Method for erecting low-clearance power-failure-free prefabricated box girder under 220KV high-voltage line

Abstract

The invention relates to the technical field of installation and construction of precast beams by adopting unconventional means, and discloses a low-clearance power-failure-free precast box girder erection method under a 220KV high-voltage line, which comprises the following steps: installing a bridge girder erection machine, lifting the beams by the bridge girder erection machine, dropping the beams to a transverse moving rail, pushing and transversely moving, circularly pushing and transversely moving, transversely moving to a beam position and dropping the beams. Finally, the descending speed and the descending point of the beam body are accurately controlled, so that the beam body is vertically aligned and smoothly contacted with the support; a beam span with the clearance height meeting the safe operation condition of the bridge girder erection machine is selected for bridge girder erection machine installation, after the bridge girder erection machine is installed, an inclined lifting technology is adopted to lift a box girder to a cover beam in place, a hydraulic girder moving device is used for transversely pushing and translating the prefabricated box girder to a designed position, and finally installation of the prefabricated box girder at the position with insufficient clearance under the high-voltage line is achieved. The problems that in an existing method, the coordination difficulty of construction after power failure of a power department is often large, the construction procedure handling period is long, and the site construction period requirement cannot be met are solved.

Description

Technical Field

[0001] The invention relates to the technical field of prefabricated beam installation and construction using unconventional means, and specifically to a method for erecting a low-headroom, power-off-free prefabricated box beam under a 220KV high-voltage line. Background Art

[0002] Prefabricated box girder is a commonly used structural type in bridge engineering. It is a concrete component produced in a factory or prefabrication yard, usually with a box-shaped cross-section. It can provide a large load-bearing capacity and good bending resistance. At the same time, it has a light weight, making transportation and installation more convenient. At the same time, prefabricated box girder has become an important material and technical choice in modern bridge construction with its superior structural performance and construction convenience.

[0003] When erecting traditional prefabricated box girders, the prefabricated box girders are first transported from the factory to the construction site. At the construction site, the bridge foundation and supports are completed as per the design requirements, and the erection area is cleaned. The box girder is lifted by a crane and moved vertically above the bridge foundation. The box girder is accurately placed on the designed supports to ensure its correct position. The box girder is then connected and reinforced to ensure its stability and meet structural requirements. Finally, an inspection is carried out to ensure that the erection of the box girder meets the standards. However, when implementing the traditional method, it is necessary to select a beam span whose clearance height meets the safe operating conditions of the bridge erection machine for the installation of the bridge erection machine. It is difficult to use the inclined lifting technology to lift the box girder into place on the cap beam, and it is difficult to complete the horizontal jacking and translation of the prefabricated box girder by a crane. At the same time, it is necessary to coordinate with the power department for construction after a power outage, which is often difficult to coordinate and the construction procedures are long, which cannot meet the on-site construction period requirements. Summary of the invention

[0004] The purpose of the present invention is to provide a method for erecting a low-headroom, power-off-free prefabricated box beam under a 220KV high-voltage line, which solves the problem in the background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for erecting a low-headroom, power-off-free prefabricated box girder under a 220KV high-voltage line comprises the following steps:

[0007] S1. Installation of bridge erection machine: Arrange and assemble the bridge erection machine in the selected safety area to ensure its stability. By precisely controlling the lifting and displacement of the bridge erection machine, the prefabricated box girder is stably lifted from the transport vehicle and accurately placed at the designed position within the safety clearance defined by the high-voltage line.

[0008] S2. Lifting the beam of the bridge erecting machine: The bridge erecting machine is preset at a suitable position to ensure a safe vertical distance from the high-voltage line; after starting the bridge erecting machine, the rising speed of the beam and the line clearance are strictly monitored, and the tension and position of the hook are continuously adjusted to avoid any risk of cable contact or flashing;

[0009] S3, lowering the beam to the transverse track: operate the bridge erecting machine to lift the box beam to a position above the transverse track, and then slowly lower it through precise mechanical control to ensure that the box beam is aligned with the track and there is no lateral deviation; during the entire lowering process, continuously monitor the safety clearance of the high-voltage line to ensure that the operation is carried out without causing electrical hazards;

[0010] S4, Pushing and lateral movement: Use special pushing equipment to ensure close contact between the beam and the lateral movement track, and then gradually apply thrust to push the box beam smoothly to the designed position;

[0011] S5. Cyclic pushing and transverse movement operation: by setting multiple pushing points and using the pushing device to apply force section by section, the box girder is moved transversely to the designed position in sequence. After pushing, the stability of the girder and the safe clearance with the high-voltage line are checked in time to ensure that there is no collision risk during the operation. During the cycle, the operator maintains a high degree of coordination and monitoring, and adjusts the pushing force and rhythm in time to achieve a smooth and smooth movement of the box girder until the overall installation is completed;

[0012] S6. Horizontal movement to the beam position: First, ensure that the box beam is firmly on the horizontal movement track, then use the horizontal movement equipment to slowly and steadily move the beam body horizontally with appropriate thrust, carefully monitor the clearance distance between the beam body and the high-voltage line to avoid electrical hazards caused by improper operation, and perform necessary docking and fixing to ensure the stability and safety of the beam body, providing a reliable foundation for subsequent construction;

[0013] S7, beam drop: Precisely control the speed and drop point of the beam so that it is vertically aligned and smoothly contacts the support. Continuously monitor the clearance distance of the high-voltage line to ensure safety and prevent any electrical interference. Then perform final fixing and stabilization measures to ensure that the box girder can withstand future loads and environmental conditions, thereby completing the efficient and safe erection of the bridge.

[0014] Preferably, the installation of the bridge erecting machine in S1 specifically further comprises the following steps:

[0015] a. Site preparation and equipment inspection: Clean and level the construction site to make the installation environment of the bridge erector suitable. At the same time, conduct a comprehensive inspection of all components of the bridge erector, including mechanical structure, electrical system, safety devices, etc., to ensure that all components are intact;

[0016] b. Foundation construction: According to the design requirements, a stable foundation is set up on site to make the anchoring point of the bridge erecting machine stable and reliable, ensuring its bearing capacity and stability;

[0017] c. End crossbeam installation: Place the end crossbeam of the bridge erector on the pre-designed track or support for preliminary positioning and fixing. The end crossbeam is the main load-bearing structure of the bridge erector, and its levelness and stability must be ensured;

[0018] d. Main beam assembly: transport the main beam of the bridge erecting machine to the construction site in sections and assemble it to ensure that the connection between each section of the beam is firm and reliable;

[0019] e. Installation of lifting system: Install the lifting system of the bridge erector, including the hydraulic lifting device and control system, and ensure that all functions operate normally, and can accurately control the lifting and lateral movement of the beam;

[0020] f. Safety inspection and trial operation: After all parts are installed, a comprehensive safety inspection is carried out, including structural stability, mechanical transmission, electrical safety, etc., to ensure that there are no potential safety hazards. Then the bridge crane is tested to check whether its functions are normal and whether various operations are sensitive and reliable;

[0021] g. Formal erection preparation: After the trial run is successful, formal erection preparation work will be carried out, including determining the position of the prefabricated box beam, adjusting the coordinates and angle of the bridge erection machine, and ensuring the accuracy and safety of the erection process;

[0022] h. Beam dropping and fixing: According to the on-site construction requirements, the beam dropping operation is carried out to accurately lower the prefabricated box beam to the designed position, and then the final fixing and adjustment are carried out to make the box beam stable and meet the load-bearing requirements of the bridge.

[0023] Preferably, the bridge erecting machine lifting beam in S2 specifically includes the following steps:

[0024] a. Before lifting the beam, conduct a comprehensive inspection of the lifting system of the bridge erector, including the hydraulic system, electrical control system, sensors and safety devices, to ensure that all equipment is in good condition;

[0025] b. Move the prefabricated box beam to the lifting position of the bridge erection machine, and align the beam body with the center line of the lifting device through the positioning device and measuring tools, and control the error within the allowable range;

[0026] c. Connect the lifting device (such as hook, sling, etc.) to the reserved lifting point of the box beam to ensure that the connection is firm and not loose;

[0027] d. Use the bridge erection machine to slowly lift the box girder and avoid sudden acceleration or deceleration to reduce the impact on the girder;

[0028] e. Control the lifting height of the box beam. When it is close to the set height, slow down the lifting speed and make fine adjustments to make the beam reach the preset height;

[0029] f. After the box girder is lifted to the set height, it is fixed to prevent it from accidental movement during subsequent operations.

[0030] Preferably, the installation of the bridge-building machine in S1 also includes the installation of the lifting system, by connecting and debugging the electrical system of the bridge-building machine, including a control cabinet, sensors, monitoring equipment, etc. In addition, the debugging of the electrical system must be carried out in the absence of high voltage electricity to ensure that the communication and control signals between various devices are accurate.

[0031] Preferably, the cyclic pushing and lateral shifting operation in S5 further includes the following steps:

[0032] a. Ensure that the prefabricated box beam is fixed on the transverse track to avoid movement or tilting during the transverse movement. Necessary monitoring equipment and sensors are installed on the beam and track to monitor various parameters of the transverse movement process in real time, such as the position, posture, hydraulic pressure, etc. of the beam;

[0033] b. Preliminarily align the box girder with the lateral movement direction and the target position so that it will not deviate too much during the lateral movement;

[0034] c. Apply a top thrust through the hydraulic jack to slowly move the beam horizontally;

[0035] d. During the transverse movement, the operator observes the position of the beam in real time through the monitoring equipment to ensure that the deviation from the target position is within the allowable range;

[0036] e. When the beam approaches the target position, reduce the pushing speed and make fine adjustments to align it with the target position;

[0037] f. After confirming that the beam is stable, remove the jacking device and prepare for the next step of construction.

[0038] Preferably, during the lateral movement, the pushing speed needs to be controlled to maintain a uniform speed to avoid sudden acceleration or deceleration causing vibration or displacement of the beam. At the same time, multiple cycles of pushing are required, each time pushing a short distance (several centimeters to tens of centimeters), and then releasing the pressure, adjusting and realigning, and then pushing again. In addition, the position and posture of the beam need to be checked after each cycle to ensure a smooth lateral movement.

[0039] Preferably, the movement process also includes adjusting the posture, and the posture adjustment includes finding that the beam body is deflected during the lateral movement, and appropriately adjusting the thrust direction and size by controlling the pushing device of the hydraulic system to make fine adjustments. At the same time, support points are applied to each side or bottom of the beam body, and the posture of the beam body is corrected through local lifting or fine-tuning to ensure that it returns to the ideal horizontal and vertical position.

[0040] Preferably, the step of transversely moving to the beam position in S6 further comprises the following steps:

[0041] a. Determine the target position: According to the set position, clarify the final placement position of the prefabricated box beam, and make relevant marks on the ground to ensure the position is accurate, and verify the clearance between the beam and the 220KV high-voltage line;

[0042] b. Transverse operation: Use the alignment device to perform preliminary alignment on the prefabricated box beam to ensure that its axis is parallel to the transverse track;

[0043] c. Real-time monitoring: During the entire lateral movement process, the monitoring system is used to observe the position of the beam in real time to ensure that it moves along the predetermined path on the track, and the thrust is fine-tuned to ensure that the beam is in the correct position;

[0044] d. Arrival at beam position: When the box beam reaches the predetermined position, precise fine-tuning is performed to ensure perfect docking between the beam and the support.

[0045] Preferably, after reaching the beam position in step d, the step further includes the following steps:

[0046] (1) Temporary fixation: Use a supporting device to temporarily fix the prefabricated box beam to ensure that it does not move and improve construction safety;

[0047] (2) Remove the transverse moving device: After ensuring that the beam is stable, remove the transverse moving device and prepare for subsequent construction steps;

[0048] (3) Safety inspection: confirm the safe distance between the high-voltage wire and the beam body to ensure the safety of the construction area. Preferably, the temporary fixation in (1) also includes the following steps:

[0049] 1. Determine the specific location where the prefabricated box girder needs to be temporarily fixed;

[0050] 2. Select appropriate jacks, support frames and steel pads according to the set prefabricated box size and weight, and ensure that these devices have sufficient load-bearing capacity and stability to support the prefabricated box beam;

[0051] 3. Ensure that the jack is in close contact with the prefabricated box girder, and use bolts to firmly connect it to the prefabricated box girder to ensure that the connection is firm and reliable and can withstand the weight of the prefabricated box girder and various forces during the construction process.

[0052] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0053] 1. Select the beam span whose clearance height meets the safe operation conditions of the bridge erection machine for the installation of the bridge erection machine. After the installation of the bridge erection machine, the box beam is lifted to the cap beam using the tilting lifting technology, and the prefabricated box beam is pushed and moved horizontally to the designed position using the hydraulic beam shifting device. Finally, the prefabricated box beam is installed at the place where the clearance under the high-voltage line is insufficient. This solves the problem that the existing method needs to coordinate with the power department for construction after power outage, which is often difficult to coordinate, has a long construction procedure processing cycle, and cannot meet the on-site construction period requirements;

[0054] 2. The present invention can effectively reduce the impact and vibration during the construction process by setting up the method of dropping the beam to the transverse track, ensure the stability and safety of the beam body, avoid damage to the prefabricated components, and use a dedicated transverse movement device to achieve precise control and improve the accuracy of beam positioning. At the same time, the transverse movement operation can be cyclically performed, making the construction process more efficient and coherent, reducing the pause time, helping to save time and labor costs of the method of the present invention, improving overall construction efficiency and safety, and thus achieving higher engineering quality and economic benefits;

[0055] 3. The present invention can realize a continuous and seamless construction process through the setting of cyclic jacking and lateral movement operations, significantly improve construction efficiency and accuracy, reduce the time that the beam is suspended in the air, and thus reduce safety hazards. In addition, this operation mode is equipped with a real-time monitoring system, which can accurately control the position and posture of the beam, reduce human errors and equipment failure rates, adapt to different construction environments, save manpower and material resources, and improve the safety and economy of construction as a whole, making the erection of prefabricated box beams more efficient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a flow chart of the method of the present invention;

[0057] Figure 2 A specific flow chart for installing the bridge erecting machine of the present invention;

[0058] Figure 3 It is a specific flow chart of the bridge erecting machine lifting beam of the present invention;

[0059] Figure 4 A temporarily fixed flow chart of the present invention;

[0060] Figure 5 It is a flow chart after the present invention reaches the beam position;

[0061] Figure 6 It is a specific flow chart of the present invention for transverse movement to the beam position;

[0062] Figure 7 The figure is a flow chart of the cyclic pushing and lateral shifting operation of the present invention. DETAILED DESCRIPTION

[0063] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Please refer to Figure 1 - Figure 5, a method for erecting prefabricated box girders with low clearance and power outage-free under a 220KV high-voltage line, comprising: installing a bridge erecting machine: arranging and assembling the bridge erecting machine in a selected safe area to ensure its stability, and by precisely controlling the lifting and shifting of the bridge erecting machine, the prefabricated box girder is stably lifted from the transport vehicle, and accurately placed at the designed position within the safe clearance defined by the high-voltage line; lifting the beam by the bridge erecting machine: the bridge erecting machine is preset at a suitable position to ensure a safe vertical distance from the high-voltage line; after starting the bridge erecting machine, the rising speed of the beam body and the line clearance are strictly monitored, and the tension and position of the hook are continuously adjusted to avoid any risk that may cause cable contact or flashover; dropping the beam to the transverse track: operating the bridge erecting machine to lift the box girder to a position higher than the transverse track, and then through a precise machine The box girder is slowly lowered under mechanical control to ensure that the box girder is aligned with the track and there is no lateral deviation; during the entire descending process, the safety clearance of the high-voltage line is continuously monitored to ensure that the operation is carried out without causing electrical hazards; jacking and lateral movement: a special jacking device is used to ensure the close contact between the beam body and the lateral movement track, and then the thrust is gradually applied to push the box girder smoothly to the designed position; cyclic jacking and lateral movement operation: by setting multiple jacking points, the jacking device is used to apply force section by section to move the box girder transversely to the designed position in turn. After jacking, the stability of the beam body and the safety clearance with the high-voltage line are checked in time to ensure that there is no collision risk during the operation. During the cycle, the operator maintains a high degree of coordination and monitoring, and adjusts the jacking force and rhythm in time to achieve stable and smooth movement of the box girder. , until the overall installation is completed; Transverse movement to the beam position: first ensure that the box beam is firmly on the transverse track, and then use the transverse movement equipment to slowly and steadily move the beam body laterally through appropriate thrust, carefully monitor the clearance distance between the beam body and the high-voltage line to avoid electrical hazards caused by improper operation, and at the same time perform necessary docking and fixation to ensure that the beam body is stable and safe, providing a reliable foundation for subsequent construction; Beam drop: Accurately control the speed and drop point of the beam body so that it is vertically aligned and smoothly contacts the support, continuously monitor the clearance distance of the high-voltage line to ensure safety and prevent any electrical interference, and then perform final fixation and stabilization measures to ensure that the box beam can withstand future loads and environmental conditions, thereby completing the efficient and safe erection of the bridge; The specific installation of the bridge erection machine is also Including: Site preparation and equipment inspection: clean and level the construction site to make the installation environment of the bridge erector suitable. At the same time, conduct a comprehensive inspection of all components of the bridge erector, including mechanical structure, electrical system, safety devices, etc., to ensure that the functions of each component are intact; Foundation construction: according to the design requirements, set up a stable foundation in the site to make the anchoring base of the bridge erector stable and reliable, ensuring its bearing capacity and stability; End beam installation: place the end beam of the bridge erector on the pre-designed track or support for preliminary positioning and fixing. The end beam is the main load-bearing structure of the bridge erector, and its level and stability must be guaranteed; Main beam assembly: transport the main beam of the bridge erector to the construction site in sections and assemble it to ensure that the connection between each section of the beam is firm and reliable;Installation of lifting system: Install the lifting system of the bridge erector, including the hydraulic lifting device and control system, and ensure that all functions operate normally, and can accurately control the lifting and lateral movement of the beam; Safety inspection and trial operation: After all components are installed, conduct a comprehensive safety inspection, including structural stability, mechanical transmission, electrical safety, etc., to ensure that there are no safety hazards, and then conduct a trial operation of the bridge erector to check whether its functions are normal and whether all operations are sensitive and reliable; Formal erection preparation: After the trial operation is successful, conduct formal erection preparation work, including determining the position of the prefabricated box beam, adjusting the coordinates and angle of the bridge erector, and ensuring the accuracy and safety of the erection process; Beam dropping and fixing: According to the on-site construction requirements, carry out the beam dropping operation, accurately drop the prefabricated box beam to the designed position, and then perform the final fixing and adjustment to make the box beam stable and meet the load-bearing requirements of the bridge;

[0065] By connecting and debugging the electrical system of the bridge crane, including the control cabinet, sensors, monitoring equipment, etc., in addition, the debugging of the electrical system must be carried out without high voltage electricity to ensure that the communication and control signals between various devices are accurate;

[0066] The specific procedures for lifting the beam by the bridge erection machine include: before lifting the beam, a comprehensive inspection of the lifting system of the bridge erection machine, including the hydraulic system, electrical control system, sensors and safety devices, is carried out to ensure that all equipment is in good condition; the prefabricated box beam is moved to the lifting position of the bridge erection machine, and the center line of the beam body and the lifting device are aligned through the positioning device and the measuring tool, and the error is controlled within the allowable range; the lifting device (such as hooks, slings, etc.) is connected to the reserved lifting points of the box beam to ensure that the connection is firm and not loose; the box beam is slowly lifted by the bridge erection machine to avoid sudden acceleration or deceleration to reduce the impact on the beam body; the lifting height of the box beam is controlled, and when it is close to the set height, the lifting speed is slowed down and fine-tuned to make the beam body reach the predetermined height; after the box beam is lifted to the set height, it is fixed to prevent it from accidentally moving in subsequent operations;

[0067] The installation of the bridge crane also includes the installation of the lifting system, which is done by connecting and debugging the electrical system of the bridge crane, including the control cabinet, sensors, monitoring equipment, etc. In addition, the debugging of the electrical system must be carried out without high voltage electricity to ensure that the communication and control signals between various devices are accurate.

[0068] During operation, a beam span with a clearance height that satisfies the safe operating conditions of the bridge-building machine is selected for installation of the bridge-building machine. After the bridge-building machine is installed, the box beam is lifted into place on the cap beam using the inclined lifting technology, and the prefabricated box beam is laterally pushed and shifted to the designed position using the hydraulic beam shifting device. Finally, the prefabricated box beam is installed in places where the clearance under the high-voltage line is insufficient. This solves the problem that the existing method requires coordination with the power department, but construction after a power outage is often difficult to coordinate, the construction procedures are long, and the on-site construction period requirements cannot be met.

[0069] Please refer to Figure 6 , the transverse movement to the beam position also includes determining the target position: according to the set position, clarify the final placement position of the prefabricated box beam, and make relevant marks on the ground to ensure the accuracy of the position, and verify the clearance between the beam body and the 220KV high-voltage line; transverse movement operation: the prefabricated box beam is preliminarily aligned through the alignment device to ensure that its axis is parallel to the transverse movement track; real-time monitoring: during the entire transverse movement process, the monitoring system is used to observe the position of the beam body in real time to ensure that it moves along the predetermined path on the track, and the thrust is fine-tuned to ensure that the beam body is in the correct position; arrival at the beam position: when the box beam reaches the predetermined position, precise fine-tuning is performed to ensure that the beam body and the support are perfectly docked;

[0070] After reaching the beam position, the following steps are also included: temporary fixation: using a support device to temporarily fix the prefabricated box beam to ensure that it does not move, thereby improving construction safety; removal of the transverse movement device: after ensuring that the beam is stable, the transverse movement device is removed to prepare for subsequent construction steps; safety inspection: confirming the safe distance between the high-voltage line and the beam to ensure the safety of the construction area;

[0071] Temporary fixation also includes determining the specific location where the prefabricated box girder needs to be temporarily fixed; selecting appropriate jacks, support frames and steel pads according to the set prefabricated box size and weight; ensuring that the jacks are in close contact with the prefabricated box girder and using bolts to firmly connect them to the prefabricated box girder.

[0072] During operation, it can effectively reduce the impact and vibration during the construction process, ensure the stability and safety of the beam body, avoid damage to prefabricated components, and use special transverse movement equipment to achieve precise control and improve the accuracy of beam positioning. At the same time, the transverse movement operation can be carried out in a cycle, making the construction process more efficient and coherent, reducing pause time, helping to save time and labor costs of the method of the present invention, improving overall construction efficiency and safety, thereby achieving higher engineering quality and economic benefits.

[0073] Please refer to Figure 7 The cyclic jacking and transverse operation also includes ensuring that the prefabricated box beam is fixed on the transverse track to avoid movement or tilting during the transverse movement, and setting necessary monitoring equipment and sensors on the beam and track to monitor various parameters of the transverse movement process in real time, such as the position, posture, hydraulic pressure, etc. of the beam; initially aligning the box beam with the transverse direction and the target position so that it will not deviate too much during the transverse movement; applying jacking force through the hydraulic jack to slowly move the beam transversely; during the transverse movement, the operator observes the position of the beam in real time through the monitoring equipment so that its deviation from the target position is within the allowable range; when the beam approaches the target position, the jacking speed is reduced and fine-tuned to finally align it with the target position; after confirming that the beam is stable, remove the jacking device and prepare for the next step of construction;

[0074] During the lateral movement, the pushing speed needs to be controlled and kept at a constant speed to avoid sudden acceleration or deceleration that may cause vibration or displacement of the beam. At the same time, multiple cycles of pushing are required, each time pushing a short distance (a few centimeters to tens of centimeters), then releasing the pressure, adjusting and realigning, and then pushing again. In addition, the position and posture of the beam need to be checked after each cycle to ensure a smooth lateral movement.

[0075] The movement process also includes adjusting the posture, which includes finding that the beam body is deflected during the lateral movement, and controlling the jacking device of the hydraulic system to appropriately adjust the thrust direction and size to make fine adjustments, and at the same time, applying support points on each side or bottom of the beam body, and correcting the posture of the beam body through local lifting or fine adjustments to ensure that it is restored to the ideal horizontal and vertical position;

[0076] During operation, a continuous and seamless construction process can be achieved, which significantly improves construction efficiency and accuracy, reduces the time that the beam is suspended in the air, and thus reduces safety hazards. In addition, this operation mode is equipped with a real-time monitoring system, which can accurately control the position and posture of the beam, reduce human errors and equipment failure rates, adapt to different construction environments, save manpower and material resources, and overall improve the safety and economy of construction, making the erection of prefabricated box beams more efficient and reliable.

[0077] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit thereof, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line, characterized in that: The following steps are involved: S1. Installation of bridge erection machine: Arrange and assemble the bridge erection machine in the selected safety area to ensure its stability. By precisely controlling the lifting and displacement of the bridge erection machine, the prefabricated box girder is stably lifted from the transport vehicle and accurately placed at the designed position within the safety clearance defined by the high-voltage line. S2. Lifting beam of bridge erecting machine: The bridge erecting machine is preset at a suitable position to ensure a safe vertical distance from the high-voltage line; After starting the bridge erection machine, strictly monitor the rising speed of the beam and the line clearance, and continuously adjust the tension and position of the hook to avoid any risk of cable contact or flashing; S3, lowering the beam to the transverse track: operate the bridge erecting machine to lift the box beam to a position above the transverse track, and then slowly lower it through precise mechanical control to ensure that the box beam is aligned with the track and there is no lateral deviation; during the entire lowering process, continuously monitor the safety clearance of the high-voltage line to ensure that the operation is carried out without causing electrical hazards; S4, Pushing and lateral movement: Use special pushing equipment to ensure close contact between the beam and the lateral movement track, and then gradually apply thrust to push the box beam smoothly to the designed position; S5. Cyclic pushing and transverse movement operation: by setting multiple pushing points and using the pushing device to apply force section by section, the box girder is moved transversely to the designed position in sequence. After pushing, the stability of the girder and the safe clearance with the high-voltage line are checked in time to ensure that there is no collision risk during the operation. During the cycle, the operator maintains a high degree of coordination and monitoring, and adjusts the pushing force and rhythm in time to achieve a smooth and smooth movement of the box girder until the overall installation is completed; S6. Horizontal movement to the beam position: First, ensure that the box beam is firmly on the horizontal movement track, then use the horizontal movement equipment to slowly and steadily move the beam body horizontally with appropriate thrust, carefully monitor the clearance distance between the beam body and the high-voltage line to avoid electrical hazards caused by improper operation, and perform necessary docking and fixing to ensure the stability and safety of the beam body, providing a reliable foundation for subsequent construction; S7, beam drop: Precisely control the speed and drop point of the beam so that it is vertically aligned and smoothly contacts the support. Continuously monitor the clearance distance of the high-voltage line to ensure safety and prevent any electrical interference. Then perform final fixing and stabilization measures to ensure that the box girder can withstand future loads and environmental conditions, thereby completing the efficient and safe erection of the bridge.

2. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 1 is characterized in that: The installation of the bridge erecting machine in S1 specifically includes the following steps: a. Site preparation and equipment inspection: Clean and level the construction site to make the installation environment of the bridge erector suitable. At the same time, conduct a comprehensive inspection of all components of the bridge erector, including mechanical structure, electrical system, safety devices, etc., to ensure that all components are intact; b. Foundation construction: According to the design requirements, a stable foundation is set up on site to make the anchoring point of the bridge erecting machine stable and reliable, ensuring its bearing capacity and stability; c. End crossbeam installation: Place the end crossbeam of the bridge erector on the pre-designed track or support for preliminary positioning and fixing. The end crossbeam is the main load-bearing structure of the bridge erector, and its levelness and stability must be ensured; d. Main beam assembly: transport the main beam of the bridge erecting machine to the construction site in sections and assemble it to ensure that the connection between each section of the beam is firm and reliable; e. Installation of lifting system: Install the lifting system of the bridge erector, including the hydraulic lifting device and control system, and ensure that all functions operate normally, and can accurately control the lifting and lateral movement of the beam; f. Safety inspection and trial operation: After all parts are installed, a comprehensive safety inspection is carried out, including structural stability, mechanical transmission, electrical safety, etc., to ensure that there are no potential safety hazards. Then the bridge crane is tested to check whether its functions are normal and whether various operations are sensitive and reliable; g. Formal erection preparation: After the trial run is successful, formal erection preparation work will be carried out, including determining the position of the prefabricated box beam, adjusting the coordinates and angle of the bridge erection machine, and ensuring the accuracy and safety of the erection process; h. Beam dropping and fixing: According to the on-site construction requirements, the beam dropping operation is carried out to accurately lower the prefabricated box beam to the designed position, and then the final fixing and adjustment are carried out to make the box beam stable and meet the load-bearing requirements of the bridge.

3. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 1 is characterized in that: The bridge erection machine beam lifting in S2 specifically includes the following steps: a. Before lifting the beam, conduct a comprehensive inspection of the lifting system of the bridge erector, including the hydraulic system, electrical control system, sensors and safety devices, to ensure that all equipment is in good condition; b. Move the prefabricated box beam to the lifting position of the bridge erection machine, and align the beam body with the center line of the lifting device through the positioning device and measuring tools, and control the error within the allowable range; c. Connect the lifting device (such as hook, sling, etc.) to the reserved lifting point of the box beam to ensure that the connection is firm and not loose; d. Use the bridge erection machine to slowly lift the box girder and avoid sudden acceleration or deceleration to reduce the impact on the girder; e. Control the lifting height of the box beam. When it is close to the set height, slow down the lifting speed and make fine adjustments to make the beam reach the preset height; f. After the box girder is lifted to the set height, it is fixed to prevent it from accidental movement during subsequent operations.

4. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 2 is characterized in that: The installation of the bridge-building machine in S1 also includes the installation of the lifting system, which is achieved by connecting and debugging the electrical system of the bridge-building machine, including the control cabinet, sensors, monitoring equipment, etc. In addition, the debugging of the electrical system must be carried out without high voltage electricity to ensure that the communication and control signals between various devices are accurate.

5. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 1 is characterized in that: The cyclic pushing and lateral shifting operation in S5 further includes the following steps: a. Ensure that the prefabricated box beam is fixed on the transverse track to avoid movement or tilting during the transverse movement. Necessary monitoring equipment and sensors are installed on the beam and track to monitor various parameters of the transverse movement process in real time, such as the position, posture, hydraulic pressure, etc. of the beam; b. Preliminarily align the box girder with the lateral movement direction and the target position so that it will not deviate too much during the lateral movement; c. Apply a top thrust through the hydraulic jack to slowly move the beam horizontally; d. During the transverse movement, the operator observes the position of the beam in real time through the monitoring equipment to ensure that the deviation from the target position is within the allowable range; e. When the beam approaches the target position, reduce the pushing speed and make fine adjustments to align it with the target position; f. After confirming that the beam is stable, remove the jacking device and prepare for the next step of construction.

6. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 5, characterized in that: During the lateral movement process, the pushing speed needs to be controlled to maintain a uniform speed to avoid sudden acceleration or deceleration that may cause vibration or displacement of the beam. At the same time, multiple cycles of pushing are required, each time pushing a short distance (several centimeters to tens of centimeters), and then releasing the pressure, adjusting and realigning, and then pushing again. In addition, the position and posture of the beam need to be checked after each cycle to ensure a smooth lateral movement process.

7. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 6 is characterized in that: The movement process also includes adjusting the posture, which includes discovering that the beam is deflected during the lateral movement, and controlling the pushing device of the hydraulic system to appropriately adjust the thrust direction and size to make fine adjustments. At the same time, support points are applied to each side or bottom of the beam, and the posture of the beam is corrected through local lifting or fine-tuning to ensure that it returns to the ideal horizontal and vertical position.

8. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 1, characterized in that: The lateral movement to the beam position in S6 specifically further comprises the following steps: a. Determine the target position: According to the set position, clarify the final placement position of the prefabricated box beam, and make relevant marks on the ground to ensure the position is accurate, and verify the clearance between the beam and the 220KV high-voltage line; b. Transverse operation: Use the alignment device to perform preliminary alignment on the prefabricated box beam to ensure that its axis is parallel to the transverse track; c. Real-time monitoring: During the entire lateral movement process, the monitoring system is used to observe the position of the beam in real time to ensure that it moves along the predetermined path on the track, and the thrust is fine-tuned to ensure that the beam is in the correct position; d. Arrival at beam position: When the box beam reaches the predetermined position, precise fine-tuning is performed to ensure perfect docking between the beam and the support.

9. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 8, characterized in that: After reaching the beam position in step d, the following steps are also included: (1) Temporary fixation: Use a supporting device to temporarily fix the prefabricated box beam to ensure that it does not move. Improve construction safety; (2) Remove the transverse moving device: After ensuring that the beam is stable, remove the transverse moving device and prepare for subsequent construction steps; (3) Safety inspection: confirm the safe distance between the high-voltage line and the beam to ensure the safety of the construction area.

10. The method for erecting low-headroom, power-off-free prefabricated box beams under a 220KV high-voltage line according to claim 9, characterized in that: The temporary fixation in (1) further comprises the following steps:

1. Determine the specific location where the prefabricated box girder needs to be temporarily fixed; 2. Select appropriate jacks, support frames and steel pads according to the set prefabricated box size and weight; 3. Ensure that the jack is in close contact with the prefabricated box girder and use bolts to firmly connect it to the prefabricated box girder.

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