Pushing construction method of curved steel box girder ramp bridge

Abstract

The application discloses a curve steel box girder ramp bridge jacking construction method, which comprises the following steps: step S1, all steel box girders are matched and manufactured into stereoscopic segments in a factory, a jacking and pushing platform and a track beam are erected, a jacking device is installed, and a steel box girder hoisting and lifting device is installed; step S2, a steel box girder segment is hoisted and installed and adjusted, a steel guide beam is hoisted and installed and adjusted, and the interface between the steel guide beam and the steel box girder segment is welded; step S3, the steel box girder is slid and jacked, and the step S3 specifically comprises the following steps: step S31, the whole is jacked forward by a designed distance until the frontmost slider of the steel box girder slides out of the track beam, and then the frontmost slider of the steel box girder is removed; step S32, the whole is jacked forward by a set distance, and the front slider of the guide beam is on the track beam; and step S5, after a concrete beam segment is poured and formed, the remaining support is removed. The application realizes jacking and positioning of the steel box girder and guarantees the reliability of construction quality.

Description

Technical Field

[0001] This invention relates to the field of bridge construction. More specifically, this invention relates to a method for the incremental launching construction of a curved steel box girder ramp bridge. Background Technology

[0002] To overcome the problems of mid-span collapse, cracking of top and bottom slabs and webs in long-span PC continuous box girder bridges, engineers at home and abroad have begun to design and construct facing steel-concrete composite structure bridges in recent years. This means replacing the PC box girder in the mid-span of the main span with a steel box girder. Compared with traditional long-span PC continuous beam or continuous rigid frame bridges, the steel box girder segment in the middle span is often constructed by integral jacking due to various limitations, which can greatly shorten the construction period. However, this type of bridge also brings several technical challenges that must be solved. One is the problem of combining the steel box girder with the PC box girder. The other is the problem of jacking the steel box girder in the middle span. When using the jacking method, how to ensure the overturning stability of the steel box girder itself during the jacking process, and the reliability of the connection construction quality of the steel-concrete composite section after jacking. Summary of the Invention

[0003] The purpose of this invention is to provide a method for jacking construction of curved steel box girder ramp bridges, so as to realize the jacking and positioning of the steel box girder and ensure the reliability of construction quality.

[0004] The technical solution adopted by this invention to solve this technical problem is: a method for jacking construction of a curved steel box girder ramp bridge, comprising the following steps:

[0005] Step S1: All steel box girders are manufactured into three-dimensional segments in the factory; an assembly and jacking platform and track beams are erected; the jacking device is installed; and the steel box girder lifting equipment is installed.

[0006] Step S2: Lift, install, and adjust the steel box girder segments; lift, install, and adjust the steel guide beam; weld the interface between the steel guide beam and the steel box girder segments.

[0007] Step S3: The steel box girder is jacked and pushed by sliding, specifically including:

[0008] Step S31: Push the entire steel box girder forward by the designed distance until the frontmost slider of the steel box girder slides out of the track, and then remove the frontmost slider of the steel box girder.

[0009] Step S32: Push the entire structure forward a set distance, and the slider at the front end of the guide beam will move onto the track beam;

[0010] Step S33: Push the steel box girder in a cycle with a set distance L. Each push distance L is used to remove the slider at the front end of the steel box girder that is off track.

[0011] Step S34: Continue pushing forward until the steel beam is in place;

[0012] Step S4: Lower the beam and remove the steel guide beam and track beam;

[0013] Step S5: After the concrete beam segment is cast and formed, remove the remaining supports.

[0014] Preferably, the steel guide beam is a two-piece variable-height I-beam structure, and the two I-beam structures are connected by a connection system composed of I-beams and channel steel.

[0015] Preferably, in step S2, the steel box girder segments are hoisted using supports. After the first segment is hoisted, anti-displacement measures are set up. After subsequent steel box girder segments are hoisted, they are temporarily fixed to the previously hoisted segments using clamps. Welding of the main girder segments and steel guide beam segments is carried out after all the main girder segments and steel guide beam segments are hoisted.

[0016] Preferably, it also includes a positioning and anti-eccentricity device, which includes a limiting mechanism, a positioning mechanism, and an anti-eccentricity mechanism;

[0017] The limiting mechanism includes a pair of limiting plates symmetrically arranged on both sides of the starting end of the track beam. The pair of limiting plates extend from the starting end of the track beam to the initial sliding end of the steel box beam, and the distance between the pair of limiting plates gradually increases. Distance sensors are symmetrically installed on the pair of limiting plates.

[0018] The adjustment mechanism includes temporary blocks and adjustment cylinders. The temporary blocks are symmetrically arranged on both sides near the limiting mechanism, and the lateral distance between the two sets of temporary blocks is greater than the lateral distance between the two sets of limiting mechanisms. The adjustment cylinders are fixed on the temporary blocks and are used to adjust the lateral position of the steel guide beam.

[0019] The anti-eccentric loading mechanism is located near the adjustment mechanism. The anti-eccentric loading mechanism is located at the center of the two sets of adjustment mechanisms. The anti-eccentric loading mechanism includes a temporary block, a first slide rail, a limiting block, and a gripper assembly. The first slide rail is installed laterally on the temporary block. Limiting blocks are installed at both ends of the first slide rail. The gripper assembly includes a semi-circular front gripper and a semi-circular rear gripper. The front gripper and the rear gripper are controlled to move on the first slide rail by a moving hydraulic cylinder. The front gripper and the rear gripper are attracted or released by an electromagnet.

[0020] The controller, which is connected to the distance sensor, the adjusting cylinder, the moving cylinder, and the electromagnet, is configured as follows:

[0021] When the steel guide beam moves to the limiting mechanism, the distance sensor detects the distance between the steel guide beam and the two sides of the strain height I-beam structure and the distance sensor, and transmits the detection data to the controller. The controller calculates the difference between the detected distance and the set distance, and then controls the gripper assembly to move to the center position below the steel guide beam. The front and rear grippers clamp the connection system of the steel guide beam, and then the adjustment cylinder controls the adjustment cylinder to correct the steel guide beam according to the difference.

[0022] Preferably, in step S3, the jacking device uses a hydraulic jacking device to complete the jacking;

[0023] The hydraulic pusher includes a clamping seat, a hydraulic cylinder, and a sliding component; the clamping seat is a wedge-shaped clamping block structure, and the clamping seat can clamp or release the track; the two ends of the hydraulic cylinder are respectively hinged to the clamping seat and the sliding component; the sliding component is rigidly connected to the rear end of the steel box girder.

[0024] The hydraulic jacking process includes:

[0025] Step 1: The clamping seat clamps with the sliding rail, and the piston rod pin at the front end of the hydraulic cylinder is connected to the sliding component; the hydraulic cylinder extends, pushing the sliding component forward.

[0026] Step 2: The hydraulic cylinder extends one stroke, and the component slides forward one step.

[0027] Step 3: After one stroke of the cylinder extension is completed, the sliding component remains stationary, the hydraulic cylinder retracts, causing the clamping seat to release from the sliding track, and dragging the clamping seat forward;

[0028] Step 4: After the hydraulic pusher completes one stroke of cylinder retraction, drag the clamping seat forward one step, and complete one crawling stroke. Then, repeat step 1 again, and repeat this process to move the component to its final position.

[0029] Preferably, the control of the jacking construction includes the following steps:

[0030] Graded loading slip

[0031] a1) When the sliding begins, the pressure of the hydraulic cylinder of the hydraulic jacking device is gradually increased, successively to 20% and 40% of the required pressure. If everything is normal, the load can continue to 60%, 80%, 90%, and 100% until the structure is separated from the jacking support system.

[0032] a2) After the structural load is completely transferred to the hydraulic jacking cylinder, the hydraulic jacking cylinder extension pressure is gradually increased, successively to 20% and 40% of the required pressure. If everything is normal, the load can continue to be increased to 60%, 80%, 90%, and 100% until the structure is about to move.

[0033] a3) When the sliding structure is about to move, stop the sliding propulsion and maintain the pressure of the propulsion system; conduct a comprehensive inspection of the hydraulic jacking device and equipment system and structural system, and only continue sliding after confirming that there are no problems with the stability and safety of the overall structure.

[0034] formal slip

[0035] b1) Pre-set the pump source pressure value according to the design sliding load, thereby controlling the maximum output thrust and lifting force of the hydraulic jack;

[0036] b2) Control the error of each pusher within 20mm, thereby controlling the synchronous sliding of the entire sliding unit;

[0037] b3) When maintaining a certain synchronous sliding state, there is basically no lateral horizontal force in the horizontal direction, and the sliding support system is calculated to be safe under the sliding condition. Lateral blocks are set at the corresponding positions of the sliding unit, and the whole sliding process is safe and reliable.

[0038] Preferably, it also includes a slip monitoring system, which includes a computer synchronous control system, a stroke sensor and an oil pressure sensor mounted on the hydraulic cylinder;

[0039] The slip synchronization monitoring steps include:

[0040] Based on the reaction force values ​​of each jacking point under the sliding jacking condition calculated in advance, the maximum jacking force and jacking force of each hydraulic jacking device are set in the computer synchronous control system; when the jacking force or jacking force exceeds the set value, the hydraulic jacking device automatically adopts overflow unloading.

[0041] A mechanical and hydraulic self-locking system is installed in the hydraulic circuit. When the hydraulic jack stops working or encounters a power outage, the lifting cylinder can be automatically locked for a long time to prevent it from sinking, thus ensuring the safety of the structure.

[0042] The present invention has at least the following beneficial effects: the method for launching curved steel box girder ramp bridges solves the problem of launching steel box girders in the mid-span section, ensuring the stable and anti-overturning launching of the steel box girder, and the construction period can be greatly shortened by using the construction method of this application.

[0043] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the hoisting and welding of the steel guide beam and steel box girder of the present invention;

[0045] Figure 2 This is a schematic diagram of the steel box girder top-pushing process of the present invention;

[0046] Figure 3 This is a schematic diagram of the track beam on the steel guide beam of the present invention;

[0047] Figure 4 This is a schematic diagram of the steel box girder being pushed into place according to the present invention;

[0048] Figure 5 This is a schematic diagram of the dismantling of the steel guide beam according to the present invention;

[0049] Figure 6This is a schematic diagram of the concrete beam segment casting and forming process of the present invention;

[0050] Figure 7 This is a schematic diagram of the hydraulic pusher structure of the present invention;

[0051] Figure 8 This is a schematic diagram of the positioning and anti-eccentricity device of the present invention;

[0052] Figure 9 This is a schematic diagram of the steel guide beam structure of the present invention;

[0053] Explanation of reference numerals in the attached drawings: 1. Steel box girder segment; 2. Steel guide beam; 3. Track beam; 4. Concrete beam segment; 5. Clamping seat; 6. Hydraulic cylinder; 7. Sliding component; 8. Limiting plate; 9. Distance sensor; 10. Adjusting cylinder; 11. First slide rail; 12. Limiting block; 13. Gripper assembly; 14. Variable height I-beam structure; 15. Connecting system. Detailed Implementation

[0054] The present invention will now be described in detail and completely with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be particularly noted that the technical solutions and features provided in various parts of the present invention, including the following description, can be combined with each other without conflict.

[0055] Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows:

[0057] like Figures 1-9 As shown, the present invention provides a method for jacking construction of a curved steel box girder ramp bridge, comprising the following steps:

[0058] Step S1: All steel box girders are manufactured into three-dimensional segments in the factory; an assembly and jacking platform and track beam 3 are erected; the jacking device is installed; and the steel box girder lifting equipment is installed.

[0059] Step S2, as follows Figure 1 As shown, the steel box girder segment 1 is lifted, installed, and adjusted; the steel guide beam 2 is lifted, installed, and adjusted; and the interface between the steel guide beam 2 and the steel box girder segment 1 is welded.

[0060] Step S3: The steel box girder is jacked and pushed by sliding, specifically including:

[0061] Step S31, as follows Figure 2 As shown, the entire structure is pushed forward by the designed distance until the frontmost slider of the steel box girder slides out of the track, and then the frontmost slider of the steel box girder is removed.

[0062] Step S32: Push the entire structure forward a set distance, and the slider at the front end of the guide beam moves onto the track beam 3;

[0063] Step S33: Push the steel box girder in a cycle with a set distance L. Each push distance L is used to remove the slider at the front end of the steel box girder that is off track.

[0064] Step S34: Continue pushing forward until the steel box girder is in place;

[0065] Step S4: Lower the beam and remove the steel guide beam 2 and track beam 3;

[0066] Step S5: After the concrete beam segment 4 is poured and formed, remove the remaining supports.

[0067] This technical solution may also include the following technical details to better achieve the technical effect: The steel guide beam 2 consists of two variable-height I-beam structures 14, connected by a connection system 15 composed of I-beams and channel steel. The guide beam is made of Q345 steel. The guide beam is butt-welded to the web, top plate, and bottom plate of adjacent segments, and the plate thickness is as similar as possible to the top plate, bottom plate, and web of the adjacent steel beam segments. A ramp is provided at the front end of the guide beam to facilitate the mounting of the track beam 3 when the maximum cantilever is reached.

[0068] This technical solution may also include the following technical details to better achieve the technical effect: In step S2, the steel box girder segment 1 is hoisted using a support frame. After the first segment is hoisted, anti-displacement measures are set. After subsequent steel box girder segments 1 are hoisted, they are temporarily fixed with the previously hoisted segments using a plate. After all the main girder segments and steel guide beams 2 are hoisted, the main girder segments and steel guide beams 2 segments are welded.

[0069] This technical solution may also include the following technical details to better achieve the technical effect: it also includes a positioning and anti-eccentricity device, which includes a limit mechanism, a positioning mechanism and an anti-eccentricity mechanism;

[0070] The limiting mechanism includes a pair of limiting plates 6 symmetrically arranged on both sides of the starting end of the track beam 3. The pair of limiting plates 6 extend from the starting end of the track beam 3 to the initial sliding end of the steel box beam, and the distance between the pair of limiting plates 6 gradually increases. Distance sensors 9 are symmetrically installed on the pair of limiting plates 6.

[0071] The adjustment mechanism includes temporary blocks and adjustment cylinders 10. The temporary blocks are symmetrically arranged on both sides near the limiting mechanism, and the lateral distance between the two sets of temporary blocks is greater than the lateral distance between the two sets of limiting mechanisms. The adjustment cylinders 10 are fixed on the temporary blocks and are used to adjust the lateral position of the steel guide beam 2.

[0072] The anti-eccentric loading mechanism is located near the adjustment mechanism and is positioned at the center of the two adjustment mechanisms. The anti-eccentric loading mechanism includes a temporary block, a first slide rail 11, a limiting block 12, and a gripper assembly 13. The first slide rail 11 is horizontally installed on the temporary block, and the limiting blocks 12 are installed at both ends of the first slide rail 11. The gripper assembly 13 includes a semi-circular front gripper and a semi-circular rear gripper. The front gripper and the rear gripper are controlled to move on the first slide rail 11 by a moving hydraulic cylinder. The front gripper and the rear gripper are attracted or released by an electromagnet.

[0073] The controller, which is connected to the distance sensor 9, the adjusting cylinder 10, the moving cylinder, and the electromagnet, is configured as follows:

[0074] When the steel guide beam 2 moves to the limiting mechanism, the distance sensor 9 detects the distance between the steel guide beam 2 and the two sides of the strain height I-shaped structure 14 and the distance sensor 9, and transmits the detection data to the controller. The controller calculates the difference between the detected distance and the set distance, and then controls the gripper assembly 13 to move to the center position below the steel guide beam 2, and clamps the connecting system 15 of the steel guide beam 2 through the front and rear grippers. Then, the controller controls the adjustment cylinder 10 to correct the steel guide beam 2 according to the difference.

[0075] The positioning and anti-eccentricity device can perform a precise correction before the steel guide beam 2 is placed on the track beam 3, helping the steel guide beam 2 to smoothly move onto the track beam 3. During the lateral positioning and correction of the steel guide beam 2, the anti-eccentricity mechanism locks the steel guide beam 2, correcting any deviations that occur during the jacking process and preventing the steel beam from overturning.

[0076] This technical solution may also include the following technical details to better achieve the technical effect: the jacking device in step S3 uses a hydraulic jacking device to complete the jacking;

[0077] The hydraulic pusher includes a clamping seat 5, a hydraulic cylinder 6, and a sliding component 7; the clamping seat 5 is a wedge-shaped clamping block structure, and the clamping seat 5 can clamp or release the track; the two ends of the hydraulic cylinder 6 are respectively hinged to the clamping seat 5 and the sliding component 7; the sliding component 7 is rigidly connected to the rear end of the steel box girder.

[0078] The clamping seat 5 of the hydraulic crawler has a one-way self-locking function. When the cylinder extends, the wedge-shaped clamping block works (clamps), automatically locking the sliding track; when the cylinder retracts, the clamping block does not work (releases), and moves in the same direction as the cylinder.

[0079] The hydraulic jacking process includes:

[0080] Step 1: The clamping seat 5 clamps with the sliding rail, and the piston rod pin at the front end of the hydraulic cylinder 6 is connected to the sliding component 7; the hydraulic cylinder 6 extends, pushing the sliding component 7 to slide forward;

[0081] Step 2: The hydraulic cylinder 6 extends one stroke, and the component slides forward one step;

[0082] Step 3: After one stroke of the cylinder extension is completed, the sliding component 7 remains stationary, the hydraulic cylinder 6 retracts, causing the clamping seat 5 to release from the sliding track, and dragging the clamping seat 5 forward;

[0083] Step 4: After the hydraulic pusher completes one stroke of cylinder retraction, drag the clamping seat 5 forward by one step, and complete one crawling stroke. Then, repeat step 1 again, and repeat this process to move the component to its final position.

[0084] In this embodiment, the hydraulic jacking device is a device that can automatically clamp the track to generate a reaction force, thereby achieving the pushing action. This device can eliminate the need for a reaction frame, saving the problem of reinforcing the reaction point, saving time and effort. Furthermore, due to its rigid connection with the steel box girder, synchronous control is easier to achieve, resulting in high positioning accuracy.

[0085] This technical solution may also include the following technical details to better achieve the technical effect: The control of the jacking construction includes the following steps:

[0086] Graded loading slip

[0087] a1) When the sliding begins, the pressure of the hydraulic cylinder 6 of the hydraulic pusher is gradually increased, successively to 20% and 40% of the required pressure. If everything is normal, the load can continue to 60%, 80%, 90%, and 100% until the structure is separated from the pusher support system.

[0088] a2) After the structural load is completely transferred to the hydraulic jacking cylinder, the hydraulic jacking cylinder extension pressure is gradually increased, successively to 20% and 40% of the required pressure. If everything is normal, the load can continue to be increased to 60%, 80%, 90%, and 100% until the structure is about to move.

[0089] a3) When the sliding structure is about to move, stop the sliding propulsion and maintain the pressure of the propulsion system; conduct a comprehensive inspection of the hydraulic jacking device and equipment system and structural system, and only continue sliding after confirming that there are no problems with the stability and safety of the overall structure.

[0090] formal slip

[0091] b1) Pre-set the pump source pressure value according to the design sliding load, thereby controlling the maximum output thrust and lifting force of the hydraulic jacking device to ensure the safety of the entire sliding device;

[0092] b2) The computer control system uses the distance signal fed back by the grid sensor to control the error of each pusher within 20mm, thereby controlling the synchronous sliding of the entire sliding unit;

[0093] b3) When maintaining a certain synchronous sliding state, there is basically no lateral horizontal force in the horizontal direction (considered at 5% for safety), and the sliding support system is calculated to be safe under the sliding condition. Lateral blocks are set at the corresponding positions of the sliding unit, and the whole sliding process is safe and reliable.

[0094] During the actual sliding process, the hydraulic pusher is a hydraulic system. Through flow control, the acceleration of the pusher during startup and shutdown is almost zero, resulting in very little impact on the pusher support.

[0095] This technical solution may also include the following technical details to better achieve the technical effect: it also includes a slip monitoring system, which includes a computer synchronous control system, a stroke sensor and an oil pressure sensor installed on the hydraulic cylinder 6;

[0096] The slip synchronization monitoring steps include:

[0097] Based on the reaction force values ​​of each jacking point under the sliding jacking condition calculated in advance, the maximum jacking force and jacking force of each hydraulic jacking device are set in the computer synchronous control system. When the jacking force or jacking force exceeds the set value, the hydraulic jacking device automatically adopts overflow unloading to prevent severe uneven load distribution at the jacking point, which could cause damage to the structure or temporary facilities.

[0098] A mechanical and hydraulic self-locking system is installed in the hydraulic circuit. When the hydraulic jack stops working or encounters a power outage, the lifting cylinder can be automatically locked for a long time to prevent it from sinking, thus ensuring the safety of the structure.

[0099] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for jacking construction of a curved steel box girder ramp bridge, characterized in that, Includes the following steps: Step S1: All steel box girders are manufactured into three-dimensional segments in the factory; an assembly and jacking platform and track beams are erected; and the jacking device is installed. Install steel box girder lifting and hoisting equipment; Step S2: Lift, install, and adjust the steel box girder segments; lift, install, and adjust the steel guide beam; weld the interface between the steel guide beam and the steel box girder segments; the steel guide beam consists of two variable-height I-beam structures, connected by a connection system composed of I-beams and channel steel. Step S3: The steel box girder is jacked and pushed by sliding, specifically including: Step S31: Push the entire steel box girder forward by the designed distance until the frontmost slider of the steel box girder slides out of the track, and then remove the frontmost slider of the steel box girder. Step S32: Push the entire structure forward a set distance, and the slider at the front end of the guide beam will move onto the track beam; Step S33: Push the steel box girder in a cycle with a set distance L. Each push distance L is used to remove the slider at the front end of the steel box girder that is off track. Step S34: Continue pushing forward until the steel beam is in place; In step S3, the jacking device uses a hydraulic jacking device to complete the jacking; The hydraulic pusher includes a clamping seat, a hydraulic cylinder, and a sliding component; the clamping seat is a wedge-shaped clamping block structure, and the clamping seat can clamp or release the track; the two ends of the hydraulic cylinder are respectively hinged to the clamping seat and the sliding component; the sliding component is rigidly connected to the rear end of the steel box girder. The hydraulic jacking process includes: Step 1: The clamping seat clamps with the sliding rail, and the piston rod pin at the front end of the hydraulic cylinder is connected to the sliding component; the hydraulic cylinder extends, pushing the sliding component forward. Step 2: The hydraulic cylinder extends one stroke, and the component slides forward one step. Step 3: After one stroke of the cylinder extension is completed, the sliding component remains stationary, the hydraulic cylinder retracts, causing the clamping seat to release from the sliding track, and dragging the clamping seat forward; Step 4: After the hydraulic pusher completes one stroke of cylinder retraction, drag the clamping seat forward one step, and completes one crawling stroke. Then, repeat step 1 again, and repeat this process to move the component to its final position. Step S4: Lower the beam and remove the steel guide beam and track beam; Step S5: After the concrete beam segment is cast and formed, remove the remaining supports. It also includes a positioning and anti-eccentricity device, which includes a limit mechanism, a positioning mechanism and an anti-eccentricity mechanism; The limiting mechanism includes a pair of limiting plates symmetrically arranged on both sides of the starting end of the track beam. The pair of limiting plates extend from the starting end of the track beam to the initial sliding end of the steel box beam, and the distance between the pair of limiting plates gradually increases. Distance sensors are symmetrically installed on the pair of limiting plates. The adjustment mechanism includes temporary blocks and adjustment cylinders. The temporary blocks are symmetrically arranged on both sides near the limiting mechanism, and the lateral distance between the two sets of temporary blocks is greater than the lateral distance between the two sets of limiting mechanisms. The adjustment cylinders are fixed on the temporary blocks and are used to adjust the lateral position of the steel guide beam. The anti-eccentric loading mechanism is located near the adjustment mechanism. The anti-eccentric loading mechanism is located at the center of the two sets of adjustment mechanisms. The anti-eccentric loading mechanism includes a temporary block, a first slide rail, a limiting block, and a gripper assembly. The first slide rail is installed laterally on the temporary block. Limiting blocks are installed at both ends of the first slide rail. The gripper assembly includes a semi-circular front gripper and a semi-circular rear gripper. The front gripper and the rear gripper are controlled to move on the first slide rail by a moving hydraulic cylinder. The front gripper and the rear gripper are attracted or released by an electromagnet. The controller, which is connected to the distance sensor, the adjusting cylinder, the moving cylinder, and the electromagnet, is configured as follows: When the steel guide beam moves to the limiting mechanism, the distance sensor detects the distance between the steel guide beam and the two sides of the strain height I-beam structure and the distance sensor, and transmits the detection data to the controller. The controller calculates the difference between the detected distance and the set distance, and then controls the gripper assembly to move to the center position below the steel guide beam. The front and rear grippers clamp the connection system of the steel guide beam. After that, the adjustment cylinder is controlled to correct the steel guide beam according to the difference. The control of jacking construction includes the following steps: Graded loading slip a1) When the sliding begins, the hydraulic jacking device gradually increases the pressure of the lifting hydraulic cylinder, successively to 20% and 40% of the required pressure. If everything is normal, continue to load to 60%, 80%, 90%, and 100% until the structure is separated from the jacking support system. a2) After the structural load is completely transferred to the hydraulic jacking cylinder, the hydraulic jacking cylinder extension pressure is gradually increased, successively to 20% and 40% of the required pressure. If everything is normal, continue loading to 60%, 80%, 90%, and 100% until the structure is about to move. a3) When the sliding structure is about to move, pause the sliding propulsion and maintain the pressure of the propulsion system; conduct a comprehensive inspection of the hydraulic jacking device and equipment system, and the structural system, and only continue sliding after confirming that there are no problems with the stability and safety of the overall structure; formal slip b1) Pre-set the pump source pressure value according to the design sliding load, thereby controlling the maximum output thrust and lifting force of the hydraulic jack; b2) Control the error of each pusher within 20mm, thereby controlling the synchronous sliding of the entire sliding unit; b3) When maintaining a certain synchronous sliding state, there is basically no lateral horizontal force in the horizontal direction, and the sliding support system is calculated to be safe under the sliding condition. Lateral blocks are set at the corresponding positions of the sliding unit, and the whole sliding process is safe and reliable.

2. The method for jacking construction of curved steel box girder ramp bridges as described in claim 1, characterized in that, In step S2, the steel box girder segments are hoisted using supports. After the first segment is hoisted, anti-displacement measures are set up. After subsequent steel box girder segments are hoisted, they are temporarily fixed to the previously hoisted segments using clamps. After all the main girder segments and steel guide beams are hoisted, the main girder segments and steel guide beam segments are welded.

3. The method for jacking construction of curved steel box girder ramp bridges as described in claim 1, characterized in that, It also includes a slip monitoring system, which includes a computer synchronous control system, a stroke sensor and an oil pressure sensor mounted on the hydraulic cylinder; The slip synchronization monitoring steps include: Based on the reaction force values ​​of each jacking point under the sliding jacking condition calculated in advance, the maximum jacking force and jacking force of each hydraulic jacking device are set in the computer synchronous control system; when the jacking force or jacking force exceeds the set value, the hydraulic jacking device automatically adopts overflow unloading. A mechanical and hydraulic self-locking system is installed in the hydraulic circuit. When the hydraulic jack stops working or encounters a power outage, the lifting cylinder can be automatically locked for a long time to prevent it from sinking, thus ensuring the safety of the structure.

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