Subway construction method for embedded track using precast track plates.

Abstract

To provide a method for constructing embedded subway tracks using precast track plates. [Solution] The method includes a site survey conducted by engineers in advance to confirm the location of protective doors, inspect the quality of the delivered precast track plates and precast rail supports, ensure that there are no cracks or damage to the appearance of the precast plates, set the strength level of the base concrete to C35, provide one 20mm wide expansion joint every 10m, and align the center line of the expansion joint with the center line of the plate joint, including construction preparation and surface treatment S1. Compared to conventional construction methods in which the precast track plates are first installed, temporary fasteners are laid after the track plate installation is complete, and then the precast concrete rail supports are transported to the site and installed manually, this method saves construction time by first assembling the precast track plates and precast rail supports in the track plate factory and transporting them together to the construction site for installation.

Description

Technical Field

[0001] The present invention relates to the field of railway transportation, and particularly to a method for constructing an embedded track with assembled precast track slabs for subways.

Background Art

[0002] Railway transportation refers to a means of transportation or transportation system in which operating vehicles need to run on specific tracks. Urban railway transportation is defined as "generally, a general term for high-speed mass transportation public transportation that uses electric energy as power and runs in a wheel-rail manner."

[0003] In conventional railway transportation construction, the construction period is long, the occupied area is large, dust and noise are serious, which has a great impact on urban transportation and residents' lives. The construction site of the line is in the urban area, and the types of equipment required for construction are very many, the excavation volume is large, the noise is large, and it is affected by the land use and the types of urban railway transportation. At present, for the construction method of the embedded track with assembled precast slabs, there is a lack of a mature systematic construction method, so there are problems such as reduced efficiency during construction and difficulty in guaranteeing quality.

[0004] Therefore, in order to improve this, the inventor of the present invention proposes a method for constructing an embedded track with assembled precast track slabs for subways.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The object of the present invention is to address the problems in existing conventional railway transportation construction, such as a long construction period, a large occupied area, serious dust and noise, and a lack of a mature systematic construction method, resulting in reduced efficiency during construction and difficulty in guaranteeing quality.

Means for Solving the Problems

[0006] To achieve the objectives of the above invention, the present invention provides a method for constructing an embedded track using precast track plates for subways, in order to improve upon the above-mentioned problems.

[0007] The present application is specifically as follows:

[0008] A method for constructing embedded tracks using precast track plates for subways,

[0009] Engineers conduct a preliminary site survey to confirm the location of protective doors, inspect the quality of the delivered precast track plates and precast rail supports, guarantee that there are no cracks or damage to the appearance of the precast plates, set the strength level of the base concrete to C35, install one 20mm wide expansion joint every 10m, align the center line of the expansion joint with the center line of the plate joint, fill the expansion joint with a 20mm thick closed-cell polyethylene foam plate, seal the top surface with a 30mm thick polyurethane sealant, and also install expansion joints at changes in the track bed structure to match the expansion and contraction of the upper and lower layers. This is the construction preparation and surface treatment S1.

[0010] Using a gantry crane and trolley, the precast track plates are lifted and transported to the laying point, the track plates are initially laid using a small gantry crane for tunnels, the deviation of the centerline and height of the precast plates is controlled to within ±5 mm during the initial laying, anti-lifting pressure bars are attached, the track support system is installed and reinforced, and one set of precast track plates and precast rail supports is installed at 2.5 m intervals in the factory assembly S2.

[0011] Construction survey S3 using the CPIII control network involves attaching a plate adjustment jig to the lifting hole of the track plate, performing precise adjustment of the track plate using a total station via the CPIII control point, and for the precise adjustment of precast plates in curved sections, adopting the half-arrow distance adjustment principle, performing horizontal adjustment first, followed by height adjustment.

[0012] Installation of base formwork and concrete construction S4,

[0013] Laying of reinforcing mesh for self-compacting concrete, laying of track plates, precise adjustment of track plates, fixing of track plates S5,

[0014] Injection of self-filling concrete S6,

[0015] Laying and welding of steel rails S7,

[0016] Polishing of the steel rail and application of adhesive S8,

[0017] Installation of groove liner boards S9,

[0018] Installation of the orbit adjustment assembly S10,

[0019] Precise adjustment of the orbit S11,

[0020] The track plate is protected and its end is sealed S12,

[0021] The concrete casting of the polymer vibration damping material S13,

[0022] This includes track cleaning and re-surveying (S14).

[0023] As a preferred technical solution of this invention, in the injection of self-filling concrete, a 4 mm thick polypropylene nonwoven geotextile isolation layer is installed between the self-filling concrete layer and the bottom surface of the track plate, the geotextile is attached to the bottom surface of the track plate before shipment, the self-filling concrete has a strength of C40 and a thickness of 90 mm, the self-filling concrete is sufficiently filled into the track plate, measures are taken to prevent the track plate from lifting during placement, leakage prevention and prevention of contamination of the track plate are guaranteed during placement, exhaust holes are installed in the formwork during placement, the formwork and support can be removed when the strength of the self-filling concrete reaches 10 MPa, and vehicle operation and load application are possible when the strength reaches 70% of the design strength.

[0024] As a preferred technical solution of the present application, in the laying of steel rails, after the construction of the integral roadbed is completed, the laying of steel rails is carried out. In order to meet the requirements of rail welding and temporary vehicle passage, temporary fixing can be carried out as necessary. The iron floor plate and elastic floor plate under the rail are installed and arranged with two pre-embedded sleeves separated. When rail welding is completed, the stoppers fixed temporarily are removed and recovered.

[0025] As a preferred technical solution of the present application, in the welding of steel rails, all 60 kg / m steel rails are adopted for track laying, and a mobile rail contact welding vehicle is used to carry out on-site flash welding construction of steel rails. The welding method is the same as that of the stopper-type track structure. After the welding of the steel rails is completed, rust removal and polishing of the steel rails are carried out.

[0026] As a preferred technical solution of the present application, in the laying of the channel floor plate, the steel channel floor plate and the steel channel bottom plate are sequentially installed at the designed positions of the plate supports. An elastic floor plate is pasted in the center of the steel channel bottom plate. The hole positions are aligned with the hole positions of the supports. Vibration damping blocks are pasted and installed on both sides of the steel rail at the support positions, and they cannot enter the concrete rail receiving groove. On the steel channel bottom plate, welded steel channels are arranged on both the left and right sides of the steel rail. The side walls of the welded steel channels are aligned with the side walls of the rail supports. Short shims with a thickness of 2 mm + 4 mm + 2 mm are combined and arranged at the designed positions, and long shims are arranged on the side of the steel channel. The long shims are bent to tighten the ends of the short shims.

[0027] As a preferred technical solution of the present application, in the cleaning of the steel rail and the channel area, after removing the elastic clips, lift the steel rail with the plate joint, prop it up with wooden corner materials, and then polish the steel rail. After polishing and rust removal, the steel rail and the track plate surface are cleaned in a timely manner. Wash the oil stain on the steel rail surface until it feels non-greasy by hand. Lift the rust on the lower jaw of the rail head of the steel rail, polish the rail abdomen so that the surface is smooth and clean, and at the same time, pay attention to avoiding and preventing the adhesion and contamination of floating dust, oil, and water throughout the process of polishing and process change. At the same time, clean the floating dust and extra garbage in the channel area to ensure that there is no water and oil pollution.

[0028] As a preferred technical solution of the present application, in the installation of the track adjustment assembly, a total station and a track inspection trolley are used to precisely adjust the steel rail. The order of the steel rail precise adjustment is to first perform height adjustment, and then perform gauge adjustment. The height adjustment is achieved by combining height adjustment shims of different thicknesses, and the horizontal position adjustment of the steel rail is achieved by the pushing depth of the wedge block. The track adjustment assembly consists of a pair of retaining frames and a pair of wedge blocks, which are arranged at equal intervals along the groove area. It is necessary to ensure that a set of track adjustment assemblies is arranged at the end position of the track slab and no track adjustment assembly is arranged in the steel groove at the slab joint.

[0029] As a preferred technical solution of the present application, in the precise track adjustment, for height adjustment, a total station is used in combination with a track inspection trolley to collect the height data of the rail top surface at the arrangement positions of each height adjustment shim. Based on the designed height at the rail bottom, the arrangement thicknesses of the height adjustment shims and the rail cant shims under the rail at each point are calculated, and the deviation thickness value is marked on the rail top. According to the marked numerical value, the height adjustment shims are correspondingly increased or decreased. After laying the height adjustment shims at the predetermined positions, the track inspection trolley is used to collect and compare the height data again, and the above steps are repeated until each point meets the design requirement value. For horizontal adjustment, first, one steel rail is used as the reference rail to adjust the plane position. The plane position is adjusted by loosening and tightening the wedge block. After adjusting to the predetermined position for each point, the wedge block is tightened to complete the adjustment of the reference rail. After the adjustment of the reference rail is completed, the plane position of the other steel rail is further adjusted. After adjusting to the predetermined position for each point, the wedge block is tightened to complete the precise adjustment of the other steel rail.

[0030] As a preferred technical method of this invention, in protecting the track plate and sealing its ends, when reapplying adhesive, the adhesive is reapplied to the adhesive interface damaged in the previous step; when sealing the end faces of the groove region, the ends of the groove region are sealed using foamed adhesive in combination with foamed plate; when protecting the top surface of the steel rail, the top surface of the steel rail is protected by attaching adhesive tape, which is attached to the side of the rail head at a point not lower than the lower jaw of the rail head on both sides of the steel rail; the upper surface of the track bed is protected by laying oilcloth, and the protective tape and oilcloth must not penetrate deeply into the steel plate on the side of the steel groove.

[0031] As a preferred technical method of this invention, in the placement of polymer vibration damping material, the polymer vibration damping material consists of two components, A and B, and all of component B is shaken before use to avoid uneven mixing of the precipitate. At the time of placement, one bucket of component B is poured into the bucket of component A, and the mixture is thoroughly stirred for 2 minutes using an automatic stirring device to ensure a uniform mixture. Placement is started from one side of the steel rail, and after the polymer material overflows from the bottom of the rail on the other side, placement is carried out on the other side to prevent air pockets at the bottom of the rail and to avoid the material overflowing from the rail receiving groove during placement. After completion, continuously spread any bubbles on the surface of the polymer material to ensure there are no large or densely packed bubbles on the surface. The pouring height should be controlled between -5mm and 0mm relative to the top surface of the rail support groove. After each operation is completed, the protective material and residual adhesive on the work surface should be cleaned, and the stirring head of the stirrer should be thoroughly cleaned. Waterproofing and light shielding should be used during curing to prevent perturbation of the steel rail by external forces. After the material has hardened, the torque should be reconfirmed using a torque wrench and retightened until the design torque value reaches 250 N·m to 300 N·m. [Effects of the Invention]

[0032] Compared to conventional technology, the present invention has the following beneficial effects.

[0033] In the present invention,

[0034] 1. In conventional railway construction processes, the construction cycle is long, the occupied area is large, dust and noise are serious problems, and there is a lack of mature and systematic construction methods, which leads to decreased efficiency during construction and difficulty in guaranteeing quality. To address these issues, this invention proposes a construction method that, compared to the conventional method which requires first constructing precast track plates, laying temporary fasteners after the track plate construction is complete, and then transporting precast concrete rail supports to the site and manually installing the rail supports, first assembles the precast track plates and precast rail supports in the track plate factory, and then transports and installs them together at the construction site. This saves the construction time required to subsequently install the rail supports, reduces the occupied area of ​​necessary equipment, reduces noise and dust generated during construction, and improves construction efficiency.

[0035] 2. This invention saves the cost of temporary fasteners used in conventional construction methods, thereby reducing construction costs. The track structure is a unit slab type, adopting a design concept in which the slab and groove are separated, and a continuous support groove structure is formed by connecting precast plates and precast rail supports with high-strength bolts. By assembling and continuously optimizing the structure in the factory, the problems of limited construction space, concentrated crossing work, and restricted use of large machinery are solved. Embedded track construction has the characteristics of a high degree of mechanization and installation quality, a short cycle, ease of operation, and high overall benefits.

[0036] 3. This invention improves the contact relationship between wheels and rails by embedding steel rails into the track bed through continuous support and elastic fixing, effectively suppressing vibration noise of the track and vehicles from the source and propagation path, providing a quieter living environment for residents along urban railway lines, reducing noise pollution to the surrounding environment, having an excellent stray current prevention effect, contributing to ensuring the electrical safety of the rail transit system, reducing equipment failures and safety risks caused by stray currents, and improving the operational reliability of the rail transit system.

[0037] 4. This invention clarifies the construction steps and requirements for embedded track construction using precast precast panels, making the construction process more orderly and efficient, reducing uncertainty and rework during construction, shortening the construction cycle, accelerating the progress of rail transit projects, and specifies in detail each stage of construction, including quality inspection of precast track panels and precast rail supports in construction preparation and surface treatment, installation of expansion joints, and precision adjustment requirements during the track panel laying process, thereby ensuring that construction quality meets design requirements and improving the overall performance and service life of the track system.

[0038] 5. Based on the characteristics of the route and environmental evaluation requirements, this invention adopts a new type of embedded track bed structure using precast panels in high-vibration damping sections. Through continuous practice and innovation of construction methods, it can be adapted to rail transit projects with different geological conditions, route environments, and operational requirements, and has the potential for broad application. [Brief explanation of the drawing]

[0039] [Figure 1] This is a block diagram of the process flow of the embedded track construction method for precast track plates for subways provided by this application. [Figure 2] This is a block diagram of the in-trench construction principle of the embedded track construction method for precast track plates for subways provided by this application. [Figure 3] This is a schematic cross-sectional view of a precast embedded track bed for a subway system provided by this application. [Figure 4] This is a schematic diagram of the elastic groove structure within the precast track plate section of the embedded track construction method for subways using precast track plates provided by this application. [Figure 5] This is a schematic diagram illustrating the installation of a precast rail support for the embedded track construction method of precast track plates for subways provided by this application. [Figure 6]This is a schematic diagram of the planar curve adjustment control point of the precast plate in the embedded track construction method for subways using precast track plates provided by this application. [Figure 7] This is a schematic diagram showing the position of temporary fasteners for the embedded track construction method of precast track plates for subways provided by this application. [Figure 8] This is a schematic diagram of the polished area of ​​the embedded track construction method for subways using precast track plates provided by this application. [Figure 9] This is a schematic diagram showing the installation of steel grooves at plate joints in the embedded track construction method for precast track plates for subways provided by this application. [Figure 10] This is a schematic diagram of shim installation for the embedded track construction method of precast track plates for subways provided by this application. [Figure 11] This is a schematic diagram of the rail support coating for the embedded track construction method of precast track plates for subways provided by this application. [Figure 12] This is a schematic diagram of the in-groove installation of the track adjustment assembly for the embedded track construction method of precast track plates for subways provided by this application. [Figure 13] This is a schematic diagram of the arrangement of the track adjustment assembly for the embedded track construction method of precast track plates for subways provided by this application. [Figure 14] This is a schematic diagram of the groove for precise adjustment of steel rails in the embedded track construction method of precast track plates for subways provided by this application. [Figure 15] This is a schematic diagram of the steel rail and ballast protection area for the precast track plate type embedded track construction method for subways provided by this application. [Modes for carrying out the invention]

[0040] To enable those skilled in the art to better understand the technical concept of the present invention, the technical concept in the embodiments of the present invention will be described clearly and completely below, together with the drawings of the embodiments. Clearly, the embodiments described are only a selection of embodiments of the present invention, not all embodiments. All other embodiments that can be obtained by those skilled in the art without creative effort based on the embodiments of the present invention are all within the scope of the protection of the present invention.

[0041] As described in the background information, conventional railway construction methods suffer from long construction cycles, large occupied areas, serious dust and noise issues, and a lack of mature, systematic construction methods, resulting in decreased efficiency during construction and difficulty in guaranteeing quality.

[0042] To solve this technical problem, the present invention provides an embedded track construction method for subways using precast track plates, applicable to the railway transportation sector.

[0043] Specifically, please refer to Figures 1 to 15. The embedded track construction method for subways using precast track plates is as follows:

[0044] Engineers conduct a preliminary site survey to confirm the location of protective doors, inspect the quality of the delivered precast track plates and precast rail supports, guarantee that there are no cracks or damage to the appearance of the precast plates, set the strength level of the base concrete to C35, install one 20mm wide expansion joint every 10m, align the center line of the expansion joint with the center line of the plate joint, fill the expansion joint with a 20mm thick closed-cell polyethylene foam plate, seal the top surface with a 30mm thick polyurethane sealant, and also install expansion joints at changes in the track bed structure to match the expansion and contraction of the upper and lower layers. This is the construction preparation and surface treatment S1.

[0045] Using a gantry crane and trolley, precast track plates are lifted and transported to the laying point, the track plates are initially laid using a small gantry crane for tunnels, the deviation of the centerline and height of the precast plates during the initial laying is controlled to within ±5 mm, anti-lifting pressure bars are attached, the track support system is installed and reinforced, and one set of precast track plates and precast rail supports is installed at 2.5 m intervals in the factory assembly S2.

[0046] Construction survey S3 using the CPIII control network involves attaching a plate adjustment jig to the lifting hole of the track plate, performing precise adjustment of the track plate using a total station via the CPIII control point, and for the precise adjustment of precast plates in curved sections, adopting the half-arrow distance adjustment principle, performing horizontal adjustment first, followed by height adjustment.

[0047] Installation of base formwork and concrete construction S4,

[0048] Laying of reinforcing mesh for self-compacting concrete, laying of track plates, precise adjustment of track plates, fixing of track plates S5,

[0049] Injection of self-filling concrete S6,

[0050] Laying and welding of steel rails S7,

[0051] Polishing of the steel rail and application of adhesive S8,

[0052] Installation of groove liner boards S9,

[0053] Installation of the orbit adjustment assembly S10,

[0054] Precise adjustment of the orbit S11,

[0055] The track plate is protected and its end is sealed S12,

[0056] The concrete casting of the polymer vibration damping material S13,

[0057] This includes track cleaning and re-surveying (S14).

[0058] Compared to conventional construction methods that require the installation of precast track plates first, followed by the laying of temporary fasteners after the track plate installation is complete, and then the transport of precast concrete rail supports to the site for manual installation, this method first assembles the precast track plates and precast rail supports in the track plate factory, transports them together to the construction site, and installs them. This saves the time required for the subsequent installation of rail supports, reduces the construction cycle, requires less space for necessary equipment, reduces noise and dust generated during construction, and improves construction efficiency.

[0059] To enable those skilled in the art to better understand the technical aspects of the present invention, the technical aspects of embodiments of the present invention will be clearly and completely described below, in conjunction with the drawings.

[0060] Example 1 Please refer to Figures 1 to 15. The embedded track construction method for precast track plates used in subways is as follows:

[0061] Engineers conduct a preliminary site survey to confirm the location of protective doors, inspect the quality of the delivered precast track plates and precast rail supports, guarantee that there are no cracks or damage to the appearance of the precast plates, set the strength level of the base concrete to C35, install one 20mm wide expansion joint every 10m, align the center line of the expansion joint with the center line of the plate joint, fill the expansion joint with a 20mm thick closed-cell polyethylene foam plate, seal the top surface with a 30mm thick polyurethane sealant, and also install expansion joints at changes in the track bed structure to match the expansion and contraction of the upper and lower layers. This is the construction preparation and surface treatment S1.

[0062] Using a gantry crane and trolley, the precast track plates are lifted and transported to the laying point. A small tunnel gantry crane is used to initially lay the track plates, controlling the deviation of the centerline and height of the precast plates during the initial laying to within ±5 mm. Anti-lifting pressure bars are installed, the track support system is installed and reinforced, and one set is installed every 2.5 m.

[0063] By adjusting various screw members incorporated into the track support system, the geometric dimensions and stability of the track are controlled in the factory-assembled precast track plates and precast rail supports S2.

[0064] A plate adjustment jig is attached to the lifting hole of the track plate, and the track plate is precisely adjusted using a total station at the CPIII control point. For the precise adjustment of the precast plates in curved sections, the principle of semi-straight-arrow distance adjustment is adopted, with horizontal adjustment performed first, followed by height adjustment.

[0065] For horizontal adjustment, first, the cross marks on the center line of the precast plate (control point 1 and control point 2) are set as the reference control points of the precast plate, and using precision adjustment jigs at the four corners of the precast plate, the cross marks on each precast plate are positioned on the center line of the track. For height adjustment, the control points at the four corners of the precast plate (control points 3 to 6) are adjusted to adjust the height of the precast plate to the predetermined position, and the distance between the center lines of the track plates is set to 200 + 10 mm. This is construction survey S3 using the CPIII control network.

[0066] Installation of base formwork and concrete construction S4,

[0067] Laying of reinforcing mesh for self-compacting concrete, laying of track plates, precise adjustment of track plates, fixing of track plates S5,

[0068] Injection of self-filling concrete S6,

[0069] Laying and welding of steel rails S7,

[0070] Polishing of the steel rail and application of adhesive S8,

[0071] Installation of groove liner boards S9,

[0072] Installation of the orbit adjustment assembly S10,

[0073] Precise adjustment of the orbit S11,

[0074] The track plate is protected and its end is sealed S12,

[0075] The concrete casting of the polymer vibration damping material S13,

[0076] This includes track cleaning and re-surveying (S14).

[0077] In the injection of self-compacting concrete, a 4mm thick polypropylene nonwoven geotextile isolation layer is installed between the self-compacting concrete layer and the bottom surface of the track plate. The geotextile is attached to the bottom surface of the track plate before shipment. The self-compacting concrete has a strength of C40 and a thickness of 90mm. The self-compacting concrete is sufficiently filled into the track plate, free from obvious air bubbles. Measures are taken to prevent the track plate from lifting during placement, and leak prevention and contamination of the track plate are ensured. Exhaust holes are installed in the formwork during placement. The formwork and support can be removed when the strength of the self-compacting concrete reaches 10MPa. Vehicle operation and load application are permitted when the strength reaches 70% of the design strength.

[0078] In the laying of steel rails, after the construction of the integrated track bed is completed, the steel rails are laid, and temporary fixing can be performed as needed to meet the requirements for rail welding and temporary vehicle traffic. Steel sill plates and elastic sill plates are installed under the rails, separated by two pre-embedded sleeves, and the fasteners that were temporarily fixed during rail welding are released and retrieved.

[0079] For welding steel rails, 60kg / m steel rails are used for all track laying, and flash welding of the steel rails is performed on-site using a mobile rail contact welding vehicle. The welding method is the same as that used for fastener-type track structures, and rust removal and polishing of the steel rails are performed after welding is complete.

[0080] Regarding the steel rail welding requirements,

[0081] 1. Inspect the end faces (vertical and horizontal), end curvature, and straightness of the rail body of the steel rail, and ensure that the inclination of the end faces of the steel rail is 0.8 mm or less.

[0082] 2. The end face of the steel rail and the rail web within a 500 mm radius from the end face are subjected to rust removal and polishing treatment.

[0083] 3. After polishing the steel rail surface and jaw area, positioning is performed using a welding machine, the weld seam is aligned with the center position of the rail welding machine's jaw, and a knife edge ruler is used to inspect that the left-right and height misalignment of the two steel rails does not exceed 0.5 mm.

[0084] 4. After confirming the alignment of the steel rail, the hydraulic system is activated to clamp the rail, then the data acquisition system is activated, the welding program is started, and after each flash stage is performed in sequence, the upsetting is performed and deburring is completed, and at the same time the straightness of the weld seam is detected to prevent the occurrence of low joints.

[0085] 5. Using a grinder, polish the weld seams and the top, sides, and bottom surfaces of the rail heads.

[0086] 6. After the grinding of the weld seam position is completed, a normalizing process is performed using a medium-frequency normalizing device, and after the welding head is cooled to room temperature, precision grinding is performed using a tracing-type steel rail grinding machine. After the grinding is completed, measurements using a 1-meter ruler show that the non-straightness of the rail top surface of the steel rail welded joint is 0 mm to 0.3 mm, the non-straightness of the inner working surface of the rail head is 0.3 mm or less, the protrusion of the rail bottom is 1 mm or less, and the grinding depth is 0.5 mm or less.

[0087] Example 2 The embedded track construction method for subways using precast track plates provided in Example 1 is further optimized, specifically as shown in Figures 1 to 15, In laying the groove base plate, the steel groove base plate and steel groove bottom plate are sequentially attached to the design position of the plate support base, an elastic base plate is attached to the center of the steel groove bottom plate, the hole position is aligned with the hole position of the support base, and vibration damping blocks are attached to both sides of the steel rail at the support base position, preventing them from entering the concrete rail support groove. Welded steel grooves are placed on both the left and right sides of the steel rail on the steel groove bottom plate, the side walls of the welded steel grooves are aligned with the side walls of the rail support base, and short shims with thicknesses of 2 mm + 4 mm + 2 mm are placed in combination at the design position, and a long shim (150 mm x 10 mm x 2 mm) is placed on the steel groove side, and the long shim is bent and the ends of the short shims are tightened.

[0088] Based on the position of the welded steel groove, the retaining plate, heavy-duty spring washer, and flat washer are positioned, the steel groove is pressed against both sides (to ensure that the shim is in close contact with the steel groove), and the bolts are screwed into the support sleeve and tightened.

[0089] When applying the adhesive, the adhesive consists of two components, A and B (which turn red after mixing). Before use, component B must be uniformly stirred by hand at high speed for at least 3 minutes. The adhesive should be applied evenly using a short-bristle thumb roller brush (with a replaceable brush head), ensuring there are no gaps or drips. The application should be thin, not thick. There is no need to apply the adhesive to the bottom of the rail. However, the adhesive should be applied to the lower jaw of the rail head, the top surface of the vibration damping block, and the upper part of the inner wall of the steel groove at the plate joint.

[0090] When installing the track plates, ensure that there is no moisture, dust accumulation, or foreign matter on the track surface before installation, and that the track plates are free from oil stains and damage.

[0091] When installing the elastic base plates, they should be laid continuously in the center, with no overlaps or gaps at the edges, and the plates should be tightly adhered to the bottom of the groove during bonding to ensure the flatness of the base plate surface.

[0092] When installing height adjustment shims, a combined thickness of 13 mm is placed in the groove beforehand, and the actual thickness is adjusted according to the results of subsequent precision adjustment measurements. The spacing between height adjustment shims is set to 1 m, and the spacing at the plate edges can be made closer or wider. No height adjustment shims are installed in the steel grooves at the plate joints.

[0093] When installing rail cant shims, the rail cant shims should be laid above the height adjustment shims. When laying them, care must be taken to ensure that the thinner side of the shim faces inward towards the track plate and that the height adjustment shims are not placed in the steel grooves of the plate joints.

[0094] In cleaning the steel rails and groove areas, after removing the elastic clips, the steel rails are lifted at the plate joints, raised with wooden lumber, and then polished. After polishing and rust removal, the steel rails and track plates are cleaned in a timely manner. The oil stains on the surface of the steel rails are thoroughly washed until they feel clean to the touch. After polishing, the surface of the lower jaw of the rail head and the rail body is polished to a smooth and clean state. Care is taken to avoid and prevent contamination by airborne dust, oil, and water throughout the polishing and process changeover process. At the same time, airborne dust and excess debris in the groove areas are thoroughly cleaned, ensuring that there are no water or oil contaminants.

[0095] In installing the track adjustment assembly, the steel rails are precisely adjusted using a total station and a track inspection trolley. The precise adjustment sequence for the steel rails is to adjust the height first, followed by the track gauge. Height adjustment is achieved by combining shims of different thicknesses, and the horizontal position of the steel rails is adjusted by the depth of the wedge-shaped blocks. The track adjustment assembly consists of one pair of retaining frames and one pair of wedge-shaped blocks, and is arranged at equal intervals (550 mm ± 10 mm) along the groove area. It is necessary to ensure that one set of track adjustment assemblies is placed at the end of the track plate, and that no track adjustment assemblies are placed in the steel grooves of the plate joints.

[0096] In precise track adjustment, for height adjustment, a total station is used in combination with a track inspection trolley to collect height data of the rail top surface at the placement position of each height adjustment shim. Based on the design height of the rail bottom, the placement thickness of the height adjustment shims and rail cant shims under the rail at each point is calculated. The deviation thickness value (height adjustment amount) is marked on the rail top, and the height adjustment shims are increased or decreased accordingly according to the marked value. After laying the height adjustment shims in the predetermined positions, the height data is collected and compared again using the track inspection trolley, and these steps are repeated until each point meets the design requirements. For horizontal adjustment, first, the planar position is adjusted using one steel rail as the reference rail, and the planar position is adjusted by loosening and tightening the wedge-shaped blocks. After adjusting each point to the predetermined position, the wedge-shaped blocks are tightened to complete the adjustment of the reference rail. After the adjustment of the reference rail is completed, the planar position of the other steel rail is further adjusted, and after adjusting each point to the predetermined position, the wedge-shaped blocks are tightened to complete the precise adjustment of the other steel rail.

[0097] For the protection and sealing of the track plate ends, when reapplying adhesive, reapply adhesive to the adhesive interface damaged in the previous step; for sealing the end faces of the groove area, seal the ends of the groove area using foamed adhesive in combination with foamed plate; for protecting the top surface of the steel rail, protect the top surface of the steel rail by attaching adhesive tape, and attach it to the sides of the rail head at a point not lower than the lower jaw of the rail head on both sides of the steel rail; protect the upper surface of the track bed (both sides of the rail receiving groove) by laying oil cloth, and ensure that the protective tape and oil cloth do not penetrate deeply into the steel plate on the side of the steel groove.

[0098] Example 3 The embedded track construction method for precast track plates for subways provided in Example 1 or 2 is further optimized, specifically as shown in Figures 1 to 15. In the placement of the polymer vibration damping material, the polymer vibration damping material consists of two components, A and B. All of component B is shaken before use to avoid uneven mixing of sediment. At the time of placement, one bucket of component B is poured into the bucket of component A (pour until component B is empty), and the mixture is thoroughly stirred for 2 minutes using an automatic stirring device to ensure uniform mixing. Placement is started from one side of the steel rail, and after the polymer material overflows from the bottom of the rail on the other side, placement is repeated on the other side, and air pockets at the bottom of the rail are removed. To prevent the material from overflowing from the rail support groove during placement, to continuously smooth out any air bubbles on the polymer material surface after placement is complete, ensuring that there are no large or densely packed air bubbles on the surface, to control the placement height between -5mm and 0mm relative to the top surface of the rail support groove, to clean the protective material and residual adhesive from the work surface after each operation is completed, and to thoroughly clean the stirring head of the mixer, to waterproof and shield from light during curing (within 72 hours after placement), to prevent perturbation of the steel rail by external forces, and after the material has hardened, to reconfirm the torque using a torque wrench and to retighten until the design torque value reaches 250 N·m to 300 N·m.

[0099] The method for manufacturing polymer vibration-damping materials includes the following steps.

[0100] In S1, during the screening process, polyurethane prepolymer samples are obtained, their chemical structure is determined by infrared spectroscopy, and their molecular weight distribution is measured using gel permeation chromatography. Polyurethane prepolymers with a molecular weight distribution between 1000 and 5000 are then selected.

[0101] S2. In the pretreatment, the selected polyurethane prepolymer is placed in a vacuum drying oven and dried at 60-80°C for 2-4 hours to remove any trace moisture and avoid the appearance of bubble defects in the subsequent reaction.

[0102] In the production of component S3 and A, the polyurethane prepolymer is added to a reaction vessel equipped with a stirrer, stirring is started, the stirring speed is controlled to 50-150 revolutions per minute, and stirring is continued for 10-30 minutes to uniformly disperse the polyurethane prepolymer. Then, the plasticizer is added, and stirring is continued for 15-30 minutes to thoroughly mix the plasticizer with the polymer to improve the flexibility and processability of the material. Subsequently, calcium carbonate, which is the filler, is added, and the filler needs to be pre-dried. After addition, the stirring speed is increased to 100-200 revolutions per minute, and stirring is continued for 30-60 minutes to ensure that the filler is uniformly dispersed in the polymer system and that a stable component A raw material system is formed.

[0103] For drying the filler, place the calcium carbonate filler in an oven and dry it at 105-120°C for 2-4 hours to remove any moisture and immediately place the dried filler in an airtight container to prevent re-absorption of moisture.

[0104] In the sieving of the filler, a sieve with a mesh size of 200 to 300 is used to sieve the dried calcium carbonate filler, removing large impurities and ensuring that the particle size of the filler is uniform.

[0105] In the production of component S4 and component B, the isocyanate-based curing agent must first be added to a clean container and subjected to a heating and melting treatment. The heating temperature should be controlled to 40-80°C, and after complete melting, the organotin-based catalyst should be added and stirred uniformly for 5-15 minutes to uniformly disperse the catalyst in the curing agent and form the raw material for component B.

[0106] In selecting the curing agent, an isocyanate-based curing agent is chosen, and the purity of the curing agent and the isocyanate group content are detected.

[0107] In S5, quality inspections are performed on the manufactured components A and B. For component A, the viscosity, density, and solid content are detected. Viscosity is detected using a rotational viscometer, density is detected using a densimeter, and solid content is calculated by drying the sample until a constant weight is reached. For component B, the active hydrogen content and viscosity index are detected. Active hydrogen content is detected using a chemical analysis method, and viscosity is detected similarly using a rotational viscometer.

[0108] S6. In packaging and storage, components A and B that have passed inspection should be packaged separately. Component A may be packaged in a plastic bucket, while component B, due to its high activity, should be packaged in a well-sealed container to prevent reaction with moisture in the air. Packaged components A and B should be stored in a dry, shaded, and well-ventilated warehouse, avoiding direct sunlight and high temperatures, controlling the storage temperature between 5 and 30°C, and regularly inspecting the stock materials during storage to ensure the stability of their quality.

[0109] [Table 1]

[0110] [Table 2]

[0111] [Table 3]

[0112] [Table 4]

[0113] The principle and process of the construction method provided by the present invention are as follows:

[0114] The embedded track system using precast precast panels employs precast track panels and precast rail supports. The precast track panels and precast rail supports are precast manufactured in a factory. The processed and molded finished precast track panels and precast rail supports are assembled together in the factory beforehand, transported by vehicle to the track laying site, and stored there. For the base concrete construction of the precast panels, concrete pouring is completed using a concrete mixer truck before the laying of the precast panels. Within the track laying site, the assembled precast track panels and rail supports are lifted onto track trolleys using gantry cranes and truck cranes, and then operated by track vehicles. The precast plates are transported to the work site, where a track laying machine is used to lift and lay the precast plates. The geometric position of the precast plates is adjusted using the track CPIII control network and its associated measurement system and jig equipment. After the precise adjustment is complete, the self-filling concrete edge formwork and anti-lifting device are installed. Self-filling concrete is injected, the track steel rails and elastic base plates are laid, and shims for height adjustment are installed. Long rails are constructed using a mobile flash contact welding machine. After the rail welding is complete, a track inspection vehicle is used for precise adjustment. Finally, polymer vibration damping material is poured, and after passing the quality inspection, the track is opened, completing the embedded track construction.

[0115] The precast plate embedded track construction method completes the pre-assembly of precast plates and precast rail supports, laying and precise adjustment of the precast plates, self-filling concrete, laying and welding of steel rails, precise adjustment of the track, and installation of polymer material in the grooves within the factory. This enables accurate and rapid adjustment of the embedded track, solving the challenges of on-site installation of rail supports, which involves limited space, numerous intersections, and high safety risks. This method can be directly disseminated and applied to the construction of precast plate embedded tracks in subways of major cities, significantly improving construction quality and efficiency, facilitating coordination and management by the client during construction, and ensuring that the design objectives and construction schedule requirements of the precast plate embedded track structure are met. Furthermore, it significantly reduces confusion in construction control management and waste of resources, generating significant social and economic benefits.

[0116] Clearly, the embodiments described above represent only a portion of the present invention, not all embodiments, and while the accompanying drawings show preferred embodiments of the present invention, they do not limit the scope of the patent. The present invention can be realized in many different forms, and conversely, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and complete. Although the present invention has been described in detail with reference to the embodiments described above, those skilled in the art can still modify the technical ideas described in each of the specific embodiments described above, or equally substitute some of the technical features thereof. Equivalent structures made using the contents of the specification and drawings of the present invention that are directly or indirectly applicable to other related technical fields are all similarly included within the scope of the patent protection of the present invention.

Claims

1. Engineers conduct a site survey in advance to confirm the location of protective doors, inspect the quality of the delivered precast track plates and precast rail supports, guarantee that there are no cracks or damage to the appearance of the precast plates, set the strength level of the base concrete to C35, install one 20 mm wide expansion joint every 10 m, align the center line of the expansion joint with the center line of the plate joint, fill the expansion joint with a 20 mm thick closed-cell polyethylene foam plate, seal the top surface with a 30 mm thick polyurethane sealant, and also install expansion joints at changes in the track bed structure to match the expansion and contraction of the upper and lower layers. This is the construction preparation and surface treatment S1. Using a gantry crane and trolley, precast track plates are lifted and transported to the laying point, the track plates are initially laid using a small gantry crane for tunnels, the deviation of the centerline and height of the precast plates during the initial laying is controlled to within ±5 mm, anti-lifting pressure bars are attached, the track support system is installed and reinforced, and one set of precast track plates and precast rail supports is installed at intervals of 2.5 m in the factory assembly S2. Construction survey S3 using a CPIII control network involves attaching a plate adjustment jig to the lifting hole of the track plate, performing precise adjustment of the track plate using a total station via a CPIII control point, and employing the principle of semi-straight-arrow distance adjustment for the precast plates in curved sections, performing horizontal adjustment first, followed by height adjustment. Installation of base formwork and concrete construction S4, Laying of reinforcing mesh for self-filling concrete, laying of track plates, precise adjustment of track plates, fixing of track plates S5, Injection S6 of self-filling concrete, Laying and welding of steel rails S7, Polishing of the steel rail and application of adhesive S8, Installation of groove liner boards S9, Installation of the track adjustment assembly S10, Precise adjustment of the trajectory S11, The track plate is protected and its end is sealed S12, The casting of the polymer vibration damping material S13, Track cleaning and re-surveying S14, A method for constructing an embedded track using precast track plates for subways, characterized by the following features.

2. In the injection of self-compacting concrete, a 4 mm thick polypropylene nonwoven geotextile isolation layer is installed between the self-compacting concrete layer and the bottom surface of the track plate. The geotextile is attached to the bottom surface of the track plate before shipment. The self-compacting concrete has a strength of C40 and a thickness of 90 mm. The self-compacting concrete is sufficiently filled into the track plate. Measures are taken to prevent the track plate from lifting during placement, and leak prevention and contamination of the track plate are guaranteed during placement. Exhaust holes are installed in the formwork during placement. The formwork and support can be removed when the strength of the self-compacting concrete reaches 10 MPa. Vehicle operation and load application are permitted when the strength reaches 70% of the design strength. A method for constructing an embedded subway track using precast track plates, as described in claim 1.

3. In the laying of steel rails, the steel rails are laid after the construction of the integrated track bed is completed. To meet the requirements for rail welding and temporary vehicle traffic, temporary fixing can be performed as needed. Steel sill plates and elastic sill plates are installed under the rails, separated by two pre-embedded sleeves. The fasteners that were temporarily fixed during rail welding are released and retrieved. The method for constructing an embedded track using precast track plates for subways, as described in claim 2.

4. For welding steel rails, 60 kg / m steel rails are used for all track laying, and flash welding of the steel rails is performed on-site using a mobile rail contact welding vehicle. The welding method is the same as that used for fastener-type track structures, and rust removal and polishing of the steel rails are performed after welding is complete. A method for constructing an embedded track using precast track plates for subways, as described in claim 3.

5. In laying the groove base plate, the steel groove base plate and steel groove bottom plate are sequentially attached to the design position of the plate support base, an elastic base plate is attached to the center of the steel groove bottom plate, the hole position is aligned with the hole position of the support base, vibration damping blocks are attached to both sides of the steel rail at the support base position, preventing entry into the concrete rail support groove, welded steel grooves are placed on both the left and right sides of the steel rail on the steel groove bottom plate, the side walls of the welded steel grooves are aligned with the side walls of the rail support base, short shims of thickness 2 mm + 4 mm + 2 mm are placed in combination at the design position, and a long shim is placed on the steel groove side, the long shim is bent and the ends of the short shims are tightened. A method for constructing an embedded track using precast track plates for subways, as described in claim 4.

6. In cleaning the steel rails and groove areas, after removing the elastic clips, the steel rails are lifted at the plate joints, raised with wooden blocks, and then polished. After polishing and rust removal, the steel rails and track surfaces are cleaned in a timely manner. Oil stains on the surface of the steel rails are thoroughly washed until they feel clean to the touch. Rust on the lower jaw of the rail heads is loosened, and the rail bodies are polished to ensure the surface is smooth and clean. Care is taken to avoid and prevent contamination by airborne dust, oil, and water throughout the polishing and process changeover processes, while also thoroughly cleaning airborne dust and excess debris from the groove areas and ensuring that there are no water or oil contaminants. The method for constructing an embedded track using precast track plates for subways, as described in claim 5.

7. In installing the track adjustment assembly, the steel rails are precisely adjusted using a total station and a track inspection trolley. The precise adjustment sequence for the steel rails is to adjust the height first, followed by the track gauge. Height adjustment is achieved by combining shims of different thicknesses, and the horizontal position of the steel rails is adjusted by the depth of the wedge-shaped blocks. The track adjustment assembly consists of one pair of retaining frames and one pair of wedge-shaped blocks, which are arranged at equal intervals along the groove area. It is necessary to ensure that one set of track adjustment assemblies is placed at the end of the track plate, and that no track adjustment assemblies are placed in the steel grooves of the plate joints. A method for constructing an embedded track using precast track plates for subways, as described in claim 6.

8. In precise track adjustment, for height adjustment, a total station is used in combination with a track inspection trolley to collect height data of the rail top surface at the placement position of each height adjustment shim. Based on the design height of the rail bottom, the placement thickness of the height adjustment shims and rail cant shims under the rail at each point is calculated, the deviation thickness value is marked on the rail top, and the height adjustment shims are increased or decreased accordingly according to the marked value. After laying the height adjustment shims in the predetermined position, the height data is collected and compared again using the track inspection trolley, and these steps are repeated until each point meets the design requirements. For horizontal adjustment, first, the planar position is adjusted using one steel rail as the reference rail, and the planar position is adjusted by loosening and tightening the wedge-shaped block. After adjusting each point to the predetermined position, the wedge-shaped block is tightened to complete the adjustment of the reference rail. After the adjustment of the reference rail is completed, the planar position of the other steel rail is further adjusted, and after adjusting each point to the predetermined position, the wedge-shaped block is tightened to complete the precise adjustment of the other steel rail. A method for constructing an embedded track using precast track plates for subways, as described in claim 7.

9. For the protection and sealing of the track plate ends, when reapplying adhesive, reapply adhesive to the adhesive interface damaged in the previous step; for sealing the end faces of the groove area, seal the ends of the groove area using foam board in combination with foam adhesive; for protecting the top surface of the steel rail, protect the top surface of the steel rail by attaching adhesive tape, and attach it to the sides of the rail head at a point not lower than the lower jaw of the rail head on both sides of the steel rail; protect the top surface of the track bed by laying oil cloth, and ensure that the protective tape and oil cloth do not penetrate deeply into the steel plate on the side of the steel groove. A method for constructing an embedded track using precast track plates for subways, as described in claim 8.

10. In the placement of polymer vibration damping material, the polymer vibration damping material consists of two components, A and B. All of component B is shaken before use to avoid uneven mixing of the precipitate. At the time of placement, one bucket of component B is poured into the bucket of component A, and the mixture is thoroughly stirred for two minutes using an automatic stirring device to ensure uniform mixing. Placement is started from one side of the steel rail, and after the polymer material overflows from the bottom of the rail on the other side, placement is carried out on the other side to prevent air pockets at the bottom of the rail and to avoid the material overflowing from the rail support groove during placement. After placement is complete, high volume Continuously spread the material to remove any air bubbles from the surface, ensuring there are no large or densely packed bubbles on the surface. The pouring height should be controlled between -5 mm and 0 mm relative to the top surface of the rail support groove. After each operation is completed, clean the protective material and any remaining adhesive from the work surface, and thoroughly clean the stirring head of the mixer. During curing, waterproof and light shielding should be used to prevent perturbation of the steel rail by external forces. After the material has cured, reconfirm the torque using a torque wrench and retighten until the design torque value reaches 250 N·m to 300 N·m. A method for constructing an embedded track using precast track plates for subways, as described in claim 9.

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