A drainage plate with adjustable water flow and a method for adjusting

Abstract

The application relates to the technical field of geotechnical engineering foundation treatment, in particular to a drainage plate with adjustable water flow and a regulating method. The drainage plate comprises a core plate, a filter membrane and a joint, the filter membrane wraps the periphery of the core plate, the core plate has at least two independently arranged drainage channels, the core plate comprises a rubber matrix and polyacrylic hydrogel dispersed in the rubber matrix, the rubber matrix is integrally shaped into a continuous drainage framework through a mold, and the polyacrylic hydrogel forms an interpenetrating network in the rubber matrix; the joint has switches matched with the number of the drainage channels, and the water outlet of each drainage channel is connected with one switch to adjust the water flow of the core plate. According to the scheme, the drainage capacity can be dynamically adjusted according to the foundation consolidation process through the design of adjustable water flow, the risk of filter membrane blockage is reduced, and the advantages of improved drainage efficiency, shortened foundation reinforcement period and ensured treatment effect stability are achieved.

Description

Technical Field

[0001] This application relates to the field of geotechnical engineering foundation treatment technology, and in particular to a drainage board with adjustable water flow and an adjustment method. Background Technology

[0002] Plastic drainage boards are the most widely used vertical water-guiding structures in drainage consolidation methods for soft soil foundations. In actual engineering scenarios, the soil and rock properties, drainage path length, and consolidation load levels of soft soil foundations are complex and variable, and the drainage capacity requirements differ significantly at different consolidation stages. For example, in the early stage of consolidation, there is a high risk of pore water pressure and fine particle migration and loss, requiring appropriate restriction of water flow to reduce the probability of filter layer clogging. In the middle stage of consolidation, a large flow rate of drainage is required to accelerate soil settlement. In the later stage of consolidation, only a small flow rate of stable drainage is needed to ensure uniform consolidation. The water flow performance of traditional drainage boards is fixed at the factory and cannot be dynamically adapted to the actual construction conditions on site. During use, problems such as initial filter layer clogging and insufficient drainage efficiency in the middle stage are prone to occur, which prolongs the reinforcement cycle and results in unstable treatment effects. In addition, traditional drainage core boards are mostly made of rigid plastics such as polypropylene and high-density polyethylene. Under the high lateral pressure of deep soil, they are prone to irreversible plastic compression deformation, which causes the internal drainage channels to narrow or even completely close, resulting in a significant reduction in water permeability and severely weakening the reinforcement effect of deep soft soil foundations. Summary of the Invention

[0003] To overcome the problems existing in related technologies, this application provides a drainage board with adjustable water flow and an adjustment method. Through the design of adjustable water flow, the drainage capacity can be dynamically adjusted according to the foundation consolidation process, reducing the risk of filter membrane clogging. It has the advantages of improving drainage efficiency, shortening the foundation reinforcement cycle, and ensuring stable treatment effect.

[0004] The first aspect of this application provides a drainage board with adjustable water flow rate, including a core board, a filter membrane and a connector. The filter membrane wraps around the outer periphery of the core board. The core board has at least two independently arranged drainage channels. The core board includes a rubber matrix and polyacrylic acid hydrogel dispersed in the rubber matrix. The rubber matrix is ​​integrally molded into a continuous drainage skeleton by a mold. The polyacrylic acid hydrogel forms an interpenetrating network in the rubber matrix. The connector has a switch that adapts to the number of drainage channels, with a corresponding switch connected to the outlet of each drainage channel to adjust the water flow of the core plate.

[0005] In some embodiments, the rubber matrix is ​​selected from any one of ethylene propylene diene monomer (EPDM), chloroprene rubber, butyl rubber, cis-butadiene rubber, and styrene-butadiene rubber.

[0006] In some embodiments, the core plate has a compressive strength of 1~6MPa and an elongation at break of 100%~700%.

[0007] In some embodiments, when the rubber matrix is ​​EPDM rubber, the core board is prepared by the following steps: S1. Place EPDM rubber in a two-roll mill at a temperature of 50~70℃ and plasticize it 3~5 times; then add acrylic acid, peroxide crosslinking agent, hydrogel crosslinking agent and initiator, and mix at 40℃ for 10~15 minutes to obtain a blended rubber compound; the acrylic acid is a sodium acrylate aqueous solution with a neutralization degree of 60%~80%. S2. The blended rubber compound is pre-pressed and shaped under conditions of 5~10MPa and 80~100℃, and then extruded through a mold at 125~140℃ to obtain a core board blank with the drainage channel. S3. The core board blank is placed in a hot air channel at 140~180℃ for 8~15 minutes to vulcanize and complete the initial cross-linking of the rubber network, thus obtaining the pre-formed core board. S4. Immerse the pre-formed core board in a water bath at 60~80℃ for 2~6 hours to initiate in-situ polymerization of acrylic acid, forming an interpenetrating network of polyacrylic acid hydrogel. After cleaning and drying, the core board is obtained.

[0008] In some embodiments, the Mooney viscosity ML(1+4)125°C of the EPDM rubber is 40~60.

[0009] In some embodiments, the amount of acrylic acid added is 15% to 40% of the total weight of the EPDM rubber; The peroxide crosslinking agent is selected from any one of dicumyl peroxide, bis(tert-butylperoxy)propylbenzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and the amount of peroxide crosslinking agent added is 0.5% to 1.5% of the molar amount of acrylic acid; The hydrogel crosslinking agent is N,N-methylenebisacrylamide, and the amount of hydrogel crosslinking agent added is 0.5% to 2% of the molar amount of acrylic acid; The initiator is potassium persulfate, and the amount of initiator added is 0.1% to 0.5% of the molar amount of acrylic acid.

[0010] In some embodiments, the surface of the nonwoven geotextile is coated with a functional coating, the dry film thickness of which is 30-80 μm; The functional coating is prepared by the following method: (1) Mix carboxylated EPDM emulsion, acrylic prepolymer, peroxide crosslinking agent, hydrogel crosslinking agent and additives evenly to obtain a dispersion emulsion; (2) The dispersion emulsion is coated on the surface of the nonwoven geotextile and cured by hot air at 80~110℃ for 3~8 minutes to obtain the functional coating.

[0011] In some embodiments, the nonwoven geotextile and the core board are integrally formed by thermal bonding, and the equivalent pore size O of the nonwoven geotextile is... 95 The thickness is 70~120μm; The heat-applied integral molding specifically refers to: After obtaining the core board blank, before vulcanization, the following operations are performed: the nonwoven geotextile is laid flat on the pre-pressing platform, the core board blank is placed on top of the nonwoven geotextile, and another layer of nonwoven geotextile is laid flat to cover the upper surface of the core board blank. A pressure of 0.3~0.5MPa is applied by the pressure roller to embed the semi-molten rubber on the surface of the core board into the fiber pores of the geotextile. Finally, the sides of the upper and lower layers of nonwoven geotextile are sewn together with stitches to fix them.

[0012] In some embodiments, the connector includes an integrated base and a cover plate, the cover plate being fastened to the integrated base, the integrated base having a number of diversion chambers equal to the number of drainage channels, each diversion chamber being connected to the drainage channels through an interface, and the water outlets of the diversion chambers converging into a main water collection pipe inside the integrated base; The switch includes a plug, a valve stem, and an operating handle. The plug is placed in the diversion chamber and is positioned opposite to the inlet of the diversion chamber. The guide hole passing through the integrated seat cover plate is connected to the diversion chamber. One end of the valve stem is connected to the plug, and the other end is connected to the operating handle. When the valve stem moves axially, it can drive the plug to insert into the inlet to form an interference seal, or move away from the inlet to form a drainage passage.

[0013] A second aspect of this application provides a method for adjusting water flow rate, which is applied to the aforementioned drainage board with adjustable water flow rate, and includes the following steps: S11. Based on geological survey data and consolidation theory calculations, estimate the water flow thresholds for each stage of foundation treatment. S12. Match the number of drainage channels to be opened based on the estimated water flow threshold. S13. By opening and closing the corresponding diversion chambers through the valves, the total water flow area of ​​the connected drainage channels is matched with the current required water flow. S14. During the foundation consolidation process, based on the real-time monitoring settlement-time curve or pore water pressure dissipation data, repeat step S13.

[0014] The technical solution provided in this application may include the following beneficial effects: The adjustable drainage board provided in this application includes a core board, a filter membrane, and a connector. The core board has at least two independently arranged drainage channels. The core board is composed of a rubber matrix and polyacrylic acid hydrogel filled inside the rubber matrix. The rubber matrix provides a flexible skeletal support for the drainage channels, ensuring that the drainage channels can recover their original shape after being squeezed by high soil lateral pressure, thereby avoiding the problem of permanent attenuation of water flow capacity. The polyacrylic acid hydrogel forms a continuous and interconnected network in the rubber matrix. When the core board undergoes elastic deformation under soil lateral pressure, the polyacrylic acid hydrogel can deform synchronously with the rubber matrix, and its own three-dimensional network pore structure will not undergo irreversible collapse and closure, further ensuring the continuity of the entire cross-section of the drainage channel and avoiding the problem of water flow failure under pressure. At the same time, the polyacrylic acid hydrogel also has extremely low frictional resistance, which can reduce the adsorption of soil particles, especially clay particles, on the inner wall of the channel, ensuring long-term drainage efficiency, facilitating rapid water flow, and maintaining efficient drainage even under low hydraulic gradients. When the water flow needs to be adjusted, it can be done simply by opening or closing the corresponding joints, which is a significant advantage that can adapt to the differentiated drainage needs of the entire foundation consolidation stage. Attached Figure Description

[0015] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0016] Figure 1 This is a schematic diagram of the structure of the drainage board shown in the embodiments of this application; Figure 2 This is a schematic diagram of the connector structure shown in the embodiments of this application.

[0017] Figure label: 1. Core board; 2. Filter membrane; 3. Connector; 30. Switch; 31. Integrated base; 32. Diversion chamber; 33. Interface; 34. Main water collection pipe. Detailed Implementation

[0018] Preferred embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0019] See Figure 1 and Figure 2This application proposes a drainage board with adjustable water flow rate, including a core board 1, a filter membrane 2 and a connector 3. The filter membrane 2 wraps around the outer periphery of the core board 1. The core board 1 has at least two independently arranged drainage channels. The core board 1 includes a rubber matrix and polyacrylic acid hydrogel dispersed in the rubber matrix. The rubber matrix is ​​integrally molded into a continuous drainage skeleton by a mold. The polyacrylic acid hydrogel forms an interpenetrating network in the rubber matrix. The connector 3 has a switch 30 that adapts to the number of drainage channels. Each outlet of the drainage channel is connected to a corresponding switch 30 to adjust the water flow of the core plate 1.

[0020] Specifically, the drainage board provided in this application has a basic drainage function composed of drainage channels within the core board 1 and an interpenetrating network of pores formed by polyacrylic acid hydrogel in a rubber matrix. A filter membrane 2 is wrapped around the outer periphery of the core board 1, preventing fine soil particles from entering the drainage channels while allowing water to flow freely. The filter membrane 2 can be made of non-woven geotextile, woven geotextile, or polyester fiber filter cloth, and can be bonded to the core board 1 by wrapping, bonding, sewing, or heat fusion. To adapt to drainage needs at different cycles, each drainage channel outlet is equipped with an independent switch 30, allowing for on-demand adjustment of the overall water flow by independently opening and closing the corresponding drainage channel.

[0021] The core board 1 has at least two independent drainage channels that extend along its length. The cross-sectional dimensions of these channels can be set to be the same or different depending on the required water flow. The core board 1 is composed of a rubber matrix and an in-situ composite polyacrylic acid hydrogel within the rubber matrix. The rubber matrix can be integrally molded into a continuous drainage framework using a melt extrusion molding process. For example, the rubber matrix material can be extruded under high temperature and pressure using an extrusion die to form a continuous drainage channel structure with a preset shape and size. The rubber matrix provides stable elastic support for the drainage channels and can autonomously recover its initial shape after deformation under stress, avoiding the problem of permanent attenuation of water flow capacity due to pressure deformation. The polyacrylic acid hydrogel forms an interpenetrating network within the rubber matrix and can be composited into the interior of the rubber matrix through an in-situ polymerization process, forming a continuous and interconnected pore network. Together with the macroscopic drainage channels, this forms a full-section drainage system with main and capillary micro-channels, thereby achieving full-section, multi-directional water flow capacity for the drainage board. For example, in the case of polyacrylic acid hydrogel, the raw materials can be mixed with the rubber matrix before cross-linking. Under the action of mechanical shear force, the raw materials are broken into emulsion microspheres. Under the action of cross-linking and initiators, a polymerization reaction occurs in the rubber matrix, thereby forming an interpenetrating network structure. Polyacrylic acid hydrogel also has hydrophilic properties. It can swell moderately when exposed to water, which can fill the gap between the drainage channel and the interface 33 of the switch 30 or the micro-damage to the core plate 1 caused by construction, preventing the intrusion of mud and sand and the short circuit of water flow, thus improving the sealing performance of the drainage system. After absorbing water, polyacrylic acid hydrogel can also form a lubricating water film. This water film can reduce water flow resistance and reduce the adsorption and deposition of soil particles, thereby alleviating the problem of drainage channel blockage and ensuring long-term drainage efficiency.

[0022] When installing the drainage board of this application on the foundation, a board insertion machine can be used to temporarily fix the head of the drainage board to the pipe shoe at the bottom of the casing. When the casing is driven to the predetermined depth and pulled up, the pipe shoe is separated from the bottom of the casing, so that the drainage board is left at the predetermined depth.

[0023] In this embodiment, the rubber matrix and polyacrylic hydrogel complement each other through an interpenetrating structure. The rubber matrix provides structural support and resistance to deformation and rebound, ensuring the long-term structural stability of the macroscopic drainage channel. The polyacrylic hydrogel, on the other hand, optimizes the functions of capillary water conduction and sealing to prevent siltation. The combination of the two solves the problem of easy deformation and failure of the traditional rigid core plate 1, and avoids the defects of easy siltation and high flow resistance of the single elastic core plate 1. With the independent opening and closing multi-channel structure, the water flow can be dynamically adjusted to meet the differentiated drainage needs of the entire foundation consolidation cycle.

[0024] Furthermore, the rubber matrix is ​​selected from any one of EPDM rubber, chloroprene rubber, butyl rubber, cis-butadiene rubber, and styrene-butadiene rubber.

[0025] Specifically, the selection of the aforementioned rubber can be comprehensively determined by considering the aging resistance requirements, long-term deformation elasticity, extrusion processing compatibility, and project cost control objectives of the engineering application scenario. For example, for scenarios with high requirements for weather resistance and chemical corrosion resistance, such as soft soil treatment in coastal areas, leachate drainage from landfills, and high-altitude outdoor engineering, ethylene propylene diene monomer (EPDM) rubber can be selected. Its main chain is a saturated ethylene-propylene copolymer structure, which does not contain active unsaturated double bonds. Its resistance to ozone aging, ultraviolet aging, and acid and alkali corrosion is significantly better than that of general-purpose rubber. At the same time, its elastic recovery rate at room temperature is ≥95%, and it can still completely restore the flow cross section of the drainage channel after repeated compression deformation under high soil lateral pressure loads above 300 kPa, demonstrating outstanding deformation resistance. For scenarios requiring high cost control and stable weather resistance, such as subgrade reinforcement of conventional inland municipal roads and soft soil treatment for building construction projects, chloroprene rubber (CR) is the preferred choice. Its molecular chain incorporates polar chlorine atoms, resulting in superior weather resistance, tear resistance, and adhesion and sealing to filter membranes 2 and pipe interfaces 33 compared to general-purpose diene rubbers. With an elastic recovery rate ≥90%, it meets long-term deformation resistance requirements under normal working conditions. Furthermore, its raw material procurement cost is lower than that of EPDM rubber, offering higher cost-effectiveness in engineering applications. If the project has extremely high requirements for the water tightness and air tightness of the drainage board, butyl rubber with extremely low gas permeability can be selected. If the project is located in a cold region and requires the drainage board to maintain elasticity in temperatures below -30℃, cis-butadiene rubber with excellent low-temperature toughness can be selected, flexibly adapting to various differentiated engineering needs.

[0026] Furthermore, the compressive strength of the core plate 1 is 1~6 MPa, and the elongation at break is 100%~700%. If the compressive strength is less than 1 MPa, the rubber matrix has problems with insufficient cross-linking and structural stiffness. In this case, the core plate 1 will undergo excessive deformation under the conventional lateral soil pressure of 200~300 kPa, resulting in the macroscopic drainage channel cross-section compression ratio exceeding expectations, and thus causing the water flow attenuation range to exceed the design requirements. If the compressive strength is greater than 6 MPa, the rubber matrix has excessive cross-linking and significantly reduced elasticity. The elastic recovery rate after compression decreases, and residual plastic deformation is easily retained, affecting the recovery effect of the core plate 1. If the elongation at break is less than 100%, the rubber matrix has problems with insufficient toughness. It is prone to brittle fracture when subjected to bending and tensile loads during the installation of the drainage board, leading to the failure of the drainage channel and failing to meet the process requirements of deep foundation slab installation. If the elongation at break is higher than 700%, it indicates that the cross-linking density of the rubber molecular chain is too low, resulting in poor creep resistance. Under long-term static load on the soil, irreversible creep stretching will occur, causing the drainage channel cross-section to gradually shrink and the long-term water flow stability to be insufficient.

[0027] Furthermore, when the rubber matrix is ​​EPDM rubber, the core plate 1 is prepared through the following steps: S1. Place EPDM rubber in a two-roll mill at a temperature of 50~70℃ and plasticize it 3~5 times; then add acrylic acid, peroxide crosslinking agent, hydrogel crosslinking agent and initiator, and mix at 40℃ for 10~15 minutes to obtain a blended rubber compound; the acrylic acid is a sodium acrylate aqueous solution with a neutralization degree of 60%~80%. S2. The blended rubber compound is pre-pressed and shaped under conditions of 5~10MPa and 80~100℃, and then extruded through a mold at 125~140℃ to obtain a core board 1 blank with the drainage channel. S3. The core board 1 blank is placed in a hot air channel at 140~180℃ for 8~15 minutes to vulcanize and complete the initial cross-linking of the rubber network, thus obtaining the pre-formed core board 1. S4. Immerse the preformed core board 1 in a water bath at 60~80℃ for 2~6 hours to initiate in-situ polymerization of acrylic acid, forming an interpenetrating network of polyacrylic acid hydrogel. After cleaning and drying, the core board 1 is obtained.

[0028] Furthermore, the Mooney viscosity ML(1+4)125°C of the EPDM rubber is 40~60.

[0029] Furthermore, the amount of acrylic acid added is 15% to 40% of the total weight of the EPDM rubber; The peroxide crosslinking agent is selected from any one of dicumyl peroxide, bis(tert-butylperoxy)propylbenzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and the amount of peroxide crosslinking agent added is 0.5% to 1.5% of the molar amount of acrylic acid; The hydrogel crosslinking agent is N,N-methylenebisacrylamide, and the amount of hydrogel crosslinking agent added is 0.5% to 2% of the molar amount of acrylic acid; The initiator is potassium persulfate, and the amount of initiator added is 0.1% to 0.5% of the molar amount of acrylic acid.

[0030] In step S1, the open mill shears, extrudes, and rubs the rubber using two relatively rotating rollers. This mechanical shearing and heat break the molecular chains of the raw rubber, reducing its molecular weight and viscosity, and improving its plasticity and flowability, thus facilitating subsequent mixing and molding. Subsequently, acrylic acid, peroxide crosslinking agent, hydrogel crosslinking agent, and initiator are added, and the mixture is mixed at 40°C for 10-15 minutes to obtain the blend. Acrylic acid is a key monomer in the preparation of polyacrylic acid hydrogels. Its molecule contains carboxyl groups and carbon-carbon double bonds. The carboxyl groups can form hydrogen bonds with water molecules, giving the hydrogel its water-absorbing properties; the carbon-carbon double bonds can undergo polymerization under the action of the initiator. Specifically, using a 60%-80% neutralized sodium acrylate aqueous solution aims to improve the solubility and reactivity of acrylic acid, making it easier to form a uniform interpenetrating network in subsequent in-situ polymerization. Peroxide crosslinking agents generate free radicals upon thermal decomposition. These free radicals can attack the hydrogen atoms on the EPDM rubber molecular chains, forming macromolecular free radicals that then combine to form carbon-carbon crosslinks, thereby creating a three-dimensional network structure in the rubber molecules and improving the rubber's strength, elasticity, and heat resistance. Hydrogel crosslinking agents, such as N,N-methylenebisacrylamide, contain multiple polymerizable double bonds and can link different acrylic acid chains during acrylic acid polymerization to form a stable three-dimensional network structure, namely the polyacrylic acid hydrogel network. This crosslinking is crucial for the hydrogel to maintain its shape and water absorption properties. Initiators, such as potassium persulfate, decompose under specific conditions to generate free radicals. These free radicals can attack the carbon-carbon double bonds of acrylic acid monomers, initiating the polymerization reaction of acrylic acid and causing it to form polymer chains.

[0031] The Mooney viscosity of EPDM rubber is controlled within the range of 40-60 to ensure suitable flowability and plasticity during subsequent processing. For example, if the Mooney viscosity is too low, the rubber may be too soft, resulting in poor shape retention during extrusion molding and difficulty in forming a stable, continuous drainage skeleton; if the Mooney viscosity is too high, the rubber may be too hard, increasing the difficulty of plasticizing and mixing, leading to uneven material dispersion, and may even generate excessive shear heat during extrusion, affecting product quality. This Mooney viscosity range ensures that EPDM rubber can be fully plasticized in a two-roll mill at 50-70°C and uniformly mixed with components such as acrylic acid, peroxide crosslinking agent, hydrogel crosslinking agent, and initiator at 40°C, thereby obtaining a blended rubber compound with stable quality. Furthermore, this viscosity range facilitates the smooth formation of a core plate 1 preform with a continuous drainage skeleton during pre-compression molding of the blended rubber at 5~10MPa and 80~100℃, and during extrusion molding at 125~140℃. This avoids extrusion difficulties caused by excessively high viscosity or structural collapse caused by excessively low viscosity. The selection of EPDM rubber with this Mooney viscosity provides a good foundation for the subsequent formation of a uniform and stable interpenetrating network of polyacrylic acid hydrogel within the rubber matrix, thereby ensuring that the core plate 1 possesses the expected compressive strength, elongation at break, and adjustable water flow performance.

[0032] In step S2, pre-compression shaping involves initially compacting and shaping the blended rubber compound under certain pressure and temperature. This aims to remove air bubbles, increase density, and give it a preliminary geometric shape, providing a regular blank for subsequent extrusion molding. Die extrusion molding involves passing the pre-compressed rubber compound through a die orifice of a specific shape under high temperature and pressure to form a core plate 1 blank with a continuous drainage framework and drainage channels.

[0033] In step S3, the hot air channel is used to vulcanize the core board 1 blank. Heating causes chemical cross-linking bonds to form between the rubber molecular chains, transforming linear or branched macromolecules into a three-dimensional network structure. This improves the rubber's physical and mechanical properties, such as elasticity, strength, abrasion resistance, and aging resistance. This step primarily completes the initial cross-linking of the EPDM rubber network, forming a stable matrix framework.

[0034] In step S4, the water bath provides a constant-temperature aquatic environment for initiating the in-situ polymerization of acrylic acid. Water, as a medium, facilitates uniform heat transfer and provides the necessary solvent environment for hydrogel formation. In-situ polymerization refers to the polymerization reaction of acrylic monomers within a pre-formed rubber matrix. By immersing the preformed core plate 1 in the water bath, the initiator is activated at a specific temperature, promoting the polymerization of acrylic monomers dispersed in the rubber matrix to form a polyacrylic acid hydrogel.

[0035] Furthermore, the surface of the nonwoven geotextile is coated with a functional coating, the dry film thickness of which is 30~80μm; The functional coating is prepared by the following method: (1) Mix carboxylated EPDM emulsion, acrylic prepolymer, peroxide crosslinking agent, hydrogel crosslinking agent and additives evenly to obtain a dispersion emulsion; (2) The dispersion emulsion is coated on the surface of the nonwoven geotextile and cured by hot air at 80~110℃ for 3~8 minutes to obtain the functional coating.

[0036] Furthermore, the nonwoven geotextile and the core board 1 are integrally formed by thermal bonding, and the equivalent pore size O of the nonwoven geotextile is... 95 The thickness is 70~120μm; The heat-applied integral molding specifically refers to: After obtaining the core board 1 blank, before vulcanization, the following operations are performed: the non-woven geotextile is laid flat on the pre-pressing platform, the core board 1 blank is placed on top of the non-woven geotextile, and another layer of non-woven geotextile is laid flat to cover the upper surface of the core board 1 blank. A pressure of 0.3~0.5MPa is applied by the pressure roller to embed the semi-molten surface rubber of the core board 1 into the fiber pores of the geotextile. Finally, the sides of the upper and lower layers of non-woven geotextile are sewn together with stitches to fix them.

[0037] Furthermore, in addition to employing an equivalent pore size O, filter membrane 2... 95 In addition to a gradient structure of 70-120 μm, a vertical permeability coefficient k should also be selected. V Not less than 5×10 -4 m / s; Under a normal pressure of 50 kPa, the planar hydraulic conductivity θ ≥ 1.5 × 10⁻⁶ m / s -5 m 2 / s, ensuring rapid water flow to the drainage channel. In terms of mechanical properties, the longitudinal and transverse tensile strength of filter membrane 2 is ≥12 kN / m, the burst strength of CBR is ≥2.5 kN, the elongation at break is ≥40%, and the compression ratio after 1000 hours under long-term pressure of 100 kPa is <25%. The gradient ratio GR ≤3.0, the contact angle ≤30°, and the interfacial peel strength with core plate 1 is ≥0.8 N / mm.

[0038] Furthermore, the connector 3 includes an integrated base 31 and a cover plate. The cover plate is fastened to the integrated base 31. The integrated base 31 is provided with a number of diversion chambers 32 equal to the number of drainage channels. Each diversion chamber 32 is connected to the drainage channel through an interface 33, and the water outlets of the diversion chambers 32 converge into the main water collection pipe 34 inside the integrated base 31. The switch 30 includes a plug, a valve stem, and an operating handle. The plug is placed inside the diversion chamber 32 and is positioned opposite to the inlet of the diversion chamber 32. The guide hole passing through the cover plate of the integrated base 31 is connected to the diversion chamber 32. One end of the valve stem is connected to the plug, and the other end is connected to the operating handle. When the valve stem moves axially, it can drive the plug to insert into the inlet to form an interference seal or move away from the inlet to form a drainage passage.

[0039] This application also proposes an adjustment method for the aforementioned adjustable water flow drainage board, comprising the following steps: S11. Based on geological survey data and consolidation theory calculations, estimate the water flow thresholds for each stage of foundation treatment. S12. Match the number of drainage channels to be opened based on the estimated water flow threshold. S13. By opening and closing the corresponding diversion chamber 32 through the valve, the total water flow area of ​​the drainage channel in the connected state is matched with the current required water flow. S14. During the foundation consolidation process, based on the real-time monitoring settlement-time curve or pore water pressure dissipation data, repeat step S13.

[0040] In summary, compared to existing technologies, this application enables on-demand water distribution, providing optimal water flow throughout the entire drainage consolidation process, thereby improving drainage efficiency. Through the rubber matrix and polyacrylic hydrogel, it can flexibly adapt to varying soil conditions with different permeability, reducing the risk of filter membrane clogging while ensuring continuous unobstructed drainage paths and guaranteeing treatment effectiveness. Furthermore, in the event of accidental blockage or damage to a local drainage board, a backup drainage channel can be automatically activated, ensuring the effectiveness and continuity of the overall drainage system, improving redundancy, safety, and operational reliability. Finally, a single specification of drainage board can meet various working conditions, reducing the types of drainage boards required and thus lowering storage and management costs, ultimately achieving cost savings for the entire project.

[0041] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A drainage board with adjustable water flow rate, characterized in that, The device includes a core plate, a filter membrane, and a connector. The filter membrane wraps around the outer periphery of the core plate. The core plate has at least two independently arranged drainage channels. The core plate includes a rubber matrix and polyacrylic acid hydrogel dispersed in the rubber matrix. The rubber matrix is ​​integrally molded into a continuous drainage skeleton by a mold. The polyacrylic acid hydrogel forms an interpenetrating network in the rubber matrix. The connector has a switch that adapts to the number of drainage channels, with a corresponding switch connected to the outlet of each drainage channel to adjust the water flow of the core plate.

2. The drainage board with adjustable water flow rate according to claim 1, characterized in that, The rubber matrix is ​​selected from any one of EPDM rubber, chloroprene rubber, butyl rubber, cis-butadiene rubber, and styrene-butadiene rubber.

3. The drainage board with adjustable water flow rate according to claim 2, characterized in that, The core board has a compressive strength of 1~6MPa and an elongation at break of 100%~700%.

4. The adjustable water flow drainage board according to claim 2, characterized in that, When the rubber matrix is ​​EPDM rubber, the core board is prepared by the following steps: S1. Place EPDM rubber in a two-roll mill at a temperature of 50~70℃ and plasticize it 3~5 times; then add acrylic acid, peroxide crosslinking agent, hydrogel crosslinking agent and initiator, and mix at 40℃ for 10~15 minutes to obtain a blended rubber compound; the acrylic acid is a sodium acrylate aqueous solution with a neutralization degree of 60%~80%. S2. The blended rubber compound is pre-pressed and shaped under conditions of 5~10MPa and 80~100℃, and then extruded through a mold at 125~140℃ to obtain a core board blank with the drainage channel. S3. The core board blank is placed in a hot air channel at 140~180℃ for 8~15 minutes to vulcanize and complete the initial cross-linking of the rubber network, thus obtaining the pre-formed core board. S4. Immerse the pre-formed core board in a water bath at 60~80℃ for 2~6 hours to initiate in-situ polymerization of acrylic acid, forming an interpenetrating network of polyacrylic acid hydrogel. After cleaning and drying, the core board is obtained.

5. The adjustable water flow drainage board according to claim 4, characterized in that, The Mooney viscosity ML(1+4) of the EPDM rubber at 125°C is 40~60.

6. The drainage board with adjustable water flow rate according to claim 4, characterized in that, The amount of acrylic acid added is 15% to 40% of the total weight of the EPDM rubber; The peroxide crosslinking agent is selected from any one of dicumyl peroxide, bis(tert-butylperoxy)propylbenzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and the amount of peroxide crosslinking agent added is 0.5% to 1.5% of the molar amount of acrylic acid; The hydrogel crosslinking agent is N,N-methylenebisacrylamide, and the amount of hydrogel crosslinking agent added is 0.5% to 2% of the molar amount of acrylic acid; The initiator is potassium persulfate, and the amount of initiator added is 0.1% to 0.5% of the molar amount of acrylic acid.

7. The drainage board with adjustable water flow rate according to claim 1, characterized in that, The surface of the nonwoven geotextile is coated with a functional coating, and the dry film thickness of the functional coating is 30~80μm. The functional coating is prepared by the following method: (1) Mix carboxylated EPDM emulsion, acrylic prepolymer, peroxide crosslinking agent, hydrogel crosslinking agent and additives evenly to obtain a dispersion emulsion; (2) The dispersion emulsion is coated on the surface of the nonwoven geotextile and cured by hot air at 80~110℃ for 3~8 minutes to obtain the functional coating.

8. The adjustable water flow drainage board according to claim 4, characterized in that, The nonwoven geotextile and the core board are integrally formed by thermal bonding, and the equivalent pore size O of the nonwoven geotextile is... 95 The thickness is 70~120μm; The heat-applied integral molding specifically refers to: After obtaining the core board blank, before vulcanization, the following operations are performed: the nonwoven geotextile is laid flat on the pre-pressing platform, the core board blank is placed on top of the nonwoven geotextile, and another layer of nonwoven geotextile is laid flat to cover the upper surface of the core board blank. A pressure of 0.3~0.5MPa is applied by the pressure roller to embed the semi-molten rubber on the surface of the core board into the fiber pores of the geotextile. Finally, the sides of the upper and lower layers of nonwoven geotextile are sewn together with stitches to fix them.

9. The drainage board with adjustable water flow rate according to claim 1, characterized in that, The connector includes an integrated base and a cover plate. The cover plate is fastened to the integrated base. The integrated base has a number of diversion chambers equal to the number of drainage channels. Each diversion chamber is connected to the drainage channel through an interface, and the water outlets of the diversion chambers converge into the main water collection pipe inside the integrated base. The switch includes a plug, a valve stem, and an operating handle. The plug is placed in the diversion chamber and is positioned opposite to the inlet of the diversion chamber. The guide hole passing through the integrated seat cover plate is connected to the diversion chamber. One end of the valve stem is connected to the plug, and the other end is connected to the operating handle. When the valve stem moves axially, it can drive the plug to insert into the inlet to form an interference seal, or move away from the inlet to form a drainage passage.

10. A method for adjusting water flow rate, applied to a drainage board with adjustable water flow rate as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S11. Based on geological survey data and consolidation theory calculations, estimate the water flow thresholds for each stage of foundation treatment. S12. Match the number of drainage channels to be opened based on the estimated water flow threshold. S13. By opening and closing the corresponding diversion chambers through the valves, the total water flow area of ​​the connected drainage channels is matched with the current required water flow. S14. During the foundation consolidation process, based on the real-time monitoring settlement-time curve or pore water pressure dissipation data, repeat step S13.

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