Self-balancing system for cable launching of a stay cable

Abstract

The application discloses a self-balancing system for cable launching of a cable-stayed cable, which comprises a jacking support mechanism, a hydraulic drive mechanism and a control mechanism; the jacking support mechanism comprises a plurality of jacking jacks, the bottom surface of the base of the jacking support mechanism is fixedly provided with MGE sliding plates, the jacking support mechanism is used for driving the jacks to synchronously slide at low resistance and releasing horizontal constraint when the beam body generates longitudinal expansion and contraction deformation; the hydraulic drive mechanism comprises a hydraulic pump station and independent valve groups corresponding to the jacks one by one, each independent valve group is integrated with a reversing valve, a hydraulic lock and a safety overflow valve, and the independent valve groups are used for realizing independent regulation and control of loads at each jacking point, long-term pressure holding and automatic unloading of overpressure; the control mechanism comprises a control host and pressure sensors installed on the jacks, realizes automatic pressure compensation and overpressure alarm by collecting pressure data in real time and automatically judging and regulating. The application realizes self-adaptation of beam body deformation in the cable launching process of the cable-stayed cable, precise independent control of jacking force and intelligent monitoring and regulation in the whole process, effectively eliminates the damage of horizontal constraint force, and improves construction efficiency and safety.

Description

Technical Field

[0001] This application relates to the field of cable-stayed bridge construction and maintenance technology, specifically to a self-balancing system for cable-stayed bridge cable release. Background Technology

[0002] Cable-stayed bridges are one of the mainstream bridge types for long-span bridges and are widely used in highway and municipal river- and sea-crossing projects in my country. As the core load-bearing component of a cable-stayed bridge, the stay cables are responsible for transferring the load of the beam to the bridge towers. Throughout the entire life cycle of the bridge, cable laying procedures are required for operations such as replacing cables due to corrosion and aging, bridge reconstruction and demolition, and beam segment cutting and adjustment.

[0003] Cable release is a key procedure for the maintenance or construction adjustment of cable-stayed bridges. During the release process, the cable force is gradually released, the original force balance of the beam is broken, and the load of the beam is redistributed. This will simultaneously produce vertical settlement and longitudinal expansion and contraction deformation. A support system is needed to support the weight of the beam and bear the load of the beam to avoid beam deformation or structural damage, prevent concrete cracking and structural damage, and ensure construction safety and accuracy.

[0004] Currently, there are two main types of existing technical solutions that are most similar to this invention: The first type is a manual control scheme using rigid support pads and ordinary jacks (from patent CN107842231A): This scheme uses steel plates or precast concrete blocks as rigid support pads at the bottom of the beam, combined with traditional double-acting hydraulic jacks (such as the YDC series) to lift the beam and transfer the load. During construction, the beam is lifted manually by operating the jacks. After the original support pads are removed, the jacks hold the load. During cable lowering, pressure is monitored manually by readings, and the jack pressure is adjusted manually through valves to maintain load balance. This scheme is simple in structure and low in cost. It was used in the cable replacement construction of a 200m span cable-stayed bridge. The core drawback is that the support pads have no slippage capability, and the jacks lack a horizontal force resistance structure.

[0005] The second type is the centralized multi-point synchronous hydraulic jacking system (from the journal *Highway Transportation Technology*, 2018, Issue 5, "Research on Support Technology for Cable Laying of Long-Span Cable-Stayed Bridges"). This system consists of a centralized hydraulic pump station, multiple jacks, and a manual control console. The hydraulic circuit achieves synchronous jacking at multiple points through a diversion valve. The jacking force is manually monitored by a pressure gauge, and the pressure holding state is locked by a manual shut-off valve. For example, in the cable laying construction of a cross-sea cable-stayed bridge, this scheme uses six 500t jacks symmetrically arranged, achieving synchronous jacking through unified manual operation. This improves the coordination of multi-point support to some extent, but it lacks independent hydraulic circuit control, making it impossible to accurately adjust for changes in single-point loads, and it lacks automatic pressure replenishment or overpressure protection functions.

[0006] Although the above solutions can basically meet the requirements for cable-stayed bridge support on a small scale with low precision, they still have several inherent defects in the high-precision cable-stayed bridge construction of large-span concrete cable-stayed bridges: The inherent drawbacks and causes of existing technologies are as follows: Firstly, the existing design cannot accommodate the longitudinal expansion and contraction deformation of the beam, easily generating horizontal constraint forces that can cause structural damage. In the combination of rigid support pads and ordinary jacks, the support structure is fixed, and the jack base has no sliding design. However, when the stay cables are released, the beam will undergo longitudinal expansion and contraction deformation due to stress redistribution. The fixed support will restrict this deformation, thereby generating a large horizontal constraint force, leading to cracking of the beam concrete or damage to the jack cylinder. The cause is that the existing design does not consider the dynamic deformation requirements of the beam and lacks a sliding adaptation structure design. Secondly, the lifting force control precision is insufficient, lacking independent adjustment capabilities and safety protection mechanisms, resulting in poor long-term pressure stability. The multi-point synchronous hydraulic lifting system adopts a centralized oil circuit and diversion valve design, meaning the lifting force of each jack cannot be independently adjusted. This easily leads to situations where localized excessive or insufficient stress occurs due to uneven beam load distribution. Furthermore, it relies on manual pressure monitoring and manual locking, making real-time pressure replenishment impossible. The lack of dedicated pressure-maintaining components means that long-term pressure maintenance can easily lead to pressure decay due to leakage. Additionally, the system lacks overpressure unloading protection; when temperature changes or sudden load changes cause a rapid increase in jack pressure, it cannot automatically unload, posing a safety hazard of structural overload damage. This deficiency essentially stems from the oil circuit design's failure to achieve independent single-point control, the lack of dedicated hydraulic locks, relief valves, and other safety components, and the absence of an intelligent monitoring and feedback mechanism. Third, the construction efficiency is low, the reliance on manual labor is high, and the response lag is strong. Both of the above-mentioned schemes adopt a manual reading and manual operation control mode to adjust the load, which not only has high labor intensity and low construction efficiency, but also has a lag in response and cannot respond to the dynamic changes in load during the cable laying process in a timely manner, resulting in a longer construction period. The cause is that an automated control system has not been established and there is a lack of a closed-loop mechanism of "monitoring-alarm-control".

[0007] In summary, existing beam support technologies for cable-stayed bridge cable laying cannot adapt to the longitudinal expansion and contraction deformation of the beam and the uneven reaction force generated by the vertical support pads of the bridge dismantling scaffolds. This can easily lead to excessive horizontal constraint forces and uneven vertical reaction forces. The jacking force control accuracy is low and lacks independent adjustment capabilities, resulting in beam stress imbalance. The long-term pressure holding stability is poor, and there is no intelligent monitoring and automatic control mechanism, leading to high construction safety risks. There are significant deficiencies in beam deformation adaptation, precise control of jacking force, safety stability, and automation level, making it difficult to meet the high-quality and high-safety requirements for cable laying construction of large-span cable-stayed bridges.

[0008] Against this backdrop, the applicant proposed a new technical solution. Summary of the Invention

[0009] This invention aims to solve at least one of the technical problems existing in the prior art, specifically involving beam support and load balance control technology during the cable-stayed bridge cable release and beam segment cutting process. It mainly develops a cable-stayed bridge cable release support system capable of adaptive longitudinal deformation of the beam, independent and precise control of each lifting point, and intelligent monitoring and automatic balancing capabilities. This system is suitable for the cable dismantling and release construction scenarios of large-span concrete cable-stayed bridges. To this end, this invention proposes a self-balancing system for cable-stayed bridge cable release, and the technical solution adopted includes: A self-balancing system for cable release in a stay cable includes: The system includes a lifting support mechanism, a hydraulic drive mechanism, and a control mechanism. The lifting support mechanism comprises several lifting jacks for bearing the load of the beam, and the hydraulic drive mechanism comprises several hydraulic pump stations. The base of the lifting jack is fixedly equipped with an MGE sliding plate. The lower surface of the MGE sliding plate is used to fit against the support surface below, so as to drive the lifting jack to slide synchronously with low resistance when the beam undergoes longitudinal expansion and contraction deformation, thereby releasing the horizontal constraint. The hydraulic drive mechanism also includes independent valve groups corresponding to each lifting jack. Each independent valve group integrates a directional valve, a hydraulic lock, and a relief valve. The directional valve is used to control the extension and retraction of the corresponding lifting jack. The hydraulic lock is used to lock the oil pressure in the working chamber of the jack to achieve long-term pressure maintenance. The relief valve is used to automatically open and unload under overpressure conditions. Each lifting jack is connected to the hydraulic pump station through a corresponding independent valve group. The control oil circuit of each lifting jack is independent of each other, and the lifting force can be adjusted individually. The control mechanism includes a control host and pressure sensors corresponding to each lifting jack. The pressure sensors are installed on the corresponding lifting jacks and are used to collect the lifting pressure data of the jacks in real time. All pressure sensors are connected to the control host via signal, and the control host is connected to each hydraulic pump station via communication to control the corresponding hydraulic pump station to perform pressure replenishment actions or output alarm signals based on the real-time pressure data.

[0010] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable is provided, wherein the MGE sliding plate is an MGE engineering plastic alloy plate, the working surface of which is coated with lubricating silicone grease and the dynamic friction coefficient is not greater than 0.03.

[0011] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable includes a fully enclosed reinforced base at the lower part of the cylinder of the lifting jack, and an MGE sliding plate fixedly disposed on the bottom surface of the fully enclosed reinforced base; the fully enclosed reinforced base covers the lower outer periphery of the cylinder of the lifting jack and is used to enhance the horizontal load resistance of the cylinder of the jack.

[0012] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable is provided, wherein the lifting jack is a double-acting large-tonnage hydraulic jack, and the size of the MGE sliding plate is adapted to the bottom surface size of the base of the lifting jack.

[0013] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable has an overflow valve whose opening pressure is set to 1.25 times the reference jacking pressure. When the oil pressure in the working chamber of the jack reaches the opening pressure, the overflow valve automatically opens to unload.

[0014] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable includes a hydraulic lock, which is a hydraulically controlled check valve structure and is connected in series in the oil line between the directional valve and the lifting jack, for maintaining the pressure holding state of the jack after the hydraulic pump station is stopped.

[0015] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable includes a hydraulic pump station connected to a corresponding number of independent valve groups through at least two independent oil circuits. Each hydraulic pump station controls two lifting jacks symmetrically arranged in the transverse direction of the bridge. The extension and retraction of the two jacks are controlled by two independent directional valves. The pressure regulation of the two oil circuits does not interfere with each other.

[0016] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable includes a preset reference pressure value and a pressure compensation trigger threshold in the control host. The pressure compensation trigger threshold is 0.75 times the reference pressure value. When the real-time pressure collected by the pressure sensor is lower than the pressure compensation trigger threshold, the control host automatically starts the corresponding hydraulic pump station to extend the cylinder for pressure compensation until the real-time pressure rises back to the reference pressure value and then stops the pressure compensation action.

[0017] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable includes a preset overpressure alarm threshold in the control host. The overpressure alarm threshold is matched with the opening pressure of the overflow valve. When the real-time pressure exceeds the overpressure alarm threshold, the control host outputs an audible and visual alarm signal.

[0018] According to an embodiment of the present invention, a self-balancing system for cable release of a stay cable is provided, wherein the control host is an industrial control computer with a human-machine interface, supporting dual-mode switching between automatic and manual control; a single control host can simultaneously drive multiple hydraulic pump stations, manage multiple lifting jacks, and display the pressure and stroke data of each lifting jack in real time.

[0019] Compared with the prior art, the beneficial effects of the present invention are: The self-balancing system for cable-stayed bridge cable release is systematically innovated around three core directions: "sliding-adaptive jacking structure, independent and controllable hydraulic system, and intelligent closed-loop monitoring mechanism." These three elements work together to achieve adaptive longitudinal expansion and contraction deformation of the beam during cable release, precise and independent control of the jacking force at each jacking point, and intelligent monitoring and automatic control throughout the entire process. This effectively solves the common shortcomings of existing technologies in deformation adaptation, control accuracy, and safety stability. Specifically: In the lifting support mechanism, this invention fixes MGE sliding plates on the bottom surface of each lifting jack's base and coats them with lubricating silicone grease, reducing the dynamic friction coefficient to no more than 0.03. During cable release, when the beam undergoes longitudinal expansion and contraction due to stress redistribution, the jacks can slide synchronously with the beam with low resistance. Compared to existing rigid support schemes that use fixed bases and non-sliding designs to restrict beam deformation, this invention transforms "restricting deformation" into "accommodating deformation," completely eliminating the risk of damage to the beam's concrete structure and the jack cylinders caused by horizontal constraint forces.

[0020] In the hydraulic drive mechanism, this invention features an independent control oil circuit for each lifting jack, allowing each jack to independently adjust its extension and retraction movements and lifting force, thus achieving precise and independent control of the load at each lifting point. Compared to existing multi-point synchronous systems that use centralized oil circuits and diverter valves, which cannot be independently controlled, this invention reduces the pressure deviation from over 10% to less than 3%, effectively avoiding the problem of excessive or insufficient local stress caused by uneven load distribution on the beam.

[0021] In the hydraulic drive mechanism, the present invention integrates a hydraulic lock and a safety relief valve in each independent valve group. The two work together with the overpressure alarm function of the control host to achieve long-term stable pressure holding and automatic overpressure unloading, effectively eliminating pressure decay and overload safety hazards, forming a reliable pressure holding and safety protection mechanism, and effectively eliminating the safety hazards caused by pressure decay due to leakage and lack of overpressure protection in traditional solutions.

[0022] In the control mechanism, pressure sensors collect data in real time and the control host automatically judges and regulates, establishing a closed-loop mechanism of "monitoring-alarm-regulation". Compared with the existing technology that relies on manual reading, manual operation and response lag, the response time of this invention is shortened from minutes to seconds, greatly reducing the dependence on manual labor and labor intensity.

[0023] This invention, through innovative structural design and intelligent integration, can be adapted to existing cable-stayed bridge cable laying construction without complex modifications, improving construction efficiency by more than 40% and significantly reducing the risk of structural damage. It provides an efficient, precise, and safe beam balance control solution for cable laying construction, and has strong engineering practicality and promotional value. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the hydraulic control principle of the self-balancing system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the hydraulic pump station and lifting jack oil circuit connection in an embodiment of the present invention; Figure 3 This is a schematic diagram of the lifting jack structure according to an embodiment of the present invention; Figure 4 This is a diagram showing the interface of the control system according to an embodiment of the present invention.

[0025] Explanation of key component symbols: 10. Lifting jack; 20. MGE sliding plate; 30. Fully enclosed reinforced base; 40. Support frame load-bearing longitudinal beam; 50. Hydraulic pump station. Detailed Implementation

[0026] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0027] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0029] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0030] Example 1: This embodiment provides a self-balancing system for cable-stayed bridge cable laying, used to bear the beam load and achieve dynamic balance control during the cable laying process of a cable-stayed bridge. It is particularly suitable for cable removal and laying scenarios of large-span concrete cable-stayed bridges. Figure 1 As shown, the system mainly consists of three parts: a lifting support mechanism, a hydraulic drive mechanism, and a control mechanism.

[0031] The lifting support mechanism includes several lifting jacks 10 for bearing the load of the beam. In this embodiment, a total of four lifting jacks 10 are provided, respectively arranged at four support points at the bottom of the beam, to bear the weight of the beam and maintain its vertical stability during cable laying. Each lifting jack 10 adopts the RHD series large-tonnage double-acting hydraulic jack, with the following specific parameters: model TX-200D, rated lifting force 200 tons, rated pressure 55MPa, stroke 150mm, minimum height 420mm, and bottom dimensions 400mm×400mm. The double-acting design allows the jack to achieve bidirectional piston extension and retraction driven by hydraulic oil, facilitating both active lifting and active unloading.

[0032] To further improve the structural safety and deformation adaptability of jacks during cable-stayed cable laying operations, such as Figure 3 As shown, in this embodiment, a fully enclosed reinforced base 30 is provided at the lower part of the cylinder of the lifting jack 10. This base covers the lower outer periphery of the jack cylinder and is used to improve the cylinder's resistance to horizontal loads, preventing damage to the cylinder due to the horizontal displacement tendency of the beam. At the same time, an MGE sliding plate 20 is fixedly installed on the bottom surface of the base of each lifting jack 10. The MGE sliding plate 20 is an MGE engineering plastic alloy plate, and its lower surface is used to fit against the supporting surface below (such as a steel bracket or concrete foundation, which in this embodiment fits against the support longitudinal beam 40 of the bracket). During use, a lubricating silicone grease is applied to its working surface, which can reduce the dynamic friction coefficient to no more than 0.03. Through the above structural design, when the beam undergoes longitudinal expansion and contraction deformation due to stress redistribution during the cable release process, the lifting jack 10 can slide synchronously with the beam under the low-resistance sliding action of the MGE sliding plate 20, effectively releasing the horizontal constraint and significantly reducing the horizontal force on the support caused by friction. At the same time, the size of the MGE sliding plate 20 is matched with the bottom size of the jack base to ensure uniform sliding support.

[0033] like Figure 1 , 2As shown, the hydraulic drive mechanism includes several hydraulic pump stations 50 and independent valve groups corresponding to each lifting jack 10. In this embodiment, two hydraulic pump stations 50 are configured, model TX-P10T2, with a rated pressure of 55MPa, a flow rate of 10L / min, and a power of 5kW. Each hydraulic pump station 50 controls two lifting jacks 10 arranged in the transverse direction, that is, each pump station is connected to the corresponding number of independent valve groups through two independent oil circuits, thereby controlling the independent operation of the two jacks. The hydraulic control principle of the self-balancing system is as follows: Figure 1 As shown, each lifting jack 10 is equipped with an independent valve group, which integrates a directional valve (not shown in the figure), a hydraulic lock, and a relief valve. The directional valve allows each jack to have its own independent control oil circuit, enabling independent control of the jack's extension and retraction movements under control commands. The pressure control of the two independent oil circuits does not interfere with each other. The hydraulic lock uses a hydraulically controlled check valve structure, connected in series between the directional valve and the jack, to lock the oil pressure in the jack's working chamber after the hydraulic pump station 50 stops, achieving long-term pressure maintenance and preventing beam subsidence due to oil pressure leakage. The relief valve automatically opens to unload under overpressure conditions. The opening pressure of the relief valve is set to 1.25 times the reference lifting pressure. When the internal pressure of the jack reaches this threshold, it automatically opens to unload, preventing overload damage to the jack or beam due to temperature changes or sudden load changes. In addition, each jack is also equipped with a pressure sensor to monitor the lifting force in real time and transmit it to the control system via fieldbus.

[0034] The control mechanism includes a control host and pressure sensors (such as those corresponding to each lifting jack 10) Figure 1 (As shown). The control host adopts an industrial control computer (PC) with a human-machine interface, supporting automatic and manual control dual-mode switching. A single control host can simultaneously drive multiple hydraulic pump stations 50 and manage multiple lifting jacks 10. In this embodiment, the control system includes one computer, which can drive the operation of 16 pump stations and 32 jacks. The pressure and stroke of the 32 jacks are displayed through the human-machine interface (e.g., Figure 4(As shown). Pressure sensors are installed on the corresponding lifting jacks 10 to collect the lifting pressure data of the jacks in real time. All pressure sensors are connected to the control host, which is also connected to each hydraulic pump station 50 for communication. The pressure and stroke data of each jack are displayed in real time through the human-machine interface. The control host has a preset reference pressure value and a pressure compensation trigger threshold (0.75 times the reference value). Its control logic is as follows: when the real-time pressure collected by the pressure sensor is lower than the pressure compensation trigger threshold, the system issues an alarm indication and automatically starts the hydraulic pump station 50 corresponding to that point to extend the cylinder and replenish oil until the real-time pressure rises back to the reference pressure value and then stops the pressure compensation action. At the same time, the control host also has a preset overpressure alarm threshold (matched with the opening pressure of the relief valve, i.e., 1.25 times the reference pressure value). When the real-time pressure exceeds this threshold, the control host outputs an audible and visual alarm signal, which, together with the automatic unloading of the relief valve, forms a dual safety protection of "automatic pressure relief + alarm indication". The collaborative working relationship of the above components is as follows: the oil port of the lifting jack 10 is connected to the hydraulic pump station 50 through a high-pressure oil pipe and an independent valve group, forming an independent control oil circuit; the signal cable of the pressure sensor is connected to the data acquisition module of the control host, and the control signal output terminal of the control host is connected to the solenoid valve control terminal of each hydraulic pump station 50 through a communication bus. During operation, the pressure sensor collects the lifting force data of each jack in real time and uploads it to the control host. The control host judges according to the preset benchmark pressure value and pressure compensation / alarm threshold, and automatically sends a pressure compensation command to the corresponding hydraulic pump station 50 or outputs an alarm signal to the operation interface, forming a complete closed-loop control system, realizing the precise bearing and dynamic balance control of the beam load during the cable release process.

[0035] Through the above system structure, the present invention can effectively adapt to the longitudinal expansion and contraction deformation of the beam during the cable laying process, realize independent and precise control of the lifting force at each lifting point, and has intelligent real-time monitoring, automatic pressure compensation and overpressure protection functions, which significantly improves the safety, accuracy and efficiency of cable laying construction.

[0036] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A self-balancing system for cable release in a stay cable, characterized in that, Including: The lifting support mechanism, the hydraulic drive mechanism and the control mechanism include a number of lifting jacks (10) for bearing the load of the beam, and the hydraulic drive mechanism includes a number of hydraulic pump stations (50). The bottom surface of the base of the lifting jack (10) is fixedly provided with an MGE sliding plate (20). The lower surface of the MGE sliding plate (20) is used to fit against the support surface below, so as to drive the lifting jack (10) to slide synchronously with low resistance when the beam undergoes longitudinal expansion and contraction deformation, thereby releasing the horizontal constraint. The hydraulic drive mechanism also includes independent valve groups that correspond one-to-one with each lifting jack (10). Each independent valve group integrates a reversing valve, a hydraulic lock, and a relief valve. The reversing valve is used to control the extension and retraction of the corresponding lifting jack (10). The hydraulic lock is used to lock the oil pressure in the working chamber of the jack to achieve long-term pressure holding. The relief valve is used to automatically open and unload under overpressure conditions. Each lifting jack (10) is connected to the hydraulic pump station (50) through the corresponding independent valve group. The control oil circuits of each lifting jack (10) are independent of each other and the lifting force can be adjusted individually. The control mechanism includes a control host and pressure sensors that are set one-to-one with each lifting jack (10). The pressure sensors are installed on the corresponding lifting jack (10) and are used to collect the lifting pressure data of the jack in real time. All pressure sensors are connected to the control host via signal. The control host is connected to each hydraulic pump station (50) via communication and is used to control the corresponding hydraulic pump station (50) to perform pressure replenishment action or output alarm signal according to the real-time pressure data.

2. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The MGE sliding plate (20) is an MGE engineering plastic alloy plate with a working surface coated with lubricating silicone grease and a dynamic friction coefficient of no more than 0.

03.

3. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The lower part of the cylinder of the lifting jack (10) is provided with a fully enclosed reinforced base (30), and the MGE sliding plate (20) is fixedly installed on the bottom surface of the fully enclosed reinforced base (30); the fully enclosed reinforced base (30) covers the lower outer periphery of the cylinder of the lifting jack (10) and is used to improve the horizontal load resistance of the cylinder of the jack.

4. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The lifting jack (10) is a double-acting large-tonnage hydraulic jack, and the size of the MGE sliding plate is adapted to the bottom surface size of the base of the lifting jack (10).

5. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The opening pressure of the overflow valve is set to 1.25 times the reference lifting pressure. When the oil pressure in the working chamber of the jack reaches the opening pressure, the overflow valve automatically opens to unload.

6. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The hydraulic lock is a hydraulically controlled check valve structure, which is connected in series in the oil line between the directional valve and the lifting jack (10) to maintain the pressure of the jack after the hydraulic pump station (50) stops.

7. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, Each hydraulic pump station (50) is connected to a corresponding number of independent valve groups through at least two independent oil circuits. Each hydraulic pump station (50) controls two lifting jacks (10) arranged symmetrically in the transverse direction of the bridge. The extension and retraction of the two jacks are controlled by two independent directional valves. The pressure regulation of the two oil circuits does not interfere with each other.

8. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The control host has a preset reference pressure value and a pressure compensation trigger threshold. The pressure compensation trigger threshold is 0.75 times the reference pressure value. When the real-time pressure collected by the pressure sensor is lower than the pressure compensation trigger threshold, the control host automatically starts the corresponding hydraulic pump station (50) to extend the cylinder for pressure compensation until the real-time pressure rises back to the reference pressure value and then stops the pressure compensation action.

9. The self-balancing system for cable release of a stay cable according to claim 8, characterized in that, The control host is also preset with an overpressure alarm threshold, which is matched with the opening pressure of the relief valve. When the real-time pressure exceeds the overpressure alarm threshold, the control host outputs an audible and visual alarm signal.

10. The self-balancing system for cable release of a stay cable according to claim 1, characterized in that, The control host is an industrial computer with a human-machine interface, which supports switching between automatic and manual control modes. A single control host can simultaneously drive multiple hydraulic pump stations (50), manage multiple lifting jacks (10), and display the pressure and stroke data of each lifting jack (10) in real time.

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