JP2019027152A - Reinforcement structure for use during floor slab replacement and floor slab replacement method - Google Patents

Abstract

To improve durability in respect to the downward load on existing floor slabs.SOLUTION: In a reinforcement structure for use during floor slab replacement where a part of an existing floor slab 3 laid above a bridge girder is removed and a new floor slab 30 is newly installed adjacent to the existing floor slab 3 remaining above the bridge girder, a lower surface 3s of the existing floor slab 3 is supported by a bracket extending from the new floor slab 30 newly installed adjacent to the existing floor slab 3 remaining above the bridge girder to the lower surface 3s of the existing floor slab 3. As a result, the downward load on the existing floor slab 3 is supported by the new floor slab 30, which is new and superior in strength to the existing floor slab 3. Thus, the durability in respect to the downward load of the existing floor slab 3 can be improved. Conversely, since the bracket and the lower surface 3s of the existing floor slab 3 are separated, the downward load applied to the new floor slab 30 is not transmitted to the existing floor slab 3. It is possible to prevent a load being applied to the existing floor slab 3 due to the downward load of the new floor slab 30.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a reinforcing structure at the time of floor slab replacement and a floor slab replacement method.

  The existing floor slab has been replaced with a new floor slab according to the deterioration over time of the existing floor slab installed on the bridge girder. When replacing the floor slab, it takes a long time to remove the existing floor slab installed on the bridge girder and replace it with a new floor slab. Therefore, in the time zone when the traffic volume at night is reduced, as described in Patent Document 1, a part of the existing floor slab erected on the bridge girder is full width every 1.5 to 2 m in the longitudinal direction. A technique has been proposed in which a new floor slab is installed adjacent to the existing floor slab remaining on the bridge girder and the floor slab is replaced by a short section. In the technology described in Patent Document 1, in a time zone in which daytime traffic is increased, a vehicle is installed in a section in which a new floor slab is installed or in an existing floor slab adjacent to the new floor slab. It is conceivable to reduce the traffic volume by allowing traffic to pass.

Japanese Patent No. 2578305

  By the way, the existing floor slab adjacent to the newly installed floor slab is partly removed in addition to the deterioration over time, and the strength of the existing floor slab is lowered due to the joint with the new floor slab. Therefore, when the vehicle passes through the joint between the existing floor slab and the new floor slab, there is a drawback that durability against a load below the existing floor slab is low.

  Then, an object of this invention is to provide the reinforcement structure at the time of the floor slab replacement | exchange and the floor slab replacement | exchange method which can improve the durability with respect to the downward load of an existing floor slab.

  The present invention is a reinforcing structure at the time of replacement of a floor slab in which a part of an existing floor slab installed on a bridge girder is removed and a new floor slab is newly installed adjacent to the existing floor slab remaining on the bridge girder. The existing floor slab extends from the newly installed floor slab adjacent to the existing floor slab remaining on the bridge girder to the lower surface of the existing floor slab and is separated from the lower surface of the existing floor slab. It is a reinforcement structure at the time of floor slab replacement provided with a bracket that supports a lower load on the existing floor slab to the newly installed floor slab by supporting the lower surface of the floor slab.

  According to this configuration, a part of the existing floor slab installed on the bridge girder is removed, and a new floor slab is installed next to the existing floor slab remaining on the bridge girder. In the structure, the lower surface of the existing floor slab is supported by a bracket that extends from the newly installed floor slab adjacent to the existing floor slab remaining on the bridge girder to the lower surface of the existing floor slab. Since the downward load on the floor slab is supported by the new floor slab that is newer and stronger than the existing floor slab, durability against the downward load on the existing floor slab can be improved. On the other hand, since the bracket and the lower surface of the existing floor slab are separated, the downward load on the new floor slab is not transmitted to the existing floor slab, and the load on the existing floor slab is burdened by the downward load on the new floor slab. It can be prevented from occurring.

  In this case, it is preferable that the bracket has a support height changing mechanism capable of changing a height for supporting the lower surface of the existing floor slab.

  According to this configuration, the bracket can change the height at which the lower surface of the existing floor slab is supported by the support height changing mechanism, so that the bracket depends on the height difference between the existing floor slab and the new floor slab and the load on the existing floor slab. It becomes easy to cope with the size of the deflection.

  The bracket includes a bar projecting from below the new floor slab, and a projecting material fixed to the bar and extending from the lower surface of the new floor slab to the lower surface of the existing floor slab. Preferably includes a new floor slab contact surface that contacts the lower surface of the new floor slab, and an existing floor slab contact surface that contacts the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab. is there.

  According to this configuration, the bracket includes a bar member that protrudes from below the new floor slab, and a protruding member that is fixed to the bar member and extends from the lower surface of the new floor slab to the lower surface of the existing floor slab. The overhang includes a new floor slab contact surface that contacts the lower surface of the new floor slab, and an existing floor slab contact surface that contacts the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab Therefore, the existing floor slab contact surface functions as a force point, the fixed part between the bar and the overhang material functions as a fulcrum, and the new floor slab contact surface functions as an action point, so that the existing structure is installed with a simple structure. A downward load on the floor slab can be transmitted to the new floor slab.

  The new floor slab is made of a precast floor slab made of fiber reinforced concrete, a steel slab, and a precast made of waffle type fiber reinforced concrete having a plurality of recesses surrounded by grid-like convex portions on the lower surface of the new floor slab. It is preferable that it is one of floor slabs.

  According to this configuration, the new floor slab is any one of a fiber reinforced concrete precast floor slab, a steel floor slab, and a waffle type fiber reinforced concrete precast floor slab. Therefore, it is easy to reduce the thickness of the new floor slab, It is easy to reduce the weight of the new floor slab.

  The present invention also provides an existing floor slab removal process for removing a part of the existing floor slab installed on the bridge girder, and a new adjacent to the existing floor slab remaining on the bridge girder after the existing floor slab removal process. The new floor slab installation process to install the new floor slab in the new floor slab, and the new floor slab newly installed adjacent to the existing floor slab remaining on the bridge girder in the new floor slab installation process extends to the lower surface of the existing floor slab A floor slab replacement method comprising: a reinforcing step for supporting a downward load on the existing floor slab on the new floor slab by a bracket that supports the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab It is.

  In this case, in the reinforcing step, it is preferable to support the downward load on the existing floor slab on the new floor slab by a bracket having a support height changing mechanism capable of changing the height supporting the lower surface of the existing floor slab. .

  Further, the reinforcing step includes a bar projecting from the lower side of the new floor slab, and a projecting material fixed to the bar and extending from the lower surface of the new floor slab to the lower surface of the existing floor slab, The material is a bracket including a new floor slab contact surface that contacts the lower surface of the new floor slab, and an existing floor slab contact surface that contacts the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab, It is preferable to support the downward load on the existing floor slab on the new floor slab.

  In addition, in the new floor slab installation process, a precast floor slab made of fiber reinforced concrete, a steel floor slab, and a waffle-type fiber reinforced concrete having a plurality of recesses surrounded by lattice-shaped protrusions on the lower surface of the new floor slab It is preferable to install a new floor slab of any precast floor slab.

  In this case, in the new floor slab installation process, another waffle type fiber reinforced concrete precast floor slab is installed adjacent to one waffle type fiber reinforced concrete precast floor slab installed in the new floor slab installation process. By inserting a bolt into each of the adjacent convex portions of the precast floor slab made of waffle type fiber reinforced concrete adjacent to each other, and injecting a hardening material into the gap between the precast floor slab made of waffle type fiber reinforced concrete adjacent to each other, It is preferable to integrate the waffle type fiber reinforced concrete precast slabs adjacent to each other.

  According to this configuration, in the newly installed floor slab installation process, another waffle type fiber reinforced concrete precast floor slab is adjacent to one waffle type reinforced concrete precast floor slab installed in the new floor slab installation process. Install and insert bolts into the adjacent convex parts of waffle type fiber reinforced concrete precast floor slabs adjacent to each other, and inject the hardening material into the gap between adjacent waffle type fiber reinforced concrete precast floor slabs Thus, since the waffle type fiber reinforced concrete precast floor slabs adjacent to each other are integrated, the newly installed floor slabs can be joined quickly.

  Also, in the existing floor slab removal process, the existing floor slab installed on the bridge girder is divided into a work zone and a traffic zone where vehicles can pass in the direction perpendicular to the bridge axis, and a part of the existing floor slab of the work zone is In the new floor slab installation process, it is preferable to newly install a new floor slab adjacent to the existing floor slab remaining in the work zone from which the existing floor slab has been removed in the existing floor slab removal process.

  According to this configuration, in the existing floor slab removal process, the existing floor slab installed on the bridge girder is divided into a work zone and a traffic zone in which the vehicle can pass in a direction perpendicular to the bridge axis, and the existing floor slab of the work zone is divided. In order to install a new floor slab adjacent to the existing floor slab remaining in the work zone where the existing floor slab was removed in the existing floor slab removal process, In a traffic zone where the floor slab removal process and the new floor slab installation process are not performed, the vehicle can be allowed to pass, and a decrease in traffic volume can be suppressed.

  According to the reinforcing structure and the floor slab replacement method at the time of replacing the floor slab of the present invention, it is possible to improve the durability against the downward load of the existing floor slab.

It is a perspective view showing the state where the temporary protection fence was installed in the bridge to which the reinforcement structure at the time of the floor slab replacement of the embodiment and the floor slab replacement method are applied. It is a cross-sectional view which shows the state in which the existing floor slab removal process of the floor slab replacement | exchange method of embodiment is performed in the bridge of FIG. It is a perspective view which shows the state in which the existing floor slab removal process of the floor slab replacement | exchange method of embodiment is performed. It is a cross-sectional view which shows the state in which the new floor slab installation process and reinforcement process of the floor slab replacement | exchange method of embodiment are performed. It is a perspective view which shows the state in which the new floor slab installation process and reinforcement process of the floor slab replacement | exchange method of embodiment are performed in the bridge of FIG. It is a bottom view showing one mode of a precast floor slab made of waffle type fiber reinforced concrete which is a new floor slab installed in a new floor slab installation process of the floor slab replacement method of the embodiment. It is a perspective view which shows the bracket of the reinforcement structure at the time of the floor slab replacement | exchange of embodiment. It is sectional drawing by the (alpha) line of FIG. 6 which shows the bracket of the reinforcement structure at the time of the floor slab replacement | exchange of embodiment. FIG. 7 is a cross-sectional view taken along the line β in FIG. 6, showing a precast floor slab made of waffle-type fiber reinforced concrete that is a new floor slab installed adjacent to each other in the step of installing a new floor slab of the reinforcing structure when replacing the floor slab of the embodiment. . It is a bottom view which shows the other aspect of the precast floor slab made from a waffle type fiber reinforced concrete which is a new floor slab installed in the new floor slab installation process of the floor slab replacement method of the embodiment. It is sectional drawing by the gamma ray of FIG. 10 which shows the waffle type fiber reinforced concrete precast floor slab which is the new floor slab installed adjacent to each other in the new floor slab installation process of the reinforcement structure at the time of the floor slab replacement of the embodiment . Crossing showing a state in which the reinforcing structure bracket at the time of replacement of the floor slab of the embodiment is applied between the newly installed floor slab installed in the work zone and the existing floor slab of the traffic belt in the reinforcing step of the floor slab replacement method of the embodiment FIG. It is a cross-sectional view which shows the state which supported the existing floor slab of the traffic belt adjacent to the newly installed floor slab installed in the work zone in the reinforcement process of the floor slab replacement | exchange method of embodiment by the support material attached to the bridge girder. It is a perspective view which shows the state which moved the temporary protection fence of FIG. 5, and switched the work zone and the traffic zone. It is a cross-sectional view which shows the state in which the existing floor slab removal process of the floor slab replacement | exchange method of embodiment is performed in the bridge of FIG. It is a perspective view which shows the state in which the new floor slab installation process and reinforcement process of the floor slab replacement | exchange method of embodiment are performed in the bridge of FIG.

  Hereinafter, a reinforcing structure and a floor slab replacement method according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the reinforcing structure and the floor slab replacement method at the time of floor slab replacement according to the embodiment of the present invention are constructed on the bridge girder 2 of the bridge 1 in a time zone in which, for example, night traffic is reduced. This is applied when replacing the floor slab in which a part of the existing floor slab 3 is removed and a new floor slab is newly installed adjacent to the existing floor slab 3 remaining on the bridge girder 2. During periods of heavy traffic during the day, traffic is reduced by passing vehicles through the section where the new floor slab is installed and the section of the existing floor slab 3 adjacent to the new floor slab. To do.

  As shown in FIGS. 1, 2, and 3, in the floor slab replacement method of the present embodiment, an existing floor slab removal step of removing a part of the existing floor slab 3 installed on the bridge girder 2 is performed. In the existing floor slab removal process, a temporary protective fence 6 is installed between the wall height column 4 and the wall height column 5 along the bridge axis direction X so that the existing floor slab 3 installed on the bridge girder 2 is bridged. The work band 7 is divided into a road band 8 through which the vehicle V can pass in the right-angle direction Y, and a part of the existing floor slab 3 and a part of the wall height column 4 of the work band 7 are removed.

  As shown in FIG. 2, the bridge girder 2 is reinforced by a reinforcing cable 9 prior to removing a part of the existing floor slab 3. Prior to the removal of a part of the existing floor slab 3, the bridge girder 2 and the existing floor slab 3 are reinforced by a reinforcing means (not shown). The length in the bridge axis direction X of a part of the existing floor slab 3 removed at a time in the existing floor slab removal step is, for example, 1 m to 3 m and can be 2.5 m.

  As shown in FIGS. 4, 5, and 6, the new floor in which a new floor slab 30 and a wall rail 40 are newly installed adjacent to the existing floor slab 3 remaining on the bridge girder 2 after the existing floor slab removal step. A plate installation process is performed. In the new floor slab installation process, a new floor slab 30 is newly installed adjacent to the existing floor slab 3 remaining in the work zone 7 from which the existing floor slab 3 has been removed in the existing floor slab removal process.

In the new floor slab installation step, for example, a new floor slab 30 of any one of a fiber reinforced concrete precast floor slab, a steel floor slab, and a waffle type fiber reinforced concrete precast floor slab 31a is installed. In the present embodiment, a precast floor slab 31 a made of waffle type fiber reinforced concrete is installed as the new floor slab 30. In the fiber reinforced concrete, reinforcing fibers such as synthetic fibers and steel fibers cut into several mm to several tens mm are mixed in the concrete. For example, the fiber reinforced concrete of the precast floor slab made of fiber reinforced concrete and the precast floor slab 31a made of waffle type fiber reinforced concrete according to the present embodiment has a compressive strength of 100 to 400 N / mm ² at the age of 28 days.

  As shown in FIG. 6, the precast floor slab 31 a made of waffle-type fiber reinforced concrete has a plurality of concave portions 33 whose periphery is partitioned by lattice-shaped convex portions 32 on the lower surface 30 s of the new floor slab 30. As shown in FIGS. 6 and 7, the precast floor slab 31a made of waffle type fiber reinforced concrete has shear keys 34 that are concave portions at both ends in the bridge axial direction X of the precast floor slab 31a made of waffle type fiber reinforced concrete. Each has a shear key 35 which is a convex portion.

  As shown in FIGS. 4, 6, 7, and 8, in the floor slab replacement method of the present embodiment, a new installation is performed adjacent to the existing floor slab 3 remaining on the bridge girder 2 in the new floor slab installation process. The existing floor slab is extended by the bracket 10 that extends from the newly installed floor slab 30 to the lower surface 3 s of the existing floor slab 3 and supports the lower surface 3 s of the existing floor slab 3 while being separated from the lower surface 3 s of the existing floor slab 3. A reinforcing step for supporting the load on the lower side 3 to the newly installed floor slab 30 is performed. That is, as shown in FIGS. 7 and 8, the reinforcing structure 100 at the time of replacement of the floor slab of the present embodiment includes the bracket 10 that supports the downward load on the existing floor slab 3 on the new floor slab 30.

  As shown in FIGS. 7 and 8, the bracket 10 is fixed to the bar 11 protruding from the bottom of a precast floor slab 31 a made of waffle-type fiber reinforced concrete, which is a new floor slab 30, and the new floor slab The projecting material 12 extends from the lower surface 30 s of the 30 to the lower surface 3 s of the existing floor slab 3. The overhanging material 12 separates the new floor slab contact surface 13 that contacts the lower surface 30 s of the new floor slab 30 and the lower surface 3 s of the existing floor slab 3, while the existing floor that contacts the lower surface 3 s of the existing floor slab 3. Plate contact surface 14.

  The bar 11 is, for example, a steel bar. The bar 11 includes a thread groove 11s at its upper end and its lower end. The bar 11 is suspended below the new floor slab 30 by screwing the thread groove 11s at the upper end of the bar 11 into a nut 30n embedded in the new floor slab 30.

  The overhang 12 is an H-shaped steel whose longitudinal direction is parallel to the bridge axis direction X, and includes reinforcing ribs 12r between the upper end flange and the lower end flange. The overhanging member 12 includes a hole 12h through which the bar 11 is inserted into the upper end flange and the lower end flange. The overhanging member 12 includes a new floor slab side member 16 attached to the new floor slab 30 side and an existing floor slab side member 17 attached to the existing floor slab 3 side on the upper surface of the upper end flange. Including.

  The new floor slab side member 16 and the existing floor slab side member 17 are H-section steel whose longitudinal direction is parallel to the bridge axis perpendicular direction Y. The new floor slab side member 16 includes a reinforcing rib 16r between the upper end flange and the lower end flange. The existing floor slab side member 17 includes a reinforcing rib 17r between its upper end flange and its lower end flange. The new floor slab side member 16 includes a rubber plate 16g on the upper surface of the flange at the upper end to accommodate the unevenness of the lower surface 30s of the new floor slab 30, and the new floor slab contact surface 13 is formed by the upper surface of the rubber plate 16g. Is done. The existing floor slab-side member 17 includes a rubber plate 17g on the upper surface of the flange at the upper end to accommodate the unevenness of the lower surface 3s of the existing floor slab 3, and the existing floor slab contact surface 14 is formed by the upper surface of the rubber plate 17g. Is done.

  The bar 11 is inserted through the hole 12 h of the overhang 12, and the nut 11 n is fixed to the screw groove 11 s at the lower end of the bar 11, so that the overhang 12 is inserted into the newly installed floor slab 30 via the bar 11. It is suspended below. The lower surface 30s of the new floor slab 30 and the new floor slab abutting surface 13 may be in contact with each other or may not be in contact with each other at an interval. The lower surface 30s of the new floor slab 30 and the new floor slab contact surface 13 may be integrated or may be separated. The lower surface 3s of the existing floor slab 3 and the existing floor slab contact surface 14 may be in contact with each other, or may not be in contact with each other with a gap therebetween. However, the lower surface 3s of the existing floor slab 3 and the existing floor slab contact surface 14 are not integrated but separated.

  By changing the position at which the nut 11n is fixed to the screw groove 11s at the lower end of the bar 11, the height at which the overhanging member 12 is suspended below the new floor slab 30 via the bar 11 and the existing floor The height of the plate contact surface 14 can be changed. That is, the bracket 10 of the present embodiment has a support height changing mechanism 15 that can change the height for supporting the lower surface 3s of the existing floor slab 3, and the screw groove 11s and the nut 11n at the lower end of the bar 11 have a support height. It functions as the changing mechanism 15.

  The length in the longitudinal direction along the direction Y perpendicular to the bridge axis of each of the newly installed floor slab side member 16 and the existing floor slab side member 17 is, for example, 0.2 m to 1 m. The bracket 10 should just be installed in two places near the position through which the right and left wheels of large vehicles, such as a truck, which is the site | part with the largest downward load to the existing floor slab 3, pass. In addition, the bracket 10 may be installed at the center position in the direction Y perpendicular to the bridge axis of the existing floor slab 3, which is the portion where the deflection due to the downward load on the new floor slab 30 and the existing floor slab 3 is the largest. . Each of the new floor slab side member 16 and the existing floor slab side member 17 has a longitudinal direction extending over the entire width of the new floor slab 30 and the existing floor slab 3 along the direction Y perpendicular to the bridge axis. Also good.

  When the bracket 10 is installed in the reinforcement process, for example, in the new floor slab installation process, the new floor slab 30 in which the bar 11 is suspended from the lower surface 30 s is installed and is installed below the new floor slab 30. The bracket 10 can be installed by attaching the overhanging member 12 to the lower end of the bar member 11 with the nut 11n using the scaffold. When installing the bracket 10, a sound absorbing plate installed below the newly installed floor slab 30 may be used as a scaffold.

  By repeating the existing floor slab removal process, the new floor slab installation process, and the reinforcement process as described above, the existing floor slab 3 is replaced with the new floor slab 30 part by part. The existing floor slab removal process, the new floor slab installation process, and the reinforcement process are performed during the time when traffic volume is reduced at night, and it is adjacent to the new floor slab 30 that was installed in the last new floor slab installation process during that time period. The process is interrupted when the reinforcing process for the existing floor slab 3 is completed. In a time zone in which daytime traffic increases, the vehicle is allowed to pass through the section of the work floor 7 where the new floor slab 30 is installed and the section of the existing floor slab 3 adjacent to the new floor slab 30.

  After the existing floor slab 3 supporting the lower surface 3s of the bracket 10 is replaced with the new floor slab 30, the bracket 10 installed in the reinforcing step may be left installed or removed. . When the bracket 10 is removed, the projecting member 12 is removed from the bar 11 by removing the nut 11n, and the thread groove 11s at the upper end of the bar 11 is removed from the nut 30n embedded in the new floor slab 30. Thus, the bracket 10 can be removed. Further, when the bracket 10 is removed, the bracket 11 may be removed by fusing the bar 11.

  By repeating the existing floor slab removal process, the new floor slab installation process and the reinforcement process, as shown in FIG. 9, in the new floor slab installation process, one piece of waffle-type fiber reinforced concrete installed in the new floor slab installation process Another waffle type fiber reinforced concrete precast floor slab 31a is installed adjacent to the precast floor slab 31a while fitting the shear keys 34 and 35 to each other. In the new floor slab installation process, bolts 36 are inserted into the adjacent convex portions 32 of the precast floor slabs 31a made of waffle type fiber reinforced concrete adjacent to each other, and the concave portions 33 defined by the convex portions 32 are surrounded by the bolts 36. By fixing both ends of the bolt 36 protruding inward by the nuts 36n, the waffle type fiber reinforced concrete precast floor slabs 31a adjacent to each other are integrated.

  Further, as shown in FIGS. 10 and 11, another waffle type fiber reinforced concrete precast floor slab adjacent to one waffle type fiber reinforced concrete precast floor slab 31b installed in the newly installed floor slab installation step. 31b may be installed with a gap between the web 21 which is a part of the bridge girder 2 or the connecting plate 23 protruding from the upper end of the lateral rib 22. A bolt 36 is inserted into each of the adjacent convex portions 32 of the precast floor slab 31b made of waffle type fiber reinforced concrete adjacent to each other, and the bolt 36 protruding into the concave portion 33 defined by the convex portion 32. Both ends are fixed by nuts 36n, and each of the adjacent waffle-type fiber reinforced concrete precast floor slabs 31b is integrated by injecting the curing material 37 into the gap between the adjacent waffle-type fiber reinforced concrete precast floor slabs 31b. It may be made.

  In addition, as shown in FIG. 12, the new floor in which the bracket 10 of the reinforcing structure 100 at the time of the floor slab replacement of the present embodiment is installed in the work zone 7 in the reinforcing process of the floor slab replacement method of the present embodiment as described above. It may be applied between the plate 30 and the existing floor slab 3 of the lane 8. If the flange of the bridge girder 2 becomes an obstacle and the installation of the bracket 10 is difficult, as shown in FIG. 13, the lower surface 3s of the existing floor slab 3 of the lane 8 is supported by the support member 60 attached to the bridge girder 2. May be supported.

  After the existing floor slab removal process, the new floor slab installation process, and the reinforcement process are repeated, all of the existing floor slabs 3 of the work band 7 are replaced with the new floor slab 30, as shown in FIG. The protective fence 6 is moved, and the work band 7 and the traffic band 8 are replaced. As shown in FIG. 15, a part of the existing floor slab 3 of the work band 7 and a part of the wall height column 5 are removed by the existing floor slab removal step as described above. As shown in FIG. 16, a new floor slab 30 and a wall rail 50 are newly installed adjacent to the existing floor slab 3 remaining on the bridge girder 2 by the new floor slab installation process and the reinforcement process similar to the above. . The existing floor slab removal process, the new floor slab installation process, and the reinforcement process are repeated until the entire existing floor slab 3 of the work zone 7 is replaced with the new floor slab 30.

  According to the present embodiment, a part of the existing floor slab 3 installed on the bridge girder 2 is removed, and a new floor slab 30 is newly installed adjacent to the existing floor slab 3 remaining on the bridge girder 2. In the reinforcing structure 100 at the time of replacement of the floor slab, the bracket 10 extends from the newly installed floor slab 30 adjacent to the existing floor slab 3 remaining on the bridge girder 2 to the lower surface 3 s of the existing floor slab 3. Since the lower surface 3 s of the existing floor slab 3 is supported, the downward load on the existing floor slab 3 is supported by the new floor slab 30 which is newer and stronger than the existing floor slab 3. It is possible to improve the durability against the load. On the other hand, since the bracket 10 is separated from the lower surface 3 s of the existing floor slab 3, the downward load on the new floor slab 30 is not transmitted to the existing floor slab 3, and is caused by the downward load on the new floor slab 30. It is possible to prevent the existing floor slab 3 from being burdened.

  Further, according to the present embodiment, the bracket 10 can change the height at which the lower surface 3 s of the existing floor slab 3 is supported by the support height changing mechanism 15. It becomes easy to cope with the difference and the magnitude of the deflection due to the load of the existing floor slab 3.

  Further, according to the present embodiment, the bracket 10 is fixed to the bar 11 protruding from below the new floor slab 30 and the bar 11, and from the lower surface 30 s of the new floor slab 30 to the lower surface 3 s of the existing floor slab 3. The extending material 12 is separated from the new floor slab contact surface 13 that contacts the lower surface 30 s of the new floor slab 30 and the lower surface 3 s of the existing floor slab 3. The existing floor slab abutment surface 14 that abuts the lower surface 3s of the existing floor slab 3 is included, so that the existing floor slab abutment surface 14 functions as a power point and is a fixing portion between the bar 11 and the overhanging member 12. The thread groove 11s and the nut 11n function as fulcrums, and the new floor slab abutment surface 13 functions as an action point, whereby a downward load on the existing floor slab 3 is transmitted to the new floor slab 30 with a simple structure. Can be.

  In addition, according to the present embodiment, the new floor slab 30 is one of the fiber reinforced concrete precast floor slab, the steel floor slab, and the waffle type fiber reinforced concrete precast floor slab 31a, 31b. It is easy to reduce the thickness of the floor slab and to reduce the weight of the newly installed floor slab 30.

  According to the present embodiment, in the newly installed floor slab installation process, another waffle type fiber reinforced concrete is adjacent to one waffle type fiber reinforced concrete precast floor slab 31b installed in the new floor slab installation process. Precast floor slabs 31b made of waffle type fiber reinforced concrete are installed by inserting bolts 36 into the adjacent convex portions 32 of the precast floor slabs 31b made of waffle type fiber reinforced concrete adjacent to each other. By injecting the hardening material 37 into the gaps 31b, the adjacent waffle-type fiber reinforced concrete precast floor slabs 31b are integrated with each other, so that the newly installed floor slabs 30 can be joined quickly.

  Further, according to the present embodiment, in the existing floor slab removal step, the existing floor slab 3 installed on the bridge girder 2 is changed into the work belt 7 and the traffic belt 8 through which the vehicle V can pass in the direction Y perpendicular to the bridge axis. The existing floor slab 3 is removed, and a part of the existing floor slab 3 of the work belt 7 is removed. In the new floor slab installation process, the existing floor slab 3 is removed from the existing floor slab 3 in the existing floor slab removal process. Since the new floor slab 30 is newly installed adjacently, the vehicle V can be allowed to pass through the lane 8 where the existing floor slab removal process and the new floor slab installation process are not performed, and the decrease in traffic volume is suppressed. Can do.

  As mentioned above, although embodiment of this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Bridge, 2 ... Bridge girder, 3 ... Existing floor slab, 3s ... Lower surface, 4, 5 ... Wall railing, 6 ... Temporary guard fence, 7 ... Working zone, 8 ... Traffic zone, 9 ... Reinforcement cable, 10 ... Bracket, DESCRIPTION OF SYMBOLS 11 ... Bar material, 11s ... Screw groove, 11n ... Nut, 12 ... Overhang material, 12r ... Rib, 12h ... Hole, 13 ... New floor slab contact surface, 14 ... Existing floor slab contact surface, 15 ... Support Altitude changing mechanism, 16 ... newly installed floor slab side member, 16r ... rib, 16g ... rubber plate, 17 ... existing floor slab side member, 17r ... rib, 17g ... rubber plate, 21 ... web, 22 ... side rib, 23 ... connection 30 ... New floor slab, 30s ... Lower surface, 30n ... Nut, 31a, 31b ... Precast floor slab made of waffle type fiber reinforced concrete, 32 ... Convex part, 33 ... Concave part, 34, 35 ... Shear key, 36 ... Bolt, 36n ... nut, 37 ... hardened material, 40, 50 ... wall rail, 60 ... Lifting member, 100 ... reinforcing structure, X ... bridge axis direction, Y ... bridge axis perpendicular, V ... vehicle.

Claims (10)

It is a reinforcing structure at the time of replacement of a floor slab in which a part of an existing floor slab installed on a bridge girder is removed and a new floor slab is newly installed adjacent to the existing floor slab remaining on the bridge girder. ,
Extending from the newly installed floor slab newly installed adjacent to the existing floor slab remaining on the bridge girder to the lower surface of the existing floor slab, separated from the lower surface of the existing floor slab, A reinforcing structure at the time of replacement of a floor slab, comprising a bracket that supports a lower load on the existing floor slab by supporting the lower load of the existing floor slab on the new floor slab.   The reinforcement structure at the time of floor slab replacement according to claim 1, wherein the bracket has a support height changing mechanism capable of changing a height for supporting a lower surface of the existing floor slab. The bracket is
A bar projecting from below the new floor slab,
An overhanging material fixed to the bar and extending from the lower surface of the new floor slab to the lower surface of the existing floor slab;
Have
The overhang material is
A new floor slab contact surface that contacts the lower surface of the new floor slab,
An existing floor slab contact surface that contacts the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab,
The reinforcement structure at the time of replacement of the floor slab according to claim 1 or 2.   The new floor slab is made of a fiber reinforced concrete precast floor slab, a steel floor slab, and a waffle type fiber reinforced concrete precast having a plurality of concave portions that are partitioned by lattice-shaped convex portions on the lower surface of the new floor slab. The reinforcement structure at the time of replacement of the floor slab according to any one of claims 1 to 3, which is any one of the floor slabs. An existing floor slab removal process for removing a part of the existing floor slab erected on the bridge girder;
A new floor slab installation step for newly installing a new floor slab adjacent to the existing floor slab remaining on the bridge girder after the existing floor slab removal step;
The newly installed floor slab extends from the newly installed floor slab adjacent to the existing floor slab remaining on the bridge girder in the step of installing the new floor slab to the lower surface of the existing floor slab. A reinforcing step of supporting the new floor slab with a downward load on the existing floor slab by means of a bracket that supports the lower surface of the existing floor slab while being separated from
Floor plate replacement method equipped with.   In the reinforcing step, the downward load on the existing floor slab is supported by the new floor slab by the bracket having a support height changing mechanism capable of changing a height supporting the lower surface of the existing floor slab. 5. The floor slab replacement method according to 5. In the reinforcing step,
A bar projecting from below the new floor slab,
An overhanging material fixed to the bar and extending from the lower surface of the new floor slab to the lower surface of the existing floor slab;
Have
The overhang material is
A new floor slab contact surface that contacts the lower surface of the new floor slab,
An existing floor slab contact surface that contacts the lower surface of the existing floor slab while being separated from the lower surface of the existing floor slab,
The floor slab replacement method according to claim 5, wherein a downward load on the existing floor slab is supported by the new floor slab by the bracket including the slab.   In the new floor slab installation step, a precast floor slab made of fiber reinforced concrete, a steel floor slab, and a waffle-type fiber reinforced concrete having a plurality of concave portions that are partitioned by lattice-shaped convex portions on the lower surface of the new floor slab The floor slab replacement method according to any one of claims 5 to 7, wherein any one of the precast floor slabs is installed. In the new floor slab installation process,
Next to the one waffle-type fiber reinforced concrete precast floor slab installed in the new floor slab installation step, install another waffle type fiber-reinforced concrete precast floor slab,
Bolts are inserted into the adjacent convex portions of the waffle type fiber reinforced concrete precast floor slabs adjacent to each other, and a hardening material is injected into the gaps between the waffle type fiber reinforced concrete precast floor slabs adjacent to each other. The floor slab replacement method according to claim 8, wherein each of the waffle type fiber reinforced concrete precast floor slabs adjacent to each other is integrated. In the existing floor slab removal step, the existing floor slab installed on the bridge girder is divided into a work zone and a traffic zone in which the vehicle can pass in a direction perpendicular to the bridge axis, and a part of the existing floor slab of the work zone Removed
In the new floor slab installation step, a new floor slab is newly installed adjacent to the existing floor slab remaining in the work zone from which the existing floor slab has been removed in the existing floor slab removal step. The floor slab replacement method according to any one of 9 above.

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