JP7021386B1 - How to replace the wall rail - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for replacing a wall railing, which can be constructed with a minimum of traffic regulation. SOLUTION: In a method of replacing an existing wall balustrade made of reinforced concrete (RC wall balustrade 10) with a new wall balustrade made of reinforced concrete (PCa wall balustrade 1), a draining portion 14 of an existing floor slab 11 is used. After performing the existing draining section shaving process, the new draining section pre-construction process is performed in which the new draining section 14'is preliminarily constructed before the removal of the existing wall balustrade (RC wall balustrade 10). [Selection diagram] FIG. 4

Description

The present invention relates to a method for replacing wall balustrades, and more particularly to a method for replacing existing wall balustrades with precast reinforced concrete PCa wall balustrades.

Rigidity aimed at preventing vehicles from deviating from high bridges and roads to the outside of roads and sidewalks, minimizing injury to vehicle occupants and damage to vehicles, and restoring the vehicle in the normal direction of travel. When replacing the existing wall railing, which is a guard rail, it is necessary to regulate the traffic of vehicles passing through the road. In addition, shortening the traffic regulation period leads to the reduction of economic loss, so there is an extremely strong demand to minimize the traffic regulation period. In addition, since it leads to reduction of complaints from road users, it will promote smooth progress of construction.

Therefore, in the present invention, when the existing wall balustrade is removed from the portion of the floor slab upper surface and the floor slab side surface facing the wall balustrade, the floor slab side surface portion is removed in advance, and the floor slab upper surface is removed later. However, it was decided to install a new wall railing. Since the work to remove the side of the deck (draining part) can be done without traffic regulation or with the minimum traffic regulation (lane regulation, road shoulder regulation, etc.), it is possible to minimize the traffic congestion due to traffic regulation. Because it becomes. In particular, on the side of the floor slab, which is the draining part, there are some where horizontal tightening fixing tools and horizontal tightening PC steel materials are arranged, and some where reinforcing bars are arranged from the main girder, so it is necessary to carefully remove them. .. This work to remove the side surface of the deck, which requires careful and time-consuming work, can be done without traffic regulation or with minimum traffic regulation, so traffic congestion due to traffic regulation should be minimized. Will be possible.

On the other hand, in Patent Document 1, the ground cover 5 is sequentially provided on the side portions of the plurality of girder blocks 2 from one side in the overhang direction, and the ground cover 5 is sequentially provided from one side in the overhang direction. A wall balustrade block 7 is fixedly installed by inserting a fixing bar 3 into an insertion hole through a girder block 2, and a plurality of wall balustrade blocks 7 are arranged side by side in the bridge axis direction to construct a balustrade. The construction method is disclosed (see claim 1, claims of patent document 1, paragraphs [0019] to [0028] of the specification, FIGS. 1, 2 and the like in the drawing).

However, the bridge construction method described in Patent Document 1 is used before the wall balustrade block 7 is installed in order to cover the area around the fixing tool of the PC steel material that prestresses the floor slab with concrete and treat the edges when the bridge is newly constructed. The ground cover 5 was constructed prior to the above, and it was not applicable to the replacement work of the wall railing, and of course, it was not possible to shorten the traffic regulation.

Further, in Patent Document 2, the precast concrete gutter 1 to be attached to the side opposite to the road surface 10r of the wall balustrade to be cast on the bridge 10 is attached to the precast concrete gutter to which the concrete of the precast wall balustrade is installed before the pouring. The method is disclosed (see paragraphs [0026] to [0044] in the specification of Patent Document 2, FIGS. 2 to 5 in the drawings, etc.).

However, the method of attaching the precast concrete side groove described in Patent Document 2 also accompanies the method of attaching the side groove at the time of new construction of the bridge, and the side surface of the floor slab is preliminarily constructed, and the construction of the bridge described in Patent Document 1 is performed. Like the method, it was not applicable to the replacement work of the wall railing, and of course, it was not able to shorten the traffic regulation.

Japanese Unexamined Patent Publication No. 2018-178588 Japanese Unexamined Patent Publication No. 2019-131960

Therefore, the present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to provide a method for replacing a wall railing that can be constructed with a minimum of traffic regulation.

The method for replacing the existing wall balustrade according to claim 1 is a method for replacing the existing wall balustrade made of reinforced concrete with a new wall balustrade made of reinforced concrete, and the draining portion of the existing floor slab is removed. After performing an anchor hole drilling step for drilling an anchor hole for an embedded reinforcing bar that supports a new draining portion, the existing draining portion is removed from the existing draining portion. It is characterized by performing a pre-construction process for the new draining section, which is pre-constructed before the removal of the wall balustrade.
Further, the method for replacing the existing wall balustrade according to claim 2 is a method for replacing the existing wall balustrade made of reinforced concrete with a new wall balustrade made of reinforced concrete, and the drainage portion of the existing floor slab is replaced. After performing the cutting process of the existing drainage section, the new drainage section is pre-constructed before the removal of the existing wall section, and the wall section where the new wall section is installed. The installation process is characterized in that a PCa wall balustrade made of precast reinforced concrete is fixed and installed by an anchor member that penetrates the floor slab and has bearing plates attached to both ends.

The method for replacing the wall height column according to claim 3 is the method for replacing the wall height column according to claim 1, wherein the existing draining section cutting process and the new draining section preceding construction process are lane-controlled from the temporary scaffolding. It is characterized by doing without doing.

The method for replacing the wall column according to claim 4 is the method for replacing the wall column according to claim 2. In the wall column installation step, the floor slab and the outer surface of the PCa wall column are covered with carbon fiber sheets. It is characterized by bonding.

According to the inventions according to claims 1 to 4 , after the draining portion of the existing floor slab is scraped off, the new draining portion is preliminarily constructed before the removal of the existing wall railing, so that the minimum traffic regulation is required. The existing wall railing can be replaced with a new wall railing. Further, according to the inventions according to claims 1 to 4 , the work of scraping and removing the draining portion that needs to be carefully worked can be performed as the work on the scaffolding as the work outside the lane regulation without lane regulation. can. Therefore, it is possible to carefully remove the draining portion over time without worrying about the regulation time of the lane regulation.
In addition, according to the first aspect of the present invention, since the anchor hole drilling step is performed, the next step, the pre-construction step of the new draining portion, can be efficiently performed in a shorter time.

In particular, according to the invention of claim 2 , since the PCa wall balustrade is installed, the wall balustrade can be replaced by significantly shortening the curing period in which the concrete develops a predetermined strength.
Further, according to the second aspect of the present invention, since the PCa wall balustrade is fixed by the anchor members penetrating the floor slab and having bearing plates attached to both ends, the work of installing the PCa wall balustrade can be further shortened. can.

In particular, according to the invention of claim 4 , since the carbon fiber sheet is adhered to the outer surface of the floor slab and the PCa wall balustrade, it is possible to cope with an external force in the direction opposite to the collision load from the outside of the bridge.

FIG. 1 is a vertical view of the RC wall balustrade showing the structure of the existing RC wall balustrade in the direction of the bridge axis. FIG. 2 is a process explanatory view illustrating an existing draining portion chipping step of the method for replacing a wall column according to an embodiment of the present invention. FIG. 3 is a process explanatory view showing an anchor hole drilling process of the same wall height column replacement method. FIG. 4 is a process explanatory view showing a process of pre-construction of a new drainer portion of the same wall balustrade replacement method. FIG. 5 is a process explanatory view showing a process of cutting and removing the wall balustrade of the above-mentioned wall balustrade replacement method. FIG. 6 is a process explanatory view showing a wall balustrade installation process of the wall balustrade replacement method of the same as above.

Hereinafter, an embodiment of the method for replacing the wall column according to the present invention will be described in detail with reference to the drawings.

The method for replacing the wall column according to the embodiment of the present invention is suitably applied when replacing the existing RC wall column 10 (wall column made of reinforced concrete) with PCa wall column 1 (wall column made of precast reinforced concrete). .. FIG. 1 is a vertical cross-sectional view of an RC wall balustrade showing the structure of an existing RC wall balustrade as viewed in the direction of the bridge axis.

First, the configuration of the existing RC wall railing column 10 and its surroundings will be briefly described. As shown in FIG. 1, in the existing RC wall railing section 10, a deck covering portion 12 is formed along the outer edge of the bridge so as to be stepwise higher than the upper surface of the floor slab 11, and the deck slab is formed based on this ground covering portion 12. It is projected above the ground covering portion 12 along the outer edge of 11.

Further, on the outer surface of the existing floor slab 11, a draining portion 14 is formed so that the lower end surface is lower than the general portion 13 of the floor slab 11. In this draining portion 14, the lower end surface of the draining portion 14 is lower than the lower surface of the general portion 13, so that precipitation such as rainwater wraps around from the upper surface of the deck 11 along the side surface to the lower surface of the general portion 13. It has a function to reduce the arrival at.

[How to replace the wall column]
Next, a method of replacing the wall height column according to the embodiment of the present invention will be described with reference to FIGS. 2 to 6. FIG. 2 is a process explanatory view illustrating an existing draining portion chipping step of the method for replacing a wall column according to an embodiment of the present invention.

(Draining part squeezing process: scaffolding work outside the lane regulation)
First, as shown in FIG. 2, in the method of replacing the wall balustrade according to the present embodiment, an existing draining portion shaving step is performed to squeeze the draining portion 14 corresponding to the outer surface of the existing floor slab 11. In this step, temporary scaffolding such as a suspended scaffold is installed directly under the ground covering portion 12 and outside the ground covering portion 12, and the work is performed as a non-lane regulation work in which lane regulation is not performed as the work on the scaffold.

Specifically, in this step, the draining portion 14 of the floor slab 11 shown by the shaded portion in FIG. 2 is scraped off by using a chipping machine such as an air pick. At this time, the outer lower corner portion indicated by the shaded portion of the ground covering portion 12 is also scraped off. This is to secure a space for pouring concrete and a space for inserting a rod-shaped vibrator in the process of constructing a draining section, which will be described later. However, since the floor slab 11 is in service as the main line of the road, care should be taken to keep the scraped portion to a minimum.

In this step, some unnecessary reinforcing bars of the existing draining portion 14 and the ground covering portion 12 after the concrete is scraped off are also removed.

As described in the background technology, on the side surface of the floor slab which is the draining portion 14, there are some where the horizontal tightening fixing tool and the horizontal tightening PC steel material are arranged, and some where the reinforcing bars are arranged from the main girder. It needs to be removed carefully. However, in the method of replacing the wall balustrade according to the present embodiment, since this process is performed as a scaffolding work and is an out-of-lane work that does not regulate the lane, it should be carefully performed over time without worrying about the regulation time. Is possible. Therefore, it is possible to reduce the possibility of a serious accident in which the PC steel material is accidentally damaged and cut, the tension of the prestress is released, and the PC steel material protrudes.

(Anchor hole drilling process: Scaffolding work outside lane regulation)
Next, as shown in FIG. 3, in the method of replacing the wall column according to the present embodiment, an anchor hole drilling step of drilling a lateral anchor hole 15 for an embedded reinforcing bar supporting a newly installed draining portion 14'. (See also FIG. 4). Further, in order to reduce the lane regulation work, in parallel with the drilling work of the lateral anchor hole 15, in this step, the vertical through anchor hole 17 through which the anchor member 2 described later is inserted is also drilled. Similar to the previous process, this process is also performed as non-lane regulation work without lane regulation as scaffolding work. FIG. 3 is a process explanatory view showing an anchor hole drilling step of the method of replacing the wall height column according to the present embodiment.

Specifically, in this step, since a deformed steel rod of D16 is assumed as the embedded reinforcing bar 16, a lateral anchor hole 15 having a diameter of φ26 mm and a depth of 250 mm is cut using a core drill or the like equipped with a diamond core bit. Make a hole. Further, as described later, an anchor bolt 20 having an M24 × 510 mm is assumed as the anchor member 2. Therefore, in this step, in parallel with the drilling work of the lateral anchor hole 15, the upper and lower parts having a diameter of about φ44 mm reaching the ground covering portion 12 from the lower surface of the floor slab 11 through the floor slab 11 by using a core drill or the like. A through anchor hole 17 is drilled.

In the method of replacing the wall column according to the present embodiment, the existing floor slab is considered in consideration of the case where the surrounding concrete may be peeled off during the drilling of the lateral anchor hole 15 due to the deterioration degree of the existing bridge. The floor slab thickness of 11 is 220 mm, and one step of reinforcement is provided, and one hole is drilled near the center of the deck thickness. Of course, it goes without saying that the embedded reinforcing bar 16 may be appropriately set and arranged according to the floor slab thickness of the existing floor slab 11 and the degree of deterioration of the concrete.

(Preceding construction process for new drainer: Scaffolding work outside lane regulation)
Next, as shown in FIG. 4, in the method of replacing the wall railing section according to the present embodiment, a new draining section prior construction step in which the new draining section 14'is preliminarily constructed before the removal of the existing RC wall railing section 10 is performed. conduct. Similar to the previous process and the draining part cutting process, this process is also performed as a non-lane regulation work that does not regulate the lane as a scaffolding work. FIG. 4 is a process explanatory view showing a process of pre-construction of a new drainer portion of a method for replacing a wall column according to the present embodiment.

Specifically, as the embedded reinforcing bar 16, an L-shaped D16 deformed steel rod made of a highly adherent epoxy resin-coated reinforcing bar is chemically formed in the lateral anchor hole 15 by using a chemical such as a modified vinyl ester resin or an epoxy resin. In addition to sticking to the resin, predetermined reinforcement such as force distribution is performed. After that, a formwork is installed around the embedded reinforcing bar 16 with a predetermined cover thickness of 70 mm or more, and a new drainer is filled with a time-curing material while compacting using a small rod-shaped vibrator B1 or the like. Part 14'is constructed in advance.

At this time, the newly installed draining portion 14'has a structure in which the area of the contact surface with the existing floor slab 11 which is the existing concrete is small and is in contact with the vertical surface, so that the skin is easily separated. Therefore, as the time-curing material to be cast, a material having a small shrinkage rate such as polymer cement mortar and having excellent adhesion to existing concrete is preferable.

(Wall balustrade cutting and removal process: lane regulation work)
Next, as shown in FIG. 5, in the method of replacing the wall balustrade according to the present embodiment, a wall balustrade cutting and removing step of cutting and removing the existing ground covering portion 12 and the RC wall balustrade 10 is performed. In this step, in order to remove the RC wall railing 10 which is a rigid guard fence, lane restrictions such as closing some lanes are performed. FIG. 5 is a process explanatory view showing a step of cutting and removing the wall balustrade of the method of replacing the wall balustrade according to the present embodiment.

Specifically, using a wire saw or a wall saw along the upper surface of the existing floor slab 11, the existing ground covering portion 12 and the RC wall railing section 10 above the upper surface of the existing floor slab 11 are cut and removed. do.

(Wall balustrade installation process: lane regulation work)
Next, as shown in FIG. 6, in the method of replacing the wall balustrade according to the present embodiment, a wall balustrade installation step of installing the newly installed PCa wall balustrade 1 is performed. In this process, as in the previous process, lane restrictions are applied, such as closing some lanes. FIG. 6 is a process explanatory view showing a wall balustrade installation process of the wall balustrade replacement method according to the present embodiment.

Specifically, the newly installed PCa wall bolt 1 is carried in, placed along the outer edge of the existing floor slab 11, and vertically penetrated by the above-mentioned anchor hole drilling process as lane-regulated out-of-lane scaffolding work. Anchor bolts 20 are inserted into the anchor holes 17, and the PCa wall railing column 1 is bolted and fixed by the anchor member 2 penetrating the floor slab 11. Further, as shown by the shaded area, non-shrink mortar is filled around the anchor member 2 and between the PCa wall railing column 1 and the floor slab 11.

The anchor member 2 is a member based on an anchor bolt 20 having an M24 x 510 mm length made of alloy-plated S45CH, and has a disk shape having a diameter φ140 mm × thickness 25 mm made of alloy-plated SS400 at both ends. The bearing plate 21 is attached. The bearing plate 21 is fastened with a loosening nut 22. Further, a high nut 23 made of alloy-plated SGDM is interposed directly under the bearing plate 21 embedded in the PCa wall column 1, and a predetermined distance from the lower end of the PCa wall column 1 to the bearing plate 21. Is secured. Around the high nut 23, a grid bar 24 in which a round steel having a diameter of φ6 mm is welded in a rice cake net shape and coated with an epoxy resin is arranged.

Further, in this step, a formwork is installed around the bearing plate 21 below the anchor member 2 installed below the floor slab 11, and the cement grout 25 is filled and solidified. The bearing plate 21 below the anchor member 2 is formed with a hole (not shown) for confirming the filling of the non-shrink mortar 26.

Then, in order to close and reinforce the discharge hole of the non-shrink mortar 26, a reinforcing carbon fiber sheet 3 having a vertical width of 720 mm and a grain size of 200 g / m ² in two directions is newly installed from the vicinity of the lower end of the outer surface of the deck 11. It is adhered over the outer surface of the PCa wall column 1 of the above. The carbon fiber sheet 3 has a function of countering an external force such as pushing down the PCa wall railing 1 from the outside to the inside of the bridge.

According to the method for replacing the wall column according to the embodiment of the present invention described above, the existing RC wall column 10 can be replaced with the PCa wall column 1 with the minimum traffic regulation. Further, according to the method for replacing the wall railing according to the embodiment of the present invention, the work of scraping and removing the draining portion 14 that needs to be carefully worked is regarded as the work on the scaffolding, and the lane regulation is not performed. It can be done as an outside work. Therefore, according to the method for replacing the wall column according to the embodiment of the present invention, it is possible to carefully remove the draining portion 14 over time without worrying about the regulation time of the lane regulation. Therefore, it is possible to reduce the possibility of a serious accident in which the PC steel material is accidentally damaged and cut, the tension of the prestress is released, and the PC steel material protrudes.

The method of replacing the wall column according to the embodiment of the present invention has been described in detail above, but the above-mentioned or illustrated embodiments all show one embodiment embodied in carrying out the present invention. Not too much. Therefore, the technical scope of the present invention should not be construed in a limited manner by these. In particular, the materials and dimensions of each member are exemplified as an example, and it goes without saying that the design may be changed as appropriate.

1: PCa wall balustrade (new wall balustrade)
2: Anchor member 20: Anchor bolt 21: Support plate 22: Loosening nut 23: High nut 24: Grid bar 25: Cement grout 26: Non-shrink mortar 3: Carbon fiber sheet 10: RC wall balustrade (existing wall balustrade)
11: Floor slab 12: Ground cover 13: General part (floor slab)
14: Drainer (floor slab)
15: Lateral anchor hole 16: Embedded reinforcing bar 17: Vertical through anchor hole B1: Rod-shaped vibrator

Claims (4)

It is a method of replacing the existing wall balustrade made of reinforced concrete with a new wall balustrade made of reinforced concrete.
Remove the draining part of the existing floor slab .
Next, after performing an anchor hole drilling step of drilling an anchor hole for the embedded reinforcing bar that supports the newly installed draining part,
A method for replacing a wall railing, which comprises performing a new draining part pre-construction process in which the new draining part is preliminarily constructed before the existing wall balustrade is removed. It is a method of replacing the existing wall balustrade made of reinforced concrete with a new wall balustrade made of reinforced concrete.
After performing the existing draining part shaving process to squeeze the draining part of the existing floor slab
Perform the new drainer pre-construction process to pre-construct the new drainer before removing the existing wall railing.
In the wall balustrade installation process for installing the new wall balustrade, a wall characterized by fixing and installing a PCa wall balustrade made of precast reinforced concrete with anchor members having bearing plates attached to both ends through the floor slab. How to replace the balustrade. The method for replacing a wall height column according to claim 1 or 2 , wherein the existing draining section cutting step and the new draining section preceding construction step are performed without lane restriction from the temporary scaffolding. The method for replacing a wall balustrade according to claim 2 , wherein in the wall balustrade installation step, a carbon fiber sheet is adhered to the floor slab and the outer surface of the PCa wall balustrade.

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