Special-shaped steel reinforced concrete beam mold for fabricated subway station and construction method

Abstract

The invention discloses a special-shaped steel reinforced concrete beam mold for an assembly type subway station and a construction method. The special-shaped steel reinforced concrete beam mold comprises a modular curved surface combination mechanism, a steel bar positioning guiding and preformed hole integration structure, a vacuum auxiliary vibration compacting system and a mold rigidity self-adaptive adjusting device. The modular curved surface combination mechanism is used for achieving accurate forming and efficient disassembly and assembly of special-shaped curved surfaces with different curvatures, the steel bar positioning and guiding and preformed hole integration structure is used for achieving accurate positioning of steel bars in multiple directions and leakage prevention of preformed holes, and the vacuum auxiliary vibration compacting system is used for improving the concrete pouring compactness. The mold rigidity self-adaptive adjusting device is used for dynamically compensating deformation in the mold pouring process, and the geometric dimension precision of a component is guaranteed. According to the device, deformation of the mold is controlled through strain monitoring and dynamic compensation of the hydraulic supporting rod, the process of step-by-step pouring, gradient vibration and dynamic maintenance is adopted, high-precision, high-efficiency and high-quality production of components is achieved, the mold reuse rate is high, and the construction requirements of the fabricated subway station are met.

Description

Technical Field

[0001] This invention relates to the technical field of prefabricated subway station construction technology, specifically to a mold for irregularly shaped steel-concrete beams used in prefabricated subway stations and a construction method thereof. Background Technology

[0002] In the construction of prefabricated subway stations, irregularly shaped steel-concrete composite beams are widely used in key areas such as station nodes and transfer passages because they combine the high strength of steel with the high rigidity of concrete, enabling them to adapt to complex spatial stress requirements. However, these components are characterized by complex multi-curved shapes, dense reinforcement with diverse extension directions, high requirements for concrete compaction, and susceptibility to mold deformation under stress. Existing molds and construction technologies have significant shortcomings, severely restricting project quality and efficiency. (1) The curved surface forming is difficult and the adaptability is poor: Traditional molds are mostly integral welded rigid structures. For the multi-curved surface shape of irregular beams, customized processing is required. A single mold can only adapt to a component with one curvature. When the surface parameters of the component change, it needs to be remade, and the mold reuse rate is low (less than 30%). Moreover, the installation and disassembly of the overall mold is cumbersome, and the surface forming accuracy is difficult to control (generally the deviation is ≥5mm), which cannot meet the high-precision assembly requirements of prefabricated components. (2) The quality of rebar positioning and reserved holes is difficult to control: There are multiple directions of rebar extension requirements in irregular steel-concrete beams. Traditional molds rely on manual marking for positioning, and the deviation of the rebar extension position often exceeds ±8mm, which can easily lead to the rebar not being able to be connected during on-site assembly. At the same time, the reserved hole area lacks effective sealing measures, and leakage is likely to occur during concrete pouring, forming defects such as honeycomb and pitted surface, which need to be repaired later, increasing construction costs and construction period. (3) Insufficient concrete density: There are many blind spots in the vibration of complex curved surfaces. Traditional immersion vibrators cannot cover all areas, which can easily lead to air bubbles and voids in the concrete (the density is often less than 95%), affecting the load-bearing capacity of the components. Some construction uses high-frequency attached vibrators, which can improve the vibration effect, but can easily cause local resonance deformation of the mold, further reducing the molding quality. (4) Poor mold stiffness and stability: During the concrete pouring process, the mold is easily deformed by lateral pressure, vibration load and other effects. Traditional molds increase stiffness by increasing the thickness of steel plates, which not only increases the self-weight of the mold (more than 5t / set) and makes it inconvenient to handle, but also cannot dynamically adjust the stiffness according to the real-time load. The maximum deformation often exceeds 8mm, which exceeds the allowable range of the specification (≤5mm) and affects the geometric accuracy of the component. (5) The construction process is inefficient and the maintenance effect is poor: Traditional construction adopts the "one-time pouring + later static curing" mode. One-time pouring is prone to cause temperature stress concentration inside the beam, resulting in shrinkage cracks. Static curing relies on manual control of temperature and humidity, and the curing conditions are unstable. The early strength of the components increases slowly (the 7-day strength only reaches 60% of the design value). The overall construction cycle is long and it is difficult to meet the needs of rapid construction of prefabricated projects.

[0003] Therefore, there is an urgent need for a prefabricated irregular steel-concrete beam mold for subway stations and its construction method that can achieve precise multi-curved surface forming, efficient rebar positioning, improved concrete density, adaptive and stable mold stiffness, and optimized construction process. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a prefabricated steel-concrete beam mold and construction method for prefabricated subway stations.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a prefabricated irregular steel-concrete beam mold for subway stations, including a modular curved surface combination mechanism, a steel bar positioning guide and reserved hole integrated structure, a vacuum-assisted vibration compaction system and a mold stiffness adaptive adjustment device. The modular curved surface assembly mechanism is used to achieve precise forming and efficient assembly and disassembly of irregular curved surfaces with different curvatures. The integrated structure of rebar positioning guide and reserved hole is used to achieve precise positioning of rebar in multiple directions and to prevent leakage of reserved holes. The vacuum-assisted vibration compaction system is used to improve the compactness of concrete pouring. The mold stiffness adaptive adjustment device is used to dynamically compensate for the deformation of the mold during the pouring process and ensure the geometric accuracy of the components.

[0006] Furthermore, the modular curved surface assembly mechanism includes multiple independent modular curved surface units. Each modular curved surface unit includes an arc-shaped steel plate. The back of the arc-shaped steel plate is welded with an adjustable curvature reinforcing rib. Adjusting bolts are provided at both ends of the reinforcing rib. The curvature of the arc-shaped steel plate can be adjusted by adjusting the bolts to adapt to the requirements of irregular beams with different curvatures.

[0007] Furthermore, the splicing surfaces of each modular curved surface unit are machined with mortise and tenon structures, and rubber sealing gaskets are provided at the mortise and tenon joints. The modular curved surface unit is equipped with a quick-locking mechanism on both sides. The quick-locking mechanism can quickly lock or unlock a single modular curved surface unit. Multiple modular curved surface units are spliced ​​together with the quick-locking mechanism through a mortise and tenon structure to form a complete irregular curved surface.

[0008] Furthermore, the integrated structure of rebar positioning guide and reserved hole includes a slidable rebar positioning guide groove set on the inner wall of each modular curved surface unit. The bottom of the rebar positioning guide groove is connected to a linear slide rail, and a positioning bolt is set on the linear slide rail. The lateral position of the rebar positioning guide groove can be adjusted by the positioning bolt. An angle adjustment knob is provided on the side of the rebar positioning guide groove, which can be used to adjust the angle between the rebar positioning guide groove and the inner wall of the mold.

[0009] Furthermore, the end of the rebar positioning guide groove is integrally connected with a pre-drilled hole assembly, which includes a steel sleeve and a sealing ring. The sealing ring is fixed inside the steel sleeve by a pressure ring, and the sealing ring can fit tightly against the surface of the rebar passing through the steel sleeve to prevent leakage during concrete pouring.

[0010] Furthermore, the vacuum-assisted vibration compaction system includes a closed, enclosed vacuum chamber located outside the mold. The inner wall of the enclosed vacuum chamber is covered with a breathable membrane. The enclosed vacuum chamber is connected to a vacuum pump via a vacuum tube, which enables a negative pressure environment to be created at the contact surface between the mold and the concrete.

[0011] Furthermore, the vacuum-assisted vibration compaction system also includes a telescopic high-frequency vibrator. The telescopic high-frequency vibrator is arranged at intervals along the curvature direction of the modular curved surface unit. The telescopic high-frequency vibrator is connected to a hydraulic push rod, which can control the extension and retraction of the telescopic high-frequency vibrator to cover the blind area of ​​the curved surface. The telescopic high-frequency vibrator is linked to the vacuum pump through a controller. When the vacuum pump reaches the preset pressure, the telescopic high-frequency vibrator automatically starts. The vibration time is adaptively adjusted according to the concrete slump.

[0012] Furthermore, the mold stiffness adaptive adjustment device includes a strain monitoring unit and a hydraulic strut. The strain monitoring unit is installed at the stress-bearing parts of the mold frame, including the splicing points of the modular curved surface units and the mold support points. The strain monitoring unit is used to collect strain data during the mold casting process and convert it into deformation amount to be fed back to the control system. Hydraulic struts are set up one-to-one with strain monitoring units. The hydraulic struts are connected to the hydraulic station through reversing valves. The control system adjusts the supporting force of the hydraulic struts according to the deformation data to compensate for mold deformation.

[0013] This invention also provides a construction method for prefabricated subway station irregular-shaped steel-concrete beams, using the aforementioned molds for construction, including the following steps: S1: Mold Assembly and Debugging: Based on the curved surface design parameters of the irregular steel-concrete beam, adjust the curvature of the arc-shaped steel plates of each modular curved surface unit, complete the splicing through mortise and tenon structure and quick locking mechanism, and test the surface forming accuracy; adjust the position and angle of the rebar positioning guide groove according to the rebar layout parameters, test the sealing performance of the surrounding vacuum chamber and the extension and vibration functions of the retractable high-frequency vibrator; calibrate the strain monitoring unit and hydraulic strut adjustment unit, and set the mold deformation warning value and control value; S2: Reinforcing bar and steel section installation: Hoist the precast steel section beam onto the steel section support seat inside the mold, and fix the connection node between the steel section and the mold after positioning; tie the beam reinforcement, pass the reinforcement to be extended through the reinforcement positioning guide groove and the reserved hole assembly, and check the reinforcement spacing and extension deviation; S3: Step-by-step pouring and vacuum vibration: The first pouring prioritizes covering the curved transition area of ​​the beam. During the pouring process, the vacuum pump and the corresponding retractable high-frequency vibrator are activated. The upper structure of the beam is poured before the bottom concrete sets. During the pouring process, the vibration frequency of the retractable high-frequency vibrator is dynamically adjusted according to the concrete slump. After pouring to the design elevation, the beam surface is leveled and a vacuum state is maintained. S4: Dynamic temperature curing: Turn on the built-in circulating water heating pipe of the mold, monitor the circulating water temperature in real time through the temperature sensor, adjust the water temperature in stages according to the concrete strength growth curve, and regularly test the concrete surface strength during the curing period. S5: Mold Removal and Component Acceptance: After curing, close the mold stiffness adaptive adjustment device, unlock the quick locking mechanism, and remove the modular curved surface units in the reverse order of assembly. Test the surface forming accuracy, rebar extension position deviation, concrete density and surface quality of the components. After acceptance, transfer and store them.

[0014] Furthermore, the dynamic temperature curing in step S4 includes three stages: in the initial stage after pouring, the surface humidity of the concrete is kept within the preset high humidity range, and the water temperature is maintained within the normal temperature range; in the middle stage, the water temperature is increased to accelerate the strength growth of the concrete; in the later stage, the water temperature is gradually reduced to the ambient temperature, and the cooling rate is controlled during the cooling process; when the early strength of the concrete reaches the preset proportion of the design value, curing is stopped.

[0015] The present invention has the following beneficial effects: The present invention provides a prefabricated irregular-shaped steel-concrete beam mold for subway stations: (1) The modular curved surface combination mechanism is spliced ​​with an adjustable arc steel plate and a high-precision tenon and mortise joint to adapt to the needs of irregular beams with different curvatures, improve the mold reuse rate and the surface forming accuracy to meet the high-precision assembly requirements of prefabricated components. (2) The rebar positioning guide groove can realize multi-directional position and angle adjustment. Combined with the reserved hole assembly with sealing ring, it reduces the deviation of the rebar extension position and the concrete leakage rate, and solves the problems of difficult rebar positioning and leakage of reserved holes in traditional molds. (3) The vacuum-assisted vibration compaction system accelerates the expulsion of air bubbles through a negative pressure environment, and, together with the extendable high-frequency vibrator, covers the blind area of ​​the curved surface, thereby improving the density of concrete and effectively enhancing the load-bearing capacity and durability of the components. (4) The stiffness adaptive adjustment device uses strain monitoring and hydraulic strut dynamic compensation to ensure that the maximum deformation of the mold is ≤3mm, avoiding the component size deviation caused by insufficient stiffness of traditional molds, and at the same time, it does not require excessive increase in steel plate thickness, thus reducing the self-weight of the mold. (5) The integrated method of step-by-step pouring and dynamic curing reduces concrete shrinkage cracks, increases the early strength of components by 20%, and shortens the overall construction cycle by 15%, taking into account both efficiency and quality, and meeting the needs of rapid construction of prefabricated projects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the front view of the present invention; Figure 3 This is a side view of the present invention; Figure 4 This is a schematic diagram of the integrated structure of rebar positioning guide and reserved hole in this invention; Figure 5 This is a schematic diagram of the vacuum-assisted vibration compaction system in this invention; Figure 6 This is a schematic diagram of the modular curved surface combination mechanism in this invention; Figures 1 to 6 The reference numerals in the attached figures represent: 1-modular curved surface combination mechanism, 2-integrated structure of rebar positioning guide and reserved hole, 3-vacuum-assisted vibration compaction system, 4-mold stiffness adaptive adjustment device, 10-modular curved surface unit, 11-reinforcing rib, 12-mortise and tenon structure, 13-quick locking mechanism, 20-rebar positioning guide groove, 23-reserved hole assembly, 231-sealing ring, 30-surround vacuum chamber, 31-extendable high-frequency vibrator, 32-hydraulic push rod, 40-strain monitoring unit, 41-hydraulic support rod. Detailed Implementation

[0017] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] like Figures 1 to 6As shown, a prefabricated steel-concrete beam mold for subway stations includes a modular curved surface combination mechanism 1, a steel bar positioning and guiding integrated structure with reserved holes 2, a vacuum-assisted vibration compaction system 3, and a mold stiffness adaptive adjustment device 4. Modular curved surface assembly mechanism 1 is used to achieve precise forming and efficient assembly and disassembly of irregular curved surfaces with different curvatures; Rebar positioning guide and pre-reserved hole integrated structure 2 is used to achieve precise positioning of multi-directional rebars and prevent leakage of pre-reserved holes; Vacuum-assisted vibration compaction system 3 is used to improve the compactness of concrete pouring; Mold stiffness adaptive adjustment device 4 is used to dynamically compensate for deformation during mold pouring and ensure the geometric accuracy of components.

[0019] Specifically, the modular curved surface assembly mechanism 1 includes multiple independent modular curved surface units 10. Each modular curved surface unit 10 includes an arc-shaped steel plate. The back of the arc-shaped steel plate is welded with an adjustable curvature reinforcing rib 11. Adjusting bolts are provided at both ends of the reinforcing rib 11. The curvature of the arc-shaped steel plate can be adjusted by adjusting the bolts to adapt to the requirements of irregular beams with different curvatures. The independent modular curved surface unit 10 serves as the basic disassembly unit of the mold, breaking the structural limitations of traditional integral molds and achieving the purpose of block adjustment and overall splicing. Each modular curved surface unit 10 can be independently adjusted, maintained, or replaced, without having to remake the entire mold due to changes in a single curved surface parameter, greatly improving the mold reusability. After disassembly, it is smaller in size and lighter in weight, making it easier to transport, install, and disassemble, solving the problems of cumbersome disassembly and assembly and low efficiency of traditional integral molds. Multiple units can be spliced ​​to form a complete irregular curved surface. The number of units can be flexibly increased or decreased according to the surface complexity of the irregular beam (such as multiple segments with different curvature combinations) to adapt to diverse component requirements. The curved steel plate is in direct contact with the concrete, providing a smooth and regular forming reference to ensure the appearance quality and geometric accuracy of the component's curved surface; as a load-bearing carrier, it bears the lateral pressure and vibration load during concrete pouring; and it is welded and fixed with the reinforcing rib 11 to form a stable structure of panel + frame, providing a reliable basic carrier for curvature adjustment. The adjustable curvature reinforcing rib 11 is welded to the back of the curved steel plate to form a longitudinal or transverse support frame, which offsets the lateral pressure of concrete and the stress generated by vibration, prevents the curved steel plate from undergoing unexpected deformation during use, and ensures the forming accuracy. It has deformable characteristics and can change its curvature by adjusting the driving force of the bolts, thereby driving the curved steel plate fixed to it to deform synchronously, so as to achieve curvature adjustment. Furthermore, it ensures that the force of the adjusting bolts is evenly distributed to the entire curved steel plate, preventing excessive local stress that could damage the steel plate or cause uneven curvature adjustment. The adjusting bolt changes its own extension and contraction by rotating, which generates tension or pressure on both ends of the reinforcing rib 11, forcing the reinforcing rib 11 to change its curvature. By utilizing the precision of the threaded transmission, the curvature can be finely adjusted and locked, ensuring that the curvature of the arc-shaped steel plate remains stable after reaching the design requirements, and avoiding curvature deviation during the casting process.

[0020] In this invention, each modular curved surface unit 10 has a mortise and tenon structure 12 on its splicing surface. The mortise and tenon structure 12 is a structure of tenon and mortise. Through the interlocking of the tenon and mortise, a natural positioning reference is formed, which ensures that adjacent modular curved surface units 10 can be quickly aligned when spliced, avoids lateral or longitudinal offset, and ensures the continuity and flatness of the overall curved surface after splicing. Furthermore, the mortise and tenon structure 12 has a large contact surface and uniform force distribution, which can effectively transfer the lateral pressure and vibration load generated during concrete pouring, and distribute the force of a single unit to the overall mold frame, avoiding deformation or loosening at the splice due to force concentration; in addition, the interlocking structure makes the connection between units tight, and the initial fixation can be achieved without additional positioning parts, providing a stable foundation for the subsequent locking operation of the quick locking mechanism 13, and preventing relative displacement of the units after splicing; A rubber sealing gasket is installed at the mortise and tenon joint. The rubber material has good elasticity and conformability. When compressed, it can fill the tiny gaps in the mortise and tenon joint surface to form a sealed barrier, preventing the grout from leaking from the joint during the concrete pouring process. This prevents defects such as honeycomb and pitting from appearing on the surface of the component, ensuring the quality of concrete pouring. In addition, during vibration, the rubber sealing gasket can absorb some vibration energy, reducing the collision or wear caused by resonance between adjacent units, and reducing the impact of vibration on the positioning accuracy of the joint. The modular curved surface unit 10 is equipped with quick-locking mechanisms 13 on both sides. These mechanisms enable the rapid locking or unlocking of a single modular curved surface unit 10. Multiple modular curved surface units 10 are joined with the quick-locking mechanisms 13 via tenon and mortise structures 12 to form a complete irregular curved surface. The quick-locking mechanism 13 preferably adopts a cam-type quick-locking structure, allowing for locking through simple operations (such as manual operation or pneumatic drive), eliminating the need for complex tools or cumbersome procedures. This significantly shortens mold assembly time, solves the problem of low efficiency in traditional bolted connections, and provides sufficient locking force to firmly fix adjacent modular curved surface units 10, forming a rigid, integrated mold structure that resists concrete lateral pressure and vibration loads, preventing loosening at the joints. During the operation, based on the curved surface design of the target irregular beam, the modular curved surface units 10 with adjusted curvature are first transferred to the assembly station. The tenon and mortise structure 12 of each unit splicing surface are used for docking. The tenon of one unit is inserted into the mortise of the adjacent unit. Automatic positioning is achieved through the concave and convex fit of the tenon and mortise structure 12, ensuring that the forming surfaces of adjacent units are flush and continuous, avoiding problems such as misalignment or excessive gaps. After the tenon and mortise docking is completed, the rubber sealing gasket at the tenon and mortise joint is squeezed by the adjacent unit. After elastic deformation, it fills the tiny gaps of the splicing surface, forming a sealed structure and completing the preparation for leakage protection. By driving the moving parts of the locking mechanism (such as cams, buckles, eccentric wheels, etc.), a continuous clamping force is applied to the adjacent units, so that the mating surfaces of the tenon and mortise structure 12 fit tightly together. At the same time, the rubber sealing gasket is compressed to further improve the sealing effect. After locking, each modular curved surface unit 10 forms an integral rigid mold through the positioning of the tenon and mortise structure 12 and the locking of the quick locking mechanism 13. The molded surface after splicing is continuous and flat, and has sufficient rigidity to resist the external forces during the pouring and vibration process. After the concrete is poured and cured to the specified strength, the mold is disassembled. First, the quick locking mechanism 13 is operated to release its clamping force on the adjacent units, so that each modular curved surface unit 10 returns to its independent state. Since the mortise and tenon structure 12 only provides positioning and force transmission, there is no risk of self-locking and jamming. After unlocking, each unit can be easily separated along the mortise and tenon mating direction, avoiding damage to the components or molds during disassembly. After disassembly, each modular curved surface unit 10 can be cleaned of residual concrete, and after readjusting the curvature, it can be used for the production of the next batch of irregular beams with different curvatures, realizing mold reuse.

[0021] In this invention, the integrated structure 2 for rebar positioning and pre-drilled holes includes a slidable rebar positioning guide groove 20 disposed on the inner wall of each modular curved surface unit 10. The rebar positioning guide groove 20 serves as a channel for rebar installation. The groove contour is adapted to the shape of the rebar, guiding the rebar to extend out of the mold in a preset direction, avoiding offset and bending during rebar installation, and ensuring the straightness of the rebar. It can also directly bear the radial pressure of the rebar, and restrict the lateral and longitudinal movement of the rebar through the groove wall, providing a stable installation reference surface for the rebar, replacing the crude method of traditional manual marking and positioning. The bottom of the rebar positioning guide groove 20 is connected to a linear slide rail. The linear slide rail provides a smooth and high-precision lateral movement track for the rebar positioning guide groove 20, ensuring that the guide groove moves in a straight line during the adjustment process, avoiding deviation or jamming, and ensuring the accuracy of lateral adjustment. At the same time, it can withstand the weight of the rebar positioning guide groove 20 and the rebar, as well as the external forces during construction, so that the rebar positioning guide groove 20 remains stable after adjustment and does not experience unexpected displacement, providing a reliable foundation for subsequent locking of positioning bolts. The linear slide rail is equipped with positioning bolts, which can be used to adjust the lateral position of the rebar positioning guide groove 20 to meet the high precision requirements of rebar positioning in prefabricated components. After the lateral position of the rebar positioning guide groove 20 is adjusted to the design value, the positioning bolts are tightened. The position of the rebar positioning guide groove 20 is locked by the clamping force between the positioning bolts and the linear slide rail, preventing the rebar positioning guide groove 20 from shifting during concrete pouring and vibration, and ensuring the continuous and stable positioning accuracy of the rebar. The side of the rebar positioning guide groove 20 is equipped with an angle adjustment knob. The angle adjustment knob can be used to adjust the angle between the rebar positioning guide groove 20 and the inner wall of the mold. By rotating the adjustment knob, the rebar positioning guide groove 20 is driven to rotate around the hinge point, so as to flexibly adjust the angle between the rebar positioning guide groove 20 and the inner wall of the mold. This meets the design requirements of different angles of rebar extension in irregular steel-concrete beams (such as oblique extension, vertical extension, horizontal extension, etc.). In addition, the knob has a built-in locking structure (such as threaded self-locking, pawl positioning, etc.). After adjustment to the target angle, it automatically locks to avoid angle deviation during construction, ensure that the rebar extension angle is consistent with the design, and ensure the rebar connection accuracy during component assembly.

[0022] Furthermore, the end of the rebar positioning guide groove 20 is integrally connected to a pre-drilled hole assembly 23. The pre-drilled hole assembly 23 includes a steel sleeve and a sealing ring 231. The sealing ring 231 is fixed to the inside of the steel sleeve by a pressure ring. The sealing ring 231 can fit tightly against the surface of the rebar passing through the steel sleeve to prevent leakage during concrete pouring. This provides a dual guarantee of precise guide and sealing protection for the protruding rebars of irregular steel-concrete beams. It ensures that the rebars protrude from the mold at the designed position and angle, and completely blocks the path of grout leakage from the pre-drilled hole gaps during concrete pouring, avoiding defects such as honeycomb and pitting on the surface of the component. At the same time, it simplifies structural design, improves construction reliability, and balances positioning accuracy and pouring quality.

[0023] In this invention, the vacuum-assisted vibration compaction system 3 includes a closed, enclosed vacuum chamber 30, which is located outside the mold. The enclosed vacuum chamber 30 is welded from steel plates, and a breathable membrane is attached to the inner wall of the enclosed vacuum chamber 30. The enclosed vacuum chamber 30 is connected to a vacuum pump via a vacuum tube, which creates a negative pressure environment at the contact surface between the mold and the concrete. By drawing a vacuum with the vacuum pump, a stable negative pressure is created at the contact surface between the mold and the concrete. The pressure difference drives air bubbles inside the concrete to migrate rapidly to the surface and burst. At the same time, it assists the flow of concrete slurry to fill the gaps in the curved surface, laying the foundation for the efficient operation of the subsequent vibration system. Ultimately, this significantly improves the density of the concrete, avoids the decrease in the load-bearing capacity of the component due to air bubbles and voids, and ensures the internal quality and durability of the irregular steel-concrete beam. Specifically, the enclosed surrounding vacuum chamber 30, as a closed space for forming a negative pressure environment, is made of welded steel plates and has good sealing performance and structural rigidity. It can withstand the internal and external pressure difference generated by the vacuum pump, avoid deformation or leakage of the chamber, and ensure a stable and long-lasting negative pressure environment. It is arranged around the outside of the mold, so that the negative pressure covers all curved areas of the mold (including curved transition parts and corners that are difficult to reach by traditional vibration), achieves uniform distribution of negative pressure, and avoids the residual air bubbles caused by insufficient local negative pressure. The breathable membrane allows air and water vapor inside the concrete to enter the vacuum chamber through the membrane, providing a channel for air bubbles to escape. The microporous structure of the breathable membrane can accelerate gas flow and improve exhaust efficiency. The pore size of the breathable membrane is smaller than the particle size of concrete aggregate and cement paste, which can effectively prevent concrete paste from penetrating into the vacuum chamber, avoiding paste blockage of vacuum tubes or damage to vacuum pumps. At the same time, it can prevent paste leakage at the mold joint due to excessive negative pressure. The vacuum tube serves as the connection channel between the vacuum pump and the surrounding vacuum chamber 30, accurately transmitting the negative pressure generated by the vacuum pump to the inside of the vacuum chamber, ensuring that the pressure inside the chamber drops rapidly to the preset value; and it can be equipped with multiple sets of vacuum tube interfaces according to the surrounding length of the vacuum chamber, so that the negative pressure is evenly distributed in all areas of the vacuum chamber, avoiding local negative pressure lag or pressure unevenness, and ensuring the overall exhaust effect.

[0024] In addition, the vacuum-assisted vibration compaction system 3 also includes a telescopic high-frequency vibrator 31. The telescopic high-frequency vibrator 31 is arranged at intervals along the curvature direction of the modular curved surface unit 10. The telescopic high-frequency vibrator 31 is connected to a hydraulic push rod 32. The hydraulic push rod 32 can control the telescopic high-frequency vibrator 31 to extend and retract to cover the blind area of ​​the curved surface. The telescopic high-frequency vibrator 31 is linked with the vacuum pump through a controller. When the vacuum pump reaches the preset pressure, the telescopic high-frequency vibrator 31 automatically starts. The vibration time is adaptively adjusted according to the concrete slump. Through the flexible arrangement and precise extension and retraction of the telescopic high-frequency vibrator 31, the vibration range is covered without dead angles. Furthermore, through the linkage control with the vacuum pump and the adaptive adjustment based on the concrete slump, the vibration intensity, time and negative pressure exhaust are precisely matched to maximize the concrete density, avoid internal defects such as residual air bubbles and voids, and ensure the mechanical properties and durability of the component. Specifically, the extendable high-frequency vibrator 31 transmits high-frequency vibration to the concrete slurry, disrupting the stability of air bubbles inside the slurry, causing tiny air bubbles to coalesce into larger air bubbles, while liquefying the cohesive force between slurry particles, promoting slurry flow and filling gaps, creating conditions for air bubbles to escape; and it can extend and retract along the axial direction, and with the drive of the hydraulic push rod 32, it can penetrate into curved blind areas that traditional fixed vibrators cannot reach, achieving precise vibration and avoiding air bubble residue in blind areas; The hydraulic push rod 32 provides stable and controllable telescopic power, controls the telescopic stroke and telescopic speed of the telescopic high-frequency vibrator 31, and ensures that the vibrator can accurately reach the preset vibration position without interfering with the reinforcing bars, structural steel and other components. The controller is used to establish the linkage logic between the extendable high-frequency vibrator 31 and the vacuum pump, and to set a preset negative pressure threshold. When the vacuum pump makes the vacuum chamber reach the threshold, the vibrator is automatically started to ensure that the negative pressure exhaust and high-frequency vibration are carried out synchronously, forming a synergistic effect. The vibrator destroys the bubble structure, and the negative pressure environment accelerates the expulsion of bubbles, greatly improving the exhaust efficiency. In addition, the controller can receive concrete slump detection data and automatically match the corresponding vibration time (e.g., when the slump is small, the slurry fluidity is poor, so the vibration time is extended; when the slump is large, the slurry fluidity is good, so the vibration time is shortened) to avoid over-vibration causing aggregate segregation or under-vibration causing insufficient compaction. Furthermore, the controller can uniformly control the start / stop, frequency, and extension / retraction stroke of multiple vibrators, achieving standardization and intelligentization of the vibration process, reducing human operation errors, and improving construction reliability.

[0025] In this invention, the mold stiffness adaptive adjustment device 4 includes a strain monitoring unit and a hydraulic strut 41. The strain monitoring unit is installed at the stress-bearing parts of the mold frame, including the splicing points of the modular curved surface units 10 and the mold support points. The strain monitoring unit is used to collect strain data during the mold casting process and convert it into deformation data, which is then fed back to the control system. The control system receives the deformation data from the strain monitoring unit, compares and analyzes it with the preset control value, calculates the required compensation of the support force and the adjustment direction, and sends precise control commands to the reversing valve. Furthermore, it can receive the support force feedback data from the hydraulic strut 41 and the latest deformation data from the strain monitoring unit in real time, forming a closed-loop control of monitoring-decision-execution-feedback, continuously correcting the support force parameters, and ensuring that the deformation is always controlled within the allowable range. Hydraulic struts 41 are set up one-to-one with strain monitoring units. They can precisely adjust their own support force through changes in hydraulic pressure, apply reverse support force to the deformed parts of the mold, directly offset the deformation trend, and achieve compensation wherever deformation occurs. Hydraulic struts 41 are connected to the hydraulic station through a reversing valve. The control system adjusts the support force of hydraulic struts 41 according to the deformation data to compensate for mold deformation.

[0026] The mold stiffness adaptive adjustment device 4 provides the mold with real-time sensing, dynamic response and precise compensation stiffness adaptive adjustment capability. The strain monitoring unit captures the mold stress deformation data in real time, and the control system drives the hydraulic strut 41 to dynamically adjust the support force, actively offset the deformation caused by the pouring side pressure, vibration load, etc., and control the maximum deformation of the mold within the allowable range (such as ≤3mm). This avoids the component size deviation caused by mold deformation and does not require excessive thickening of steel plates, achieving the dual goals of lightweight mold and high-precision molding.

[0027] This invention also provides a construction method for prefabricated subway station irregular-shaped steel-concrete beams, using the aforementioned molds for construction, including the following steps: S1: Mold Assembly and Debugging: Based on the curved surface design parameters of the irregular steel-concrete beam, adjust the curvature of the arc-shaped steel plate of each modular curved surface unit 10, and complete the splicing through the tenon and mortise structure 12 and the quick locking mechanism 13, and test the surface forming accuracy; adjust the position and angle of the rebar positioning guide groove 20 according to the rebar layout parameters, test the sealing performance of the surrounding vacuum chamber 30 and the extension and vibration functions of the retractable high-frequency vibrator 31; calibrate the strain monitoring unit and the hydraulic strut 41 adjustment unit, and set the mold deformation warning value and control value; S2: Reinforcing bar and steel section installation: Hoist the precast steel section beam onto the steel section support seat inside the mold, and fix the connection node between the steel section and the mold after positioning; tie the beam reinforcement, pass the reinforcement to be extended through the reinforcement positioning guide groove 20 and the reserved hole assembly 23, and check the reinforcement spacing and extension deviation; S3: Step-by-step pouring and vacuum vibration: The first pouring prioritizes covering the curved transition area of ​​the beam. During the pouring process, the vacuum pump and the corresponding retractable high-frequency vibrator 31 are activated. The upper structure of the beam is poured before the bottom concrete sets. During the pouring process, the vibration frequency of the retractable high-frequency vibrator 31 is dynamically adjusted according to the concrete slump. After pouring to the design elevation, the beam surface is leveled and a vacuum state is maintained. S4: Dynamic temperature curing: Turn on the built-in circulating water heating pipe of the mold, monitor the circulating water temperature in real time through the temperature sensor, adjust the water temperature in stages according to the concrete strength growth curve, and regularly test the concrete surface strength during the curing period. The dynamic temperature curing process includes three stages: in the initial stage after pouring, the surface humidity of the concrete is kept within the preset high humidity range, and the water temperature is maintained within the normal temperature range; in the middle stage, the water temperature is increased to accelerate the strength growth of the concrete; in the later stage, the water temperature is gradually reduced to the ambient temperature, and the cooling rate is controlled during the cooling process; when the early strength of the concrete reaches the preset proportion of the design value, curing is stopped. S5: Mold Removal and Component Acceptance: After curing, close the mold stiffness adaptive adjustment device 4, unlock the quick locking mechanism 13, remove the modular curved surface unit 10 in the reverse order of assembly, and test the surface forming accuracy, rebar extension position deviation, concrete density and surface quality of the component. After acceptance, transfer and store it.

[0028] Additionally, it should be noted that components not described in detail in this article are existing technologies.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A prefabricated steel-concrete beam mold for subway stations, characterized in that, It includes a modular curved surface combination mechanism (1), a steel bar positioning and guiding integrated structure with reserved holes (2), a vacuum-assisted vibration compaction system (3), and a mold stiffness adaptive adjustment device (4). The modular curved surface combination mechanism (1) is used to realize the forming and disassembly of irregular curved surfaces with different curvatures. The integrated structure of reinforcing bar positioning guide and reserved hole (2) is used to realize the positioning of multi-directional reinforcing bars and the leakage prevention of reserved holes. The vacuum-assisted vibration compaction system (3) is used to improve the compactness of concrete pouring. The mold stiffness adaptive adjustment device (4) is used to dynamically compensate for the deformation during the mold pouring process and ensure the geometric dimension accuracy of the component.

2. The prefabricated steel-concrete beam mold for prefabricated subway stations according to claim 1, characterized in that, The modular curved surface assembly mechanism (1) includes multiple independent modular curved surface units (10). Each modular curved surface unit (10) includes an arc-shaped steel plate. The back of the arc-shaped steel plate is welded with an adjustable curvature reinforcing rib (11). The two ends of the reinforcing rib (11) are provided with adjusting bolts. The curvature of the arc-shaped steel plate can be adjusted by the adjusting bolts to adapt to the requirements of irregular beams with different curvatures.

3. The prefabricated steel-concrete beam mold for subway stations according to claim 1, characterized in that, Each of the modular curved surface units (10) has a tenon and mortise structure (12) on its splicing surface, and a rubber sealing gasket is provided at the tenon and mortise joint. The modular curved surface unit (10) is equipped with a quick locking mechanism (13) on both sides. The quick locking mechanism (13) can quickly lock or unlock a single modular curved surface unit (10). Multiple modular curved surface units (10) are spliced ​​together with the quick locking mechanism (13) through the tenon and mortise structure (12) to form a complete irregular curved surface.

4. The prefabricated steel-concrete beam mold for subway stations according to any one of claims 1 to 3, characterized in that, The integrated structure (2) for reinforcing bar positioning guide and reserved hole includes a slidable reinforcing bar positioning guide groove (20) set on the inner wall of each modular curved surface unit (10). The bottom of the reinforcing bar positioning guide groove (20) is connected to a linear slide rail, and a positioning bolt is set on the linear slide rail. The lateral position of the reinforcing bar positioning guide groove (20) can be adjusted by the positioning bolt. An angle adjustment knob is provided on the side of the rebar positioning guide groove (20), and the angle between the rebar positioning guide groove (20) and the inner wall of the mold can be adjusted by the angle adjustment knob.

5. The prefabricated steel-concrete beam mold for prefabricated subway stations according to claim 4, characterized in that, The end of the rebar positioning guide groove (20) is integrally connected to a pre-drilled hole assembly (23). The pre-drilled hole assembly (23) includes a steel sleeve and a sealing ring (231). The sealing ring (231) is fixed to the inside of the steel sleeve by a pressure ring. The sealing ring (231) can fit tightly against the surface of the rebar passing through the steel sleeve to prevent leakage during concrete pouring.

6. The prefabricated steel-concrete beam mold for prefabricated subway stations according to claim 5, characterized in that, The vacuum-assisted vibration compaction system (3) includes a closed surrounding vacuum chamber (30), which is located on the outside of the mold. The inner wall of the surrounding vacuum chamber (30) is covered with a breathable membrane. The surrounding vacuum chamber (30) is connected to a vacuum pump through a vacuum tube. The vacuum pump can create a negative pressure environment at the contact surface between the mold and the concrete.

7. The prefabricated steel-concrete beam mold for prefabricated subway stations according to claim 5, characterized in that, The vacuum-assisted vibration compaction system (3) also includes a telescopic high-frequency vibrator (31). The telescopic high-frequency vibrator (31) is arranged at intervals along the curvature direction of the modular curved surface unit (10). The telescopic high-frequency vibrator (31) is connected to a hydraulic push rod (32). The telescopic high-frequency vibrator (31) can be controlled to extend and retract to cover the blind area of ​​the curved surface through the hydraulic push rod (32). The telescopic high-frequency vibrator (31) is linked with the vacuum pump through a controller. When the vacuum pump reaches the preset pressure, the telescopic high-frequency vibrator (31) starts automatically. The vibration time is adaptively adjusted according to the concrete slump.

8. The prefabricated steel-concrete beam mold for prefabricated subway stations according to claim 5, characterized in that, The mold stiffness adaptive adjustment device (4) includes a strain monitoring unit and a hydraulic strut (41). The strain monitoring unit is installed on the stress-bearing part of the mold frame. The stress-bearing part includes the splicing point of the modular curved surface unit (10) and the mold support point. The strain monitoring unit is used to collect strain data during the mold casting process and convert it into deformation amount to be fed back to the control system. The hydraulic struts (41) are set one-to-one with the strain monitoring units. The hydraulic struts (41) are connected to the hydraulic station through the reversing valve. The control system adjusts the supporting force of the hydraulic struts (41) according to the deformation data to compensate for the deformation of the mold.

9. A construction method for irregularly shaped steel-concrete beams used in prefabricated subway stations, characterized in that, Construction using the mold according to any one of claims 1 to 8 includes the following steps: S1: Mold assembly and debugging: According to the surface design parameters of the irregular steel-concrete beam, adjust the curvature of the arc steel plate of each modular surface unit (10), complete the splicing through the tenon structure (12) and the quick locking mechanism (13), and test the surface forming accuracy; adjust the position and angle of the steel bar positioning guide groove (20) according to the steel bar arrangement parameters, test the sealing performance of the surrounding vacuum cavity (30) and the extension and vibration function of the telescopic high frequency vibrator (31); calibrate the strain monitoring unit and the hydraulic strut (41) adjustment unit, and set the mold deformation warning value and control value; S2: Reinforcing bar and steel section installation: Hoist the precast steel section beam onto the steel section support seat inside the mold, fix the connection node between the steel section and the mold after positioning; tie the beam reinforcement, pass the reinforcement to be extended through the reinforcement positioning guide groove (20) and the reserved hole assembly (23), and check the reinforcement spacing and extension deviation; S3: Step-by-step pouring and vacuum vibration: The first pouring prioritizes covering the curved transition area of ​​the beam. During the pouring process, the vacuum pump and the corresponding retractable high-frequency vibrator (31) are started. The upper structure of the beam is poured before the bottom concrete sets. During the pouring process, the vibration frequency of the retractable high-frequency vibrator (31) is dynamically adjusted according to the concrete slump. After pouring to the design elevation, the beam surface is leveled and a vacuum state is maintained. S4: Dynamic temperature curing: Turn on the built-in circulating water heating pipe of the mold, monitor the circulating water temperature in real time through the temperature sensor, adjust the water temperature in stages according to the concrete strength growth curve, and regularly test the concrete surface strength during the curing period. S5: Mold removal and component acceptance: After curing, close the mold stiffness adaptive adjustment device (4), unlock the quick locking mechanism (13), remove the modular curved surface unit (10) in the reverse order of assembly, test the surface forming accuracy, rebar extension position deviation, concrete density and surface quality of the component, and transfer and store it after acceptance.

10. The construction method for prefabricated subway station irregular-shaped steel-concrete beams according to claim 1, characterized in that, Step S4, dynamic temperature curing, includes three stages: initially, maintaining the surface humidity of the concrete within a preset high humidity range and keeping the water temperature within the normal temperature range; in the middle stage, increasing the water temperature to accelerate the strength growth of the concrete; in the later stage, gradually reducing the water temperature to the ambient temperature and controlling the cooling rate during the cooling process; and stopping curing when the early strength of the concrete reaches the preset proportion of the design value.

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