Prefabricated subway station component prestress construction method

Abstract

The invention discloses an assembly type subway station component prestress construction method. The method comprises the following steps of construction preparation, finish rolling deformed steel bar installation, tensioning equipment installation and debugging, component translation, prestress tensioning, tensioning force and circular seam detection, anchoring and quality inspection and acceptance. Through the measures of optimizing the construction process, accurately controlling the tensioning parameters, reasonably translating the components and the like, efficient and accurate tensioning of the fabricated subway station components is achieved, it is ensured that all procedures are closely connected, the project quality and the construction efficiency are improved, and the construction cost is reduced. And meanwhile, the problems that in the prior art, assembly type subway station prestress engineering construction is unsmooth in procedure connection, insufficient in tensioning precision, prone to deformation of components and poor in circular seam control are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a prestressed construction method for prefabricated subway station components. Background Technology

[0002] With the rapid development of urban rail transit construction, prefabricated subway stations are widely used due to their advantages such as high construction efficiency and low on-site pollution. In the construction of the prefabricated subway station assembly section, prestressing engineering is interspersed in the assembly of various components, and prestressing tensioning is crucial to ensuring tight connection of components and guaranteeing the overall structural stability.

[0003] However, existing prestressed component construction methods have the following problems: First, the process is not well connected, and prestressed construction is easily separated from component assembly, resulting in delays in the construction period; second, the tensioning accuracy is insufficient, and there is a lack of an effective stress and strain dual control mechanism, which easily leads to tension force deviation or component deformation; third, the control of component circumferential joints is not good, and excessively large or small circumferential joint gaps will affect the structural stress performance; fourth, components such as base plates that are restricted by supports are difficult to be accurately positioned before tensioning, and the components are prone to twisting during the tensioning process due to misalignment.

[0004] Therefore, there is an urgent need for a prestressed construction method for prefabricated subway station components that can achieve close connection of processes, precise control of tensioning parameters, avoid component deformation, and ensure the quality of circumferential joints. Summary of the Invention

[0005] In order to overcome the problems of poor process connection, insufficient tensioning accuracy, easy deformation of components and poor control of circumferential joints in the construction of prestressed precast subway station projects in the existing technology, the present invention provides a prestressed construction method for precast subway station components.

[0006] The technical solution of this invention is as follows:

[0007] A prestressed construction method for prefabricated subway station components includes the following steps:

[0008] Installation of precision-rolled threaded steel bars: After the prefabricated components are assembled in place, install the precision-rolled threaded steel bars according to the positions and quantities required by the design.

[0009] Tensioning equipment installation and commissioning: According to the tensioning process requirements, install the core jack and pump station in place, and test and check the operation of the core jack and pump station oil pump;

[0010] Component translation: For the base plate component that is restricted by the support, multiple precision-rolled threaded steel bars are used in conjunction with multiple through-hole jacks to push the base plate component until all the positioning pins of the base plate circumferential joint are aligned and the circumferential joint gap is 3cm.

[0011] Prestressing tensioning: According to the design tension force, different precast components are tensioned using corresponding tension forces, and the tension force is applied in multiple stages during tensioning.

[0012] Tension and circumferential gap inspection: During the tensioning process, the pressure gauge is used to control the tension. Loading is stopped after the tension reaches the required tension. The elongation of the fine-rolled threaded steel and the circumferential gap of the component are measured.

[0013] Anchoring: After the tension and circumferential joint tests are passed, the anchoring operation is carried out.

[0014] As a preferred embodiment of the present invention, before the installation of the precision-rolled threaded steel bar, the following step is further included:

[0015] Construction preparation: During the assembly of precast components, prepare precision-rolled threaded steel bars according to the positions and quantities required by the design, and check the appearance quality of the precision-rolled threaded steel bars; at the same time, calibrate and use the through-hole jacks and pressure gauges.

[0016] As a preferred embodiment of the present invention, in the installation step of the precision-rolled threaded steel bar, the precision-rolled threaded steel bar is inserted into the reserved tensioning hole of the prefabricated component, so that the precision-rolled threaded steel bar is connected to the pre-tightened screw sleeve in the reserved tensioning hole, and the insertion depth reaches the design requirement of 180mm.

[0017] As a preferred embodiment of the present invention, the component translation step specifically includes the following sub-steps:

[0018] One end of each of the three precision rolled threaded steel bars is inserted into the three reserved tensioning holes at the bottom and on both sides of the base plate component and connected to the pre-tightening screw sleeves in the holes. The other end is fitted with three through-hole jacks and anchor plates and nuts.

[0019] The bottom plate component is pushed synchronously by three through jacks, and the center offset of the bottom plate component is corrected. After the through jacks have completed their stroke, they are reset and the anchor plate and nut are moved forward and fixed. The bottom plate component is pushed again until all the positioning pins of the bottom plate component's circumferential joint are aligned and the circumferential joint gap is 3cm.

[0020] As a preferred embodiment of the present invention, the prestressing tensioning step specifically includes the following sub-steps:

[0021] Start the oil pump slowly to load the through-hole jack evenly, and observe the pressure gauge reading and the condition of the circumferential joint of the precast component;

[0022] During tensioning, the tension force is applied in three stages, with the initial tension force being 10-20% of the tensioning control force;

[0023] After reaching the initial tension, hold the load for 2 minutes and observe whether each tensioning hole is evenly stressed.

[0024] Load the tensioning force at a uniform rate to 50%, hold the load for 2 minutes, and observe the deformation of the precast components, the elongation of the fine-rolled threaded steel bars, and the operation of the through-hole jack. If any abnormality is found, stop the tensioning immediately.

[0025] If there are no abnormalities, continue to apply the load evenly until the tension control force is reached, and hold the load for 2 minutes after reaching the tension control force.

[0026] As a preferred embodiment of the present invention, in the tension and circumferential joint detection steps, if the tension of multiple through-hole jacks simultaneously cannot meet the total tension requirement, the through-hole jacks can be tensioned separately in batches. After the tension of the through-hole jacks in the same batch is loaded to the control value, they are anchored, and then the remaining through-hole jacks are loaded.

[0027] As a preferred embodiment of the present invention, in the tension and circumferential joint detection steps, when measuring the elongation of the fine-rolled threaded steel, if the deviation between the actual elongation and the theoretical elongation is not within ±6%, tensioning is suspended, the cause is investigated, and corresponding measures are taken to adjust before construction continues.

[0028] As a preferred embodiment of the present invention, in the tension and circumferential gap detection steps, when measuring the circumferential gap of the component, it is determined whether the circumferential gap of the component meets the requirement of 5-7mm. If the circumferential gap of the component is greater than 7mm, the tension is further increased until the circumferential gap of the component meets the requirement.

[0029] As a preferred embodiment of the present invention, the maximum over-tension force is not greater than 0.9 times the standard value of the yield strength of the prestressed tendon of the fine-rolled threaded steel.

[0030] As a preferred embodiment of the present invention, after the anchoring step, the following step is further included:

[0031] Quality inspection and acceptance: In accordance with the quality inspection and acceptance standards, a comprehensive inspection of the construction process and component quality is carried out. After the inspection is passed, the next process begins.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. Closely integrated process: Prestressing tensioning is interspersed throughout the component assembly process. Through precise installation, translation, and tensioning procedures, delays in the overall construction period due to prestressing construction are avoided.

[0034] 2. High tensioning accuracy: The stress-strain dual control method combined with the graded loading process, along with regular equipment calibration, ensures that the deviation of tension force and elongation is within the specified range;

[0035] 3. Controllable component deformation: Through synchronous jacking and correction (especially for base plate components) and deformation monitoring during staged loading, component torsion deformation is effectively avoided;

[0036] 4. Reliable quality of circumferential joints: Clearly define the standard for controlling the circumferential joint gap (3cm pre-position, 5-7mm final gap), and ensure reasonable stress on the circumferential joint through dynamic adjustment of tension. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of a prestressed construction method for prefabricated subway station components according to an embodiment of the present invention. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also stated that the embodiments described below are for illustrative purposes only and are not intended to limit the invention.

[0040] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0041] Please see Figure 1 This embodiment provides a prestressed construction method for prefabricated subway station components, including the following steps:

[0042] S1. Construction Preparation

[0043] During the assembly of precast components, preparing precision-rolled threaded steel bars according to the design requirements in terms of location and quantity, and inspecting the appearance quality of the precision-rolled threaded steel bars, can ensure that the precision-rolled threaded steel bars used meet the design standards in terms of specifications and appearance. This avoids the subsequent tensioning effect and the prestressed performance of the components being affected by defects in the materials themselves (such as cracks, corrosion, etc.), thus ensuring the quality of the project from the source.

[0044] At the same time, the through-hole jacks and pressure gauges are calibrated and used in a matching manner. The calibration period shall not exceed six months to ensure that the force values ​​measured and applied by the equipment are accurate and reliable. Because the performance of the equipment may change over time and with the increase in the number of uses, regular calibration can detect and correct such changes in a timely manner, ensuring that prestress is applied accurately in accordance with the design requirements during the construction process.

[0045] In addition, when abnormal phenomena occur during use or after the tensioning equipment is repaired, it should be recalibrated to adjust the equipment status in a timely manner and restore it to normal working performance. This will prevent inaccurate tension due to equipment failure or unstable performance, which could affect the prestress distribution and structural safety of the components.

[0046] S2, Installation of precision rolled threaded steel bars

[0047] After the precast components are assembled in place, precision-rolled threaded steel bars are installed according to the design requirements in terms of location and quantity. During installation, the precision-rolled threaded steel bars are inserted into the pre-reserved tensioning holes in the precast components, connecting them to the pre-tightening screw sleeves within the holes, with an insertion depth meeting the design requirement of 180mm. This connection method ensures a firm and reliable connection between the precision-rolled threaded steel bars and the components; and the 180mm insertion depth can withstand the enormous tensile force generated during tensioning, preventing the precision-rolled threaded steel bars from being pulled out of the components during tensioning, and ensuring that the prestress is effectively transferred to the components.

[0048] S3. Installation and commissioning of tensioning equipment

[0049] According to the tensioning process requirements, the tensioning equipment, such as the manhole jack and pump station, is installed and positioned, ensuring that the equipment connections are secure and the oil pipes are well-sealed without leakage. This effectively prevents safety accidents caused by loose equipment connections or oil pipe leaks during the tensioning process. Simultaneously, the operation of the manhole jack and pump station's oil pump is tested and checked to ensure stable pressure and that the tensioning stroke meets the requirements, providing hardware support for the accurate application of prestress. Stable pressure ensures that the tension force is applied evenly according to design requirements, avoiding fluctuations in pressure that could cause inconsistent prestress and affect the structural performance of the component; a compliant tensioning stroke ensures that the precision-rolled threaded steel is stretched to the appropriate length, achieving the predetermined prestressing effect.

[0050] S4, Component Translation

[0051] Due to the support constraints on the base plate components, the maximum distance between the hoisting position and the installation position can reach 650mm. For the base plate components with support constraints, three precision-rolled threaded steel bars are threaded through three pre-reserved tensioning holes at the bottom and sides of the base plate components, respectively, and connected to the pre-tightening screw sleeves inside the holes. The other ends are fitted with three through-hole jacks, anchor plates, and nuts, providing an effective means of translation for the constrained base plate components. The three through-hole jacks push synchronously, correcting the center offset of the base plate components (by adjusting the stroke of the three through-hole jacks) to prevent the components from twisting and deforming. After the through-hole jacks have pushed 180mm of their stroke, they are reset, and the anchor plates and nuts are moved forward to fix them. The base plate components are then pushed again until all the positioning pins of the circumferential joint of the base plate components are aligned and the circumferential joint gap is 3cm, ensuring a tight and accurate connection between the components, laying the foundation for subsequent splicing and overall structural stability.

[0052] The 180mm advance interval allows construction workers ample time to observe the component's movement and status, promptly identifying and addressing potential issues such as component jamming or jack malfunctions, thus ensuring the quality and safety of the component's translation. The 3cm circumferential gap facilitates grouting and sealing between components, improving the structure's waterproofing and overall integrity; and the locating pin alignment ensures the component's accurate position within the plane, resulting in a more rational stress distribution within the structure.

[0053] S5, Prestressed tensioning

[0054] According to the design tension force, the corresponding tension force is used for tensioning operations on different precast components. The magnitude of the tension control force for different precast components is shown in Table 1. During tensioning, the tension force is applied in multiple stages.

[0055] Table 1. Tension Control Force Table for Precast Components

[0056] Serial Number Component parts Total tension force of the tensioning rod (kN) Total tension force of a single tension bar (kN) 1 Top slab components 2022 404 2 Side wall components 883 294 3 Base plate components 1992 285

[0057] Staged tension loading:

[0058] 1) Start the oil pump slowly to load the through-hole jack evenly, and observe the pressure gauge reading and the condition of the circumferential joint of the precast component. This can prevent excessive local stress on the precast component due to sudden excessive tension, which can lead to stress concentration.

[0059] 2) During tensioning, the tension force is applied in three stages. The initial tension force is 10-20% of the tension control force, allowing the component to adapt to the tension force. This allows the prestress to be gradually and evenly distributed in the concrete component, ensuring a more reasonable stress distribution on the structure and improving the stability and load-bearing capacity of the structure.

[0060] 3) After reaching the initial tension, hold the load for 2 minutes and observe whether each tensioning hole is evenly stressed. This can help to detect uneven stress distribution in the tensioning holes in time, so that adjustments can be made to ensure that each tensioning hole can effectively transmit prestress and further ensure that the overall stress distribution of the component is uniform.

[0061] 4) Load the tensioning force at a uniform rate to 50%, hold the load for 2 minutes, and observe the deformation of the precast components, the elongation of the fine-rolled threaded steel bars, and the operation of the through-hole jack. If any abnormality is found, such as cracks in the components, stop the tensioning immediately.

[0062] 5) If there are no abnormalities, continue to apply the load evenly until the tension control force is reached, and hold the load for 2 minutes after reaching the tension control force.

[0063] S6, Tension and Circumferential Joint Inspection

[0064] During tensioning, the tension force is controlled by observing the pressure gauge. Loading is stopped once the required tension is reached, and the elongation of the fine-rolled threaded steel and the circumferential gap of the component are measured. A dual stress-strain control method is used during tensioning, with stress control as the primary method and the elongation of the fine-rolled threaded steel as a check, ensuring that the circumferential gap width meets the requirements. This method allows for more precise control of the tension force. Relying solely on pressure gauge control may result in inaccurate tension force due to gauge errors or equipment malfunctions. Combining this with elongation verification allows for timely detection and correction, ensuring accurate tension force and guaranteeing that the prestressed performance of the structure meets design standards. The corresponding tension force values ​​for the pressure gauges are shown in Table 2.

[0065] Table 2. Pressure gauge readings and corresponding tension values.

[0066]

[0067]

[0068] If the tension applied simultaneously by multiple through-hole jacks is insufficient to meet the total tension requirement, the through-hole jacks can be tensioned in batches. Once the tension of each batch of through-hole jacks reaches the control value, they are anchored, and then the remaining through-hole jacks are applied. This method allows for flexible handling of problems that may arise during tensioning, ensuring that each through-hole jack accurately applies tension to the component, ultimately meeting the design requirements for the total tension and ensuring the safety and stability of the structure.

[0069] When measuring the elongation of precision-rolled threaded steel bars, if the deviation between the actual elongation and the theoretical elongation is not within ±6%, tensioning should be suspended. The cause should be investigated, and appropriate measures should be taken to adjust the situation before construction resumes. This method allows for the timely detection of potential problems during construction, such as unsuitable performance of prestressed tendons, malfunction of tensioning equipment, or quality defects in components. By suspending construction and investigating the cause, further escalation of the problem can be prevented, ensuring the smooth progress of subsequent construction and the quality of the project.

[0070] The formula for calculating elongation is as follows:

[0071]

[0072] Where P is the applied preload (unit: N); L is the initial length of the reinforcing bar (unit: m); E is the modulus of elasticity (taken as 2 × 10⁻⁶). 5 MPa); A is the cross-sectional area of ​​the steel bar (unit: mm). 2 ).

[0073] Table 3 Theoretical Elongation of Fine-Rolled Threaded Steel Bars

[0074] Serial Number Component parts Total tension force of a single tension bar (kN) Theoretical elongation (mm) 1 roof 404 3.97 2 side walls 294 2.89 3 base plate 285 2.80

[0075] When measuring the circumferential gap of the components, it is determined whether the circumferential gap meets the requirement of 5-7mm. If the circumferential gap is greater than 7mm, the tension is further increased until the circumferential gap meets the requirement. At the same time, the maximum over-tension is controlled to not exceed 0.9 times the standard value of the yield strength of the prestressed tendon of the fine-rolled threaded steel, that is, the tension must not exceed 837KN. In this way, the width of the circumferential gap of the components can be precisely controlled, ensuring that the connection between the components is tight and reliable. An appropriate circumferential gap width can ensure that the components have a certain adjustment space during tensioning, and can also ensure that the integrity of the structure and its waterproof performance will not be affected by the excessively large circumferential gap during subsequent use.

[0076] S7, Anchoring

[0077] After the tension and circumferential joint tests are passed, anchoring work is carried out. Tighten the nuts to ensure that the anchoring is firm and reliable, effectively fixing the position of the precision-rolled threaded steel bar. This prevents the precision-rolled threaded steel bar from moving due to various factors (such as vibration, external forces, etc.) during subsequent construction or component use, thereby avoiding prestress loss caused by positional changes, ensuring that the component maintains the prestress state required by the design for a long time, and maintaining the stability and load-bearing capacity of the structure.

[0078] S8. Quality Inspection and Acceptance

[0079] In accordance with the quality inspection and acceptance standards, a comprehensive inspection of the construction process and component quality is conducted. Only after passing the inspection can the next process begin. The quality inspection and acceptance standards include the "Code for Acceptance of Construction Quality of Concrete Structures" (GB50204-2015) and related specifications, ensuring that the entire prestressed construction project of the prefabricated subway station components meets national and industry quality standards.

[0080] During inspection, the quality certification documents of the prestressed materials, the calibration records of the tensioning equipment, and various data records during the tensioning process are checked. Specifically, checking the quality certification documents of the prestressed materials confirms that the prestressed materials used, such as the precision-rolled threaded steel bars, meet the design requirements and relevant standards and specifications; checking the calibration records of the tensioning equipment ensures that the tensioning equipment, such as the mandrel jacks and pressure gauges, is within its calibration period and has passed calibration, and that the equipment is operating normally; checking the various data records during the tensioning process provides detailed data support for assessing construction quality. In addition, a visual inspection of the prestressed components is conducted to ensure there are no cracks, deformations, or other defects, guaranteeing the overall quality of the components.

[0081] This embodiment of the prestressed construction method for prefabricated subway station components achieves efficient and precise tensioning of components by optimizing the construction process, accurately controlling tensioning parameters, and rationally translating components. This ensures close connection between each process, improving project quality and construction efficiency. By rationally arranging the sequence of prestressing engineering and component assembly, each process is carried out in an orderly manner, avoiding delays in prestressing construction that could affect the overall construction period. A stress-strain dual-control method is adopted, with stress control as the primary method and the elongation of the precision-rolled threaded steel as a check, ensuring that the tension force meets design requirements while guaranteeing that the circumferential joint width of the components meets standards. During component translation, synchronous jacking and real-time correction prevent component twisting and deformation, ensuring accurate positioning. Strict quality inspection and acceptance are conducted according to specifications to ensure that the prestressing materials are of qualified quality, the tensioning equipment operates normally, and the components are free of defects, thus improving the overall project quality.

[0082] In this embodiment, staged tensioning is a key technical means to ensure the quality and safety of the project, and its purpose is mainly reflected in the following aspects:

[0083] (1) Ensure uniform prestress transmission: If tensioning is performed all at once, the huge tension force may cause stress concentration in some areas, resulting in uneven distribution of prestress in the concrete member. However, by using staged tensioning, the prestress can be applied to the concrete evenly, effectively avoiding stress concentration and ensuring that the prestress is evenly transmitted throughout the member, making the structure more rationally stressed and improving the stability and load-bearing capacity of the structure.

[0084] (2) Reduce prestress loss: Prestress loss is an important factor affecting the performance of prestressed members. In the staged tensioning process, there is a certain holding time after each stage of tensioning, which helps to better coordinate the deformation between the prestressing tendons and concrete, reduce the prestress loss caused by factors such as elastic compression of concrete and relaxation of prestressing tendons, and ensure the safety and durability of the structure.

[0085] (3) Facilitates observation and control: During the tensioning of precast components, staged tensioning provides construction personnel with multiple opportunities for observation and adjustment. During each stage of tensioning, personnel can closely observe the elongation of the prestressing tendons, the deformation of the components, and the operating status of the tensioning equipment. If any abnormalities are detected, such as unintended elongation or cracks appearing in the components, tensioning can be stopped promptly, the cause analyzed, and appropriate adjustments taken. This effectively avoids quality accidents caused by uncontrolled tensioning, ensuring construction quality.

[0086] In one embodiment, before assembling the precast components, waterproof materials such as EPDM sealing gaskets and EPDM sponge rubber are pre-installed. After installation, the components are left to stand for at least one hour to allow sufficient time for the waterproof materials to adapt to the installation environment, such as temperature and humidity, before assembling and tensioning the precast components. During tensioning, to avoid excessive local stress in the components and damage to the waterproof materials, a 4-5mm thick steel gasket is inserted into the area of ​​the precast component with the highest stress (i.e., the corresponding tensioning hole position) when 1cm remains in the component's circumferential joint, preventing excessive compression of the waterproof materials. After tensioning, before anchoring the precast components, water-swellable rubber rings are installed in their tensioning holes. These water-swellable rubber rings have unique water-swellable properties. When a small amount of water seeps in, the rubber ring expands rapidly, blocking any potential seepage channels and forming a reliable waterproof barrier, further enhancing the waterproof effect of the precast components.

[0087] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0088] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0089] The present invention has been described above with reference to the accompanying drawings. Obviously, the implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A prestressed construction method for prefabricated subway station components, characterized in that, Includes the following steps: Installation of precision-rolled threaded steel bars: After the prefabricated components are assembled in place, install the precision-rolled threaded steel bars according to the positions and quantities required by the design. Tensioning equipment installation and commissioning: According to the tensioning process requirements, install the core jack and pump station in place, and test and check the operation of the core jack and pump station oil pump; Component translation: For the base plate component that is restricted by the support, multiple precision-rolled threaded steel bars are used in conjunction with multiple through-hole jacks to push the base plate component until all the positioning pins of the base plate circumferential joint are aligned and the circumferential joint gap is 3cm. Prestressing tensioning: According to the design tension force, different precast components are tensioned using corresponding tension forces, and the tension force is applied in multiple stages during tensioning. Tension and circumferential gap inspection: During the tensioning process, the pressure gauge is used to control the tension. Loading is stopped after the tension reaches the required tension. The elongation of the fine-rolled threaded steel and the circumferential gap of the component are measured. Anchoring: After the tension and circumferential joint tests are passed, the anchoring operation is carried out.

2. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, Before the installation of the precision-rolled threaded steel bar, the following steps are also included: Construction preparation: During the assembly of precast components, prepare precision-rolled threaded steel bars according to the positions and quantities required by the design, and check the appearance quality of the precision-rolled threaded steel bars; at the same time, calibrate and use the through-hole jacks and pressure gauges.

3. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, In the installation step of the precision-rolled threaded steel bar, the precision-rolled threaded steel bar is inserted into the reserved tensioning hole of the precast component, so that the precision-rolled threaded steel bar is connected to the pre-tightened screw sleeve in the reserved tensioning hole, and the insertion depth reaches the design requirement of 180mm.

4. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, The component translation step specifically includes the following sub-steps: One end of each of the three precision rolled threaded steel bars is inserted into the three reserved tensioning holes at the bottom and on both sides of the base plate component and connected to the pre-tightening screw sleeves in the holes. The other end is fitted with three through-hole jacks and anchor plates and nuts. The bottom plate component is pushed synchronously by three through jacks, and the center offset of the bottom plate component is corrected. After the through jacks have completed their stroke, they are reset and the anchor plate and nut are moved forward and fixed. The bottom plate component is pushed again until all the positioning pins of the bottom plate component's circumferential joint are aligned and the circumferential joint gap is 3cm.

5. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, The prestressing tensioning step specifically includes the following sub-steps: Start the oil pump slowly to load the through-hole jack evenly, and observe the pressure gauge reading and the condition of the circumferential joint of the precast component; During tensioning, the tension force is applied in three stages, with the initial tension force being 10-20% of the tensioning control force; After reaching the initial tension, hold the load for 2 minutes and observe whether each tensioning hole is evenly stressed. Load the tensioning force at a uniform rate to 50%, hold the load for 2 minutes, and observe the deformation of the precast components, the elongation of the fine-rolled threaded steel bars, and the operation of the through-hole jack. If any abnormality is found, stop the tensioning immediately. If there are no abnormalities, continue to apply the load evenly until the tension control force is reached, and hold the load for 2 minutes after reaching the tension control force.

6. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, In the tension and circumferential joint detection steps, if the tension of multiple through-hole jacks simultaneously cannot meet the total tension requirement, the through-hole jacks can be tensioned separately in batches. After the tension of the through-hole jacks in the same batch is loaded to the control value, they are anchored, and then the remaining through-hole jacks are loaded.

7. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, In the tension and circumferential joint detection steps, when measuring the elongation of the precision rolled threaded steel, if the deviation between the actual elongation and the theoretical elongation is not within ±6%, tensioning should be suspended, the cause investigated, and appropriate measures taken to adjust before construction continues.

8. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, In the tension and circumferential gap detection steps, when measuring the circumferential gap of the component, it is determined whether the circumferential gap of the component meets the requirement of 5-7mm. If the circumferential gap of the component is greater than 7mm, the tension is further increased until the circumferential gap of the component meets the requirement.

9. The prestressed construction method for prefabricated subway station components according to claim 8, characterized in that, The maximum over-tension force shall not exceed 0.9 times the standard value of the yield strength of the prestressed tendon of the fine-rolled threaded steel.

10. The prestressed construction method for prefabricated subway station components according to claim 1, characterized in that, Following the anchoring step, the following step is also included: Quality inspection and acceptance: In accordance with the quality inspection and acceptance standards, a comprehensive inspection of the construction process and component quality is carried out. After the inspection is passed, the next process begins.

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