Steel truss bridge pushing and falling construction method

Abstract

The invention discloses a steel truss bridge pushing and falling construction method which improves the precision of a pre-assembly stage and ensures that the overall shape and structure of a bridge body meet the design requirements by adopting a laser measuring instrument, high-precision calculation, temperature control and other means. According to the steel truss bridge pushing and falling construction method, advanced walking type pushing equipment is used, parameters and configuration of the equipment are adjusted, the pushing construction efficiency and precision are improved, it is ensured that the bridge body stably and accurately moves to the designed position, and the construction efficiency is improved. According to the steel truss bridge pushing and falling construction method, the measuring point positions are arranged on the bridge body, displacement and deformation are monitored in real time, finite element analysis and equipment adjustment are combined, accurate control in the pushing process is ensured, and structural deformation and displacement deviation in the pushing process are effectively prevented.

Description

Technical Field

[0001] The invention relates to the technical field of steel truss bridge construction, in particular to a steel truss bridge jacking and bridge lowering construction method. Background Art

[0002] Steel truss bridges are widely used in railway and highway bridge projects. Their construction process is complex and requires high precision. Traditional bridge construction methods mainly include support method, cantilever method and top-pushing method. Among them, top-pushing method is widely used because it can reduce the use of temporary supports and improve construction efficiency. Walking top-pushing construction technology is a modern top-pushing construction method. By using walking top-pushing equipment, the bridge body can be moved smoothly during the construction process.

[0003] However, in actual construction, there are still many technical difficulties in precision control, equipment use, real-time monitoring and adjustment during the jacking and bridge lowering stages, such as: (1) Linear control in the pre-assembly stage, including steel bridge assembly measurement control, steel structure pre-arching control, steel structure temperature deformation control, and steel structure welding deformation control; (2) Overall control of the jacking process, including displacement monitoring and adjustment during the jacking process, and deformation monitoring and control during the jacking process; (3) Construction during the bridge lowering stage, including displacement control during the bridge lowering stage, control of seismic bearing installation during the bridge lowering stage, and equipment selection during the bridge lowering stage.

[0004] Therefore, how to improve the accuracy and efficiency of jacking construction and ensure that the bridge body is accurately in place during the bridge lowering stage is an urgent problem that needs to be solved in the current engineering field. Summary of the invention

[0005] The object of the present invention is to provide a method for jacking and lowering a steel truss bridge to solve the problems existing in the existing steel truss bridge construction mentioned in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution, a method for jacking and lowering a steel truss bridge, comprising the following steps: S1: Pre-assembly stage precision control Ensure that the overall shape and structure of the bridge meet the design requirements; S2: Walking type jacking construction Use walking type pushing equipment to move the bridge from the pre-assembly position to the designed position; S3: Pushing process monitoring and adjustment Ensure precise control of the jacking process by real-time monitoring and adjustment of equipment; S4: Preparation for the bridge landing phase Install the limit devices and prepare the bridge landing equipment; S5: Bridge closure in stages The bridge body is lowered in stages to gradually reach the designed position; S6: Installation and adjustment after bridge drop Ensure the final position of the bridge is accurate and carry out necessary adjustments and installation work.

[0007] Preferably, the precision control of the pre-assembly stage in step S1 specifically includes the following steps: S11: Steel bridge assembly measurement control, using laser measuring instruments to perform high-precision measurement of the assembly to ensure that the connection accuracy of each bridge component reaches ±1mm; S12: Pre-arch control of steel structure. The pre-arch value is determined through overall calculation, and the pre-arch adjustment is carried out using jacks and support frames during the assembly process. The pre-arch height is controlled at 10-15mm. S13: Temperature deformation control of steel structure, monitor and adjust the temperature of steel structure, use heating or cooling equipment to control the temperature within the range of 15-25℃ to avoid deformation caused by thermal expansion and contraction; S14: For steel structure welding deformation control, a segmented welding process is adopted, the welding sequence is from inside to outside, and an anti-deformation fixture is used to control the welding deformation within ±2mm.

[0008] Preferably, the walking-type jacking construction in step S2 specifically includes the following steps: S21: Complete the assembly of all steel structure components of the bridge on the railway embankment on the canal side, ensuring assembly accuracy and that the misalignment between all components does not exceed 2mm; S22: Use walking type jacking equipment to push the steel bridge, the jacking equipment includes multiple vertical and horizontal jacks, the rated lifting force of the vertical jack is 500 tons, and the rated thrust of the horizontal jack is 200 tons; S23: Adjust the height of the vertical jack of the walking jacking equipment out of the cylinder to optimize the jacking speed and control the time of each jacking stroke within 5 minutes. Reduce time consumption by adjusting the height of the jacking equipment out of the cylinder.

[0009] Preferably, the monitoring and adjustment of the pushing process in step S3 specifically includes the following steps: S31: Set up measurement points on the bridge body, with one measurement point every 10 meters, to measure the displacement, deformation, deflection and offset of the bridge body; S32: Real-time monitoring of the deflection, offset and displacement of the bridge body is carried out using a total station and displacement sensor, with a monitoring frequency of once every 5 seconds; S33: Use the transverse jack to correct the bridge body and make adjustments based on real-time monitoring data. The correction accuracy is controlled within ±1mm; S34: Conduct finite element analysis and add lower chord member partitions, support frames and guide beams based on the analysis results to ensure the stability and safety of the bridge structure during the jacking process.

[0010] Preferably, the preparation for the bridge drop stage in step S4 specifically includes the following steps: S41: Install the limit device, including the longitudinal limiter and the transverse limiter. The installation accuracy of the limiter is controlled within ±0.5mm; S42: Measure the distance between the bridge body and the pier using a laser distance meter to ensure that the measurement accuracy is within ±1mm; S43: Prepare a bridge lowering equipment in the form of a combination of a large jack and a small jack. The rated lifting force of the large jack is 1,000 tons, and the rated lifting force of the small jack is 200 tons, to ensure the safety of the equipment during the bridge lowering process.

[0011] Preferably, the phased bridge lowering in step S5 specifically comprises the following steps: S51: The bridge is lowered in stages by controlling the bridge lowering equipment to gradually lower it, with each lowering height not exceeding 100mm, to ensure that the bridge falls gradually and smoothly; S52: Real-time monitoring of the displacement and offset of the bridge body, using displacement sensors and total stations, with a monitoring frequency of once every 5 seconds; S53: Make necessary adjustments based on monitoring data and use horizontal and vertical jacks for fine-tuning to ensure the stability and accuracy of the bridge during the falling process. The adjustment error is controlled within ±1mm.

[0012] Preferably, the installation and adjustment after the bridge is dropped in step S6 specifically includes the following steps: S61: Ensure that the bridge is accurately located at the designed position, make final position adjustments, and use laser measuring instruments and total stations for precision testing to ensure that the bridge position error is within ±1mm; S62: Install the seismic bearings, including sliding bearings and fixed bearings. Use hydraulic jacks for precise positioning during installation to ensure that the contact surface between the bearings and the bridge body and piers is uniform; S63: Carry out final accuracy inspection and adjustment on the bridge body to ensure that it meets the design requirements. Use total station to measure the entire bridge to ensure that the overall accuracy error is within ±1mm.

[0013] Preferably, in step S11, the steel bridge assembly measurement control includes using a laser measuring instrument to perform high-precision measurement to ensure that the assembly accuracy meets the design requirements and the measurement error is controlled within ±0.5 mm.

[0014] Preferably, in step S22, the walking jacking equipment includes vertical and horizontal jacks, and the moving path of the bridge body is controlled by adjusting the height and direction of these jacks. The lifting speed of the vertical jack is controlled at 2 mm / s, and the pushing speed of the horizontal jack is controlled at 1 mm / s.

[0015] Preferably, in step S41, the limit device includes a plurality of limiters for controlling the lateral and longitudinal displacements of the bridge body during the staged descent. The installation positions and quantities of the limiters are arranged according to the actual conditions of the bridge body to ensure that the bridge body does not deviate during the descent. The installation accuracy of the limiters is controlled within ±0.5 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The steel truss bridge jacking and bridge lowering construction method improves the accuracy of the pre-assembly stage by using laser measuring instruments, high-precision calculations and temperature control, ensuring that the overall shape and structure of the bridge meet the design requirements and effectively reducing the adjustment workload in subsequent construction; 2. The steel truss bridge jacking and bridge lowering construction method uses advanced walking jacking equipment and adjusts the parameters and configuration of the equipment to improve the efficiency and accuracy of jacking construction, ensuring that the bridge body moves smoothly and accurately to the designed position; 3. The steel truss bridge jacking and bridge lowering construction method ensures precise control during the jacking process by arranging measurement points on the bridge body, monitoring displacement and deformation in real time, and combining finite element analysis and adjustment equipment, effectively preventing structural deformation and displacement deviation during the jacking process; 4. The steel truss bridge jacking and bridge lowering construction method ensures the smooth progress of the bridge lowering process by installing a limit device and preparing efficient bridge lowering equipment, thus avoiding the deviation of the bridge body and equipment failure during the bridge lowering process; 5. The steel truss bridge jacking and bridge lowering construction method ensures that the bridge falls to the designed position smoothly and safely by lowering the bridge body in stages and monitoring and adjusting the displacement in real time, thus avoiding structural stress concentration and bridge body damage caused by a large drop; 6. The steel truss bridge jacking and bridge lowering construction method ensures the accuracy of the bridge body in the final position through precise installation and adjustment measures, improves the stability and seismic resistance of the bridge body, and ensures the long-term safe operation of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of a steel truss bridge jacking and bridge lowering construction method of the present invention; Figure 2 It is a specific flow chart of the precision control of the pre-assembly stage of the present invention; Figure 3It is a specific flow chart of the walking type jacking construction of the present invention; Figure 4 A specific flow chart of monitoring and adjusting the pushing process of the present invention; Figure 5 A specific flow chart prepared for the bridge drop stage of the present invention; Figure 6 It is a specific flow chart of the staged bridge drop of the present invention; Figure 7 A specific flow chart of the installation and adjustment after the bridge is dropped according to the present invention; Figure 8 This is a map of measurement points arranged on the bridge body in step S31 of the present invention. DETAILED DESCRIPTION

[0018] 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.

[0019] In the description of the invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] See also Figure 1-8 The present invention provides a technical solution: a method for jacking and lowering a steel truss bridge, comprising the following steps: S1: Pre-assembly stage precision control Ensure that the overall shape and structure of the bridge meet the design requirements; S2: Walking type jacking construction Use walking type pushing equipment to move the bridge from the pre-assembly position to the designed position; S3: Pushing process monitoring and adjustment Ensure precise control of the jacking process by real-time monitoring and adjustment of equipment; S4: Preparation for the bridge landing phase Install the limit devices and prepare the bridge landing equipment; S5: Bridge closure in stages The bridge body is lowered in stages to gradually reach the designed position; S6: Installation and adjustment after bridge drop Ensure the final position of the bridge is accurate and carry out necessary adjustments and installation work.

[0022] Specifically, the integrity and continuity of the construction process are ensured through six steps: precision control in the pre-assembly stage, walking-type jacking construction, monitoring and adjustment of the jacking process, preparation for the bridge drop stage, staged bridge drop, and installation and adjustment after the bridge drop. The precision control in the pre-assembly stage ensures the structural accuracy of the bridge body in the initial state and reduces the adjustment work in the subsequent construction. The walking-type jacking construction method improves the construction efficiency and accuracy through advanced equipment and technology. Real-time monitoring and adjustment during the jacking process ensure the stability and accuracy of the bridge body during the jacking process. The full preparation in the bridge drop stage and the implementation of the bridge drop in stages ensure that the bridge body drops to the designed position smoothly and safely. Finally, the installation and adjustment work after the bridge drop ensures the accuracy of the final position of the bridge body and enhances the stability and seismic performance of the bridge. Through the comprehensive application of this series of steps, the method of the present invention effectively solves the technical problems in the jacking and bridge drop construction of steel truss bridges, significantly improves the construction efficiency and quality, and ensures the safe and stable operation of the bridge.

[0023] Among them, the precision control of the pre-assembly stage in step S1 specifically includes the following steps: S11: Steel bridge assembly measurement control, using laser measuring instruments to perform high-precision measurement of the assembly to ensure that the connection accuracy of each bridge component reaches ±1mm; S12: Pre-arch control of steel structure. The pre-arch value is determined through overall calculation, and the pre-arch adjustment is carried out using jacks and support frames during the assembly process. The pre-arch height is controlled at 10-15mm. S13: Temperature deformation control of steel structure, monitor and adjust the temperature of steel structure, use heating or cooling equipment to control the temperature within the range of 15-25℃ to avoid deformation caused by thermal expansion and contraction; S14: For steel structure welding deformation control, a segmented welding process is adopted, the welding sequence is from inside to outside, and an anti-deformation fixture is used to control the welding deformation within ±2mm.

[0024] Specifically, laser measuring instruments are used to measure the assembly with high precision to ensure the connection accuracy of each component of the bridge body. This high-precision measurement technology can significantly reduce the misalignment and connection errors between components and improve the structural accuracy of the overall bridge body. At the same time, the pre-arch value is determined through overall calculation, and the pre-arch adjustment is carried out by using jacks and support frames during the assembly process to control the pre-arch height within the range of 10-15mm. This precise pre-arch control measure can effectively compensate for the deflection change of the bridge body during the jacking process and ensure the flatness of the bridge body in the final position. In addition, by monitoring and adjusting the temperature of the steel structure, the temperature is controlled within the range of 15-25℃ using heating or cooling equipment to avoid deformation caused by thermal expansion and contraction, thereby further improving the accuracy and stability of the structure. In terms of welding deformation control, a segmented welding process is adopted, and the welding sequence is carried out from the inside to the outside. Anti-deformation fixtures are used to effectively control the welding deformation within ±2mm. Through a series of refined control measures, the high precision and high quality of the pre-assembly stage are ensured, laying a solid foundation for the subsequent jacking and bridge drop construction.

[0025] The walking jacking construction of step S2 specifically includes the following steps: S21: Complete the assembly of all steel structure components of the bridge on the railway embankment on the canal side, ensuring assembly accuracy and that the misalignment between all components does not exceed 2mm; S22: Use walking type jacking equipment to push the steel bridge, the jacking equipment includes multiple vertical and horizontal jacks, the rated lifting force of the vertical jack is 500 tons, and the rated thrust of the horizontal jack is 200 tons; S23: Adjust the height of the vertical jack of the walking jacking equipment out of the cylinder to optimize the jacking speed and control the time of each jacking stroke within 5 minutes. Reduce time consumption by adjusting the height of the jacking equipment out of the cylinder.

[0026] Specifically, claim 3 describes in detail the specific measures for the walking jacking construction. First, all the steel structure components of the bridge are assembled on the railway embankment on one side of the canal to ensure the assembly accuracy. The misalignment between all components does not exceed 2mm, which provides a basic guarantee for the smooth and precise movement of the bridge during the jacking process. The equipment parameters of multiple vertical and horizontal jacks are accurately calculated and configured to provide sufficient force to push and support the bridge, ensuring the stability and safety of the bridge during the jacking process. At the same time, by adjusting the cylinder height of the vertical jack of the walking jacking equipment to optimize the jacking speed, the time of each jacking stroke is controlled within 5 minutes. This optimization measure can significantly improve the efficiency of jacking construction and reduce the construction period. In addition, the configuration and parameter adjustment of the jacking equipment can also flexibly respond to various construction challenges according to the on-site conditions, ensure the precise control of the bridge during the jacking process, and avoid structural deformation and displacement deviation caused by improper operation of the jacking equipment. In summary, the walking jacking construction method improves the efficiency and accuracy of construction through advanced equipment and technical means, and ensures the stability and safety of the bridge during the jacking process.

[0027] The monitoring and adjustment of the pushing process in step S3 specifically includes the following steps: S31: Set up measurement points on the bridge body, with one measurement point every 10 meters, to measure the displacement, deformation, deflection and offset of the bridge body; S32: Real-time monitoring of the deflection, offset and displacement of the bridge body is carried out using a total station and displacement sensor, with a monitoring frequency of once every 5 seconds; S33: Use the transverse jack to correct the bridge body and make adjustments based on real-time monitoring data. The correction accuracy is controlled within ±1mm; S34: Conduct finite element analysis and add lower chord member partitions, support frames and guide beams based on the analysis results to ensure the stability and safety of the bridge structure during the jacking process.

[0028] For details, please refer to the attached manual. Figure 8 , which is a point map of measurement points arranged on the bridge body in step S31, wherein A1, A2, B1, B2, C1, C2, and D are all measurement points.

[0029] Specifically, measurement points are arranged on the bridge body. Through these measurement points, various data of the bridge body during the jacking process can be obtained in real time, and possible problems can be discovered and handled in time. The deflection, offset and displacement of the bridge body are monitored in real time, and the total station and displacement sensor are used. The monitoring frequency is once every 5 seconds. This high-frequency monitoring measure ensures the timeliness and accuracy of the monitoring data, which helps to grasp the status of the bridge body in real time during the jacking process. The bridge body is corrected by a transverse jack, and adjustments are made according to the real-time monitoring data. The correction accuracy is controlled at ±1mm. Through this precise correction measure, the offset of the bridge body during the jacking process can be effectively controlled to ensure the accuracy of the jacking path. The application of finite element analysis enables the structural stress and deformation during the jacking process to be comprehensively analyzed and estimated, providing a scientific basis for jacking construction. This series of monitoring and adjustment measures ensures precise control and structural stability during the jacking process, effectively prevents structural deformation and displacement deviation during the jacking process, and improves the safety and reliability of jacking construction.

[0030] Specifically, a three-dimensional finite element model of a steel truss bridge is established using finite element software. The model needs to include all key structural parts of the bridge body, such as the main truss, cross beam, support frame, guide beam, etc. The finite element analysis defines the material properties for each component in the model, including elastic modulus, Poisson's ratio, density, etc. These properties should be set according to the actual steel parameters to ensure the accuracy of the simulation results. Actual construction loads and environmental loads are applied to the model, including deadweight, jacking force, support reaction force, temperature change, etc. It is also necessary to simulate the dynamic loads and impact loads that may occur during the construction process. Finite element analysis also needs to define the connection relationship and boundary conditions between the bridge body and the supporting structure, such as hinged and fixed connections, among which the setting of boundary conditions should reflect the actual connection state between the bridge body and the support frame, guide beam, etc. during the actual construction process. Finite element analysis also needs to perform static analysis to calculate the stress, strain and deformation of the bridge body under various working conditions, especially the structural deformation and stress concentration areas that may occur during the jacking process. If necessary, finite element analysis needs to be performed dynamically to simulate the dynamic response during the jacking process and evaluate the impact of dynamic loads on the bridge during movement and its impact on structural stability. Finite element analysis can analyze the calculation results and identify possible structural weaknesses and stress concentration areas. Based on the analysis results, the rationality and safety of the existing design and construction plan are evaluated. Based on the results of the finite element analysis, the bridge design and construction plan are optimized, for example, adding a diaphragm to the lower chord member to increase local stiffness; adding a support frame to disperse stress; optimizing the guide beam design to ensure uniform force during the jacking process.

[0031] The preparation for the bridge drop phase in step S4 specifically includes the following steps: S41: Install the limit device, including the longitudinal limiter and the transverse limiter. The installation accuracy of the limiter is controlled within ±0.5mm; S42: Measure the distance between the bridge body and the pier using a laser distance meter to ensure that the measurement accuracy is within ±1mm; S43: Prepare a bridge lowering equipment in the form of a combination of a large jack and a small jack. The rated lifting force of the large jack is 1,000 tons, and the rated lifting force of the small jack is 200 tons, to ensure the safety of the equipment during the bridge lowering process.

[0032] Specifically, installing a limit device can effectively control the lateral and longitudinal displacement of the bridge body during the bridge lowering process, ensuring that the bridge body remains on the predetermined track during the lowering process and avoiding deviation. Secondly, measuring the distance between the bridge body and the bridge piers. Through precise distance measurement, accurate data support can be provided for the subsequent bridge lowering process to ensure the accuracy of the bridge lowering operation. Prepare a bridge lowering device in the form of a combination of large jacks and small jacks. This combination of bridge lowering equipment can ensure that the equipment can provide sufficient support and lifting force at different stages and under different weight loads to ensure the smooth progress of the bridge lowering process. Through precise equipment configuration and high-precision measurement, the smoothness, safety and efficiency of the bridge lowering stage are ensured, and possible deviations and failures in the bridge lowering process are avoided, providing a solid guarantee for the final accurate landing of the bridge body at the designed position.

[0033] The phased bridge closing in step S5 specifically includes the following steps: S51: The bridge is lowered in stages by controlling the bridge lowering equipment to gradually lower it, with each lowering height not exceeding 100mm, to ensure that the bridge falls gradually and smoothly; S52: Real-time monitoring of the displacement and offset of the bridge body, using displacement sensors and total stations, with a monitoring frequency of once every 5 seconds; S53: Make necessary adjustments based on monitoring data and use horizontal and vertical jacks for fine-tuning to ensure the stability and accuracy of the bridge during the falling process. The adjustment error is controlled within ±1mm.

[0034] Specifically, this staged descent method can effectively control the descent speed and height of the bridge, avoiding structural stress concentration and damage to the bridge caused by a one-time large-scale descent. Real-time monitoring of the displacement and offset of the bridge, and high-frequency monitoring measures ensure real-time acquisition and analysis of data during the descent process, which helps to promptly discover and deal with problems that may arise during the descent. Make necessary adjustments based on the monitoring data, and through fine-tuning measures, effectively correct deviations that occur during the descent process to ensure that the bridge falls smoothly along the predetermined trajectory and speed. The use of staged fine control and real-time adjustment ensures the safety and stability of the bridge during the descent process, avoids structural damage and position deviations caused by improper descent, and lays the foundation for the bridge to finally land accurately at the designed position.

[0035] The installation and adjustment after the bridge is dropped in step S6 specifically includes the following steps: S61: Ensure that the bridge is accurately located at the designed position, make final position adjustments, and use laser measuring instruments and total stations for precision testing to ensure that the bridge position error is within ±1mm; S62: Install the seismic bearings, including sliding bearings and fixed bearings. Use hydraulic jacks for precise positioning during installation to ensure that the contact surface between the bearings and the bridge body and piers is uniform; S63: Carry out final accuracy inspection and adjustment on the bridge body to ensure that it meets the design requirements. Use total station to measure the entire bridge to ensure that the overall accuracy error is within ±1mm.

[0036] Specifically, through high-precision measurement and adjustment, it is possible to ensure that the bridge body is accurately positioned after the bridge is dropped, avoiding the influence of position deviation on the bridge body structure and overall performance. When installing the seismic bearing, hydraulic jacks are used for precise positioning to ensure that the contact surface between the bearing and the bridge body and piers is uniform. The precise positioning installation method can effectively improve the installation accuracy of the bearing, ensure that the bearing can play an effective role when the bridge body is subjected to earthquakes or other external forces, and improve the seismic performance of the bridge body. Finally, the final precision inspection and adjustment of the bridge body can fully ensure the installation accuracy of each part of the bridge body and the stability of the overall structure. This series of installation and adjustment measures ensures the accurate position and stable state of the bridge body after the bridge is dropped, improves the overall performance and service life of the bridge body, and ensures the long-term safe operation of the bridge.

[0037] Among them, in step S11, the steel bridge assembly measurement control includes using a laser measuring instrument to perform high-precision measurement to ensure that the assembly accuracy meets the design requirements and the measurement error is controlled within ±0.5mm.

[0038] Specifically, laser measuring instruments have the characteristics of high precision and high reliability, which can effectively reduce measurement errors and improve assembly accuracy. Through high-precision measurement, the position accuracy and connection quality of each component of the steel bridge during the assembly process can be ensured, and the misalignment and joint problems between components can be reduced, thereby improving the overall structural stability and durability of the bridge body. In addition, high-precision measurement can also reduce the adjustment workload in subsequent construction, improve construction efficiency, and reduce construction costs.

[0039] Among them, in step S22, the walking jacking equipment includes vertical and horizontal jacks, and the moving path of the bridge body is controlled by adjusting the height and direction of these jacks. The lifting speed of the vertical jack is controlled at 2mm / s, and the pushing speed of the horizontal jack is controlled at 1mm / s.

[0040] Specifically, the above parameters are precisely calculated and configured to ensure smooth movement and precise control of the bridge body during the jacking process. By adjusting the height and direction of the jack, it is possible to flexibly respond to complex situations at various construction sites, ensuring that the path of the bridge body during the jacking process is accurate and the movement is smooth, avoiding structural deformation and displacement deviations caused by improper equipment operation. In addition, the optimized configuration and operation of the jacking equipment can also improve the efficiency of jacking construction, shorten the construction period, and reduce construction costs.

[0041] Among them, in step S41, the limit device includes multiple limiters, which are used to control the lateral and longitudinal displacement of the bridge body during the staged falling process. The installation position and number of the limiters are arranged according to the actual situation of the bridge body to ensure that the bridge body will not deviate during the falling process. The installation accuracy of the limiter is controlled within ±0.5mm.

[0042] Specifically, the installation accuracy of the limiter is controlled within ±0.5mm to ensure that the bridge body will not deviate during the falling process. The limiter can effectively control the position deviation of the bridge body during the falling process, ensuring that the bridge body falls smoothly according to the predetermined trajectory and speed, avoiding structural stress concentration and bridge body damage caused by a large drop. In addition, through the precise arrangement of the limiter, the displacement of the bridge body can be adjusted in real time during the falling process to ensure the stability and accuracy of the falling process. Through this precise installation and use method of the limiter, the safety and reliability of the bridge falling process can be effectively improved, the accuracy and stability of the bridge body in the final position can be ensured, and a reliable guarantee for the long-term safe operation of the bridge is provided.

[0043] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for jacking and lowering a steel truss bridge. It is characterized in that The following steps are involved: S1: Pre-assembly stage precision control Ensure that the overall shape and structure of the bridge meet the design requirements; S2: Walking type jacking construction Use walking type pushing equipment to move the bridge from the pre-assembly position to the designed position; S3: Pushing process monitoring and adjustment Ensure precise control of the jacking process by real-time monitoring and adjustment of equipment; S4: Preparation for the bridge landing phase Install the limit devices and prepare the bridge landing equipment; S5: Bridge closure in stages The bridge body is lowered in stages to gradually reach the designed position; S6: Installation and adjustment after bridge drop Ensure the final position of the bridge is accurate and carry out necessary adjustments and installation work.

2. A method for jacking and lowering a steel truss bridge according to claim 1, characterized in that: in, The precision control of the pre-assembly stage in step S1 specifically includes the following steps: S11: Steel bridge assembly measurement control, using laser measuring instruments to perform high-precision measurement of the assembly to ensure that the connection accuracy of each bridge component reaches ±1mm; S12: Pre-arch control of steel structure. The pre-arch value is determined through overall calculation, and the pre-arch adjustment is carried out using jacks and support frames during the assembly process. The pre-arch height is controlled at 10-15mm. S13: Temperature deformation control of steel structure, monitor and adjust the temperature of steel structure, use heating or cooling equipment to control the temperature within the range of 15-25℃ to avoid deformation caused by thermal expansion and contraction; S14: For steel structure welding deformation control, a segmented welding process is adopted, the welding sequence is from inside to outside, and an anti-deformation fixture is used to control the welding deformation within ±2mm.

3. A method for jacking and lowering a steel truss bridge according to claim 1, characterized in that: in, The walking jacking construction of step S2 specifically includes the following steps: S21: Complete the assembly of all steel structure components of the bridge on the railway embankment on the canal side, ensuring assembly accuracy and that the misalignment between all components does not exceed 2mm; S22: Use walking type jacking equipment to push the steel bridge, the jacking equipment includes multiple vertical and horizontal jacks, the rated lifting force of the vertical jack is 500 tons, and the rated thrust of the horizontal jack is 200 tons; S23: Adjust the height of the vertical jack of the walking jacking equipment out of the cylinder to optimize the jacking speed and control the time of each jacking stroke within 5 minutes. Reduce time consumption by adjusting the height of the jacking equipment out of the cylinder.

4. A method for jacking and lowering a steel truss bridge according to claim 1, characterized in that: in, The monitoring and adjustment of the pushing process in step S3 specifically includes the following steps: S31: Set up measurement points on the bridge body, with one measurement point every 10 meters, to measure the displacement, deformation, deflection and offset of the bridge body; S32: Real-time monitoring of the deflection, offset and displacement of the bridge body is carried out using a total station and displacement sensor, with a monitoring frequency of once every 5 seconds; S33: Use the transverse jack to correct the bridge body and make adjustments based on real-time monitoring data. The correction accuracy is controlled within ±1mm; S34: Conduct finite element analysis and add lower chord member partitions, support frames and guide beams based on the analysis results to ensure the stability and safety of the bridge structure during the jacking process.

5. The method for jacking and lowering a steel truss bridge according to claim 1 is characterized in that: in, The preparation for the bridge drop phase in step S4 specifically includes the following steps: S41: Install the limit device, including the longitudinal limiter and the transverse limiter. The installation accuracy of the limiter is controlled within ±0.5mm; S42: Measure the distance between the bridge body and the pier using a laser distance meter to ensure that the measurement accuracy is within ±1mm; S43: Prepare a bridge lowering equipment in the form of a combination of a large jack and a small jack. The rated lifting force of the large jack is 1,000 tons, and the rated lifting force of the small jack is 200 tons, to ensure the safety of the equipment during the bridge lowering process.

6. The method for jacking and lowering a steel truss bridge according to claim 1 is characterized in that: in, The phased bridge closing in step S5 specifically includes the following steps: S51: Lower the bridge in stages, by controlling the bridge lowering equipment to gradually lower it, with each lowering height not exceeding 100mm, to ensure that the bridge lowers gradually and smoothly; S52: Real-time monitoring of the displacement and offset of the bridge body, using displacement sensors and total stations, with a monitoring frequency of once every 5 seconds; S53: Make necessary adjustments based on monitoring data and use horizontal and vertical jacks for fine-tuning to ensure the stability and accuracy of the bridge during the falling process. The adjustment error is controlled within ±1mm.

7. The method for jacking and lowering a steel truss bridge according to claim 1 is characterized in that: in, The installation and adjustment after the bridge is dropped in step S6 specifically includes the following steps: S61: Ensure that the bridge is accurately located at the designed position, make final position adjustments, and use laser measuring instruments and total stations for precision testing to ensure that the bridge position error is within ±1mm; S62: Install the seismic bearings, including sliding bearings and fixed bearings. Use hydraulic jacks for precise positioning during installation to ensure that the contact surface between the bearings and the bridge body and piers is uniform; S63: Carry out final accuracy inspection and adjustment on the bridge body to ensure that it meets the design requirements. Use total station to measure the entire bridge to ensure that the overall accuracy error is within ±1mm.

8. The method for jacking and lowering a steel truss bridge according to claim 2 is characterized in that: in, In step S11, the steel bridge assembly measurement control includes using a laser measuring instrument to perform high-precision measurement to ensure that the assembly accuracy meets the design requirements and the measurement error is controlled within ±0.5mm.

9. A method for jacking and lowering a steel truss bridge according to claim 3, characterized in that: in, In step S22, the walking jacking equipment includes vertical and horizontal jacks, and the moving path of the bridge body is controlled by adjusting the height and direction of these jacks. The lifting speed of the vertical jack is controlled at 2mm / s, and the pushing speed of the horizontal jack is controlled at 1mm / s.

10. A method for jacking and lowering a steel truss bridge according to claim 5, characterized in that: in, In step S41, the limit device includes a plurality of limiters for controlling the lateral and longitudinal displacement of the bridge body during the staged descent. The installation position and quantity of the limiters are arranged according to the actual situation of the bridge body to ensure that the bridge body will not deviate during the descent. The installation accuracy of the limiters is controlled within ±0.5mm.

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