Composite metal waterstop for expansion joint of high-speed railway bridge and mounting method of composite metal waterstop

Abstract

The invention relates to the technical field of water-stop belts, in particular to a composite metal water-stop belt for a high-speed railway bridge expansion joint and an installation method, and solves the problems that an interface of an existing high-speed railway bridge water-stop belt is prone to debonding corrosion, anchoring is loosened, the operation and maintenance cost is high, and maintenance is difficult. The waterstop comprises a U-shaped corrugated cold-rolled composite bimetallic base material, the base material is provided with a nickel-based diffusion barrier layer, and a gradient functional interface layer composed of a sacrificial anode layer, an insulating passivation layer and a self-lubricating bonding layer is wrapped between the nickel-based diffusion barrier layer and a sealing body. The metal base material is matched with the fixing side plates in the box girder expansion joint in an inserted mode through the fixing strips at the two ends. The cold-rolled composite bimetallic base material is matched with the nickel-based diffusion barrier layer, so that the structural strength and corrosion resistance are guaranteed, brittle compounds are prevented from being formed on a composite interface, and the interface bonding force is improved; the U-shaped structure is matched with the longitudinal corrugated deformation design, stress can be evenly dispersed, sufficient allowance is provided for bridge telescopic deformation, and the requirement for multi-dimensional deformation caused by beam body temperature change and loads is met.

Description

Technical Field

[0001] This invention relates to the field of waterstop technology, specifically to a composite metal waterstop for expansion joints of high-speed railway bridges and its installation method. Background Technology

[0002] With the continuous large-scale construction of high-speed railway networks and the increasing demand for long-term safe operation, long-span, high-smoothness bridges have become a core component of high-speed railway lines. Bridge expansion joints, as key structures for compensating for temperature deformation, load-induced deformation, and concrete shrinkage and creep, directly determine the durability of the bridge substructure, the safety of high-speed railway operation, and the overall life-cycle maintenance costs through their water-stopping and sealing performance. Waterstops, as the core functional component of expansion joint sealing systems, are used long-term in the complex outdoor environment of high-speed railways. They not only need to withstand large-scale temperature cycles, acid rain and de-icing agent corrosion, and continuous high-frequency micro-vibrations from train passage, but also need to adapt to the complex deformation of the beam in multiple dimensions. This places far more stringent technical requirements on their deformation adaptability, long-term sealing performance, corrosion resistance, durability, and ease of maintenance than on ordinary highway bridges.

[0003] Currently, the waterstops commonly used in high-speed railway bridge expansion joint projects are mainly divided into three categories: pure rubber waterstops, ordinary metal waterstops, and metal-rubber composite waterstops. In actual engineering applications, each of these categories has technical bottlenecks that are difficult to address simultaneously. Commonly used waterstops for high-speed railway bridges generally suffer from problems such as easy delamination and cracking of the metal substrate composite interface, easy debonding and corrosion of the metal-rubber composite interface, lack of leakage warning margin in the sealing structure, and easy slippage and loosening of the anchoring structure. They are unable to meet the dual requirements of long-term service and low-cost operation and maintenance of high-speed railway projects and cannot fully adapt to the long-term service and operation and maintenance requirements of high-speed railway lines. Summary of the Invention

[0004] To address the problems and shortcomings of waterstops in high-speed railway bridges, such as interface debonding and corrosion, easy anchoring loosening, and high operation and maintenance costs, this invention provides a composite metal waterstop for expansion joints of high-speed railway bridges and its installation method. Through multi-structure collaborative optimization, the sealing durability and deformation adaptability of the waterstop are improved, and modular online operation and maintenance are achieved, meeting the long-term service requirements of high-speed railways.

[0005] The solution adopted by this invention to solve its technical problem is: a composite metal waterstop for expansion joints of high-speed railway bridges, comprising: The metal substrate is a U-shaped composite metal sheet with a corrugated deformation structure. A fixed side plate is anchored in the expansion joint of the box girder, and the metal substrate is installed through the fixed side plate; The sealing body is composited with the metal substrate through a self-lubricating adhesive layer. The sealing body has at least two independent cavities extending along the length of the waterstop, including a warning cavity near the water-facing side and a buffer cavity near the back water-facing side. A gradient functional interface layer, which covers the surface of the area where the metal substrate and the sealing body are combined, includes a sacrificial anode layer, an insulating passivation layer and a self-lubricating adhesive layer arranged sequentially from the surface of the metal substrate outward.

[0006] Furthermore, the metal substrate is a cold-rolled composite bimetallic sheet, comprising a structural base layer and a corrosion-resistant surface layer, wherein a diffusion barrier layer is provided between the structural base layer and the corrosion-resistant surface layer, and the diffusion barrier layer is a nickel-based plating layer.

[0007] Furthermore, the corrugated deformable structure is a longitudinal corrugation extending along the bridge's expansion and contraction direction.

[0008] Furthermore, the sacrificial anode layer is made of a zinc-aluminum-magnesium rare earth alloy, the insulating passivation layer is a silane insulating layer, and the self-lubricating adhesive layer is a modified rubber layer containing solid lubricating particles.

[0009] Furthermore, the fixed side plate is located on the inner side of both ends of the U-shaped metal substrate, and a fixing groove is provided on the outer side of the fixed side plate. Fixing strips adapted to the size of the fixing grooves are provided on both ends of the metal substrate. The metal substrate is inserted into the fixing grooves through the fixing strips, and anchoring holes are provided on the fixed side plate and the metal substrate. After installation, the fixed side plate and the metal substrate are anchored in the expansion joint of the box girder.

[0010] Furthermore, a one-way drain valve is provided at the bottom of the warning cavity, and the opening direction of the one-way drain valve is from the inside of the cavity to the outside of the cavity.

[0011] A method for installing a composite metal waterstop for expansion joints of high-speed railway bridges includes the following steps: S1: Expansion joint pretreatment, clean the installation groove of the box girder expansion joint, and ensure that the inner wall of the groove is flat and free of impurities and rust; S2: Pre-installation of fixed side plates: Anchor the fixed side plates to the preset installation positions of the box girder expansion joints to ensure the verticality and horizontality of the fixed side plates during installation. S3: Assemble the main body of the waterstop by inserting the fixing strip of the metal substrate into the fixing groove of the fixing side plate to complete the positioning and matching of the metal substrate and the fixing side plate. S4: Anchoring reinforcement, installing anchors into the expansion joint of the box girder through anchoring holes, anchoring the fixed side plate and the metal substrate together in the expansion joint, and reserving deformation allowance in the direction of bridge expansion for the metal substrate during the assembly process. S5: Sealing treatment, sealing and filling the gap between the fixing groove and the fixing strip, and the connection between the waterstop body and the expansion joint; S6: Functional component debugging, complete the on / off test of the one-way drain valve of the warning chamber.

[0012] The beneficial effects of this invention are: The cold-rolled composite bimetallic substrate of this invention, combined with a nickel-based diffusion barrier layer, ensures both structural strength and corrosion resistance while preventing the formation of brittle compounds at the composite interface and enhancing interfacial bonding. The U-shaped structure, combined with a longitudinal corrugated deformation design, evenly disperses stress, providing ample allowance for bridge expansion and contraction, and adapting to the multi-dimensional deformation requirements caused by beam temperature changes and loads. The sacrificial anode layer, insulating passivation layer, and self-lubricating adhesive layer work synergistically to achieve electrochemical protection of the metal substrate, cut off the electrochemical corrosion path at the interface, reduce the interfacial dynamic friction coefficient, dissipate the energy of high-frequency micro-vibrations in high-speed rail, suppress fretting wear, and significantly improve the long-term stability of the metal-rubber composite interface, preventing debonding and cracking.

[0013] The sealing body's warning chamber and buffer chamber form a double seal. When the water-facing surface is slightly damaged, water enters the warning chamber first, providing sufficient warning time for leakage maintenance. The buffer chamber can absorb heavy-load impacts through elastic deformation, improving the sealing effect. The one-way drain valve in the warning chamber can automatically drain accumulated water and prevent debris from entering, avoiding freezing damage to the chamber and extending the service life of the sealing body. The fixed side plate and metal substrate are positioned by fixing strips and fixing grooves, and are integrated with anchoring holes for a firm connection that can resist high-frequency micro-vibrations and prevent the waterstop from slipping and loosening. The plug-in design combined with the pre-installation process of the fixed side plate improves on-site assembly efficiency and facilitates standardized construction. Attached Figure Description

[0014] Figure 1 This is an exploded view of the present invention. Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is an exploded view of the present invention. Figure 4 This is a schematic diagram of the internal structure of the sealing body of the present invention. Figure 5 This is a schematic diagram of the layered structure of the present invention; Figure 6 This is a schematic diagram of the installation of the waterstop strip of the present invention in a bridge expansion joint; Figure 7 This is a schematic diagram of the intelligent monitoring unit of the present invention.

[0015] In the diagram: 1. Metal substrate; 11. Structural base layer; 12. Nickel-based diffusion barrier layer; 13. Corrosion-resistant surface layer; 14. Fixing strip; 2. Gradient functional interface layer; 21. Sacrificial anode layer; 22. Insulating passivation layer; 23. Self-lubricating adhesive layer; 3. Sealing body; 31. Warning cavity; 32. Buffer cavity; 33. Groove; 4. Wear-resistant lining strip; 5. Drain valve; 6. Wiring channel; 7. Fixing side plate; 8. Fixing groove; 9. Optical fiber; 10. Fiber optic demodulator. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the accompanying drawings are simplified schematic diagrams, intended to clearly illustrate the structural relationships and process logic related to the innovative points of the present invention. While conventional details that can be implemented by those skilled in the art without creative effort (such as bolt thread specifications, sealant application processes, power modules of control circuits, etc.) are not described in detail, they should be understood as naturally encompassed in the specific implementation of the present invention and fall within the protection and implementation scope of this technical solution. Example

[0017] like Figure 1 and Figure 2 As shown, the composite metal waterstop mainly consists of four parts: a metal substrate 1, a gradient functional interface layer 2, a sealing body 3, and a fixed side plate 5. The metal substrate 1 is made of composite metal sheet with a U-shaped structure, stamped to form a corrugated deformation structure. The gradient functional interface layer 2 is applied to the upper surface of the metal substrate 1, i.e., the area where it is composited with the sealing body 3. This layer consists of a sacrificial anode layer 21, an insulating passivation layer 22, and a self-lubricating adhesive layer 23, arranged sequentially from the inside out. The sealing body 3 is bonded to the metal substrate 1 via hot-pressing vulcanization through the self-lubricating adhesive layer 23. The sealing body 3 has two independent cavities extending along its length: a warning cavity 31 near the water-facing side and a buffer cavity 32 near the back-water side. A replaceable wear-resistant liner 4 is also provided on the top water-facing side of the sealing body 3.

[0018] In this embodiment, the metal substrate is a cold-rolled composite bimetallic sheet, which is formed by combining a structural base layer 11 and a corrosion-resistant surface layer 13 through a cold rolling and vacuum brazing process. The structural base layer 11 is made of low-carbon steel strip with a thickness of 4.5 mm to ensure the main body strength and deformation resistance; the corrosion-resistant surface layer 13 is made of 0.3 mm thick 304 stainless steel foil to resist external corrosion. Before the composite, a nickel-based diffusion barrier layer 12 with a thickness ranging from 2-5 μm is pre-plated on the surface of the structural base layer 11. The nickel-based plating can effectively prevent iron atoms from diffusing into the stainless steel layer during the high-temperature brazing process, avoiding the formation of brittle intermetallic compounds, and ensuring that the measured value of the composite interface bonding force reaches 320-350 MPa (design requirement ≥300 MPa).

[0019] The corrugated deformation structure of the metal substrate 1 adopts an integrated stamping design with longitudinal sinusoidal corrugations. The longitudinal direction (bridge expansion and contraction direction) is a sinusoidal corrugation, with a wave height H1 designed to be 50mm (allowable tolerance ±2mm) and a wavelength L1 of 100mm (allowable tolerance ±3mm). These parameters were obtained through finite element simulation optimization, which can provide a ±100mm expansion and contraction allowance while uniformly distributing bending stress throughout the entire wave amplitude range, avoiding stress concentration at sharp corners.

[0020] The metal substrate 1 has fixed side plates 5 at both ends for fixing to the bridge beam. The fixed side plates 5 can be installed later or pre-cast and fixed in the concrete of the box girder and protective layer. A fixing groove 8 is provided on the outer side of the fixed side plate 5. Fixing strips 14 with the same size as the fixing groove 8 are provided on the vertical surfaces of both ends of the metal substrate 1. The metal substrate 1 is inserted into the fixing groove 8 through the fixing strips 14 to achieve the installation and positioning of the metal substrate 1. Anchoring holes are opened on the fixed side plates 5 and the metal substrate 1. After the fixed side plates and the metal substrate are installed, they are anchored in the expansion joint of the box girder to further achieve the stable installation of the waterstop.

[0021] Figure 5 This is a schematic diagram of the layered structure of the gradient functional interface layer 2, which shows the three-layer transition structure from the metal substrate 1 to the sealing body 3: The first layer, sacrificial anode layer 21, is prepared using a zinc-aluminum-magnesium rare earth alloy through a cold spraying process. This coating is directly metallurgically bonded to the metal substrate 1 to form a conductive path. A strip-shaped exposed area is reserved at the anchoring area. During installation, these exposed areas are connected to the pre-embedded steel bars in the beam via wires to form a sacrificial anode cathodic protection system, which can provide electrochemical protection for the exposed edges of the substrate.

[0022] The second layer, an insulating passivation layer 22, is locally prepared only on the water-facing side, specifically in the corrugated deformation area covered by the sealing body 3, using a silane insulation process. This layer isolates the metal substrate 1 from any conductive fillers that may be added to the rubber of the sealing body 3, cutting off the formation path of the interfacial micro-cells and completely resolving the electrochemical corrosion problem.

[0023] The third layer: self-lubricating adhesive layer 23, is made of modified EPDM rubber with added PTFE micro powder and tackifying resin, and is produced as a thin sheet with a thickness of 0.3-0.5 mm through calendering. The uniformly distributed PTFE micro powder forms a micro-lubricating layer at the interface, reducing the dynamic friction coefficient of the interface to 0.12, which can effectively dissipate high-frequency micro-vibration energy and suppress fretting wear.

[0024] The sealing body 3 is integrally vulcanized from flame-retardant and weather-resistant modified EPDM rubber. Its internal dual-cavity structure consists of an outer water-facing warning cavity 31 and an inner, larger sealing buffer cavity 32. The two cavities are separated by a rubber partition and are independent of each other. When the water-facing surface of the warning cavity 31 is slightly damaged, water enters this cavity first. Due to the partition, water will not immediately seep into the inner buffer cavity 32, thus providing early warning time for leakage. The arched structure of the buffer cavity 32 allows it to absorb energy through its elastic deformation under heavy impact, thus providing a buffering effect. A dovetail-shaped groove 33 is provided at the top of the water-facing surface of the sealing body 3 for installing a replaceable wear-resistant liner 4.

[0025] The wear-resistant liner 4 is made of highly wear-resistant modified EPDM, with a dovetail-shaped insert at its bottom that fits into the dovetail-shaped groove 33 at the top of the sealing body 3. Before fitting, a layer of high-temperature modified butyl rubber adhesive is evenly coated inside the groove 33. The two ends of the liner are mechanically fixed to the sealing body 3 by stainless steel countersunk locking pieces. When the liner wears out, simply remove the locking pieces at both ends, use a special tool to pull the old liner out of the groove 33, clean off any residual adhesive, apply new adhesive, and press in the new liner to complete the replacement; there is no need to remove the entire waterstop.

[0026] Miniature silicone one-way drain valves 5 are installed at both ends of the warning chamber 31 (near the expansion joint end beam). The opening pressure of the drain valve 5 is designed to be 0.01 MPa. When water accumulates in the warning chamber 31 due to leakage and the water pressure exceeds 0.01 MPa, the valve automatically opens to drain the accumulated water; when the water in the chamber is emptied or the external water pressure is greater than that inside the chamber, the valve automatically closes under the elastic action of the silicone, preventing external water and debris from entering. This design can prevent long-term water accumulation in the warning chamber 31 from causing damage due to freezing in winter or the growth of microorganisms.

[0027] This invention also discloses an installation method for a composite metal waterstop for expansion joints of high-speed railway bridges. Applied to the aforementioned composite metal waterstop, this method achieves precise and stable installation of the waterstop to the box girder expansion joint through standardized pretreatment, pre-installation, assembly, anchoring, sealing, and debugging steps. Simultaneously, it ensures sufficient deformation allowance for the waterstop to adapt to the multi-dimensional deformation requirements of the bridge. Furthermore, it allows for modular replacement during later maintenance without dismantling the entire waterstop structure, significantly reducing operation and maintenance costs. Specifically, it includes the following steps: (1) Expansion joint pretreatment: Clean the installation groove of the box girder expansion joint, use grinding equipment to remove the floating rust, welding slag and impurities on the inner wall of the groove, and ensure that the inner wall of the groove is flat and dry, without obvious protrusions or depressions, so as to provide a flat base surface for the subsequent installation of fixed side plates.

[0028] (2) Pre-installation of fixed side plate: Transport the fixed side plate to the preset installation position of the expansion joint. With the center line of the bridge expansion joint as the reference, the fixed side plate is symmetrically positioned. First, the fixed side plate is welded to the pre-embedded steel parts in the expansion joint by welding. Then, the fixed side plate is reinforced by expansion bolts to achieve double anchoring of the fixed side plate. Ensure that the verticality of the fixed side plate is ≤0.5° and the horizontal deviation is ≤2mm to prevent the subsequent metal substrate assembly from being stuck due to the offset of the fixed side plate.

[0029] (3) Assembly of the main body of the waterstop: hoist the prefabricated composite metal waterstop body to the installation position, align the fixing strips at both ends of the metal substrate with the fixing groove of the fixing side plate, and slowly insert the fixing strips into the fixing groove. During the insertion process, ensure the fit between the fixing strip and the fixing groove, and avoid hard prying that could cause deformation of the fixing strip or the fixing groove. This completes the initial positioning and matching of the metal substrate and the fixing side plate.

[0030] (4) Anchoring reinforcement: Align the metal substrate with the anchoring holes of the fixed side plate, install high-strength anchoring bolts into the anchoring holes, and tighten the bolts in sequence to achieve the integral anchoring of the fixed side plate and the metal substrate; During the anchoring process, adjust the assembly position of the metal substrate according to the design expansion and contraction of the bridge expansion joint, so that the corrugated deformation structure of the metal substrate is in a natural and relaxed state, and the actual expansion and contraction stroke of the corrugated structure is not less than 1.2 times the design expansion and contraction of the bridge, so as to reserve sufficient margin for the deformation under the temperature change and load of the bridge.

[0031] (5) Sealing treatment: Weather-resistant polysulfide sealant is used to fully fill and seal the gap between the fixing groove and the fixing strip, the bolt holes of the anchor bolts, and the connection between the waterstop body and the expansion joint groove. After the sealant is applied, it is smoothed to ensure that the sealing layer surface is continuous and without cracks. At the same time, a rubber end sealing plate is installed between the end of the waterstop body and the end beam of the expansion joint. The end sealing plate is fixed by pressure strips and bolts to achieve full sealing of the end of the waterstop.

[0032] (6) Functional component debugging: Test the one-way drain valve at the bottom of the warning chamber. Inject clean water into the warning chamber and check whether the one-way drain valve drains water only to the outside of the chamber and whether there is any leakage after closing. If there is any problem with the drain valve being stuck or leaking, replace it in time. Example

[0033] Based on Example 1, this embodiment adds an intelligent monitoring unit to further improve the waterproofing effect of the waterstop, such as... Figure 7As shown, the intelligent monitoring unit includes at least one monitoring optical fiber, which is threaded through a pre-set threading channel 6 within the warning cavity 31 or buffer cavity 32. During the vulcanization molding of the sealing body 3, two PTFE lubrication sleeves (i.e., threading channels 6) are integrally embedded inside the side walls of the warning cavity 31 and buffer cavity 32. After the waterstop is vulcanized and cooled as a whole, ordinary commercial strain sensing optical fibers and leakage monitoring optical fibers are respectively threaded into the corresponding PTFE sleeves. The strain sensing optical fiber is used to monitor the strain distribution of the waterstop along its length in real time and can inversely measure the deformation; the leakage monitoring optical fiber is used to locate the leakage point. The two ends of the optical fiber 9 are led out through waterproof connectors and connected to the fiber optic demodulator 10 on site. The demodulated data is transmitted to the bridge maintenance platform via a wireless transmission module (4G / 5G or LoRa). Since the optical fiber is not pre-embedded in the vulcanization process but is threaded in later, there is no need to use expensive high-temperature resistant special optical fibers, which significantly reduces costs, and the damaged optical fiber can be directly pulled out and replaced.

[0034] In daily operation, the maintenance platform monitors the status of the waterstop in real time through intelligent monitoring units. When the monitoring system issues a warning signal for leakage or abnormal strain, or when on-site inspections reveal that the wear-resistant liner has worn to the design threshold or the one-way drain valve has failed, there is no need to dismantle the entire structure of the waterstop. The damaged monitoring fiber can be directly pulled out of the cable channel for replacement, or the fasteners of the wear-resistant liner can be removed, the old liner can be pulled out, and the new liner can be installed. Alternatively, the one-way drain valve of the warning chamber can be directly replaced. The entire maintenance process is simple to operate and does not affect the normal operation of the high-speed railway bridge, realizing online operation and maintenance of the waterstop.

[0035] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite metal waterstop for expansion joints of high-speed railway bridges, characterized in that, include: The metal substrate is a U-shaped composite metal sheet with a corrugated deformation structure. A fixed side plate is anchored in the expansion joint of the box girder, and the metal substrate is installed through the fixed side plate; The sealing body is composited with the metal substrate through a self-lubricating adhesive layer. The sealing body has at least two independent cavities extending along the length of the waterstop, including a warning cavity near the water-facing side and a buffer cavity near the back water-facing side. A gradient functional interface layer, which covers the surface of the area where the metal substrate and the sealing body are combined, includes a sacrificial anode layer, an insulating passivation layer and a self-lubricating adhesive layer arranged sequentially from the surface of the metal substrate outward.

2. The composite metal waterstop for expansion joints of high-speed railway bridges according to claim 1, characterized in that, The metal substrate is a cold-rolled composite bimetallic sheet, comprising a structural base layer and a corrosion-resistant surface layer. A diffusion barrier layer is provided between the structural base layer and the corrosion-resistant surface layer, and the diffusion barrier layer is a nickel-based plating layer.

3. The composite metal waterstop for expansion joints of high-speed railway bridges according to claim 1, characterized in that, The corrugated deformation structure is a longitudinal corrugation extending along the direction of bridge expansion and contraction.

4. The composite metal waterstop for expansion joints of high-speed railway bridges according to claim 1, characterized in that, The sacrificial anode layer is made of zinc-aluminum-magnesium rare earth alloy, the insulating passivation layer is a silane insulating layer, and the self-lubricating adhesive layer is a modified rubber layer containing solid lubricating particles.

5. The composite metal waterstop for expansion joints of high-speed railway bridges according to claim 1, characterized in that, The fixed side plate is located on the inner side of both ends of the U-shaped metal substrate. A fixing groove is provided on the outer side of the fixed side plate. Fixing strips adapted to the size of the fixing grooves are provided on both ends of the metal substrate. The metal substrate is inserted into the fixing grooves through the fixing strips. Anchoring holes are provided on the fixed side plate and the metal substrate. After installation, the fixed side plate and the metal substrate are anchored in the expansion joint of the box girder.

6. The composite metal waterstop for expansion joints of high-speed railway bridges according to claim 1, characterized in that, The bottom of the warning cavity is equipped with a one-way drain valve, which opens from the inside of the cavity to the outside.

7. A method for installing a composite metal waterstop for expansion joints of high-speed railway bridges, applied to the composite metal waterstop described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Expansion joint pretreatment, clean the installation groove of the box girder expansion joint, and ensure that the inner wall of the groove is flat and free of impurities and rust; S2: Pre-installation of fixed side plates: Anchor the fixed side plates to the preset installation positions of the box girder expansion joints to ensure the verticality and horizontality of the fixed side plates during installation. S3: Assemble the main body of the waterstop by inserting the fixing strip of the metal substrate into the fixing groove of the fixing side plate to complete the positioning and matching of the metal substrate and the fixing side plate. S4: Anchoring reinforcement, installing anchors into the expansion joint of the box girder through anchoring holes, anchoring the fixed side plate and the metal substrate together in the expansion joint, and reserving deformation allowance in the direction of bridge expansion for the metal substrate during the assembly process. S5: Sealing treatment, sealing and filling the gap between the fixing groove and the fixing strip, and the connection between the waterstop body and the expansion joint; S6: Functional component debugging, complete the on / off test of the one-way drain valve of the warning chamber.

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