Construction method for hoisting whole section of steel beam of extra-large cable bent tower bridge

Abstract

The invention relates to a whole-section hoisting construction method for a steel beam of an extra-large cable bent tower bridge, which belongs to the technical field of bridge construction and comprises the following steps of: 1, erecting a steel beam section splicing platform below a main tower; secondly, a lower cross beam of the main tower is constructed, and a bracket is assembled; thirdly, after bracket construction is completed, steel beam sections are spliced on the bracket in a scattered mode to complete installation of the lifting station, and a suspended load test is conducted; 4, the value of K is determined, and the spliced steel beam sections are anchored on the cross beams according to the design requirements; 5, the steel beam sections are pre-spliced after being subjected to section pre-splicing; sixthly, the steel beam sections are lifted through a lifting station; seventhly, a girder erection crane takes a girder and erects a steel girder section; the limiting protection mechanism judges whether the pressure change rate exceeds a threshold value or not, if yes, the step 8 is executed, and if not, the step 9 is executed; 8, the limiting protection mechanism enables the girder erection crane to be locked, the crane is prevented from moving, and operation is stopped; and 9, repeating the steps 4-7 until folding is completed.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a method for hoisting a whole section of a steel beam of an extra-large cable tower bridge. Background Art

[0002] With the popularization of concepts such as factory production, modularization, and prefabrication and assembly in the civil engineering industry, prefabricated buildings have been widely used in engineering fields such as bridge engineering. For example, in bridge engineering, the segmental prefabrication and assembly method is a construction method in which the bridge structure is divided into several segment blocks, which are formed in a factory or a prefabrication yard near the bridge site, and then transported to the bridge site. The segments are assembled into an overall structure using prestressed technology.

[0003] Among them, the cantilever assembly method is a commonly used method for splicing steel beam segments. When there are conditions for transporting heavy blocks under the bridge, the prefabricated parts can be extended along the longitudinal direction of the bridge by cantilever hoisting. The general construction method simply uses a hanger to fix the hanger. Due to the rigidity of the hanger rod and the easy shaking after positioning, it affects the subsequent segment assembly accuracy; while the bracket method for segment positioning has a greater impact on the site, materials, etc., and it is difficult to adjust the accuracy. For this reason, CN106012868B discloses a precise positioning construction control method for a symmetrical cantilever assembly bridge, including the following steps: (1) during the prefabrication of the reference block segment, a sleeve is reserved or a hole is opened, and the reference block prefabrication is installed by the wet connection method. (1) Make the suspended segment and pour the wet joint concrete; (2) During the pouring of the cap beam, the sleeve is embedded in the structure, and the suspension system is fastened and installed by the screw rod pre-installed in the sleeve of the cap beam. At the same time, the suspension system is supported by an adjustable screw jack; (3) The prefabricated segment of the reference block is hoisted to the end of the suspension beam through the hanger and fixed to the suspension system; (4) Through measurement and verification, the reference block segment is adjusted to the designed position using the suspension system, and then the external tie rod is passed through the cap beam, and the internal support device is installed between the prefabricated reference segment and the cap beam; (5) After the fixation is completed, the formwork is installed, the concrete is poured, and the equal strength tension is performed to form a rigid frame system to achieve accurate positioning of the reference block;

[0004] However, in the above scheme, shaking occurs during the overall lifting process and accidents may occur to the beam erecting crane due to the shaking, such as damage to the traction mechanism or breakage of the traction cable. It is impossible to promptly prevent the occurrence of accidents when shaking occurs, and the safety of the overall lifting construction project is low. Therefore, a method for lifting the entire section of the steel beam of a super-large cable tower bridge with high construction safety is needed. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for hoisting the entire section of a steel beam of an extra-large pylon bridge, which has the characteristics of high construction safety.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for hoisting a whole section of a steel beam of an extra-large pylon bridge comprises the following steps:

[0008] Step 1: Set up a steel beam segment assembly platform under the main tower and in front of the pier along the transverse bridge, and set up a trestle to transport the steel beam members to the pier platform;

[0009] Step 2: Carry out the construction of the crossbeam under the main tower, install the embedded parts during the construction of the crossbeam, and after the construction of the crossbeam is completed and the concrete strength meets the requirements, use the tower crane to hoist the segment bracket steel components and assemble the bracket;

[0010] Step 3: After the bracket construction is completed, use the heavy tower crane arranged between the two bridges to hoist the steel beam rods, and assemble the steel beam segments on the bracket. Then use the tower crane to hoist the lifting station components, complete the installation of the lifting station, and conduct a lifting test;

[0011] Step 4: Determine the K value, anchor the assembled steel beam segments on the beams according to the design requirements, use a heavy tower crane to hoist the steel components and auxiliary equipment of the beam erection crane, and install the beam erection crane on the steel beam segments;

[0012] Step 5: The steel beam segments are pre-assembled and accepted on the pre-assembly platform under the bridge. The steel beam segments are slid to the lifting points of the lifting station under the main tower, and the positions and numbers of the lifting points are determined.

[0013] Step 6: Use the lifting station to lift the steel beam segment to the bridge deck elevation, move it horizontally to the bridge deck, and place it on the beam transport trolley;

[0014] Step 7: The beam transport trolley transports the steel beam segment to the rear of the beam erection crane, uses the beam erection crane to take the beam and move the steel beam segment horizontally to the front of the erection, assembles the entire segment, installs high-strength bolts, hangs and tensions the corresponding inclined cables, and the beam erection crane moves forward symmetrically and step by step. When the beam erection crane takes the beam and drives the steel beam segment to move horizontally, the limit protection mechanism determines whether the pressure change rate exceeds the threshold value. If the judgment result is yes, execute step 8, otherwise execute step 9;

[0015] Step 8: The limit protection mechanism locks the beam erecting crane to prevent the crane from moving and stop the operation;

[0016] Step 9: Repeat steps 4 to 7 until the closure is complete.

[0017] As a preferred technical solution of the present invention, step seven includes: the pressure detector performs pressure detection on the steel cable and uploads the pressure data to the control module, the control module calculates the pressure change rate according to the pressure data uploaded successively, and determines whether the pressure change rate is greater than a threshold.

[0018] As a preferred technical solution of the present invention, step eight includes: the control module instructs the spring spring to release, so that the main spring pops up, pushing the slide upward, and the anchoring cylinder moves upward under the drive of the slide and anchors with the slide rail. The anchoring cylinder is anchored with the slide rail hole to complete the locking of the beam erecting crane.

[0019] As a preferred technical solution of the present invention, the step five also includes: fixing the steel beam segment by using a fixed box lifting device; the step six also includes: the lifting station lifts the fixed box lifting device, and then lifts the steel beam segment.

[0020] As a preferred technical solution of the present invention, the process of fixing the steel beam segment by using the fixed box lifting equipment in step five includes the following steps: opening the lifting equipment blocking plate, transporting the required steel beam segment to the limited box lifting equipment by crane, rotating the power gear to rotate the force transmission shaft, and then, through the transmission of the force transmission gear, driving the inner wall to move forward and backward along the guide rail, thereby causing the suction cup to fit closely with the plate, connecting the vacuum pump to the reserved vacuum hole, starting the vacuum pump, and after the suction cup completely fixes the steel beam segment, closing the vacuum valve, repeating this process until all suction cups are completely fixed, closing the blocking plate, lifting, and transporting to the designated position, opening the blocking plate, opening the vacuum valves in turn, and taking out the plate.

[0021] As a preferred technical solution of the present invention, the determination of the K value includes the following steps: inspecting the part that needs to be bolted, then clamping the component with one chuck of the torque testing machine and the component with the other chuck, starting the torque testing machine to apply torque T, and displaying the value of the axial tension on the bolt at this time on the digital tension display, and adopting a graded loading method until the axial tension on the bolt reaches the maximum allowable value N, where N = (0.5~0.7)σs×A1, σs is the yield limit of the bolt material, and A1 is the area of ​​the dangerous section of the bolt.

[0022] As a preferred technical solution of the present invention, the control module is pre-input with a change rate threshold K0, the pressure detector performs pressure detection on the steel cable, and uploads the pressure data at each time point to the control module, the control module calculates the pressure change rate K based on several pressure data uploaded successively, and determines whether the pressure change rate K is greater than the threshold K0.

[0023] As a preferred technical solution of the present invention, the step three also includes: after the construction of the bracket is completed, a pre-compression test is performed on the completed bracket to eliminate non-elastic deformation.

[0024] As a preferred technical solution of the present invention, in step seven, the limit protection mechanism is also used to provide traction for the beam erecting crane. At this time, the hydraulic jack provides power to push the rotating shaft to move. The rotating shaft drives the rotating shaft to rotate through the force arm, and the driving shaft drives the slider to move on the guide rail.

[0025] The beneficial effects of the present invention are:

[0026] (1) By setting a limit protection mechanism, when the traction cable or traction mechanism fails and the pressure change rate exceeds the threshold, the limit protection mechanism locks the beam crane to prevent the steel arm from falling and causing harm to workers, thereby improving construction safety;

[0027] (2) By setting up a limited fixed box lifting device, the transported plates are fixed in the device before lifting, thereby effectively controlling the shaking of the plates during the lifting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0029] Figure 1 This is a flow chart of the construction method for hoisting the entire section of the steel beam of the extra-large pylon bridge;

[0030] Figure 2 Install the flow chart for the beam segment;

[0031] Figure 3 It is a flow chart of the bolting process;

[0032] Figure 4 This is a flow chart of the lifting process;

[0033] Figure 5 Flow chart for the use of the limit protection mechanism of the beam erecting crane;

[0034] Figure 6 This is a schematic diagram of the main construction steps of the steel beam segment;

[0035] Figure 7 This is a schematic diagram of the main construction steps 2 of the steel beam segment;

[0036] Figure 8 This is a schematic diagram of the main construction steps of the steel beam segment three;

[0037] Fig. 9 This is a schematic diagram of the main construction steps of the steel beam segment;

[0038] Fig.10 It is a schematic diagram of the main construction steps of the steel beam segment five;

[0039] Fig.11 This is a schematic diagram of the main construction steps of the steel beam segment six;

[0040] Fig.12 It is a schematic diagram of a limited fixed assembled building hoisting equipment;

[0041] Fig.13 This is a schematic diagram showing the transmission parts of the prefabricated building hoisting equipment;

[0042] Fig.14 This is a schematic diagram of the instrument for measuring the k value;

[0043] Fig.15 This is a schematic diagram of a beam erecting crane;

[0044] Fig.16 A top view of the protection device of the limit protection mechanism;

[0045] Fig.17 A side sectional view of a protection device of a position limiting protection mechanism;

[0046] Fig.18 This is a schematic diagram of the connection between the spring spring piece and the limit piece of the limit protection device;

[0047] Description of main component symbols:

[0048] In the figure: 1. Main tower; 2. Steel beam assembly platform; 3. Pier platform; 4. Cross beam; 5. Tower crane; 6. Bracket; 7. Heavy tower crane; 8. Steel beam segment; 9. Beam erecting crane; 91. Tilt boom; 10. Lifting station; 11. Beam transport trolley; 12. Position limit protection mechanism; 12-1. Guide rail; 12-2. Sliding block; 12-3. Force transmission rod; 12-4. Push shaft; 12-5. Hydraulic jack; 12-2-1. Anchor cylinder; 12-2-2. Spring spring; 12-2-3. Main spring; 12-2-4. Pressure sensor; 12-2-5. Sensing wire; 12-2-6. Position limit plate; 12-2-7. Sliding plate; 12 -2A, rotating shaft; 12-2B, spring; 12-6A, tension spring; 12-6B, metal support; 13, limit protection mechanism of beam crane; 13-1, power gear; 13-2, force transmission rotating shaft; 13-3, force transmission gear; 13-4, driving rotating shaft; 13-5, air guide tube; 13-6, vacuum valve; 13-7, suction cup; 13-8, guide rail; 13-9, exhaust hole; 15, tension display; 15-1, nut of the bolt to be tested; 15-2, bolt rod of the bolt to be tested; 15-3, force transmission frame; 15-4, force transmission frame; 15-5, tension screw; 15-6, tension sensor; 15-7, tension screw. DETAILED DESCRIPTION

[0049] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0050] See also Figure 1-18 A method for hoisting a whole section of a steel beam of a super-large cable tower bridge comprises the following steps:

[0051] Step 1: Under the main tower 1 and in front of the pedestal, a steel beam segment 8 assembly platform is set up along the transverse bridge, and a trestle is set up. The trestle is used to transport the steel beam members to the pier platform 3;

[0052] Specifically, the pier platform 3 is a platform arranged on the side of the main tower 1 along the longitudinal bridge direction, and the steel beam segment 8 assembly platform is arranged on one side of the pier platform 3;

[0053] Meanwhile, step one also includes: setting a steel beam member storage area, setting a steel beam segment pre-assembly area, the pre-assembly area meets the acceptance of accommodating 8 steel beam segments 8, and the 8 steel beam segments 8 can be placed on the pre-assembly area at the same time to wait for hoisting;

[0054] At the same time, in this embodiment, since there is no beam transport channel on the pier side, a trestle is set up to transport the steel beams to the pier platform 3 (3);

[0055] After step 1 is completed, proceed to step 2: construct the cross beam 4 under the main tower 1.

[0056] Specifically, when the main tower 1 is constructed to the height of the beam 4, the beam 4 is constructed, and embedded parts are installed during the construction of the beam 4 so that the beam 4 can be overlapped with the bracket 6. After the construction of the beam 4 is completed and the concrete strength meets the requirements, the tower crane 5 is used to hoist the steel components of the segment bracket 6, and the bracket 6 is assembled on the embedded parts to complete the construction;

[0057] In this embodiment, the bridge has two sections, so after the construction, there are two independent bridge decks, and two brackets 6 are provided for the construction of the two bridge decks;

[0058] After the construction of the bracket 6 is completed, step three is performed: the heavy tower crane 75 arranged between the two bridges is used to hoist the steel beam rod, and the first section of the steel beam segment 8 is assembled on the bracket 6. Subsequently, the tower crane 5 is used to hoist the lifting station 10 components, the installation of the lifting station 10 is completed, and the lifting test of the lifting station 10 is carried out. Specifically, the lifting station 10 is set in the gap formed between the two bridge deck positions and is at a height slightly higher than the bridge deck. The setting position of the lifting station 10 ensures that the bottom of the lifting station 10 coincides with the pre-assembly area;

[0059] Then, step 4 is performed: determine the K value, anchor the assembled steel beam segment 8 on the cross beam 4 according to the design requirements, so that the first steel beam segment 8 is formed on the main tower 1, and use the heavy tower crane 75 to hoist the steel components and auxiliary equipment of the suspended beam crane 9, and install the suspended beam crane 9 on the edge of the bridge deck formed by the surface of the first steel beam segment 8;

[0060] Then, step five is performed: after the steel beam segment 8 is pre-assembled on the platform of the pre-assembly area under the bridge and accepted, the steel beam segment 8 is slid to the lifting point directly below the lifting station 10, and the position and number of the lifting points are determined;

[0061] Then, step six is ​​performed: the steel beam segment 8 is lifted by the lifting station 10, and after being lifted to the bridge deck elevation, it is moved horizontally to the bridge deck and placed on the beam transport trolley 11;

[0062] Specifically, after the first steel beam segment 8 is formed on the main tower 1, a beam transport trolley 11 is placed on the surface of the steel beam segment 8, and the starting point of the beam transport trolley 11 is located on one side of the lifting station 10, and the end point of the travel is located at the position behind the beam erecting crane 9;

[0063] When in use, the lifting station 10 lifts the steel beam segment 8 from the pre-assembly area to a height above the bridge deck, and then rotates to place the steel beam segment 8 on the beam transport trolley 11;

[0064] Then, step seven is executed: the beam transporting trolley 11 transports the steel beam segment 8 to the rear of the beam erecting crane 9, and the beam erecting crane 9 is used to take the beam and move the steel beam segment 8 horizontally to the front of the current steel beam segment 8, assemble the entire segment, install high-strength bolts, hang and tension the corresponding inclined cables, and complete the extension of the bridge deck. At this time, the newly installed steel beam segment 8 constitutes a new bridge deck, and the beam erecting crane 9 is advanced forward to the far end of the newly installed steel beam segment 8;

[0065] When the beam erecting crane 9 takes the beam and drives the steel beam segment 8 to move horizontally, there is a probability of shaking and accidents caused by shaking to the beam erecting crane 9, such as damage to the traction mechanism or breakage of the traction steel cable. The above scheme cannot timely prevent accidents from occurring when shaking occurs, and the safety of the overall hoisting construction project is low. Therefore, when the beam erecting crane 9 takes the beam and drives the steel beam segment 8 to move horizontally, the limit protection mechanism 12 determines whether the pressure change rate exceeds the threshold value. When the judgment result is yes, step eight is executed, otherwise step nine is executed;

[0066] Step eight is: the position limiting protection mechanism 12 locks the beam erecting crane 9 to prevent the crane from moving and stop the operation;

[0067] Step nine is: repeat steps four to seven until the closure of the bridge is completed.

[0068] In the above step 7, specifically, the position limiting protection mechanism 12 also includes a control module. At the same time, when assembling the beam erecting crane 9 in step 4, the position limiting protection mechanism 12 is installed at the beam erecting crane 9;

[0069] Specifically, the beam erecting crane 9 includes an inclined boom 91 with a tightened sling, the steel cable passes over the upper end of the inclined boom 91 and hangs down, the lower end of the steel cable is used to connect the hook, and a slide rail is arranged below the inclined boom 91; at the same time, the limit protection mechanism 12 includes a hydraulic jack 12-5, the output end of the hydraulic jack 12-5 is provided with a driving shaft 13-412-2A12-4, the driving shaft 13-412-2A12-4 is connected with a force transmission rod 12-3, the force transmission rod 12-3 is hinged with a slider 12-2, the slider 12-2 is slidably arranged on the slide rail, and a plurality of accommodating holes are arranged on the surface of the slide rail;

[0070] When in use, the hydraulic jack 12-5 provides power to push the rotating shaft 13-412-2A12-4 to move, and the rotating shaft 12-2A pushes the force transmission rod 12-3 to rotate through the force arm. The force transmission rod 12-3 drives the slider 12-2 to move on the guide rail 13-812-1, providing part of the traction force for the tensioning cable of the beam crane 9.

[0071] By setting up the limit protection mechanism 12, when the traction cable or traction mechanism fails and causes the pressure change rate to exceed the threshold, the limit protection mechanism 12 locks the beam erecting crane 9 to prevent the steel arm from falling and causing injuries to workers, thereby improving construction safety. At the same time, the limit protection mechanism 12 is also used to provide traction for the beam erecting crane 9 to improve construction efficiency.

[0072] In the process of locking the beam erecting crane 9 by the limit protection mechanism 12 in step eight, specifically, the control module is pre-input with a change rate threshold value K0, the pressure detector performs pressure detection on the steel cable, and uploads the pressure data at each time point to the control module, the control module calculates the pressure change rate K according to the pressure data uploaded successively, and determines whether the pressure change rate K is greater than the threshold value K0;

[0073] At the same time, the slider 12-2 of the limit protection mechanism 12 is a hollow structure near the end of the slide rail, and a slide 12-2-7 is slidably arranged in the hollow structure. The slide 12-2-7 can be close to or away from the slide rail in the hollow structure. A plurality of anchoring cylinders 12-2-1 are arranged on the surface of the slide 12-2-7 close to the slide rail, and the surface of the slide 12-2-7 away from the slide rail is connected to the main spring 12-2B12-2-3. A limit plate 12-2-6 is arranged on the inner wall of the hollow structure, and the slide 12-2-7 is controlled by the limit plate 12-2-6. The slide 12-2-7 is controlled by the limit plate 12-2-6. In the state, the main spring 12-2B12-2-3 is squeezed. When the control module determines that the pressure change rate exceeds the threshold, the command pressure sensor 12-2-4 transmits a signal through the sensing wire 12-2-5, and the limit plate 12-2-6 releases the control. The main spring 12-2B12-2-3 releases elastic potential energy, drives the slide 12-2-7 close to the slide rail, and then drives the anchoring cylinder 12-2-1 to insert into the receiving hole of the slide rail, so that the slider 12-2 is anchored to the slide rail, completing the locking of the beam crane 9. The spring 12-2B slide 12-2-7 further controls the slide 12-2-7 to prevent it from moving backward;

[0074] At the same time, a spring 12-2B spring piece 12-2-2 is provided on the inner wall of the hollow structure, and the spring 12-2B spring piece 12-2-2 is used to prevent the slide 12-2-7 from moving away from the slide rail after the anchoring cylinder 12-2-1 is inserted into the receiving hole of the slide rail.

[0075] In the above process, step five also includes: fixing the steel beam segment 8 by using a fixed box hoisting device; step six also includes: the lifting station 10 lifts the fixed box hoisting device and then lifts the steel beam segment 8;

[0076] Specifically, the fixed box lifting equipment includes a hollow rectangular box, and also includes a power gear 13-1, a power transmission shaft 13-212-2A, a power transmission gear 13-3, and a driving shaft 13-412-2A12-4; a receiving cavity is arranged on each side of the box, and each receiving cavity is in a rectangular shape. The inner wall of each receiving cavity close to the inner side of the box is surrounded by the box to form a receiving cavity, and a guide rail 13-812-1 is arranged above the box, and the inner wall of each receiving cavity is slidably arranged on the guide rail 13-812-1, and the inner wall of each receiving cavity can be moved along the guide rail 13 -812-1 is close to or away from the center of the box, the power gear 13-1 and the force transmission shaft 13-212-2A are arranged in the box accommodating chamber, the power gear 13-1 is connected to the force transmission shaft 13-212-2A, the force transmission shaft 13-212-2A is connected to the inner wall through a force transmission gear 13-3, the force transmission shaft 13-212-2A drives the movement of the push shaft 13-412-2A12-4 in the accommodating chamber through the force transmission gear 13-3, and then drives the inner wall to move along the guide rail 13-812-1 close to or away from the middle of the box;

[0077] A number of suction cups 13-7 are arranged on the inner wall, and the suction cups 13-7 are pushed by the inner wall to contact the steel beam segment 8 located between the two accommodating cavities. Each suction cup 13-7 is connected to the air extraction hole 13-9 through a rubber air guide tube 13-5. A vacuum valve 13-6 is arranged between the air guide tube 13-5 and the air extraction valve. After the air extraction work is completed, the vacuum valve 13-6 is closed to ensure that the steel beam segment 8 and the limited fixed box lifting equipment are stably connected through the suction cup 13-7.

[0078] In the above step 4, the determination of the K value includes the following steps: inspecting the part to be bolted, then clamping the component with one chuck of the torque tester and clamping the component with the other chuck, starting the torque tester to apply the torque T, and displaying the value of the axial tension on the bolt at this time on the digital tension display, and adopting a graded loading method until the axial tension on the bolt reaches the maximum allowable value N, where N = (0.5-0.7)σs×A1, σs is the yield limit of the bolt material, A1 is the area T of the dangerous section of the bolt, and T = K Qp d;

[0079] Specifically, it displays the axial tensile force value that the bolt is subjected to under the action of the torque applied by the torque testing machine. On the torque testing machine, one chuck clamps the component and the other chuck clamps the component. The torque testing machine is started to apply the torque T, and the digital tensile display shows the axial tensile force value borne by the bolt at this time.

[0080] In the above process, after the construction of the bracket 6 in step 3 is completed, the completed bracket 6 is subjected to a pre-compression test to eliminate non-elastic deformation. The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments of equivalent changes without departing from the scope of the technical solution of the present invention. However, any brief modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for hoisting the entire section of a steel beam of an extra-large pylon bridge, characterized in that: The following steps are involved: Step 1: Set up a steel beam segment assembly platform along the transverse direction of the main tower; Step 2: Carry out the construction of the crossbeam under the main tower, and then assemble the bracket; Step 3: After the bracket construction is completed, the steel beam segments are assembled on the bracket, and then the lifting station is installed on the bracket; Step 4: Determine the K value, anchor the assembled steel beam segments on the beams according to the design requirements, install a beam erecting crane on the steel beam segments, and slide a limit protection mechanism at the boom of the beam erecting crane; Step 5: Assemble the steel beam segments at the lifting point of the lifting station; Step 6: Use the lifting station to lift the steel beam segment and place it on the beam transport trolley; Step 7: The beam transport trolley transports the steel beam segment to the rear of the beam erecting crane, and uses the beam erecting crane to take the beam and move the steel beam segment horizontally to the front of the erection, assemble the entire segment, hang and tension the corresponding inclined cable, and the beam erecting crane moves forward. When the beam erecting crane takes the beam and drives the steel beam segment to move horizontally, the limit protection mechanism determines whether the pressure change rate of the steel cable exceeds the threshold value. If the judgment result is yes, execute step 8, otherwise execute step 9; Step 8: The limit protection mechanism locks the beam erecting crane to prevent the crane from moving and stop the operation; Step 9: Repeat steps 4 to 7 until the closure is complete.

2. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The step seven includes: the pressure detector performs pressure detection on the steel cable, calculates the pressure change rate according to the pressure data uploaded successively, and determines whether the pressure change rate is greater than a threshold value.

3. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 2 is characterized in that: The process of locking the beam erecting crane by the limit protection mechanism in step eight includes: the limit protection mechanism instructs the main spring inside to spring open, pushing the slide plate upward, and the anchoring cylinder moves toward the slide rail provided on the boom under the drive of the slide plate, and is inserted into the slide rail hole, so that the anchoring cylinder is anchored to the slide rail hole, thereby anchoring the limit protection mechanism to the boom, completing the locking of the beam erecting crane.

4. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The step five also includes: fixing the steel beam segment by using a fixed box lifting device; the step six also includes: the lifting station lifts the fixed box lifting device, thereby lifting the steel beam segment.

5. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The process of fixing the steel beam segment by using the fixed box lifting equipment in step five includes the following steps: opening the lifting equipment blocking plate, transporting the required steel beam segment to the limited box lifting equipment by crane, turning the power gear to rotate the power transmission shaft, and then driving the inner wall to move forward and backward along the guide rail through the transmission of the power transmission gear, thereby causing the suction cup to fit closely with the plate, connecting the vacuum pump to the reserved vacuum hole, starting the vacuum pump, and after the suction cup completely fixes the steel beam segment, closing the vacuum valve, repeating this process until all suction cups are completely fixed, closing the blocking plate, lifting, and transporting to the designated position, opening the blocking plate, opening the vacuum valves in turn, and taking out the plate.

6. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The determination of the K value includes the following steps: inspect the part that needs to be bolted, then clamp the component with one chuck of the torque testing machine and clamp the component with the other chuck, start the torque testing machine to apply torque T, and display the value of the axial tension on the bolt at this time on the digital tension display, and use a graded loading method until the axial tension on the bolt reaches the maximum allowable value N, where N = (0.5~0.7)σs×A1, σs is the yield limit of the bolt material, and A1 is the area of ​​the dangerous section of the bolt.

7. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The control module is pre-input with a change rate threshold K0. The pressure detector detects the pressure of the steel cable and uploads the pressure data at each time point to the control module. The control module calculates the pressure change rate K based on several pressure data uploaded successively, and determines whether the pressure change rate K is greater than the threshold K0.

8. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized in that: The step three also includes: after the bracket construction is completed, a pre-compression test is performed on the completed bracket to eliminate non-elastic deformation.

9. The method for hoisting the entire section of a steel beam of a super-large pylon bridge according to claim 1 is characterized by: In step seven, the limit protection mechanism is also used to provide traction for the beam erecting crane. At this time, the hydraulic jack provides power to push the shaft to move. The shaft drives the shaft to rotate through the force arm, and the shaft drives the slider to move on the guide rail.

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