JP2017122353A - Replacement method of concrete slab and replacement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a replacement method of a concrete slab which reduces displacement prevention work on a flange and the cutting removal work of concrete when replacing the concrete slab, and dispenses with accurate positioning in a site, and a replacement structure.SOLUTION: When replacing an existing concrete slab to a new slab 21, a joining member 31 extending to a bridge axial direction is attached to a lower face of the new slab 21 in advance, an existing concrete part 12 on a flange 11 of an existing bridge main girder 10 is partially cut and left intermittently, a closed cross section space is formed of the joining member 31, the existing concrete part 12 and the new slab 21 with respect to the intermittently-left existing concrete part 12, then, the joining member, the existing concrete part and the new slab are integrated with one another by new concrete 24, a closed cross section space is formed of the joining member 31, the flange 11 of the existing bridge main girder 10 and the new slab 21 with respect to a partially-cut part 19 which is obtained by partially cutting the existing concrete part 12, and then, the joining member, the flange on the existing main girder and the new concrete are integrated with one another by the new concrete 24.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a concrete floor slab replacement method and a replacement structure that need to be renewed due to aging in the bridge field.

  In the bridge field, the floor slab in service may be replaced due to aging.

  In Patent Document 1, a steel floor slab having a connecting rib that can form a rectangular space on the flange is removed by removing the reinforced concrete floor slab that has to be replaced with the stopper remaining on the flange of the main girder. A construction method is disclosed in which a main girder and a steel deck are integrated by installing and injecting concrete into a rectangular space and solidifying it.

  On the other hand, in Patent Document 2, a reinforced concrete floor slab that needs to be replaced is cut and removed along the flange width end of the main girder, leaving a concrete block on the flange, and at a plurality of intervals in the longitudinal direction of the concrete block at appropriate intervals A new floor slab joint space is formed on the flange by partially cutting and separating them, and then the new floor slab is placed on the concrete block and fixed to the new floor slab. A construction method is disclosed in which a plate is inserted into a joining space and joined by a flange and a bolt.

JP 60-059210 A JP-A-62-045804

  However, in the construction method described in Patent Document 1, it is necessary to dismantle and remove only the reinforcing bars and concrete that cover the main girder flanges in a state where the slip stoppers remain. Numerous stoppers are densely installed on the main girder flange by welding, etc., and it is a great effort to dismantle and remove only the reinforcing bars and concrete that cover these existing stoppers. And work time. Moreover, there exists a possibility of damaging the existing stopper at the time of dismantling.

  On the other hand, the construction method described in Patent Document 2 is a construction method in which a plurality of longitudinal locations of the concrete block on the flange are partially cut and removed at an appropriate interval. However, it is necessary to insert the joining plate fixed to the new floor slab into the joining space and join it with a flange and a bolt. In this case, the flange of the main girder of the existing bridge and the joint plate fixed to the new floor slab are accurately aligned at the site, and the drilling of bolt holes to the flange of the main girder of the existing bridge and the site It is difficult to perform the bolt joining at this point, and there is a problem that the work period is extended.

  The present invention has been made to solve such problems. When replacing a concrete floor slab, the displacement of the flange and the cutting and removing work of the concrete are reduced, and the on-site accurate alignment is performed. The purpose of the present invention is to provide a concrete floor slab replacement method and a replacement structure that do not need to be used.

  In order to solve the above problems, the present invention has the following features.

  [1] A concrete slab replacement method that replaces an existing concrete slab with a newly installed floor slab, in which a connecting member extending in the direction of the bridge axis is attached to the lower surface of the new floor slab and Exclude the existing concrete floor slab, excluding the existing concrete part on the flange, and then partly cut the existing concrete part on the upper flange of the existing bridge main girder to leave it intermittently. For the section, a closed section space is formed by the joint member, the existing concrete section, and the new floor slab, and the new concrete is placed in the closed section space, whereby the new floor slab and the upper flange of the existing bridge main girder Is formed, and a closed section space is formed by the joint member, the upper flange of the existing bridge main girder, and the new floor slab for the partially cut portion obtained by partially cutting the existing concrete portion. A concrete floor slab characterized by integrating the new floor slab and the upper flange of the existing bridge main girder by placing new concrete in the surface space, thereby integrating the new floor slab and the existing bridge main girder. Replacement method.

  [2] The concrete slab replacement method according to [1], wherein the newly installed slab is a steel slab.

  [3] The concrete slab replacement method according to [1] or [2], wherein a spacer is installed between the lower end of the joining member and the upper flange of the existing bridge main girder.

  [4] The concrete slab replacement method according to [1] or [2], wherein the lower end of the joining member and the upper flange of the existing bridge main girder are joined by welding.

  [5] In any one of the above [1] to [4], in the cross section in the bridge axis direction, the existing concrete portion is cut obliquely so that the lower portion of the partially cut portion is wide and the upper portion is narrow. Replacement method for concrete floor slabs.

  [6] A concrete slab replacement structure in which an existing concrete slab is replaced with a new floor slab, and a joint member extending in the direction of the bridge axis is attached to the lower surface of the new floor slab, and the upper flange of the existing bridge main girder The existing concrete part remains intermittently on the upper part, and the existing concrete part remaining intermittently is formed by the new concrete provided in the closed section space formed by the joining member, the existing concrete part, and the new floor slab. The new floor slab and the upper flange of the existing bridge main girder are integrated, and on the upper flange other than the intermittently existing existing concrete portion, the joint member, the upper flange of the existing bridge main girder, and the new floor slab The new floor slab and the upper flange of the existing bridge main girder are integrated by the new concrete provided in the closed cross-section space formed, thereby integrating the new floor slab and the existing bridge main girder. Concrete floor version of the replacement structure, characterized in that is.

  [7] The concrete floor slab replacement structure according to [6], wherein the new floor slab is a steel floor slab.

  [8] The concrete slab replacement structure according to [6] or [7], wherein a spacer is installed between the lower end of the joining member and the upper flange of the existing bridge main girder.

  [9] The concrete floor slab replacement structure according to [6] or [7], wherein the lower end of the joining member and the upper flange of the existing bridge main girder are welded.

  [10] Any of the above [6] to [9], wherein the existing concrete part is cut obliquely so that the lower part of the partially cut part is wide and the upper part is narrow in the cross section in the bridge axis direction Replacement structure for concrete floor slabs as described in 1.

  In the present invention, when replacing the concrete floor slab, it is possible to replace the concrete floor slab without reducing slippage on the flange and cutting and removing the concrete, and without requiring accurate on-site alignment. It can be carried out.

It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 2 of this invention. It is a figure which shows Embodiment 2 of this invention. It is a figure which shows Example 1 of this invention. It is a figure which shows Example 1 of this invention. It is a figure which shows Example 2 of this invention. It is a figure which shows Example 3 of this invention. It is a figure which shows Example 3 of this invention.

  Embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
Embodiment 1 of the present invention is shown in FIGS. 1-3, the structure (replacement structure) after replacing the existing concrete floor slab with the new floor slab 21 by the concrete floor slab replacement method of the present invention is shown.

  FIG. 1A is a cross-sectional view in the direction of the bridge axis of the joint between the newly installed floor slab 21 and the upper flange 11 of the main girder 10 of the existing bridge. On the upper flange 11 of the main girder 10 of the existing bridge, the existing concrete portion 12 left by cutting and removing the concrete slab is intermittently positioned in the bridge axis direction. A portion between the existing concrete portion 12 and the existing concrete portion 12 is referred to as a partial cut portion 19. In other words, the part on the upper flange 11 other than the existing concrete part 12 remaining intermittently is the partial cut part 19. The partial cut portion 19 is provided with a stopper 25 such as a headed stud, and a reinforcing bar (or reinforcing bar lattice) 29 is arranged. Further, a reinforcing bar (or reinforcing bar grid) 29 is also arranged above the existing concrete portion 12 as appropriate. The deck plate 22 of the new floor slab 21 is provided with a placement hole 28 for placing the new concrete 24, and the new concrete 24 allows the new floor slab 21 and the upper flange 11 of the main girder 10 of the existing bridge. And are integrated. By the way, the existing concrete floor slab has already been cut except for the existing concrete portion on the upper flange 11 of the main girder 10 of the existing bridge.

  As shown in FIG. 1B, the AA cross section of FIG. 1A, with respect to the existing concrete portion 12, a reinforcing bar (or reinforcing bar lattice) 29 is installed above the existing concrete portion 12. The new floor slab 21 has a joining member 31 extending in the bridge axis direction on the lower surface, and the lower end of the joining member 31 is placed on the upper flange 11 via a spacer 32 for height adjustment and water stoppage. By installing, the joint member 31, the existing concrete part 12, and the new floor slab 21 form a closed section space (a space in which the section is closed), and the new concrete 24 is placed in this closed section space. Thus, the new floor slab 21 and the upper flange 11 of the main girder 10 of the existing bridge are integrated.

  Here, the new floor slab 21 is a steel floor slab, and has a steel deck plate 22 and a steel U rib 23. The new floor slab 21 can be applied to various types of steel floor slabs such as a V rib, a flat rib, and a valve plate rib type in addition to the U rib. Further, as the spacer 32, an elastic material such as a resin, a sealing material, or rubber can be applied.

  As shown in the cross section A′-A ′ of FIG. 1A in FIG. 1C, a slip stopper 26 is provided on the inner surface of the joining plate portion 31. These are arranged at positions that do not interfere with the reinforcing bars 29 and the existing concrete portion 12.

  As shown in FIG. 1D, which is a cross section taken along the line BB in FIG. 1A, the partially cut portion 19 is provided with a detent 25 such as a headed stud and a reinforcing bar (or reinforcing bar lattice) 29. The new floor slab 21 has a joining member 31 extending in the bridge axis direction on the lower surface, and the lower end of the joining member 31 is placed on the upper flange 11 via a spacer 32 for height adjustment and water stoppage. By installing, a closed section space is formed by the joining member 31, the upper flange 11 and the new floor slab 21, and the new concrete 24 is placed in this closed section space, so that the new floor slab 21 and the existing floor slab are installed. The upper flange 11 of the bridge main girder 10 is integrated.

  In addition, as shown in FIG. 1 (e) along the B'-B 'cross section of FIG. A slip stopper 26 is installed, and the new floor slab 21 and the upper flange 11 of the main girder 10 of the existing bridge are integrated by the new concrete 24.

  In this way, the new floor slab 21 and the upper flange 11 of the main girder 10 of the existing bridge are integrated in each of the existing concrete portion 12 and the partially cut portion 19, so that the main floor of the new floor slab 21 and the existing bridge are integrated. The girder 10 is integrated.

  Here, it is preferable to roughen the surface 27 of the existing concrete portion 12 in order to improve the adhesion with the new concrete 24. For the new concrete 24, various materials such as ordinary concrete, super fast cement / concrete, non-shrink mortar, and rubber latex mortar can be applied.

  The length of the partially cut portion 19 in the bridge axis direction is preferably about 200 mm to 800 mm in consideration of workability. In addition, the center distance in the bridge axis direction of the partially cut portion 19 is preferably about 1 m to 3 m in consideration of workability and joining of the upper flange 11 of the existing bridge main girder 10 and the new floor slab 21.

  In addition, instead of the spacer 32 shown in FIG. 1B, as shown in FIG. 2, the upper flange 11 of the existing bridge main girder 10 and the lower end of the joining member 31 are joined by welding 33 to form a closed cross-section space. May be.

  Further, in order to increase the rigidity of the new floor slab 21, it is preferable to provide the horizontal spar 34 on the new floor slab 21 at intervals of about 2 m in the bridge axis direction. An example of the cross beam 34 is shown in FIG.

  As described above, in the first embodiment, when the existing concrete slab is replaced with the new floor slab 21, the joining member 31 having the slippage 26 on the inner side surface and extending in the bridge axis direction is attached to the new floor slab 21. Install it on the bottom. Then, after removing the existing concrete floor slab except for the existing concrete portion on the upper flange 11 of the main girder 10 of the existing bridge, a large number of existing detents 13 are densely installed by welding or the like to be dismantled and removed. The existing concrete portion 12 on the upper flange 11 of the difficult existing bridge main girder 10 is partially cut out and left intermittently, and the rebar 29 is provided above the existing concrete portion 12 with respect to the existing concrete portion 12 left intermittently. The joint member 31, the existing concrete portion 12 and the new floor slab 21 form a closed section space, and the new concrete 24 integrates the new floor slab 21 and the upper flange 11 of the existing bridge main girder 10. Let Further, for the partially cut portion 19, a stopper 25 such as a headed stud is installed on the upper flange 11 of the existing bridge main girder 10, and a reinforcing bar 29 is arranged above the upper flange 11. A closed section space is formed by the upper flange 11 of the bridge main girder 10 and the new floor slab 21, and the new floor slab 21 and the upper flange 11 of the existing bridge main girder 10 are integrated with the new concrete 24. As a result, the upper flange of the existing bridge main girder 10 can be reduced without the need to cut and remove the stopper 13 and the concrete portion 12 on the flange 11 of the existing bridge main girder 10 and without requiring accurate positioning on site. 11 and the new floor slab 21 can be joined. Thereby, the new floor slab 21 and the existing bridge main girder 10 can be integrated, and it becomes possible to replace the concrete floor slab that greatly reduces the labor and work time on site.

  In addition, in the joint portion between the newly installed floor slab 21 and the upper flange 11 of the existing bridge main girder 10, resistance to displacement in the bridge axis direction becomes a problem, but the new floor slab 21 and the existing bridge shown in FIG. As shown in the cross-sectional view in the bridge axis direction of the joint portion with the upper flange 11 of the main girder 10, the existing concrete portion 12 has a plurality of rectangular stoppers (block divers) inside the reinforced concrete structure by the new concrete 24 and the reinforcing bar 29. Therefore, a large resistance to the displacement in the bridge axis direction can be obtained.

  In addition, the concrete floor slab replacement method for constructing the concrete floor slab replacement structure shown in the first embodiment will be described in Example 1 described later.

[Embodiment 2]
A second embodiment of the present invention is shown in FIG. FIG. 4 corresponds to FIG. 1A in the first embodiment of the present invention, and the basic configuration of the second embodiment is the same as that of the first embodiment.

  In addition, in the second embodiment, as shown in FIG. 4, the existing concrete portion 12 is cut obliquely so that the lower portion of the partially cut portion 19 is wide and the upper portion is narrow in the cross section in the bridge axis direction. Yes.

  Thus, in this Embodiment 2, since the existing concrete part 12 is cut diagonally so that the lower part of the partial cut part 19 is wide and the upper part is narrow, as shown in FIG. It is possible to prevent the reinforcing bars 29 and the surrounding concrete 24 below the partially cut portions 19 from being pulled out in the vertical direction, and as a result, the strength and durability can be further improved.

  As Example 1 of the present invention, a concrete floor slab replacement method for constructing the concrete floor slab replacement structure shown in the first embodiment will be described.

  In Example 1, the concrete slab is replaced by a construction procedure as shown in FIG. 6 (FIGS. 6A and 6B).

(Construction procedure 1)
First, as shown in FIG. 6-1 (a), the concrete floor slab 1 that needs to be replaced is along the place that enters the inner side of the upper flange 11 of the existing bridge main girder 10 by about 30 mm to 50 mm. Then, the concrete floor slab 1 is cut in the direction of the bridge axis (cut line I), and the rest of the concrete part 12 on the upper flange is left and removed. Next, the concrete part 12 is partially cut in the direction perpendicular to the bridge axis at intervals in the bridge axis direction (cut line II).

(Construction procedure 2)
And as shown to FIGS. 6-1 (b), the cut | disconnected concrete part is removed. As described above, the remaining portion is referred to as the existing concrete portion 12, and the cut and removed portion is referred to as the partial cut portion 19. Here, it is preferable that the existing concrete portion 12 has a rough surface 27 in order to improve adhesion to the new concrete 24.

(Construction procedure 3)
Next, as shown in FIG. 6C, a stopper 25 such as a headed stud is installed in the partially excised portion 19 and a reinforcing bar (or reinforcing bar lattice) 29 is arranged. In addition, reinforcing bars (or reinforcing bar lattices) 29 are appropriately arranged above the existing concrete portion 12 and in the partially cut portions 19.

(Construction procedure 4)
Next, as shown in FIG. 6D, the new floor slab 21 is installed on the upper flange 11 of the existing bridge main girder 10. At this time, a spacer (not shown) for height adjustment and water stoppage is installed in the bridge axis direction at the end of the upper flange 11. The newly installed floor slab 21 has a joining member 31 extending in the bridge axis direction, and a closed cross-section space can be formed by installing the lower end of the joining member 31 on the upper flange 11 via a spacer. . In addition, a stopper 26 is disposed in advance on the inner surface of the joining plate portion 31 that forms a closed cross-sectional space. Further, a placement hole 28 is provided in advance on the upper surface of the new floor slab 21 (deck plate 22).

(Construction procedure 5)
Finally, as shown in FIG. 6-2 (e), by placing and hardening the new concrete 24 from the placement hole 28 provided in advance on the upper surface of the new floor slab 21 (deck plate 22), The upper flange 11 of the main girder 10 of the existing bridge and the new floor slab 24 are joined and integrated. When placing concrete, it is preferable to provide a separate air vent (not shown) to check the internal air vent and fillability. Moreover, it is preferable to close the casting hole and the air vent hole after the casting.

  As Example 2 of the present invention, FIG. 7 shows a case where the concrete floor slabs having three or more main girders are collectively replaced (collective construction).

  Also in this case, as shown in FIGS. 7A, 7B, and 7C, the construction procedure (construction procedures 1 to 5) similar to that of the first embodiment can be performed.

  As Example 3 of the present invention, FIG. 8 (FIGS. 8-1 and 8-2) shows a case where concrete floor slabs having three or more main girders are sequentially replaced (sequential construction). This sequential construction is performed while ensuring partial service.

  First, as shown in FIGS. 8-1 (a), (b), and (c), the concrete floor slab part 2 is constructed by performing construction on a part 2 of the concrete floor slab 1 that needs to be replaced. The remaining part 3 is left behind. At this time, the remaining concrete slab 3 is reinforced so as to be partially usable.

  Then, after the construction of the new floor slab 21 is completed on the part 2 of the concrete floor slab 1 that needs to be replaced, the new floor slab 21 that has undergone the construction is used, and this time, FIG. As shown in (d), the remaining concrete slab 3 is constructed, and the newly installed floor slabs 21 are joined together by welding or the like.

1 Concrete floor slab that needs replacement 2 Part of concrete floor slab that needs replacement 3 Remaining concrete floor slab 10 Main girder of existing bridge 11 Upper flange 12 Existing concrete part 13 Existing detent 19 Partially cut part 21 New floor slab 22 Deck plate 23 U-rib 24 New concrete 25 Slip-off 26 Slip-off 27 Roughening 28 Punching hole 29 Reinforcement (or rebar lattice)
31 Joining member 32 Spacer 33 Welding 34 Cross beam

Claims (10)

  A concrete slab replacement method that replaces an existing concrete slab with a new floor slab, with a joint member extending in the direction of the bridge axis attached to the lower surface of the new floor slab and on the upper flange of the existing bridge main girder Exclude the existing concrete floor slab, excluding the existing concrete part, and further cut off the existing concrete part on the upper flange of the existing bridge main girder and leave it intermittently. The joint member, the existing concrete part and the new floor slab form a closed section space, and the new floor slab and the upper flange of the existing bridge main girder are integrated by placing the new concrete in this closed section space. And forming a closed section space with the joint member, the upper flange of the existing bridge main girder, and the new floor slab. The concrete floor slab is replaced by integrating the new floor slab and the upper flange of the existing bridge main girder by placing new concrete on the wall, thereby integrating the new floor slab and the existing bridge main girder. Construction method.   2. The concrete floor slab replacement method according to claim 1, wherein the new floor slab is a steel slab.   The method for replacing a concrete slab according to claim 1 or 2, wherein a spacer is installed between the lower end of the joining member and the upper flange of the existing bridge main girder.   The method for replacing a concrete slab according to claim 1 or 2, wherein the lower end of the joining member and the upper flange of the existing bridge main girder are joined by welding.   The replacement of a concrete floor slab according to any one of claims 1 to 4, wherein the existing concrete part is cut obliquely so that the lower part of the partially cut part is wide and the upper part is narrow in the cross section in the bridge axis direction. Construction method.   A concrete slab replacement structure in which an existing concrete slab is replaced with a new floor slab, and a joining member extending in the direction of the bridge axis is attached to the lower surface of the new floor slab, and on the upper flange of the existing bridge main girder The existing concrete part remains intermittently, and the existing concrete part that remains intermittently is newly installed by the new concrete provided in the closed section space formed by the joining member, the existing concrete part, and the new floor slab. The plate and the upper flange of the existing bridge main girder are integrated, and the upper flange other than the existing concrete portion that remains intermittently is formed by the joining member, the upper flange of the existing bridge main girder, and the new floor slab. The new floor slab and the upper flange of the existing bridge main girder are integrated by the new concrete provided in the closed section space, so that the new floor slab and the existing bridge main girder are integrated. Concrete floor version of the replacement structure, characterized in that.   The replacement structure for a concrete floor slab according to claim 6, wherein the new floor slab is a steel slab.   The concrete floor slab replacement structure according to claim 6 or 7, wherein a spacer is installed between the lower end of the joining member and the upper flange of the existing bridge main girder.   8. The concrete floor slab replacement structure according to claim 6, wherein the lower end of the joining member and the upper flange of the existing bridge main girder are welded together.   The concrete floor slab according to any one of claims 6 to 9, wherein the existing concrete portion is cut obliquely so that the lower portion of the partially cut portion is wide and the upper portion is narrow in the cross section in the bridge axis direction. Replacement structure.

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