral edge portion 31a of the steel deck 30 and the edge portion (outer peripheral edge portion 32a) along the bridge axial direction Z and the bridge width direction X of the reinforced concrete slab 14. Is provided with a gap S.

Then, as shown in FIG. 18B, the temporary fixing plate is provided so as to straddle the gap S between the outer peripheral edge portion 31a of the deck plate 31 and the outer peripheral edge portion 32a along the bridge axis direction Z of the reinforced concrete floor slab 14. Over 55. The temporary fixing plate 55 is provided with a bolt hole 55b, and the temporary fixing plate 55 is bridged so that the bolt hole 55b is coaxial with the bolt hole 31b. Then, the bolts 57 are inserted into the bolt holes 55b and 31b and tightened with the nuts 57a to fix the temporary fixing plate 55, and then the temporary pavement portion 56 is attached to the steel plate 30 on the upper surface side of the temporary fixing plate 55. It is constructed substantially flush with the pavement portion 34 provided in advance on the upper surface of the above surface and the pavement portion 15 on the reinforced concrete slab 14.

As shown in FIG. 19, the floor slab structure constructed in this manner includes at least a part of the reinforced concrete floor slab 14 other than the portion provided on the upper surface 11e side of the main girder upper flange 11b of the main girder 11. The remaining reinforced concrete 21 and the remaining reinforced concrete floor slab 14 are covered with the remaining reinforced concrete 21 on the removing portion 20 (see FIG. 4) obtained by removing the remaining reinforced concrete 21 in an exposed state. It is provided with a steel plate bridge 30 arranged in the above.

Further, the steel deck slab 30 is arranged in the bridge width direction X on the lower surface side of the deck plate 31, and at least a part of one end surface or both end surfaces of the bridge width direction X is the main girder web 11a of the nearest main girder 11. It has lateral ribs 33 (33A, 33B) facing the web surface, and the lateral ribs 33 are attached to the main girder web 11a closest to the end 33e at the end 33e of the lateral rib 33. It is rigidly connected by 16.
Further, as shown in FIG. 4, the main girder 11 and the steel deck 30 are connected to each other via a slip stopper 51 and a mortar 47 that transmit a shear force in the bridge axial direction Z.

Further, mortar 47 is filled between the steel plate bridge 30, the main girder upper flange 11b, and the remaining reinforced concrete 21. Further, a temporary fixing plate 55 is bridged between the steel slab 30 and the reinforced concrete slab 14 adjacent to the steel slab 30, and the temporary pavement portion 56 is provided on the upper surface side of the temporary fixing plate 55. It is constructed almost flush with the pavement portion 34 of 30 and the pavement portion 15 on the reinforced concrete slab 14.

In this way, after the replacement of one steel plate 30 is completed, the temporary traffic regulation is lifted so that the construction zone can pass through (step S11).
When replacing the second steel plate 30, it is basically performed by sequentially repeating the above-mentioned steps. However, detailed description of each step will be omitted.
First, as shown in FIGS. 20 and 21, of the part of the reinforced concrete slab 14 adjacent to the previously replaced (newly installed) steel slab 30 in the bridge axial direction Z in the construction zone, the bridge axial direction Z By removing the portion other than the portion provided on the upper surface side of the main girder upper flange 11b within the predetermined width of the above, the removing portion 20 is provided on a part of the reinforced concrete floor slab 14, and the removing portion 20 is on the main girder. The remaining reinforced concrete 21 is left on the upper surface side of the flange 11b. Further, the horizontal rib mounting member 16 is bolted to the upper part of the main girder web 11a with a high-strength bolt.

Next, as shown in FIGS. 22 and 23, the next steel plate bridge 30 is arranged on the removal portion 20 so as to cover the remaining reinforced concrete 21 (see FIG. 5), and the height adjusting bolt 40 (FIG. 14). (See (a) and (b)) adjust the height of the steel plate 30.
Next, the horizontal rib 33 of the steel plate bridge 30 is rigidly coupled to the main girder web 11a closest to the end of the horizontal rib 33 by the horizontal rib mounting member 16.
Further, at this stage, as shown in FIG. 24, the adjacent steel plate bridges 30 and 30 are joined by the high-strength bolt 46 using the inter-panel joint 35. The inter-panel joint 35 integrates adjacent steel plate bridges 30 and 30 by two-sided shear bolt friction welding. By this inter-panel joint 35, the bridge axis direction Z and the bridge axis perpendicular direction of the deck plate 31 of the steel deck 30, and the vertical ribs 32 and the main girder horizontal and vertical ribs 32A are each joined by two-sided shear bolt friction welding. To. When the inter-panel joint 35 is provided, if the temporary fixing plate 55 that already exists is present, the temporary fixing plate 55 is removed.

Further, as shown in FIG. 24, the inter-panel joint 35 for joining the steel deck slabs 30 and 30 adjacent to each other in the bridge axis direction Z (the direction orthogonal to the paper surface in FIG. 24) is provided on the upper surface side of the deck plate 31. The joint plate 35a extending in the long side direction (bridge axis orthogonal direction) of the steel deck plate 30 and the vertical ribs 32, 32 between the vertical ribs 32, 32 and the vertical ribs 32 adjacent to each other in the bridge axis orthogonal direction on the lower surface side of the deck plate 31. It is provided between the main girder horizontal and vertical ribs 32A, and includes a plurality of joint plates 35b shorter than the joint plate 35a. Then, the deck plates 31 and 31 of the adjacent steel plate bridges 30 and 30 are sandwiched between the joint plate 35a and the joint plate 35b, and the steel plate plates 30 and 30 are joined to each other by fastening with the high-strength bolt 46. Has been done.

Further, the inter-panel joint 35 for joining the vertical ribs 32, 32 of the steel deck slabs 30 and 30 adjacent to each other in the bridge axis direction Z and the main girder horizontal and vertical ribs 32A, 32A has two joint plates 35c, 35c. I have. The joint plate 35c is arranged so as to straddle the joint portions of the steel deck slabs 30 and 30 adjacent to each other in the bridge axis direction Z. Then, the vertical ribs 32 and 32 and the main girder horizontal and vertical ribs 32A and 32A of the steel deck slabs 30 and 30 adjacent to each other in the bridge axis direction Z are sandwiched by the joint plates 35c and 35c, respectively, and fastened by the high-strength bolts 46. As a result, the steel plate bridges 30 and 30 are joined to each other.

Further, the inter-panel joint 35 for joining the steel slabs 30 and 30 adjacent to each other in the direction orthogonal to the bridge axis includes two joint plates (not shown). This joint plate is arranged so as to straddle the joints of the steel slabs 30 and 30 adjacent to each other in the direction orthogonal to the bridge axis, and extends along the short side direction of the steel slab 30. Then, the deck plates 31 and 31 of the steel deck slabs 30 and 30 adjacent to each other in the bridge axis orthogonal method are sandwiched by the joint plates, and are fastened by the high-strength bolts 46 to join the steel deck slabs 30 and 30 to each other. Has been done.

Finally, a temporary fixing plate 55 is bridged between the steel slab 30 replaced this time and the reinforced concrete slab 14 adjacent to the steel slab 30 in the bridge width direction X and the bridge axial direction Z, and this temporary fixing plate On the upper surface side of 55, the temporary pavement portion 56 is constructed substantially flush with the pavement portion 34 previously provided on the upper surface of the steel deck 30 and the pavement portion 15 on the reinforced concrete plate 14 (see FIG. 18B). ).

After replacing the next (second) steel slab 30 in this way, the required number of steel slabs 30 are replaced one after another in the same manner, so that the reinforced concrete slab is replaced by a desired distance in the bridge axial direction Z. A new steel plate bridge 30 will be newly installed in place of 14. As described above, a new steel deck 30 is newly installed for a desired distance in the bridge axis direction Z for one lane of the two lanes on each side.

Further, after a new steel slab 30 is newly installed in place of the reinforced concrete slab 14 for a desired distance in the bridge axis direction Z for one lane, as shown in FIG. 25, the other side of the two lanes on one side Similarly, for the lane (the lane on the left side in FIG. 25), a new steel slab 30 is newly installed in place of the existing reinforced concrete slab 14.
In FIG. 25, two steel slabs 30 replaced in one lane are shown, but in reality, a predetermined number of steel slabs 30 are continuously constructed (newly installed) in the bridge axial direction Z.
When the steel plate 30 is newly installed in the other lane, the steel plate 30 is newly installed in the same lane as when the steel plate 30 is newly installed. Therefore, the method is simplified below. Explain to.

When a new steel slab 30 is newly installed in place of the reinforced concrete slab 14 in the other lane of the two lanes on one side, as a preparatory process, the entire scaffolding is installed and the interfering members are removed, and then the reinforced concrete is installed. On the lower surface side of the floor slab 14, the horizontal rib mounting member 16 is bolted to the upper part of the main girder web 11a of the predetermined main girder 11 with a high-strength bolt.
Then, after restricting the upper traffic (not shown) for the other lane, as shown in FIGS. 25 and 26, the main girder 11 of at least a part of the reinforced concrete slab 14 in the other lane is used. By removing the portion other than the portion provided on the upper surface side of the girder upper flange 11b, the removing portion 20 is provided in at least a part of the reinforced concrete floor slab 14, and the removing portion 20 is provided on the upper surface side of the main girder upper flange 11b. Remaining Reinforced concrete 21 is left (reinforced concrete floor slab removal step).

Next, as shown in FIGS. 27 and 28, the steel plate bridge 30 is arranged on the removing portion 20 so as to cover the remaining reinforced concrete 21. Next, the lateral ribs 33 are rigidly coupled to the main girder web 11a closest to both ends of the lateral ribs 33 at both ends in the bridge width direction X by the lateral rib mounting members 16. The horizontal rib mounting member 16 is bolted to the main girder web 11a in advance. When the horizontal rib 33 is bolted to the horizontal rib mounting member 16, the horizontal rib mounting member 16 and the end of the horizontal rib 33 are sandwiched by the splice plate 42 and fastened with a high-strength bolt.
Next, the main girder 11 and the steel deck 30 are joined by a mortar 47 via a slip stopper 51 that transmits a shear force in the bridge axial direction Z.

Next, as shown in FIG. 29, a temporary fixing plate 55 is bridged between the steel slab 30 and the reinforced concrete slab 14 adjacent to the steel slab 30, and temporarily fixed on the upper surface side of the temporary fixing plate 55. The pavement portion 56 is constructed substantially flush with the pavement portion 34 on the upper surface side of the steel slab 30 and the pavement portion on the reinforced concrete slab 14. Further, a panel-to-panel joint is attached between the steel slab (steel slab in the other lane) 30 and the steel slab 30 installed in the lane on one side to join the panels to each other. On the upper surface side of the joint, the temporary pavement portion 56 is constructed substantially flush with the pavement portion 34 on the upper surface side of the steel deck 30 adjacent to the bridge width direction X.
Then, when the replacement of the steel deck slab 30 is completed in the planned section of the bridge, the entire construction is completed.

Also in the lane on the other side, the overlaid concrete 22 above the remaining reinforced concrete 21 is removed in the reinforced concrete plate bridge removing step.
Further, a height adjusting bolt 40 capable of adjusting the height of the steel slab 30 is screwed into the steel slab 30 so as to be in contact with the remaining reinforced concrete 21, and the height is adjusted after the steel slab arrangement step. The height of the steel deck 30 is adjusted by turning the bolt 40.
Further, after the steel plate slab arrangement step, mortar 47 is filled between the steel plate 30, the main girder upper flange 11b, and the remaining reinforced concrete 21.

According to the floor slab structure and the floor slab replacement method described above, as shown in FIGS. 1 and 2, the main girders arranged in the bridge axis direction Z on the lower surface side of the deck plate 31 in the steel slab 30 are horizontally and vertically arranged. Mortar 47 is filled so as to bury the remaining reinforced concrete 21 in the concrete removal area 2A between the ribs 32A and 32A, whereby the steel plate 30 and the main girder upper flange 11b are joined, and the rigidity and strength as a bridge. Can be secured. As a result, it is possible to reduce the structural weight as compared with the case where the conventional floor slab support bracket is used. At this time, since the remaining reinforced concrete 21 is left on the main girder 11, buckling of the main girder upper flange 11b can be suppressed.
Further, in the present embodiment, it is possible to leave the concrete between the studs (remaining reinforced concrete 21) that is difficult to remove among the reinforced concrete floor slab 14, so that the labor and time required for the concrete removing work can be reduced. it can.

Further, in the present embodiment, the slip stopper 51 embedded in the filled mortar 47 is provided at a portion in contact with the filled mortar 47. Therefore, the slip prevention member 51 can reliably transmit the shearing force in the bridge axial direction Z from the main girder 11 to the steel deck 30.

Further, in the present embodiment, since the mortar 47 is filled between the steel deck 30, the main girder upper flange 11b, and the remaining reinforced concrete 21, the reinforcing bars of the remaining reinforced concrete 21 and the concrete removal area 2A of the reinforced concrete floor slab 14 are covered. Corrosion of the exposed lower surface of the steel deck 30 and the upper surface of the main girder upper flange 11b can be prevented.
It is not necessary to require a large strength from the mortar 47. In the first place, the remaining reinforced concrete 21 is also concrete that was cast in an era when there was not sufficient construction technology, and since it was shared for a long time, it is difficult to guarantee the strength enough to enable reliable design. Therefore, it is not necessary to require a large strength for the mortar 47 to be filled therein. Further, in the residual reinforced concrete 21, the mortar 47 permeates into the cracks that greatly affect the decrease in the strength of the concrete, so that the strength can be recovered even when the residual reinforced concrete 21 has a decrease in strength.
Further, as described above, the structure is such that the remaining reinforced concrete 21 is left, and the amount of breaking the concrete of the reinforced concrete floor slab 14 can be reduced, so that noise, vibration, and dust generation can be reduced.

Further, in the present embodiment, the slip prevention member 51 can be easily fixed and projected on the inner surface 32b of the pair of main girder horizontal and vertical ribs 32A and 32A facing each other by a fixing means such as welding. Since the slip prevention member 51 is embedded in the mortar 47 to be filled, the shearing force in the bridge axial direction Z can be reliably transmitted from the main girder 11 to the steel deck 30.

Further, in the present embodiment, since it is only necessary to remove the overlaid concrete on the upper part of the remaining reinforced concrete 21, it is not necessary to remove the concrete between the studs erected on the main girder upper flange 11b. Since it takes a lot of time and effort to remove the concrete between the studs, it is possible to significantly reduce the time and effort of the removal work by leaving the concrete. The purpose of removing the overlaid concrete at the upper part is to secure a space for adjusting the road surface height and to facilitate the removal of the asphalt portion existing on the steel plate 30.

Further, in the present embodiment, a height adjusting bolt 40 whose height can be adjusted is screwed to the steel plate 30 so as to be in contact with the remaining reinforced concrete 21. Therefore, the height of the steel plate 30 can be adjusted by turning the height adjusting bolt 40, so that the height of the steel plate 30 is set at the target position, for example, equal to the height of the reinforced concrete plate 14 before replacement. can do. That is, the planned road surface height can be adjusted at the site.

Further, a temporary fixing plate 55 is bridged between the steel floor slab 30 and the reinforced concrete floor slab 14 adjacent to the steel floor slab 30, and a temporary pavement portion 56 is provided on the upper surface side of the temporary fixing plate 55. Since the pavement portion 34 of the slab 30 and the pavement portion 15 on the existing reinforced concrete slab 14 are constructed almost flush with each other, the steel floor has been updated (replaced) with the pavement portion 15 of the existing reinforced concrete slab 14. The pavement portion 34 of the plate 30 can be made continuous. For this reason, it is possible to temporarily drive the vehicle by removing the lane regulation that was performed when replacing the floor slab.

As described above, in the floor slab structure and the floor slab replacement method according to the present embodiment, the work time required for replacing the floor slab from the reinforced concrete floor slab 14 to the steel floor slab 30 can be shortened, and the main girder 11 to steel The shearing force in the bridge axis direction Z can be reliably transmitted toward the plate 30.

Next, another embodiment of the floor slab structure and the floor slab replacement method of the present invention will be described with reference to the accompanying drawings, but the same members and parts as those in the above-described first embodiment are designated by the same reference numerals. The description will be omitted, and the configuration different from that of the first embodiment will be described.

(Second Embodiment)
As shown in FIGS. 30 and 31, in the floor slab structure according to the second embodiment, the horizontal rib 330 provided on the steel floor slab 30 is provided on the main girder upper flange 11b, the deck plate 31 of the steel floor slab 30, and a pair of mains. It is a structure that is arranged in a joint region surrounded by the girder horizontal and vertical ribs 32A and 32A to function as a slip prevention member.

The lateral rib 330 according to the second embodiment connects the upper ends of the lateral lateral ribs 330A and 330B arranged on both sides of the main girder web 11a of the main girder 11 and extends along the bridge width direction X. It has a rib 331 (slip prevention member). That is, the lateral ribs 330 are integrally provided with a pair of lateral lateral ribs 330A and 330B and the passing lateral ribs 331, and are formed in a U shape that opens downward in a front view. The through lateral ribs 331 are arranged on the lower surface side of the deck plate 31 in the bridge width direction X.

The horizontal ribs 330 are continuously provided so as to penetrate the pair of main girder horizontal and vertical ribs 32A and 32A in the bridge width direction X. As shown in FIG. 30, the remaining reinforced concrete 21 left on the main girder upper flange 11b of the main girder 11 is formed with a notch 23 that opens upward and extends along the bridge width direction X. The notch 23 is formed in a slit shape so as to divide the remaining reinforced concrete 21 in the bridge axial direction Z. The notch 23 is provided with the lower portion of the through horizontal rib 331 of the horizontal rib 330 inserted from above when the steel plate 30 is placed over the main girder 11. In the through horizontal rib 331, a portion including a portion inserted into the notch portion 23 and interposed between the pair of main girder horizontal and vertical ribs 32A and 32A serves as a slip prevention member. The cutout width dimension of the cutout portion 23 can be made extremely small, and the surface of the upper surface of the main girder upper flange 11b is not required. Therefore, it is possible to reduce the time and effort required to form the notch 23 with respect to the remaining reinforced concrete 21.

In the second embodiment, the through horizontal ribs 331 of the horizontal ribs 330 in the steel plate 30 are provided so as to be interposed in the joint region between the pair of main girder horizontal and vertical ribs 32A and 32A. A through horizontal rib 331 located between the pair of main girder horizontal and vertical ribs 32A and 32A can be provided as a slip prevention member. Then, since the pair of main girder horizontal and vertical ribs 32A and the through horizontal ribs 331 between 32A are embedded in the mortar 47 to be filled, the shearing force in the bridge axial direction Z from the main girder 11 toward the steel deck 30 is ensured. Can be communicated to.
Further, in the present embodiment, since the through lateral rib 331 is fixed by the mortar 47, there is no possibility of buckling even if there is no stiffener.
Further, in the present embodiment, since the through horizontal ribs 331 are continuous between the horizontal ribs on the left and right sides of the main girder 11, the stress generated by the horizontal girder and the deck plate 31 can be reduced.

Further, in the present embodiment, the through lateral ribs 331 are continuously integrated with the pair of lateral lateral ribs 330A and 330B, and the shearing force borne by the through lateral ribs 331 can be dispersed over the entire lateral ribs 330. Therefore, the height dimensions of the lateral lateral ribs 330A and 330B can be kept small.

Although the embodiment of the floor slab structure and the floor slab replacement method according to the present invention has been described above, the present invention is not limited to the above embodiment and can be appropriately changed without departing from the spirit of the present invention.

For example, in the first embodiment, the slip-preventing member 51 having a structure protruding from the inner surface 32b of the pair of main girder horizontal and vertical ribs 32A and 32A is limited to such a stud-shaped member. There is no. For example, instead of the slip stopper 51, a slip stopper is adopted in which a bolt is inserted from the outside by making a hole in the inner surface 32b of each main girder horizontal and vertical rib 32A, and is projected so as to be arranged in the concrete removal area 2A. It is also possible to do.

Further, the slip prevention member may be configured to be a concavo-convex portion formed on the opposite inner surfaces 32b of the pair of main girder horizontal and vertical ribs 32A and 32A. In this case, for example, a checker plate (striped steel plate) having an uneven portion formed on the surface may be provided on the inner surface 32b of the main girder horizontal and vertical ribs 32A, or the main girder horizontal and vertical ribs 32A itself may be manufactured by the checker plate. Alternatively, the slip prevention member can be easily provided by adopting the main girder horizontal and vertical ribs 32A having the uneven portions formed on the inner surface 32b. Since the uneven portion formed on the main girder horizontal and vertical ribs 32A is embedded in the filled mortar 47, the main girder 11 and the steel deck 30 can reliably transmit the shear force in the bridge axial direction Z. it can.

In the above-described embodiment, the one applied to the steel main girder 11 is taken as an example, but the present invention is not limited to the steel girder, and can be applied to the concrete girder (RC, PC). In the case of a concrete girder, a hole is drilled in the remaining concrete girder, and the fixing plate 16a of the horizontal rib mounting member 16 is attached to the concrete girder with a chemical anchor or the like, so that the horizontal rib can be formed without changing other configurations. Can be rigidly connected to the main girder.

In addition, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention.

2A Concrete removal area (recess)
10 Bridge (Bridge structure)
11 Main girder 11a Main girder web 11b Main girder upper flange 14 Reinforced concrete plate 15 Pavement 16 Horizontal rib mounting member 18 High-strength bolt 20 Removal part 21 Remaining reinforced concrete (reinforced concrete)
22 Overlaid concrete 23 Notch 30 Steel plate 31 Deck plate 32 Vertical rib 32A Main girder Horizontal vertical rib 32b Inner surface 33 (33A, 33B) Horizontal rib 34 Pavement 40 Height adjustment bolt 41 Screw hole 47 Mortar (irregular material)
50 Floor slab replacement joint 51 Anti-slip member (protruding member)
330 Horizontal ribs 330A, 330B Lateral horizontal ribs 331 Through horizontal ribs (slip prevention member)

Claims (7)

It is a floor slab structure supported by the main girder of the bridge.
Reinforced concrete provided on the upper surface side of the main girder upper flange of the main girder,
A steel plate bridge arranged so as to cover the reinforced concrete and
With
The steel deck has a deck plate arranged on the reinforced concrete and main girder horizontal and vertical ribs arranged on the lower surface side of the deck plate in the bridge axis direction.
The main girder upper flange of the main girder is arranged between a pair of the main girder horizontal and vertical ribs arranged adjacent to each other in the bridge width direction.
The pair of main girder horizontal and vertical ribs are provided with a slip-preventing member in a recess formed around the reinforced concrete.
A floor characterized in that, on the upper surface side of the main girder upper flange, an amorphous material for integrally embedding the slip prevention member is filled between the pair of main girder horizontal and vertical ribs and the reinforced concrete. Plate structure. The floor slab structure according to claim 1, wherein the slip-preventing member is a protruding member projecting from the inner surfaces of the pair of main girder horizontal and vertical ribs facing each other. The floor slab structure according to claim 1 or 2, wherein the slip prevention member is a concavo-convex portion formed on the inner surfaces of the pair of main girder horizontal and vertical ribs facing each other. The steel deck has through lateral ribs arranged in the bridge width direction on the lower surface side of the deck plate.
The through horizontal ribs are continuously provided so as to penetrate the pair of main girder horizontal and vertical ribs in the bridge width direction.
The reinforced concrete has a notch that opens upward and extends along the width of the bridge.
The through lateral rib is provided in the notch in a state of being inserted from above.
The displacement preventing member, any one of claims 1 to 3, wherein the a portion interposed between the pair of main girder horizontal longitudinal ribs of the notch in the plugged in the through transverse ribs Floor slab structure described in the section. The floor slab structure according to any one of claims 1 to 4, wherein the overlaid concrete on the upper part of the reinforced concrete is removed. Any one of claims 1 to 5, wherein a height adjusting bolt capable of adjusting the height of the steel slab is screwed into the steel slab so as to be in contact with the reinforced concrete. Floor slab structure described in. A floor slab replacement method for replacing a part of an existing reinforced concrete slab supported and laid by the main girder of the bridge according to any one of claims 1 to 6 with a steel slab.
A process of removing a part of the reinforced concrete floor slab and leaving reinforced concrete on the upper surface side of the main girder upper flange.
A step of providing the slip prevention member on the pair of main girder horizontal and vertical ribs, and
A step of arranging the steel deck so as to cover the reinforced concrete and arranging the slip prevention member in the recess provided around the reinforced concrete.
A step of filling the amorphous material between the pair of main girder horizontal and vertical ribs and the reinforced concrete on the upper surface side of the main girder upper flange.
A method of replacing a floor slab, which comprises having.

Images