Watertight construction method for bridge girder ends

Abstract

To provide a girder end water cut-off method for a bridge, which enables a seal layer serving as a water cut-off structure to be constructed by simple work from both under-road side surfaces in a narrow girder expansion gap directly under an expansion device in the bridge, and enables the uniform seal layer to be formed over the entire length of the girder expansion gap.SOLUTION: A girder end water cut-off method for a bridge has: a waterproof member installing step of vertically installing waterproof members over the entire length in a length direction of a girder expansion gap by arranging a long waterproof member in the girder expansion gap from an end of the girder expansion gap under a road, and providing a certain gap over the entire length in the length direction between the vertical waterproof members; and a seal layer forming step of filling the inside of the gap with a seal material over the entire length in the length direction of the girder expansion gap by sucking air in the gap from an end on the other side of the waterproof member while causing the liquid seal material to flow into the gap from an end on one side of the waterproof member, and curing the seal material to form a seal layer.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a bridge girder end waterproofing method for constructing a sealing layer that serves as a waterproof structure in the gap between bridge girders. [Background technology]

[0002] In bridges such as river bridges and viaducts, gaps are formed between girders and between girders and abutment parapets to allow for expansion and contraction of the girders due to seasonal temperature changes. Comb-shaped expansion devices are installed at the top of the gaps to ensure the continuity of the road surface, and water-stopping materials are generally installed inside the expansion devices to prevent the infiltration of rainwater, soil, snow-melting agents, etc., and to prevent deterioration of the bridge structures below the gaps (abutments, piers, bearings, etc.) due to rainwater, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-173149 Summary of the Invention [Problem to be solved by the invention]

[0004] Since water-stopping materials are made of elastic materials and deteriorate over time, it is necessary to repair, renovate, or replace the water-stopping structures inside the expansion joint before the water-stopping performance of the material is lost in order to extend the life of the bridge. In this case, traffic restrictions are required to carry out repairs and other work on the water-stopping structures from above the road. Ideally, repairs and other work could be carried out from below the road without traffic restrictions. However, in the case of concrete bridges, there is no working space in the girder gap directly below the expansion joint, making it difficult to install water-stopping structures uniformly from below the road along the entire length of the expansion joint. Therefore, it is desirable to install water-stopping structures in the girder gap directly below the expansion joint from both sides below the road.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a water-stopping method for bridge girder ends that can construct a sealing layer that serves as a water-stopping structure in the narrow girder gap directly below an expansion joint in a bridge with simple work from both sides under the road, and that can form a uniform sealing layer over the entire length of the girder gap. [Means for solving the problem]

[0006] The watertight construction method for bridge girder ends according to the present invention is as follows: A watertight construction method for bridge girder ends in which a seal layer is constructed to form a watertight structure between bridge girders, a leak stopper member installation process in which a long leak stopper member is placed from the end of the girder gap under the road into the girder gap to install the leak stopper member over the entire length of the girder gap, and the leak stopper members are installed above and below, with a fixed gap provided between the upper and lower leak stopper members over the entire length; and a sealing layer forming process in which a liquid sealing material is poured into the gap between the upper and lower leak stop members from one end of the leak stop member while sucking air from the gap from the other end of the leak stop member, filling the gap over the entire length of the girder gap with the sealing material and hardening it to form a sealing layer.

[0007] Another embodiment of the bridge girder end waterproofing method according to the present invention is as follows: When an existing member is installed within the girder gap under the road over the entire length of the girder gap, a leak stopper member installation process is performed in which a long leak stopper member is placed below or above the existing member from the end of the girder gap into the girder gap to install the leak stopper member over the entire length of the girder gap, thereby providing a constant gap between the existing member and the leak stopper member over the entire length; This can be a watertight construction method for bridge girder ends, which includes a sealing layer formation process in which a liquid sealing material is poured into the gap between an existing member and a leak stopper member from one end of the leak stopper member while air in the gap is sucked out from the other end of the leak stopper member, filling the gap over the entire length of the girder gap with the sealing material and hardening it to form a sealing layer.

[0008] In the leak stopper installation process, the leak stopper is installed to provide a constant gap along the entire length for pouring the sealing material, thereby suppressing variations in the thickness of the sealing layer along the length of the girder gap. In the sealing layer formation process, when filling the gap formed in the leak stopper installation process with liquid sealing material, the liquid sealing material is poured into the gap from one end of the leak stopper while air is sucked out from the other end of the leak stopper. As a result, a straight sealing layer can be formed. Therefore, even in narrow girder gaps where the width is too small to ensure internal working space, a uniform sealing layer can be formed along the entire length of the girder gap, suppressing variations in deflection and thickness. Furthermore, since construction can be performed from both sides of the bridge girder under the road, work can be carried out without traffic restrictions on the road. [Effects of the Invention]

[0009] As described above, according to the present invention, a waterproof structure using a sealing layer can be constructed with simple work from both sides under the road, even in narrow girder gaps in bridges, and a uniform sealing layer can be formed along the entire length of the girder gap. This sealing layer adds waterproofing functionality to the girder gap, preventing deterioration of the bridge structure below the gap due to rainwater, etc., thereby extending the life of the bridge. [Brief explanation of the drawings]

[0010] [Figure 1]This figure shows a joint gap in which a sealing layer has been formed using the girder end waterproofing method of a bridge according to this embodiment, where (a) is a side view seen from a direction perpendicular to the bridge axis, and (b) is a cross-sectional view seen from the bridge axis direction. [Figure 2] FIG. 10 is a schematic diagram showing a state in which a sealing material is filled in the gap between the upper and lower balloons in the girder gap. [Figure 3] FIG. 10 is a process diagram for explaining the steps of the bridge girder end waterproofing method according to this embodiment, from the installation of the guide wire (FIG. 10(a)) to the installation of the lower balloon (FIG. 10(b)). [Figure 4] This is a process diagram to explain the steps in the bridge girder end waterproofing method according to this embodiment, from installing the upper balloon (Fig. 1(c)), to installing the end cover (Fig. 1(d)), to installing the material injection pipe and air suction pipe (Fig. 1(e)). [Figure 5] This is a process diagram to explain the process from installing a material feeding hopper, suction device and air relief valve (Fig. 1(f)), feeding sealing material (Fig. 1(g)), to curing the sealing material (Fig. 1(h)) in the bridge girder end waterproofing method according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is a girder-end waterproofing method for a bridge 20, in which a sealing layer 3 serving as a watertight structure is constructed in a girder gap 21 of the bridge 20. As an example, as shown in Figures 1(a) and 1(b), a construction method is shown in which a watertight material 26 that prevents the infiltration of rainwater and the like is provided inside an expansion device 25 and an expansion device web gap 21' above the girder gap 21 formed between the girder ends of a bridge girder 24 supported by bearings 23 on an abutment 22, and a sealing layer 3 is formed as an additional watertight structure inside the girder gap 21 below this watertight material 26. As shown in Figure 2, the sealing layer 3 is formed by installing leak stop members 1a and 1b above and below the girder gap 21, and pouring a liquid sealing material 3A into the gap 2 formed between the upper and lower leak stop members 1a and 1b. In this embodiment, the liquid sealing material 3A is poured into the gap 2 from one end of the gap 2 while the air in the gap 2 is sucked from the other end of the gap 2, thereby filling the gap 2 with the sealing material 3A. Each step in the girder end waterproofing method for a bridge 20 according to this embodiment will be described below.

[0012] In this specification, the direction and position of the girder gap 21 will be described with the side facing the bridge girder 24 from the abutment 22 as the upper side, and the width direction of the girder gap 21 (the direction of the bridge axis) will be described as the left-right direction, and the length direction of the girder gap 21 (direction perpendicular to the bridge axis) will be described as the front-rear direction. Also, in this specification, the "upper and lower leak stop members 1a, 1b" will be collectively referred to as the "leak stop member 1," and the "upper and lower guide wires 5a, 5b" will be collectively referred to as the "guide wire 5." A "balloon" is a subordinate concept of a "leak stop member," and is given the same symbol as the leak stop member.

[0013] (Cleaning of web surface 4) First, the area on the web surface 4 of the girder gap 21 where the sealing layer 3 is to be formed is cleaned. Although not shown, this cleaning is performed by first passing a work guide wire into the girder gap 21 from the end of the girder gap 21 on the side of the bridge, and then installing the work guide wire along the length of the girder gap 21, below the waterstop material 26 in the expansion joint web gap 21' and above the area in the girder gap 21 where the sealing layer 3 is to be formed. Next, the cleaning nozzle of a high-pressure washer is hung from this work guide wire, and the cleaning nozzle is moved back and forth using a work rope attached to the cleaning nozzle, while spraying high-pressure cleaning water onto the area of ​​the web surface 4 where the sealing layer 3 is to be formed, thereby cleaning.

[0014] (Installation of guide wire 5 for installing leak prevention member) After cleaning is completed, the work guide wires used during cleaning are removed, and guide wires 5a and 5b for installing leak-stopping members are installed vertically in parallel with each other at a predetermined gradient within the girder gap 21, as shown in FIG. 3(a). These upper and lower guide wires 5a and 5b are installed by passing them from the end of the girder gap 21, which is on the side of the bridge, into the girder gap 21. The gradient of the guide wires 5a and 5b ultimately becomes the gradient of the sealing layer 3. The gradient of the sealing layer 3 is an inclination angle for directing rainwater, etc. dripping onto the sealing layer 3 to the end of the girder gap 21, and the degree to which this gradient should be set is determined arbitrarily based on factors such as the length of the girder gap 21. In this embodiment, the gradient of the upper and lower guide wires 5a and 5b, which becomes the gradient of the sealing layer 3, is set to approximately the cross-gradient of the bridge.

[0015] (Installation of lower balloon 1a) Next, as shown in FIG. 3(b), the lower balloon 1a is placed in the girder gap 21 along the lower guide wire 5a. Here, the balloon 1 is the leak-stopping member 1. The leak-stopping member 1 is a member that holds the liquid sealing material 3A in place to prevent it from leaking when the liquid sealing material 3A is poured into the girder gap 21. The balloon 1, which is the leak-stopping member 1, is a long, bag-like member that expands when air is injected into it; in its contracted state before air is injected, it has the shape of a long, rectangular sheet, and when air is injected into it and it expands, it takes on a roughly elliptical cylindrical shape (see FIG. 2).

[0016] The procedure for installing the lower balloon 1a is to feed the deflated balloon 1a along the lower guide wire 5a from one end of the girder gap 21 toward the other end, and to position the deflated balloon 1a over the entire length of the girder gap 21. Next, air is injected into the deflated balloon 1a from the end of the balloon 1a using an air injector (not shown), causing it to expand, and the inflated balloon 1a is pressed against the left and right web surfaces 4. This allows the inflated lower balloon 1a to be installed along the lower guide wire 5a.

[0017] (Installation of upper balloon 1b) Next, as shown in FIG. 4(c), the upper balloon 1b is placed in the girder gap 21 along the upper guide wire 5b. The procedure for placing the upper balloon 1b is to feed the deflated balloon 1b from one end of the girder gap 21 toward the other end so that it is placed along the upper guide wire 5b, and to position the deflated balloon 1b in the girder gap 21 over the entire length of the girder gap 21. Next, air is injected into the deflated balloon 1b from the end of the balloon 1b using an air injector (not shown), causing it to expand, and the inflated balloon 1b is pressed against the left and right web surfaces 4. As a result, the inflated upper balloon 1b is placed along the upper guide wire 5b.

[0018] When the upper balloon 1b is placed in an inflated state, the height of the guidewire 5b is adjusted to adjust the position of the upper balloon 1b so that a certain gap 2 is formed between the upper balloon 1b and the lower balloon 1a. The gap 2 between the upper balloon 1b and the lower balloon 1a (hereinafter referred to as the "upper / lower balloon gap 2") ultimately determines the thickness of the sealing layer 3. The thickness of this sealing layer 3 can be determined arbitrarily depending on the width and length of the girder gap 21. Generally, the width of the girder gap 21 is approximately 30 mm to 75 mm, and the length of the girder gap 21 is approximately 10 m or less. In this embodiment, when the width of the girder gap 21 is 30 mm and the length of the girder gap 21 is 10 m, the height of the upper / lower balloon gap 2 is set to approximately 50 mm.

[0019] (Installation of end cover 8, material input pipe 9, air suction pipe 10) Next, as shown in FIG. 4(d), end caps 8 are installed on both ends of the gap 2 between the upper and lower balloons. The end caps 8 are made of a foam material or the like and prevent the liquid sealing material 3A from leaking out of both ends of the gap 2 between the upper and lower balloons when the liquid sealing material 3A is poured into the gap 2 between the upper and lower balloons. Then, as shown in FIG. 4(e), holes are drilled in each end cap 8 to attach a material feed tube 9 and an air suction tube 10. The material feed tube 9 is attached to the end cap 8 on the higher gradient side of the balloon 1 as the sealing material feed side, and the air suction tube 10 is attached to the end cap 8 on the lower gradient side of the balloon 1 as the air suction side. The material feed tube 9 and the air suction tube 10 are made of resin pipes or hoses. The air suction tube 10 is preferably transparent so that the flow of the sealing material 3A can be seen.

[0020] (Installation of material input hopper 11 and suction device 12) Next, as shown in FIG. 5(f), a material supply hopper 11 is installed at the open end of the material supply pipe 9, and a suction device 12 is installed at the open end of the air suction pipe 10. An air relief valve 13 is also installed in the air suction pipe 10. Note that the air relief valve 13 may not be provided. The suction device 12 is activated to suck air from the gap 2 between the upper and lower balloons. The suction force of the suction device 12 can be determined based on the viscosity of the sealing material 3A and the length of the balloon 1, and the higher the viscosity and the lower the fluidity of the sealing material 3A, the higher the suction force should be set. Note that the suction force of the suction device 12 may be set low when the sealing material 3A begins to be introduced, and then increased as the amount of sealing material 3A introduced into the gap 2 increases.

[0021] (Formation of sealing layer 3) Next, as shown in Figure 5(g), the liquid sealing material 3A begins to be charged into the material charging hopper 11, and suction by the suction device 12 begins. That is, in the gap 2 between the upper and lower balloons, the liquid sealing material 3A is poured into the gap 2 between the upper and lower balloons from the end of the balloon 1 at the higher gradient position, while the air in the gap 2 between the upper and lower balloons is suctioned from the end of the balloon 1 at the lower gradient position. As a result, the liquid sealing material 3A flows smoothly into the gap 2 between the upper and lower balloons from the end of the balloon 1 at the higher gradient position toward the end of the balloon 1 at the lower gradient position due to its own weight and the suction of the suction device 12.

[0022] The sealing material 3A is a liquid polymeric material that has fluidity and hardens through a curing reaction. The sealing layer 3 is formed by the curing of this sealing material 3A. The sealing layer 3 preferably has high adhesion to the web surface 4, high conformability (elongation), and chemical resistance and flame retardancy. Any sealing material that exhibits these properties can be used. The sealing material 3A is introduced into the material input hopper 11 by adding a curing agent to the liquid polymeric material (main component) that is the main component and stirring, then adding a curing accelerator and stirring again, and introducing the resulting mixture into the material input hopper 11 as the sealing material 3A. While the suction device 12 is sucking, the material input hopper 11 is kept filled with the sealing material 3A to prevent air from being mixed into the sealing material 3A.

[0023] When the sealing material 3A reaches the air suction tube 10, it can be determined that the entire length of the gap between the upper and lower balloons 2 has been filled with the sealing material 3A, and the air release valve 13 is opened, the suction of the suction device 12 is stopped, and the introduction of the sealing material 3A is stopped. Whether the sealing material 3A has reached the air suction tube 10 can be easily confirmed visually because the air suction tube 10 is transparent. By opening the air release valve 13, the negative pressure state within the air suction tube 10 is released, preventing the sealing material 3A from flowing into the suction device 12. Even if the air release valve 13 is not provided, the sealing material 3A can be prevented from flowing into the suction device 12 by stopping the suction of the suction device 12 at the appropriate time.

[0024] After the sealing material 3A has been filled into the gap between the upper and lower balloons 2, as shown in FIG. 5(h), the suction device 12 and air release valve 13 are removed, and the sealing material 3A is allowed to harden. After the sealing material 3A has hardened, the material supply hopper 11, material supply pipe 9, air suction pipe 10, and end cap 8 are removed, and the upper and lower balloons 1a and 1b are removed. The upper and lower balloons 1a and 1b are removed by venting the air inside and using a work rope attached to the guide wire 5. The upper and lower guide wires 5a and 5b are then removed. This completes the installation of the sealing layer 3 formed by hardening the sealing material 3A below the waterstop material 26 in the expansion joint web gap 21' within the girder gap 21. After the installation of the sealing layer 3 is completed, a drainage pipe may be installed on the side of the bridge girder at the lower gradient side of the sealing layer 3 (the end of the girder gap 21) to drain rainwater and the like that flows down the sealing layer 3 and out from the end of the girder gap 21.

[0025] According to the girder end waterproofing method (this method) for a bridge 20 according to the present embodiment, guide wires 5a, 5b are passed from the end of the girder gap 21 under the road into the girder gap 21, and the guide wires 5a, 5b are installed parallel to each other at a predetermined vertical gradient. These upper and lower guide wires 5a, 5b are then used to install balloons 1a, 1b vertically from the end of the girder gap 21 into the girder gap 21. Therefore, in a narrow girder gap 21 with a small width that does not allow for sufficient working space inside, balloons 1a, 1b can be installed parallel to each other with a constant vertical gap 2 by working from both sides of the bridge girder under the road. Furthermore, by providing a constant gap 2 between the upper and lower balloons 1a, 1b over the entire length of the girder gap 21, which allows for the injection of sealing material 3A, variation in the thickness of the sealing layer 3 along the length of the girder gap 21 can be reduced.

[0026] When filling the gap 2 with the liquid sealing material 3A, end caps 8 are placed on both ends of the gap 2, and the liquid sealing material is poured into the gap 2 from the end with the higher gradient of the balloons 1a, 1b, while the air in the gap 2 is sucked out from the end with the lower gradient of the balloons 1a, 1b by the suction device 12. This increases the airtightness of the gap 2 by the end caps 8, and the suction of air by the suction device 12 allows the gap 2 to be filled smoothly and uniformly with the sealing material 3A.

[0027] As described above, this construction method makes it possible to form a uniform sealing layer 3 by suppressing deflection and thickness variations along the entire length of a narrow girder gap 21 where the width is too small to ensure work space inside. Furthermore, this construction method allows construction from both sides of the bridge girder under the road, so work can be carried out without traffic restrictions on the road. Therefore, a watertight structure using the sealing layer 3 can be constructed with simple work even in a narrow girder gap 21, and a uniform sealing layer 3 can be formed along the entire length of the girder gap 21. Furthermore, even if the watertight performance of the watertight material 26 is gradually being lost in the expansion joint web gap 21' where the watertight material 26 is installed, by using this construction method to provide the sealing layer 3 within the girder gap 21 below the watertight material 26, the watertight performance can be maintained, thereby extending the service life of the bridge 20.

[0028] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, the balloon 1 used is one that takes on an approximately elliptical cylindrical shape when inflated, but as long as it can be pressed against the left and right web surfaces 4 in the inflated state to prevent leakage of the sealing material 3A, the shape in the inflated state may be various shapes, such as a cylindrical shape or a polygonal prism shape such as a triangular prism or a square prism. The leak-stopping member 1 may be a balloon 1 (bag-shaped member) or may be a pipe-shaped member, a rod-shaped member, a plate-shaped member, etc., as long as it can abut against the left and right web surfaces 4 to prevent leakage of the sealing material 3A, and the material may be rubber, resin, wood, metal, etc. The lower balloon 1a may be placed along the lower guide wire 5a. The leak stopper member 1 may be installed substantially horizontally without any inclination.

[0029] In another embodiment of the bridge girder end waterproofing method according to the present invention, when an existing member (e.g., a sealing member) is installed in the girder gap under the roadway along the entire length of the girder gap, a leak stopper member is placed below or above the existing member from the end of the girder gap into the girder gap to install the leak stopper member along the entire length of the girder gap, thereby providing a constant gap between the existing member and the leak stopper member along the entire length of the girder gap. Also, a sealing layer forming process is performed in which a liquid sealing material is poured into the gap from one end of the leak stopper member while air is sucked from the other end of the leak stopper member to fill the gap along the entire length of the girder gap and harden the sealing material to form a sealing layer. In this case, the leak stopper member installing process and the sealing layer forming process can be performed according to substantially the same procedures as in the above-described embodiment, except that one of the upper and lower leak stopper members 1a, 1b is replaced with the existing member, and the sealing layer 3 can be formed in the girder gap 21. This means that if existing components deteriorate, sealing performance can be added or reinforced by construction from both sides of the bridge girder. [Explanation of symbols]

[0030] 1a, 1b Balloon (leak-stop member) 2. Gap 3 Sealing Layer 3A sealing material 4 Web page 5a, 5b Guidewire 8 End lid 9 Material input pipe 10 Air suction tube 11 Material input hopper 12 Suction device 13 Air relief valve 20 Bridges 21 beam gap 21' expansion joint web gap 22 Abutment 23 Bearing 24 Bridge girder 25 Telescopic device 26 Water-stopping material

Claims

1. A watertight construction method for bridge girder ends in which a seal layer is constructed to form a watertight structure between bridge girders, a leak stopper member installation process in which a long leak stopper member is placed from the end of the girder gap under the road into the girder gap to install the leak stopper member over the entire length of the girder gap, and the leak stopper members are installed above and below, with a fixed gap provided between the upper and lower leak stopper members over the entire length; and a sealing layer formation process for forming a seal layer in a gap between upper and lower leak stop members, by pouring a liquid seal material into the gap from one end of the leak stop member while sucking air from the other end of the leak stop member, thereby filling the gap over the entire length of the girder gap and allowing the seal material to harden to form a seal layer.

2. A watertight construction method for bridge girder ends in which a seal layer is constructed to form a watertight structure between bridge girders, an installation process of a leak stopper member in which an existing member is installed within the girder gap under the road over the entire length of the girder gap, and a long leak stopper member is placed below or above the existing member from the end of the girder gap into the girder gap to install the leak stopper member over the entire length of the girder gap, thereby providing a constant gap between the existing member and the leak stopper member over the entire length; A watertight construction method for bridge girder ends, comprising a sealing layer formation process in which a liquid sealing material is poured into a gap between an existing member and a leak stopper member from one end of the leak stopper member while sucking air from the gap from the other end of the leak stopper member, filling the gap over the entire length of the girder gap with the sealing material and hardening it to form a sealing layer.

3. The leak stop member is an elongated member that can abut against a web surface that is an opposing surface of the girder gap, 3. A bridge girder end waterproofing method as described in claim 1 or 2, wherein the leak prevention member installation process includes placing a guide wire from the end of the girder gap into the girder gap, erecting the guide wire at a predetermined gradient in the vertical direction, placing the leak prevention member along the guide wire into the girder gap, and abutting the leak prevention member against the web surface and installing it at a predetermined gradient in the vertical direction.

4. 3. A watertight construction method for bridge girder ends according to claim 1 or 2, wherein the sealing layer forming process comprises installing end caps at both ends of the gap formed in the leak prevention member installation process, attaching a material feed pipe to the end cap on the sealing material feed side and pouring the sealing material into the gap through the material feed pipe, while attaching an air suction pipe to the end cap on the air suction side and sucking air from the gap using a suction device attached to the open end of the air suction pipe, and stopping suction by the suction device when the sealing material reaches the air suction pipe.

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