Subway tunnel deformation joint leakage water comprehensive treatment construction method

Abstract

The invention provides a construction method for comprehensive treatment of seepage water of a deformation joint of a subway tunnel. The construction method comprises the steps of pretreatment of a seepage part, grouting and plugging of an inclined hole, reconstruction of a waterproof layer, brushing of waterproof paint, laying of a waterproof roll, installation of a rubber waterstop, reinforcement of embedded steel bars, construction of a waterproof coating film, installation of a drainage box system, recovery of decoration equipment and the like. The method comprises the steps of mechanical cutting, high-pressure cleaning pretreatment, double-liquid alternate grouting plugging, three-layer gradient waterproof layer reconstruction, high-elasticity waterproof coating brushing, self-adhesion type polymer coiled material laying, telescopic rubber waterstop installation, diamond thin-wall drill bar planting reinforcement, multi-layer waterproof coating construction and integration of a stainless steel drainage box system. And a treatment scheme with strong systematicness and excellent waterproof performance is formed. Compared with a traditional method, gradient construction and long-term effectiveness of the waterproof layer are emphasized, the flexibility and sealing performance of the waterproof structure are enhanced, deformation is effectively dealt with, the structure is reinforced, it is ensured that leaked water is effectively discharged, and the service life of the subway tunnel is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of subway tunnel engineering maintenance, in particular to a construction method for comprehensive treatment of water leakage in subway tunnel deformation joints. Background Art

[0002] As a vital component of urban transportation, subway tunnels are crucial for their structural safety and service life. However, in actual operation, subway tunnels often face the problem of water leakage through expansion joints. Expansion joints are gaps in subway tunnel structures designed to accommodate factors such as uneven foundation settlement and temperature fluctuations. However, due to various factors, such as construction errors, material aging, and changing geological conditions, these expansion joints often become channels for water leakage.

[0003] Existing methods for treating expansion joint leakage often have numerous shortcomings. For example, some rely solely on simple grouting, ignoring the complexity of expansion joints and the impact of long-term deformation. This results in grouting material failure and a short-lived waterproofing effect. Other methods are overly complex, difficult to implement, costly, and lack quality assurance. Furthermore, some treatment methods lack reinforcement and protection of the surrounding structures, leaving the treated expansion joints vulnerable to external damage.

[0004] Therefore, the existing methods for treating water leakage in deformation joints of subway tunnels urgently need to be improved to improve the treatment effect, reduce construction difficulty and cost, and ensure the structural safety and service life of subway tunnels. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a comprehensive treatment construction method for water leakage in deformation joints of subway tunnels, which is characterized by comprising the following specific steps: S1. pre-treating the structural joints at the leakage site; S2. grouting the inclined holes on the water-facing surface to block the leakage; S3. reconstructing the waterproof layer in the deformation joint; S4. applying a single-component polyurethane waterproof coating; S5. laying a waterproof membrane layer; S6. installing an external rubber waterstop; S7. reinforcing the deformation joints with rebar; S8. applying a polyurethane waterproof coating; S9. installing a drainage box system; S10. restoring the structural decoration and equipment; wherein each process is implemented in a process logic order.

[0006] Furthermore, the S1 pretreatment includes: removing the decorative layer and electromechanical equipment around the expansion joint; removing the existing invalid water stop by mechanical cutting; and cleaning the residue in the joint with a high-pressure water jet to ensure that the cleanliness of the working surface meets the requirements of subsequent construction.

[0007] Furthermore, the S2 grouting and plugging adopts a double-liquid alternating grouting process: first, an inclined hole is drilled towards the water-facing surface of the deformation joint at an inclination angle of 45-60°, with a hole diameter of Φ18-22mm and a hole depth penetrating the secondary lining structure; oil-soluble polyurethane slurry and acrylate slurry are injected in stages, and the grouting pressure is controlled at 0.3-0.5MPa; wherein the drilling path needs to be three-dimensionally positioned to avoid the embedded waterstop, and the deviation is controlled to be less than 5cm.

[0008] Furthermore, the reconstruction of the S3 waterproof layer includes: pre-embedding a repeatable grouting pipe inside the deformation joint, using epoxy resin and cement-based penetrating crystallization material for composite grouting, and the grouting volume is controlled according to the joint width × 0.8-1.2L / m; after grouting, a three-layer gradient waterproof structure is formed, including an interface sealing layer, a flexible transition layer and a rigid support layer.

[0009] Furthermore, the construction parameters of the S4 waterproof coating are: coating thickness ≥ 2mm, cross-coating in three times, and the interval time between layers is controlled at 4-6 hours; after curing, a continuous elastic membrane layer is formed, the elongation is ≥ 450%, and the bonding strength with the concrete base is ≥ 1.5MPa.

[0010] Furthermore, the S5 waterproof membrane layer adopts self-adhesive polymer pre-laid membrane, the width of which exceeds 300mm on both sides of the expansion joint; hot melt welding is adopted for overlap during paving, the overlap width is ≥100mm, and a butyl rubber sealing tape with a width of 500mm is added to the joint.

[0011] Furthermore, the installation of the S6 waterstop includes: using 304 stainless steel pressure plates to fix the EPDM rubber waterstop, with the pressure plate spacing ≤300mm; providing a retractable Ω-shaped rib in the middle of the waterstop, with the rib height ≥30mm; and after installation, using water-expanding sealant to fill the gap between the waterstop and the concrete.

[0012] Furthermore, the S7 anchor reinforcement is specifically as follows: a diamond thin-wall drill bit is used to drill holes with a hole diameter of Φ16±0.5mm and a hole depth of 150mm; modified epoxy anchor glue is injected and then Φ14 stainless steel anchor rods are implanted, with an anchoring depth of ≥120mm and a pull-out resistance of ≥50kN; the anchor rods are arranged in a plum blossom shape with a longitudinal spacing of 500mm.

[0013] Furthermore, the construction parameters of the S8 waterproof coating include: total coating thickness ≥3mm, divided into three construction steps of primer, mid-coat and topcoat; curing time is controlled within 12-24 hours, Shore hardness after curing is ≥80A, and hydrostatic pressure resistance is ≥1.2MPa.

[0014] Furthermore, the S9 drainage box system consists of a 304 stainless steel shell, a polymer permeable filter membrane and a water pipe, and is installed at the bottom of the deformation joint; the water pipe has a slope of ≥5‰, a drainage capacity of ≥10L / min, and the end is connected to the tunnel drainage ditch; the drainage box and the structure are sealed with a water-expanding rubber strip with a compression rate of ≥40%.

[0015] Compared with the existing technology, the comprehensive treatment construction method for water leakage in deformation joints of subway tunnels in this application shows significant technical advantages. Through a series of carefully designed steps, this method not only effectively solves the fundamental problem of water leakage in deformation joints, but also takes into account construction efficiency and cost control. Specifically, the present invention adopts comprehensive measures such as pretreatment, inclined hole grouting and plugging, waterproof layer reconstruction, application of multiple waterproof coatings and coils, installation of rubber waterstops, structural reinforcement and integration of drainage box systems to form a treatment plan with strong system and excellent waterproof performance. Compared with traditional methods, the present invention pays more attention to the gradient construction and long-term effectiveness of the waterproof layer. Through the combination of composite grouting technology, high-performance waterproof coatings and coils, the durability and adaptability of the waterproof layer are significantly improved. At the same time, the design of external rubber waterstops and retractable Ω-shaped ribs enhances the flexibility and sealing of the waterproof structure, effectively coping with the long-term deformation of the deformation joints. In addition, through the reinforcement of embedded steel bars and the installation of the drainage box system, not only the surrounding structure of the deformation joint is strengthened, but also it is ensured that the leakage water can be effectively collected and discharged, avoiding further erosion of the tunnel structure by water disasters. The combined effect of this series of innovative measures not only greatly improved the governance effect and reduced the construction difficulty and cost, but also significantly extended the structural safety and service life of the subway tunnel, providing a solid guarantee for the long-term and stable operation of the subway tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic flow chart of a comprehensive construction method for treating water leakage in deformation joints of a subway tunnel according to the present application. DETAILED DESCRIPTION

[0017] The specific embodiments of the present invention are further described below with reference to the accompanying drawings, wherein the same parts are represented by the same reference numerals.

[0018] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the accompanying drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0019] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0020] This invention describes a comprehensive construction method for treating water leakage from expansion joints in subway tunnels. Based on the requirements of the "Technical Specification for Waterproofing of Underground Engineering" (GB 50108), it incorporates the four-in-one technical concept of "prevention, drainage, blocking, and reinforcement" to form a multi-level, coordinated waterproofing system. The following describes the specific implementation method in the order of steps S1-S10, covering process parameters, material selection, process integration, and technical synergy analysis.

[0021] S1. Pre-treat the structural joints at the leakage site 1. Demolition and cleaning Removal of decorative layers and equipment: Use a diamond wire saw or hydraulic cutting machine to remove the decorative layers (such as tiles, paint layers) and electromechanical equipment (lamps, cable trays) within 200mm on both sides of the expansion joint without vibration to avoid damage to the structural concrete.

[0022] Removal of failed waterstop: Use a micro milling machine to remove the aged embedded waterstop along the longitudinal direction of the expansion joint, cutting to a depth of 20mm below the surface of the secondary lining concrete to ensure that the structural joint body is completely exposed.

[0023] Cleaning inside the seam: Use 40MPa high-pressure water jet (flow rate ≥50L / min) to flush out mud, oil and loose objects in the seam. After flushing, use compressed air to blow until there is no visible residue (in accordance with the base cleanliness requirements of GB 50208).

[0024] 2. Quality acceptance Base layer moisture content detection: Use CM-03 moisture meter for multi-point detection, the base layer moisture content must be ≤8%.

[0025] Seam width measurement: Use a feeler gauge to measure the width of the expansion joint, and the error should be controlled within ±2mm. Partial repairs are required for areas exceeding the tolerance.

[0026] Technical synergy: Pretreatment provides a clean and dense working surface for subsequent grouting and waterproofing layer construction, avoiding interface bonding failure caused by impurities.

[0027] S2. Grouting of inclined holes on the water-facing surface to block water leakage 1. Drilling parameter design Hole arrangement: Set inclined holes every 300-400mm along the length of the deformation joint, with a drilling angle of 45-60°, a hole diameter of Φ18-22mm, and a hole depth that penetrates the secondary lining structure and penetrates 50mm into the surrounding rock to ensure that the leakage path is covered.

[0028] Three-dimensional positioning: Use a total station to locate the three-dimensional coordinates of the drilling path, avoiding existing embedded waterstops, with a minimum safety distance of ≥50mm and a drilling trajectory deviation of ≤5cm.

[0029] 2. Grouting materials and processes Oil-soluble polyurethane slurry: Initially inject low-viscosity slurry (viscosity ≤ 200mPa·s) with a grouting pressure of 0.3MPa, and use its water-expansion property (expansion rate ≥ 20 times) to quickly fill wide cracks.

[0030] Acrylate slurry: Secondary injection of high permeability slurry (particle size ≤ 0.1μm), grouting pressure increased to 0.5MPa, capillary pores and micro cracks to form a permeable crystalline waterproof layer.

[0031] 3. Grouting effect verification Water pressure test: A water pressure test (pressure 0.2MPa, duration 30min) is carried out 24 hours after grouting, and leakage rate ≤0.1L / min is qualified.

[0032] Necessity of process logic: The inclined hole design accurately intercepts seepage on the water-facing surface, and double-liquid grouting achieves the combined effect of "macro-leakage plugging + micro-anti-seepage".

[0033] S3. Reconstruction of waterproof layer in expansion joint 1. Pre-embedded grouting pipe and material selection Repeatable grouting pipe: Made of HDPE material (pressure resistance ≥1.0MPa), inner diameter Φ10mm, 3 pipes are pre-buried for every 1m along the seam length, and a one-way valve is installed at the exposed end to facilitate later maintenance and grouting.

[0034] Composite grouting materials: Epoxy resin: Use low-viscosity modified epoxy (curing time 30-60min) with a tensile strength ≥12MPa to seal interface microcracks.

[0035] Cement-based permeable crystallization material: active matter content ≥ 65%, 28d water resistance grade ≥ P12, providing rigid support.

[0036] 2. Gradient waterproof structure construction

[0037] Technical synergy: The three-layer gradient structure achieves "rigidity and flexibility". The flexible layer absorbs deformation stress, and the rigid layer provides structural stability.

[0038] S4. Apply one-component polyurethane waterproof coating 1. Construction process details Base treatment: Before painting, use sandpaper to polish the base to remove dust, and wipe it with acetone to remove oil stains.

[0039] Layered coating: Apply three times crosswise (primer → midcoat → topcoat), with each layer 0.5-0.8mm thick and an interval of 4-6 hours between layers (20°C environment).

[0040] Joint treatment: 300mm wide reinforced polyester cloth is laid on both sides of the expansion joint, and the coating extends 50mm into the joint.

[0041] 2. Performance indicator verification

[0042] Necessity: Single-component polyurethane coating has both elasticity and density, and serves as a flexible waterproof layer to make up for the shortcomings of the grouting rigid system.

[0043] S5. Laying waterproof membrane layer 1. Materials and construction points Membrane specifications: Self-adhesive polymer pre-laid membrane (in compliance with GB 18173.1), thickness 1.5mm, tensile strength ≥8MPa, elongation at break ≥400%.

[0044] Laying process: The overlap width of the long side of the roll is ≥100mm, and the overlap width of the short side is ≥150mm. The joints are hot-melt welded (temperature 180-200℃), and a 500mm wide butyl rubber sealing tape (thickness 2mm) is attached.

[0045] 2. Detailed node processing Corner reinforcement layer: add a 50mm radius arc transition at the corner of the expansion joint, and lay an additional layer with a width of 500mm.

[0046] End sealing: The end of the roll is fixed with a metal strip and sealed with silicone sealant.

[0047] Synergistic logic: The membrane layer serves as an external waterproof barrier, forming a "rigid and flexible complementary" composite waterproof system with the coating layer.

[0048] S6. Install external rubber waterstop 1. Material specifications and installation process Waterstop selection: Use EPDM waterstop with a hardness of 60±5 Shore A, tensile strength ≥12MPa, elongation ≥400%, and resistance to ozone aging (100pphm, no cracks at 40℃×96h).

[0049] Ω-shaped rib design: A retractable Ω-shaped rib is set in the middle of the waterstop, with a rib height of 30mm, a rib width of 50mm, a compression rebound rate of ≥85%, and can adapt to a structural deformation of ±10mm.

[0050] Fixing method: Use 304 stainless steel pressing plates (thickness 2mm, width 50mm) for fixing, the spacing between pressing plates is ≤300mm; Butyl rubber gaskets (3mm thickness) are pre-attached to the bolt holes to prevent damage to the waterstop during tightening.

[0051] Sealing treatment: The contact surface between the waterstop and the concrete is filled with water-expanding rubber strips (expansion rate ≥ 250%) and compression rate ≥ 40% to ensure that there are no leakage channels at the joints.

[0052] 2. Quality Verification Air tightness test: After installation, apply 0.1MPa air pressure to the outside of the waterstop and maintain the pressure for 30 minutes. The test is qualified if the pressure drop is ≤5%.

[0053] Deformation simulation test: A hydraulic jack is used to simulate 15mm structural displacement, and the waterstop has no tearing or debonding phenomenon.

[0054] Technical synergy: The waterstop acts as a mechanical waterproof barrier, forming an "external + internal" double protection with the S5 membrane layer. Its flexible design can release structural deformation stress.

[0055] S7. Plant reinforcement bars on both sides of the expansion joint 1. Construction parameters and processes Drilling requirements:

[0056] Rebar planting material: Anchor rod: Φ14 stainless steel threaded rod (tensile strength ≥500MPa); Anchor glue: modified epoxy resin (shear strength after curing ≥18MPa, pot life 30min).

[0057] Rebar planting process: Hole cleaning: Use a special brush and air pump to remove dust in the hole; Glue injection: The injection volume should be ≥ 80% of the hole volume to avoid bubbles; Insert the anchor rod: Rotate and insert the anchor rod to the bottom of the hole to ensure that the colloid is evenly wrapped.

[0058] 2. Reinforcement effect verification Pull-out test: 5% of the anchor rods are randomly selected for pull-out test, with a pull-out force of ≥50kN (according to JGJ 145-2013 standard); Structural monitoring: After anchoring, the tunnel convergence deformation is reduced by ≥40%, inhibiting further expansion of structural joints.

[0059] Necessity: Anchor reinforcement improves the integrity of the structure and prevents deformation joints from shifting and causing the waterproof layer to fail.

[0060] S8. Apply polyurethane waterproof coating 1. Layered construction and performance control Primer treatment: Use penetrating primer (solid content ≥ 40%), coating amount 0.3kg / m 2 , close the base layer pores; Midcoat and topcoat:

[0061] Performance indicators:

[0062] 2.Detail processing The coating on both sides of the expansion joint is thickened to 4mm to form a U-shaped waterproof bottom; The overlap width between the coating and the waterstop is ≥100mm, and the overlap is reinforced with non-woven fabric.

[0063] Synergistic logic: The coating layer fills the structural micro defects and forms an elastic superposition effect with the S4 polyurethane coating.

[0064] S9. Install the drainage box system 1. Component design and installation Drainage box structure: Shell: 304 stainless steel (thickness 1.5mm), with guide groove and water collection chamber inside; Permeable filter membrane: PP non-woven fabric (weight ≥300g / m 2 , water permeability ≥ 0.2cm / s); Water pipe: UPVC material (inner diameter Φ50mm), slope ≥5‰, the end is connected to the tunnel drainage ditch.

[0065] Installation points: The drainage box is installed close to the bottom of the expansion joint, and the length of the box exceeds the width of the joint by 200mm; The box body and the structure are sealed with water-expanding rubber strips (compression rate ≥40%), and the bolt fixing spacing is ≤200mm.

[0066] 2. Functional Verification Drainage capacity test: simulate 10L / min water seepage, system drainage efficiency ≥95%; Anti-clogging test: Inject sewage containing sediment (particle size ≤ 2mm) into the filter membrane and run it continuously for 24 hours without clogging.

[0067] Technical synergy: The drainage box serves as an emergency drainage channel, forming a "drainage and water prevention combined" system with the waterproof layer to reduce the risk of leakage.

[0068] S10. Restoration of structural decoration and equipment 1. Decorative layer restoration process Isolation layer setting: Lay 2mm thick PE isolation film on the surface of the waterproof layer to prevent the construction of the decorative layer from damaging the waterproof structure; Decoration material selection: Use lightweight moisture-proof decorative panels (density ≤ 1.2g / cm 3 ), fixed to the base layer with elastic adhesive.

[0069] Equipment reinstallation and debugging 2. Mechanical and electrical equipment installation: Cable holes in the wall should be sealed with flame-retardant sealant (fire resistance limit ≥ 1h), and the equipment brackets should be connected with the rebar anchor rods; System joint debugging: After the equipment is installed, a 72-hour full-load operation test is carried out to monitor the deformation joint area for abnormal vibration or water seepage.

[0070] Comparative Example

[0071] Implementation effect verification A subway tunnel deformation joint leakage control project was selected, and after the method of the present invention was used for construction: Short-term effect: Leakage stopped 24 hours after grouting, and the water pressure test met the standards; Mid-term follow-up: One year later, ultrasonic testing showed no hollowing or peeling of the waterproof layer; Long-term monitoring: The ground subsidence occurred three times within 5 years (cumulative deformation of 8mm), and there was no recurrence of leakage in the deformation joint area.

[0072] in conclusion This invention, through the coordinated and parameter-controlled steps S1-S10, forms a four-in-one technical system: "leakage plugging, waterproofing, drainage, and reinforcement." This overcomes the technical bottlenecks of traditional methods, which suffer from short water plugging times and poor deformation resistance. Each step is closely linked, with rigorous technical logic, and complies with the requirements of GB 50108. This provides a standardized solution for treating leakage in subway tunnel expansion joints.

[0073] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, without inventive design, a structure and embodiment similar to the technical solution should fall within the scope of protection of the present invention.

Claims

1. A comprehensive construction method for treating water leakage in deformation joints of subway tunnels, characterized in that: The specific steps include: S1. Pre-treat the structural seams at the leakage site; S2. Grouting of inclined holes on the water-facing surface to block water leakage; S3. Reconstruct the waterproof layer inside the expansion joint; S4. Apply one-component polyurethane waterproof coating; S5. Laying waterproof membrane layer; S6. Install external rubber waterstop; S7. Plant reinforcement bars on both sides of the expansion joint; S8. Apply polyurethane waterproof coating; S9. Install the drainage box system; S10. Restore structural decoration and equipment; The various steps are carried out in a logical order.

2. A comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1, characterized in that: The S1 pretreatment includes: removing the decorative layer and electromechanical equipment around the expansion joint; removing the existing invalid water stop by mechanical cutting; and cleaning the residue in the joint with a high-pressure water jet to ensure that the cleanliness of the working surface meets the requirements of subsequent construction.

3. A comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1, characterized in that: The S2 grouting and sealing adopts a double-liquid alternating grouting process: first, an inclined hole is drilled at an inclination angle of 45-60° towards the water-facing side of the deformation joint, with a hole diameter of Φ18-22mm and a hole depth that penetrates the secondary lining structure; oil-soluble polyurethane slurry and acrylate slurry are injected in stages, and the grouting pressure is controlled at 0.3-0.5MPa; the drilling path needs to be three-dimensionally positioned to avoid the embedded waterstop, and the deviation is controlled to be less than 5cm.

4. A comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1, characterized in that: The reconstruction of the S3 waterproof layer includes: pre-embedding a repeatable grouting pipe inside the deformation joint, using epoxy resin and cement-based penetrating crystallization material for composite grouting, and the grouting volume is controlled according to the joint width × 0.8-1.2L / m; after grouting, a three-layer gradient waterproof structure is formed, including an interface sealing layer, a flexible transition layer and a rigid support layer.

5. The comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1 is characterized in that: The construction parameters of the S4 waterproof coating are: coating thickness ≥ 2mm, cross-coating in three times, and the interval time between layers is controlled at 4-6 hours; after curing, a continuous elastic membrane layer is formed, the elongation is ≥ 450%, and the bonding strength with the concrete base is ≥ 1.5MPa.

6. A comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1, characterized in that: The S5 waterproof membrane layer adopts self-adhesive polymer pre-laid membrane, the width of which exceeds 300mm on both sides of the expansion joint; hot melt welding is adopted for overlapping during laying, the overlapping width is ≥100mm, and a butyl rubber sealing tape with a width of 500mm is added at the joint.

7. The comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1 is characterized in that: The installation of the S6 waterstop includes: using 304 stainless steel pressure plates to fix the EPDM rubber waterstop, with the pressure plate spacing ≤300mm; providing a retractable Ω-shaped rib in the middle of the waterstop, with the rib height ≥30mm; and after installation, using water-expanding sealant to fill the gap between the waterstop and the concrete.

8. The comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1 is characterized in that: The S7 anchor reinforcement is specifically as follows: a diamond thin-wall drill is used to drill holes with a hole diameter of Φ16±0.5mm and a hole depth of 150mm; modified epoxy anchor glue is injected and then Φ14 stainless steel anchor rods are implanted, with an anchoring depth of ≥120mm and a pull-out resistance of ≥50kN; the anchor rods are arranged in a plum blossom shape with a longitudinal spacing of 500mm.

9. The comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1 is characterized in that: The construction parameters of the S8 waterproof coating include: total coating thickness ≥3mm, three construction steps of primer, mid-coat and topcoat; curing time controlled within 12-24 hours, Shore hardness after curing ≥80A, and hydrostatic pressure resistance ≥1.2MPa.

10. A comprehensive treatment construction method for water leakage in expansion joints of subway tunnels according to claim 1, characterized in that: The S9 drainage box system consists of a 304 stainless steel shell, a polymer permeable filter membrane and a water pipe, which is installed at the bottom of the expansion joint. The water pipe has a slope of ≥5‰, a drainage capacity of ≥10L / min, and is connected to the tunnel drainage ditch at the end. The drainage box and the structure are sealed with a water-expanding rubber strip with a compression rate of ≥40%.

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