Railway existing line box girder pushing and translating beam replacement construction method and system

Abstract

This invention relates to a method and system for replacing box girders on existing railway lines by jacking and sliding, and pertains to the field of railway engineering. This technical solution significantly optimizes the construction process for replacing box girders on existing lines, enabling simultaneous movement of existing T-beams and new steel box girders, greatly shortening the railway closure window, effectively reducing interference with existing line operations, and ensuring passenger and freight transport order. Simultaneously, by constructing a dual-condition jacking and sliding system that shares a sliding support structure, the construction process is simplified, construction costs are reduced, and the adaptability of the support structure is improved, avoiding problems such as track settlement and girder displacement. Furthermore, a comprehensive pre-treatment, trial operation, and full-process monitoring system can identify potential construction hazards in advance and handle anomalies in real time, ensuring construction safety and quality. This solution is adaptable to existing line renovation scenarios, requiring no large-scale dismantling of the line, and is convenient and efficient. It can be widely applied to the replacement of T-beams with steel box girders on existing lines, possessing strong practicality and promotional value.

Description

Technical Field

[0001] This invention relates to the field of railway engineering technology, and in particular to a method and system for replacing box girders on existing railway lines by jacking and horizontally moving them. Background Technology

[0002] During the operation of existing railway lines, some existing T-beams, due to their long service life and deteriorated structural performance, may no longer meet the operational demands of increased transport loads and speed upgrades, requiring replacement and renovation to ensure railway operational safety and efficiency. Currently, beam replacement construction on existing lines mostly adopts the traditional step-by-step operation mode, which involves gradually moving the existing T-beams out of the line area and then slowly moving the new beams in and positioning them. This mode requires multiple railway closure windows, and each closure is relatively long, seriously affecting the normal passenger and freight transport order. At the same time, the sliding support structure in traditional construction is mostly designed for a single working condition. Due to the structural differences between the existing T-beams and the new steel box girders, a separate support system needs to be built, making the construction process cumbersome, costly, and difficult to guarantee the stability and adaptability of the support structure, which can easily lead to problems such as sliding track settlement and beam displacement.

[0003] In existing technologies, the jacking and pushing / translation stages of beam replacement construction lack synchronous control methods. Most rely on manual operation of single equipment, making it impossible to achieve synchronous linkage between the jacking out of the existing T-beam and the jacking in of the new steel box girder. This results in excessive posture deviations during beam relocation, easily causing structural damage or misalignment of supports. Furthermore, pre-construction procedures are inadequate, lacking scientific pre-treatment plans for key aspects such as the modification of existing pier support pads and the removal of support bolts. The monitoring system during construction is also incomplete, failing to collect key data such as beam displacement, stress, and support reactions in real time, making it difficult to promptly detect and address construction anomalies. Moreover, the lack of a systematic trial operation before formal construction leads to incomplete investigation of potential hazards, easily resulting in equipment failures and poor process coordination during the closure construction process, seriously affecting construction quality and safety. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for replacing box girders on existing railway lines by jacking and sliding them, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for replacing box girders on existing railway lines by jacking and horizontally moving them, comprising: Based on the design parameters and working conditions of the existing line beam replacement project, a jacking and translation construction system adapted to dual working conditions is constructed. The dual working conditions correspond to the existing T-beam removal working condition and the new steel box girder removal working condition, respectively. Complete the construction of the slideway foundation and track system, and build a sliding support structure that matches the jacking and translation construction system; The existing T-beams to be removed and the new steel box girders to be moved in were respectively lifted and replaced, so that the beams were detached from the original support structure and locked in the lifting and pressure-holding state; During the pre-set railway closure window, the lateral jacking and removal of the existing T-beams and the lateral jacking and removal of the new steel box girders are carried out simultaneously. The attitude data of the beams during the displacement process are collected in real time to generate a beam displacement attitude dataset. Based on the beam displacement posture dataset, the beam is corrected and lowered after it is in place, and the support installation and line restoration are completed to realize the beam replacement construction of the existing line.

[0006] In some implementations, the construction of a jacking and translation construction system adapted to dual working conditions, based on the design parameters and working characteristics of the existing line beam replacement project, includes: Based on the structural and weight parameters of the existing T-beams and the new steel box girders, corresponding jacking equipment, jacking equipment and PLC synchronous hydraulic control systems are configured respectively. A jacking and sliding subsystem is configured for the existing T-beam removal condition and a jacking and sliding subsystem is configured for the new steel box girder insertion condition. The two subsystems share part of the slide rail structure. Develop a phased construction process that matches the railway closure window period, and match the process nodes with online and offline synchronous operations.

[0007] In some embodiments, the completion of the construction of the slideway foundation and track system, and the erection of a sliding support structure matching the jacking and translation construction system, includes: The construction of bored pile foundation and reinforced concrete cap is carried out, and φ630mm steel pipe columns are installed on the cap. The columns are reinforced by channel steel connection, and the verticality of the column installation is controlled within 3‰ and not greater than 10mm. Double 700mm high H-shaped steel spreader beams are installed on the top of the steel pipe columns, and double 800mm high H-shaped steel sliding beams are installed on the spreader beams to form a sliding support frame; Slide rail steel plates and 7mm thick stainless steel friction-reducing plates are laid on the slide rail beam. Reaction groove steel plates are welded on both sides of the slide rail to form a U-shaped reaction groove structure that serves as both the back of the jacking reaction force and the sliding limit. For existing T-beam jacking operations, angle steel limiting and blocking structures are welded on both sides of the sliding track.

[0008] In some embodiments, the step of performing jacking and replacement operations on the existing T-beam to be removed and the new steel box girder to be moved in, so that the beams are detached from the original support structure and locked in a jacking and pressure-holding state, includes: For the new steel box girder, a steel distribution beam is installed at the bottom of the beam, and a 300T three-dimensional correction jack is arranged between the steel distribution beam and the slide beam. Multiple three-dimensional correction jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously. The lifting height is 3cm. After the jacks are lifted into place, the pressure is maintained by the self-locking electromagnetic leak-free valve built into the jacks. For the existing T-beam, 200T double-acting hydraulic self-locking jacks are arranged between the beam body and the slide beam. Multiple hydraulic self-locking jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously with a lifting height of 3cm. After being lifted into place, the jacks are locked by the pressure-holding nuts. During the lifting process, the displacement data of each jack is monitored in real time to control the synchronous error of the lifting point displacement to not exceed 2mm. If the error threshold is exceeded, a single-point closed-loop adjustment is performed. The 300T three-dimensional correction jack has a vertical lifting stroke of 90mm and a transverse correction stroke of ±50mm. Boat-shaped copper strips are installed on both sides of the jack base, with a spacing of 20mm between the copper strips and the reaction slot side plate. During the jacking process, the jack is guided and limited by the cooperation of the copper strips and the reaction slot, controlling the maximum error of the longitudinal displacement of the beam to not exceed 20mm. The top of the jack is equipped with a ball head structure, with a maximum rotation angle of 5 degrees, which can accommodate the angle deviation caused by the settlement of the slide, ensuring that the jack and the bottom of the beam are always in close contact and bearing force.

[0009] In some implementations, during a preset railway closure window, the lateral jacking and removal of the existing T-beams and the lateral jacking and removal of the new steel box girders are performed simultaneously. Attitude data during the beam displacement process is collected in real time to generate a beam displacement attitude dataset, including: During the railway closure window, the preliminary procedures of track protection, beam restraint removal, and existing support bolt removal should be completed first. The new steel box girder is pushed using a 120T jacking jack. The jacking jack has a built-in absolute displacement sensor and an automatic reaction shear seat at the front end. Continuous pushing is achieved through the cooperation of the shear seat and the U-shaped reaction slot. The pushing speed is controlled at 2 minutes and 10 seconds per meter, and the single pushing stroke is 1 meter. The existing T-beams were pushed and moved using 200T hydraulic self-locking jacks, which were started simultaneously with the new steel box girder pushing operation. A step-by-step translation strategy was adopted to control the synchronization error of the T-beam and the steel box girder within the preset range. During the jacking process, the horizontal displacement, vertical displacement, axis deviation, support reaction force, and structural stress data of the beam are collected in real time to generate a dataset of beam displacement posture. The construction process during the railway closure window is carried out according to the following steps: After the closure begins, the line protection is set up, and the setting and confirmation of the two horizontal and one vertical return lines are completed; the rails, sleepers, ballast, expansion joints, and transition cables at the beam joints are removed simultaneously, and the support bolts of the existing T-beams are released; the existing T-beams and the new steel box girders are simultaneously lifted by 3cm to complete the replacement and pressure holding locking; the existing T-beams are pushed out and the new steel box girders are pushed in simultaneously, and after they are in place, the beam body is corrected, the beams are lowered, and the temporary supports are adjusted; the support grouting, expansion joint installation, ballast backfilling, sleeper installation, laying and debugging of the four electrical systems, and adjustment of the contact wire parameters are completed simultaneously, and the line inspection and protection removal are completed.

[0010] In some implementations, the step of performing correction and lowering operations on the beam after it has been positioned, based on the beam displacement posture dataset, to complete the support installation and line restoration, includes: Based on the beam displacement posture dataset, the new steel box girder in the transverse and longitudinal directions is corrected by three-dimensional correction jacks after it is in place, so as to control the beam axis deviation within the allowable range. The jacks are lowered synchronously by a PLC synchronous hydraulic control system to lower the beam onto the preset temporary support, and the synchronous error of each support point during the beam lowering process is controlled to not exceed 2mm. Complete the installation of permanent supports and grouting of support pads. After grouting, install and debug the beam track structure, expansion joints, and four electrical systems. Complete the line restoration and open the line according to the preset speed limit conditions.

[0011] In some embodiments, the method further includes a pre-treatment process prior to the sealing off construction, the pre-treatment process comprising: The existing pier bearing pads were modified by removing the portion of the existing pads that overlapped with the new pads. Under the condition of limited clearance, a light electric hammer was used to complete the rebar installation and pouring of the new pads. Using the railway's three-level blockade points, the support bolts of the existing T-beams were removed and restored one by one. Bolts that could not be removed were marked and pre-treated. After completion, the existing T-beams were tested and lifted. Pre-treatment was performed on the existing beam end expansion joints, new expansion joint steel blocks were installed on the old bridge side, and matching expansion joint components were welded to the beam end of the new steel box girder and moved in synchronously with the beam body.

[0012] In some embodiments, the method further includes a trial operation procedure before the formal jacking, the trial operation procedure including: Before the formal closure and construction, a 4m jacking operation was carried out on the new steel box girder, and a 2cm jacking operation was carried out on the existing T beam. Equipment operation data, structural deformation data and synchronous control data were collected during the trial operation. Based on the trial operation data, the equipment parameters, PLC control parameters, and synchronous control strategies of the jacking and translation construction system were optimized and adjusted, and potential construction hazards were identified and resolved. For problems such as displacement deviation, abnormal stress, and equipment failure that occur during the trial operation, develop corresponding emergency response plans; The method also includes a full-process construction monitoring procedure, which includes: The system is equipped with six monitoring modules: settlement monitoring, stress monitoring, support reaction force monitoring, vertical displacement monitoring, horizontal displacement monitoring, and axis deviation monitoring, with corresponding monitoring points and instruments. Initial values ​​of each monitoring item are collected before beam replacement, real-time tracking monitoring is performed during the jacking, pushing and lowering of beam operations, and final monitoring values ​​are collected after beam lowering is completed. Set corresponding early warning thresholds for each monitoring item. When the monitoring data exceeds the early warning threshold, construction should be suspended immediately, construction parameters should be adjusted based on the monitoring data, and work should continue only after the anomaly has been eliminated.

[0013] In some implementations, the PLC synchronous hydraulic control system adopts a force and displacement integrated control mode, with a synchronous control accuracy of ±1.0mm; During the jacking operation, the stroke data of each jacking jack is collected in real time through absolute displacement sensors. The jacking stroke is automatically reset to zero after each 1m jacking stroke is completed to eliminate cumulative errors. During the jacking operation, the lifting height data of each jack is collected in real time through a pull-wire displacement sensor, and the synchronization of each jack is controlled in a closed loop. When the displacement deviation exceeds the preset threshold, the single-machine adjustment and shutdown warning are automatically triggered.

[0014] Secondly, the present invention provides a railway existing line box girder jacking and horizontal displacement girder replacement construction system, the system being applied to the railway existing line box girder jacking and horizontal displacement girder replacement construction method described above, the system comprising: The system construction unit is used to construct a jacking and translation construction system adapted to two working conditions based on the design parameters and working condition characteristics of the existing line beam replacement project. The two working conditions correspond to the existing T-beam removal working condition and the new steel box girder removal working condition, respectively. The slideway construction unit is used to complete the construction of the slideway foundation and track system, and to build a sliding support structure that matches the jacking and translation construction system. The jacking and replacement unit is used to perform jacking and replacement operations on the existing T-beams to be moved out and the new steel box girders to be moved in, so that the beams are removed from the original support structure and locked in the jacking and pressure-holding state. The synchronous jacking unit is used to simultaneously perform the lateral jacking and removal of the existing T-beam and the lateral jacking and removal of the new steel box girder within a preset railway closure window period, and to collect the attitude data of the beam displacement process in real time to generate a beam displacement attitude dataset. The beam-dropping and restoration unit is used to perform correction and beam-dropping operations on the beam after it has been placed in position, based on the beam displacement posture dataset, to complete the support installation and line restoration, and realize the beam replacement construction of the existing line.

[0015] The beneficial effects of the technical solution provided by this invention include at least the following: This technical solution significantly optimizes the existing line beam replacement construction process, enabling simultaneous movement of existing T-beams and new steel box girders. This drastically shortens the railway closure window, effectively reduces disruption to existing line operations, and ensures passenger and freight transport order. Furthermore, by constructing a dual-condition jacking and translation system that shares a sliding support structure, the construction process is simplified, construction costs are reduced, and the adaptability of the support structure is improved, avoiding issues such as track settlement and beam displacement. In addition, a comprehensive pre-treatment, trial operation, and full-process monitoring system can proactively identify potential construction hazards and address anomalies in real time, ensuring construction safety and quality. This solution is suitable for existing line renovation scenarios, requires no large-scale track dismantling, and is convenient and efficient. It can be widely applied to existing line T-beam to steel box girder replacement projects, demonstrating strong practicality and promotional value. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0017] Figure 1 The diagram illustrates a construction method for replacing box girders on an existing railway line by jacking and horizontal movement, according to an exemplary embodiment of the present invention.

[0018] Figure 2 The diagram illustrates a structural block diagram of a railway existing line box girder jacking and horizontal displacement girder replacement construction system provided by an exemplary embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 The diagram illustrates a process flow of a method for replacing box girders on an existing railway line by jacking and moving them, according to an exemplary embodiment of the present invention. This method includes the following steps: Step 101: Based on the design parameters and working conditions of the existing line beam replacement project, construct a jacking and translation construction system adapted to the dual working conditions. The dual working conditions correspond to the existing T-beam removal working condition and the new steel box girder insertion working condition, respectively.

[0022] In some embodiments, the above-mentioned jacking and translation construction system adapted to dual working conditions, based on the design parameters and working characteristics of existing line beam replacement projects, includes: Based on the structural and weight parameters of the existing T-beams and the new steel box girders, corresponding jacking equipment, jacking equipment and PLC synchronous hydraulic control systems are configured respectively. A jacking and sliding subsystem is configured for the existing T-beam removal condition and a jacking and sliding subsystem is configured for the new steel box girder insertion condition. The two subsystems share part of the slide rail structure. Develop a phased construction process that matches the railway closure window period, and match the process nodes with online and offline synchronous operations.

[0023] In this embodiment, by combining specialized equipment with different configurations for the two types of beams, the pain points of insufficient equipment adaptability and poor synchronization in the construction of beams with different weights and structures are effectively solved, ensuring the stability and accuracy of the jacking and pushing operations. The differentiated configuration and resource-sharing design of the twin system take into account the construction needs of both working conditions, avoids the waste of resources and delays caused by repeatedly building sliding track structures, and achieves the optimal balance between construction cost and efficiency.

[0024] Step 102: Complete the construction of the slide foundation and track system, and build a sliding support structure that matches the jacking and translation construction system.

[0025] In some embodiments, the above-mentioned completion of the construction of the slideway foundation and track system, and the erection of a sliding support structure matching the jacking and translation construction system, includes: The construction of bored pile foundation and reinforced concrete cap is carried out, and φ630mm steel pipe columns are installed on the cap. The columns are reinforced by channel steel connection, and the verticality of the column installation is controlled within 3‰ and not greater than 10mm. Double 700mm high H-shaped steel spreader beams are installed on the top of the steel pipe columns, and double 800mm high H-shaped steel sliding beams are installed on the spreader beams to form a sliding support frame; Slide rail steel plates and 7mm thick stainless steel friction-reducing plates are laid on the slide rail beam. Reaction groove steel plates are welded on both sides of the slide rail to form a U-shaped reaction groove structure that serves as both the back of the jacking reaction force and the sliding limit. For existing T-beam jacking operations, angle steel limiting and blocking structures are welded on both sides of the sliding track.

[0026] In this embodiment, standardized foundation construction and structural erection ensure that the support system can stably bear the weight of both types of beams, avoiding problems such as foundation settlement and structural deformation during construction. Through construction parameter control and differentiated structural design, the verticality and stability of the support frame are guaranteed. Furthermore, friction-reducing plates lower the beam displacement resistance, and U-shaped reaction grooves and angle steel limiting structures provide both jacking reaction force and beam limiting protection, adapting to the needs of dual-condition construction.

[0027] Step 103: Perform jacking and replacement operations on the existing T-beams to be removed and the new steel box girders to be moved in, so that the beams are detached from the original support structure and locked in the jacking and pressure-holding state.

[0028] In some embodiments, the above-mentioned lifting and replacement operations are performed on the existing T-beam to be removed and the new steel box girder to be moved in, respectively, so that the beam body is detached from the original support structure and locked in the lifting and pressure-holding state, including: For the new steel box girder, a steel distribution beam is installed at the bottom of the beam, and a 300T three-dimensional correction jack is arranged between the steel distribution beam and the slide beam. Multiple three-dimensional correction jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously. The lifting height is 3cm. After the jacks are lifted into place, the pressure is maintained by the self-locking electromagnetic leak-free valve built into the jacks. For the existing T-beam, 200T double-acting hydraulic self-locking jacks are arranged between the beam body and the slide beam. Multiple hydraulic self-locking jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously with a lifting height of 3cm. After being lifted into place, the jacks are locked by the pressure-holding nuts. During the lifting process, the displacement data of each jack is monitored in real time to control the synchronous error of the lifting point displacement to not exceed 2mm. If the error threshold is exceeded, a single-point closed-loop adjustment is performed. The 300T three-dimensional correction jack has a vertical lifting stroke of 90mm and a transverse correction stroke of ±175mm. Boat-shaped copper strips are installed on both sides of the jack base, with a spacing of 20mm between the copper strips and the reaction slot side plate. During the jacking process, the jack is guided and limited by the cooperation of the copper strips and the reaction slot, controlling the maximum error of the longitudinal displacement of the beam to not exceed 20mm. The top of the jack is equipped with a ball head structure, with a maximum rotation angle of 5 degrees, which can accommodate the angle deviation caused by the settlement of the slide, ensuring that the jack and the bottom of the beam are always in close contact and bearing force.

[0029] In this embodiment, the lifting control and pressure-holding locking design ensures that the beam smoothly detaches from its original support and prevents settlement or displacement after lifting, thus guaranteeing the structural stability during construction intervals. Furthermore, the three-dimensional correction jack not only adapts to the lifting requirements but also prepares for guidance, limiting, and angle adaptation during the jacking process, comprehensively ensuring the safety, stability, and accuracy of the beam replacement construction.

[0030] Step 104: During the preset railway closure window, simultaneously perform the lateral jacking and removal of the existing T-beams and the lateral jacking and removal of the new steel box girders, collect the attitude data of the beam displacement process in real time, and generate a beam displacement attitude dataset.

[0031] In some embodiments, during a preset railway closure window, the lateral jacking and removal of the existing T-beam and the lateral jacking and removal of the new steel box girder are performed simultaneously, and attitude data during the beam displacement process is collected in real time to generate a beam displacement attitude dataset, including: During the railway closure window, the preliminary procedures of track protection, beam restraint removal, and existing support bolt removal should be completed first. The new steel box girder is jacked using 120T jacking jacks. The jacking jacks have built-in absolute displacement sensors and are equipped with automatic reaction shear seats at the front end. Continuous jacking is achieved through the cooperation of the shear seats and U-shaped reaction slots. The jacking speed is controlled at 2 minutes and 10 seconds per meter, and the single jacking stroke is 1 meter. The existing T-beams were pushed and moved using 200T hydraulic self-locking jacks, which were started simultaneously with the new steel box girder pushing operation. A step-by-step translation strategy was adopted to control the synchronization error of the T-beam and the steel box girder within the preset range. During the jacking process, the horizontal displacement, vertical displacement, axis deviation, support reaction force, and structural stress data of the beam are collected in real time to generate a dataset of beam displacement posture. The construction process during the railway closure window is as follows: After the closure begins, set up line protection and complete the setting and confirmation of the two horizontal and one vertical return lines; simultaneously remove the rails, sleepers, ballast, expansion joints, and transition cables at the beam joints, and release the support bolts of the existing T-beams; control the existing T-beams and the new steel box girders to be lifted 3cm simultaneously, and complete the replacement and pressure holding locking; simultaneously push out the existing T-beams and push in the new steel box girders, and after they are in place, complete the beam correction, beam lowering, and temporary support adjustment; simultaneously complete the support grouting, expansion joint installation, ballast backfilling, sleeper installation, laying and debugging of the four electrical systems, adjustment of contact network parameters, and complete the line inspection and protection removal.

[0032] In this embodiment, the closure window period is used as a time constraint. A dual-beam synchronous operation mode is employed to minimize the construction time tied to operations, reducing the impact on existing passenger and freight transport and achieving a balance between construction efficiency and operational safety. Standardized setup of pre-construction procedures and differentiated relocation schemes ensure the orderly operation of the synchronous work, avoiding potential hazards such as process chaos and beam collisions. Displacement sensors and continuous jacking design further enhance relocation accuracy and continuity. Real-time acquisition of multi-dimensional attitude data and generation of datasets allows for real-time monitoring of the beam relocation status and timely detection of anomalies.

[0033] Step 105: Based on the beam displacement posture dataset, perform correction and beam lowering operations on the beam after it is in place, complete the support installation and line restoration, and realize the beam replacement construction of the existing line.

[0034] In some embodiments, the above-mentioned correction and lowering operations are performed on the beam after it has been positioned, based on the beam displacement posture dataset, to complete the support installation and line restoration, including: Based on the beam displacement posture dataset, the new steel box girder in the transverse and longitudinal directions is corrected by three-dimensional correction jacks after it is in place, so as to control the beam axis deviation within the allowable range. The jacks are lowered synchronously by a PLC synchronous hydraulic control system to lower the beam onto the preset temporary support, and the synchronous error of each support point during the beam lowering process is controlled to not exceed 2mm. Complete the installation of permanent supports and grouting of support pads. After grouting, install and debug the beam track structure, expansion joints, and four electrical systems. Complete the line restoration and open the line according to the preset speed limit conditions.

[0035] In this embodiment, the beam displacement posture dataset is used as a basis to make the correction and beam lowering operations more targeted, avoiding potential hazards such as beam misalignment and support damage caused by blind operation. The layered operation design ensures that the beam axis meets operational standards through precise correction, and ensures uniform stress on the beam through synchronous beam lowering control. The subsequent installation and commissioning of supporting facilities and track restoration complete the closed-loop process of beam replacement construction, which can quickly restore railway traffic capacity, open the line at the preset speed limit, minimize the continuous impact of construction on railway operation, and ensure that the beam replacement project ultimately meets operational safety standards.

[0036] In some embodiments, the method for replacing box girders on existing railway lines by jacking and horizontally moving them further includes a pre-treatment process before the closure construction, the pre-treatment process including: The existing pier bearing pads were modified by removing the portion of the existing pads that overlapped with the new pads. Under the condition of limited clearance, a light electric hammer was used to complete the rebar installation and pouring of the new pads. Using the railway's three-level blockade points, the support bolts of the existing T-beams were removed and restored one by one. Bolts that could not be removed were marked and pre-treated. After completion, the existing T-beams were tested and lifted. Pre-treatment was performed on the existing beam end expansion joints, new expansion joint steel blocks were installed on the old bridge side, and matching expansion joint components were welded to the beam end of the new steel box girder and moved in synchronously with the beam body.

[0037] In this embodiment, by specifically addressing critical components such as existing pier bearing pads, bearing bolts, and expansion joints, the system is adapted in advance to meet the installation requirements of the new beams, avoiding temporary rework due to insufficient foundation compatibility during the closure construction and maximizing the use of valuable closure time. Specialized treatments for complex conditions such as limited clearance ensure the compliance and feasibility of the modification work; pre-treatment and trial jacking of bearing bolts allow for early verification of the beam's stress state and equipment compatibility, avoiding unexpected failures during the jacking process; and pre-installation of expansion joints ensures seamless connection between the new beam installation and the expansion joint, reducing the workload of subsequent track restoration.

[0038] In some embodiments, the construction method for replacing box girders on existing railway lines by jacking and sliding also includes a trial operation procedure before the formal jacking, which includes: Before the formal closure and construction, a 4m jacking operation was carried out on the new steel box girder, and a 2cm jacking operation was carried out on the existing T beam. Equipment operation data, structural deformation data and synchronous control data were collected during the trial operation. Based on the trial operation data, the equipment parameters, PLC control parameters, and synchronous control strategies of the jacking and translation construction system were optimized and adjusted, and potential construction hazards were identified and resolved. For problems such as displacement deviation, abnormal stress, and equipment failure that occur during the trial operation, corresponding emergency response plans should be developed.

[0039] In this embodiment, trial jacking and trial lifting operations are conducted to comprehensively collect data on equipment operation, structural deformation, and synchronous control, providing a basis for optimizing the construction system. Optimizing equipment and control parameters and adjusting synchronization strategies based on trial operation data can proactively identify potential problems such as insufficient equipment compatibility and inadequate control precision, ensuring efficient linkage between equipment and the system during formal construction. Simultaneously, emergency response plans are developed to address various anomalies encountered during trial operations, ensuring preparedness and preventing unforeseen malfunctions from being unmanageable during the shutdown window period.

[0040] In some embodiments, the existing railway line box girder jacking and horizontal displacement replacement construction method further includes a full-process construction monitoring procedure, which includes: The system is equipped with six monitoring modules: settlement monitoring, stress monitoring, support reaction force monitoring, vertical displacement monitoring, horizontal displacement monitoring, and axis deviation monitoring, with corresponding monitoring points and instruments. Initial values ​​of each monitoring item are collected before beam replacement, real-time tracking monitoring is performed during the jacking, pushing and lowering of beam operations, and final monitoring values ​​are collected after beam lowering is completed. Set corresponding early warning thresholds for each monitoring item. When the monitoring data exceeds the early warning threshold, construction should be suspended immediately, construction parameters should be adjusted based on the monitoring data, and work should continue only after the anomaly has been eliminated.

[0041] In this embodiment, six monitoring modules, including settlement, stress, and support reaction forces, are deployed along with precise measuring points and instruments to provide comprehensive data support for beam condition, structural safety, and equipment operation. The continuous acquisition of initial values, real-time tracking and monitoring, and post-construction value review fully connect the construction process, enabling technicians to accurately capture the dynamic changes of each procedure.

[0042] It is worth mentioning that the PLC synchronous hydraulic control system adopts a force and displacement integrated control mode with a synchronous control accuracy of ±1.0mm. During the jacking operation, the stroke data of each jacking jack is collected in real time through absolute displacement sensors, and the system is automatically reset to zero after each 1m jacking stroke to eliminate cumulative errors. During the lifting operation, the lifting height data of each lifting jack is collected in real time through wire-type displacement sensors, and the synchronization of each jack is controlled in a closed loop. When the displacement deviation exceeds the preset threshold, the system automatically triggers single-machine adjustment and shutdown warning.

[0043] In this embodiment, the force and displacement integrated control mode overcomes the limitations of single control, preventing structural damage to the beam due to uneven stress or displacement deviation. Real-time data acquisition from dedicated sensors and automatic stroke zeroing effectively eliminate error accumulation during the jacking process, ensuring precise and controllable operation throughout long-distance jacking. Simultaneously, the closed-loop control and automatic early warning mechanism in the jacking operation can capture jack displacement deviations in real time, triggering adjustment and shutdown commands promptly to proactively avoid safety hazards caused by abnormal expansion.

[0044] Figure 2 This diagram illustrates a structural block diagram of a railway existing line box girder jacking and translation replacement construction system according to an exemplary embodiment of the present invention. This railway existing line box girder jacking and translation replacement construction system is applied to the aforementioned railway existing line box girder jacking and translation replacement construction method. The system includes: System construction unit 201 is used to construct a jacking and translation construction system adapted to dual working conditions based on the design parameters and working condition characteristics of the existing line beam replacement project. The dual working conditions correspond to the existing T-beam removal working condition and the new steel box girder removal working condition, respectively. Slide construction unit 202 is used to complete the construction of the slide foundation and track system, and to build a sliding support structure that matches the jacking and translation construction system; The jacking and replacement unit 203 is used to perform jacking and replacement operations on the existing T-beam to be moved out and the new steel box girder to be moved in, so that the beam body is separated from the original support structure and locked in the jacking and pressure-holding state. The synchronous jacking unit 204 is used to simultaneously perform the lateral jacking and removal of the existing T-beam and the lateral jacking and removal of the new steel box girder within a preset railway closure window period, and to collect the attitude data of the beam displacement process in real time to generate a beam displacement attitude dataset. The beam-dropping and restoration unit 205 is used to perform correction and beam-dropping operations on the beam after it has been placed, based on the beam displacement posture dataset, to complete the support installation and line restoration, and realize the beam replacement construction of the existing line.

[0045] It should be noted that the railway existing line box girder jacking and horizontal movement girder replacement construction system provided in the above embodiments is only an example of the above functional unit division. In actual applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the equipment can be divided into different functional units to complete all or part of the functions described above.

[0046] In summary, this technical solution significantly optimizes the existing line beam replacement construction process, enabling simultaneous removal of existing T-beams and installation of new steel box girders. This drastically shortens the railway closure window, effectively reduces disruption to existing line operations, and ensures passenger and freight transport order. Furthermore, by constructing a dual-condition jacking and translation system that shares a sliding support structure, the construction process is simplified, construction costs are reduced, and the adaptability of the support structure is improved, avoiding issues such as track settlement and beam displacement. In addition, a comprehensive pre-treatment, trial operation, and full-process monitoring system can proactively identify potential construction hazards and address anomalies in real time, ensuring construction safety and quality. This solution is suitable for existing line renovation scenarios, requires no large-scale track dismantling, and is convenient and efficient. It can be widely applied to existing line T-beam to steel box girder replacement projects, demonstrating strong practicality and promotional value.

[0047] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand this disclosure, and are not intended to limit the scope of the invention.

[0048] It is understood that the various implementation methods described in this specification can be implemented individually or in combination, and this disclosure does not limit them.

[0049] Unless otherwise stated, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this specification. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0050] The above description is merely a specific embodiment of this specification, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this specification should be included within the scope of protection of this specification. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A method for replacing box girders on existing railway lines by jacking and horizontal movement, characterized in that, include: Based on the design parameters and working conditions of the existing line beam replacement project, a jacking and translation construction system adapted to dual working conditions is constructed. The dual working conditions correspond to the existing T-beam removal working condition and the new steel box girder removal working condition, respectively. Complete the construction of the slideway foundation and track system, and build a sliding support structure that matches the jacking and translation construction system; The existing T-beams to be removed and the new steel box girders to be moved in were respectively lifted and replaced, so that the beams were detached from the original support structure and locked in the lifting and pressure-holding state; During the pre-set railway closure window, the lateral jacking and removal of the existing T-beams and the lateral jacking and removal of the new steel box girders are carried out simultaneously. The attitude data of the beams during the displacement process are collected in real time to generate a beam displacement attitude dataset. Based on the beam displacement posture dataset, the beam is corrected and lowered after it is in place, and the support installation and line restoration are completed to realize the beam replacement construction of the existing line.

2. The construction method for replacing box girders on existing railway lines according to claim 1, characterized in that, Based on the design parameters and working conditions of the existing line beam replacement project, a jacking and translation construction system adapted to dual working conditions is constructed, including: Based on the structural and weight parameters of the existing T-beams and the new steel box girders, corresponding jacking equipment, jacking equipment and PLC synchronous hydraulic control systems are configured respectively. A jacking and sliding subsystem is configured for the existing T-beam removal condition and a jacking and sliding subsystem is configured for the new steel box girder insertion condition. The two subsystems share part of the slide rail structure. Develop a phased construction process that matches the railway closure window period, and match the process nodes with online and offline synchronous operations.

3. The construction method for replacing box girders on existing railway lines according to claim 1, characterized in that, The construction of the slideway foundation and track system is completed, and a sliding support structure matching the jacking and translation construction system is erected, including: The construction of bored pile foundation and reinforced concrete cap is carried out, and φ630mm steel pipe columns are installed on the cap. The columns are reinforced by channel steel connection, and the verticality of the column installation is controlled within 3‰ and not greater than 10mm. Double 700mm high H-shaped steel spreader beams are installed on the top of the steel pipe columns, and double 800mm high H-shaped steel sliding beams are installed on the spreader beams to form a sliding support frame; Slide rail steel plates and 7mm thick stainless steel friction-reducing plates are laid on the slide rail beam. Reaction groove steel plates are welded on both sides of the slide rail to form a U-shaped reaction groove structure that serves as both the back of the jacking reaction force and the sliding limit. For existing T-beam jacking operations, angle steel limiting and blocking structures are welded on both sides of the sliding track.

4. The method for replacing box girders on existing railway lines by jacking and horizontal movement according to claim 1, characterized in that, The process of performing jacking and replacement operations on the existing T-beams to be removed and the new steel box girders to be moved in, so that the beams are detached from the original support structure and locked in a jacking and pressure-holding state, includes: For the new steel box girder, a steel distribution beam is installed at the bottom of the beam, and a 300T three-dimensional correction jack is arranged between the steel distribution beam and the slide beam. Multiple three-dimensional correction jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously. The lifting height is 3cm. After the jacks are lifted into place, the pressure is maintained by the self-locking electromagnetic leak-free valve built into the jacks. For the existing T-beam, 200T double-acting hydraulic self-locking jacks are arranged between the beam body and the slide beam. Multiple hydraulic self-locking jacks are controlled by a PLC synchronous hydraulic control system to lift synchronously with a lifting height of 3cm. After being lifted into place, the jacks are locked by the pressure-holding nuts. During the lifting process, the displacement data of each jack is monitored in real time to control the synchronous error of the lifting point displacement to not exceed 2mm. If the error threshold is exceeded, a single-point closed-loop adjustment is performed. The 300T three-dimensional correction jack has a vertical lifting stroke of 90mm and a transverse correction stroke of ±50mm. Boat-shaped copper strips are installed on both sides of the jack base, with a spacing of 20mm between the copper strips and the reaction slot side plate. During the jacking process, the jack is guided and limited by the cooperation of the copper strips and the reaction slot, controlling the maximum error of the longitudinal displacement of the beam to not exceed 20mm. The top of the jack is equipped with a ball head structure, with a maximum rotation angle of 5 degrees, which can accommodate the angle deviation caused by the settlement of the slide, ensuring that the jack and the bottom of the beam are always in close contact and bearing force.

5. The construction method for replacing box girders on existing railway lines according to claim 1, characterized in that, Within a pre-set railway closure window, the lateral jacking and removal of the existing T-beams and the lateral jacking and removal of the new steel box girders are carried out simultaneously. Attitude data during the beam displacement process is collected in real time to generate a beam displacement attitude dataset, including: During the railway closure window, the preliminary procedures of track protection, beam restraint removal, and existing support bolt removal should be completed first. The new steel box girder is pushed using a 120T jacking jack. The jacking jack has a built-in absolute displacement sensor and an automatic reaction shear seat at the front end. Continuous pushing is achieved through the cooperation of the shear seat and the U-shaped reaction slot. The pushing speed is controlled at 2 minutes and 10 seconds per meter, and the single pushing stroke is 1 meter. The existing T-beams were pushed and moved using 200T hydraulic self-locking jacks, which were started simultaneously with the new steel box girder pushing operation. A step-by-step translation strategy was adopted to control the synchronization error of the T-beam and the steel box girder within the preset range. During the jacking process, the horizontal displacement, vertical displacement, axis deviation, support reaction force, and structural stress data of the beam are collected in real time to generate a dataset of beam displacement posture. The construction process during the railway closure window is carried out according to the following steps: After the closure begins, the line protection is set up, and the setting and confirmation of the two horizontal and one vertical return lines are completed; the rails, sleepers, ballast, expansion joints, and transition cables at the beam joints are removed simultaneously, and the support bolts of the existing T-beams are released; the existing T-beams and the new steel box girders are simultaneously lifted by 3cm to complete the replacement and pressure holding locking; the existing T-beams are pushed out and the new steel box girders are pushed in simultaneously, and after they are in place, the beam body is corrected, the beams are lowered, and the temporary supports are adjusted; the support grouting, expansion joint installation, ballast backfilling, sleeper installation, laying and debugging of the four electrical systems, and adjustment of the contact wire parameters are completed simultaneously, and the line inspection and protection removal are completed.

6. The construction method for replacing box girders on existing railway lines according to claim 1, characterized in that, Based on the beam displacement posture dataset, the process of performing correction and lowering operations on the beam after it has been positioned, and completing the support installation and line restoration, includes: Based on the beam displacement posture dataset, the new steel box girder in the transverse and longitudinal directions is corrected by three-dimensional correction jacks after it is in place, so as to control the beam axis deviation within the allowable range. The jacks are lowered synchronously by a PLC synchronous hydraulic control system to lower the beam onto the preset temporary support, and the synchronous error of each support point during the beam lowering process is controlled to not exceed 2mm. Complete the installation of permanent supports and grouting of support pads. After grouting, install and debug the beam track structure, expansion joints, and four electrical systems. Complete the line restoration and open the line according to the preset speed limit conditions.

7. The construction method for replacing box girders on existing railway lines according to claim 1, characterized in that, The method also includes a pre-treatment process before the sealing construction, the pre-treatment process including: The existing pier bearing pads were modified by removing the portion of the existing pads that overlapped with the new pads. Under the condition of limited clearance, a light electric hammer was used to complete the rebar installation and pouring of the new pads. Using the railway's three-level blockade points, the support bolts of the existing T-beams were removed and restored one by one. Bolts that could not be removed were marked and pre-treated. After completion, the existing T-beams were tested and lifted. Pre-treatment was performed on the existing beam end expansion joints, new expansion joint steel blocks were installed on the old bridge side, and matching expansion joint components were welded to the beam end of the new steel box girder and moved in synchronously with the beam body.

8. The method for replacing box girders on existing railway lines by jacking and horizontal movement according to claim 1, characterized in that, The method also includes a trial operation procedure before the formal jacking, the trial operation procedure including: Before the formal closure and construction, a 4m jacking operation was carried out on the new steel box girder, and a 2cm jacking operation was carried out on the existing T beam. Equipment operation data, structural deformation data and synchronous control data were collected during the trial operation. Based on the trial operation data, the equipment parameters, PLC control parameters, and synchronous control strategies of the jacking and translation construction system were optimized and adjusted, and potential construction hazards were identified and resolved. For problems such as displacement deviation, abnormal stress, and equipment failure that occur during the trial operation, develop corresponding emergency response plans; The method also includes a full-process construction monitoring procedure, which includes: The system is equipped with six monitoring modules: settlement monitoring, stress monitoring, support reaction force monitoring, vertical displacement monitoring, horizontal displacement monitoring, and axis deviation monitoring, with corresponding monitoring points and instruments. Initial values ​​of each monitoring item are collected before beam replacement, real-time tracking monitoring is performed during the jacking, pushing and lowering of beam operations, and final monitoring values ​​are collected after beam lowering is completed. Set corresponding early warning thresholds for each monitoring item. When the monitoring data exceeds the early warning threshold, construction should be suspended immediately, construction parameters should be adjusted based on the monitoring data, and work should continue only after the anomaly has been eliminated.

9. The construction method for replacing box girders on existing railway lines according to claim 4 or 5, characterized in that, The PLC synchronous hydraulic control system adopts a force and displacement integrated control mode, with a synchronous control accuracy of ±1.0mm; During the jacking operation, the stroke data of each jacking jack is collected in real time through absolute displacement sensors. The jacking stroke is automatically reset to zero after each 1m jacking stroke is completed to eliminate cumulative errors. During the jacking operation, the lifting height data of each jack is collected in real time through a pull-wire displacement sensor, and the synchronization of each jack is controlled in a closed loop. When the displacement deviation exceeds the preset threshold, the single-machine adjustment and shutdown warning are automatically triggered.

10. A construction system for replacing box girders on existing railway lines by jacking and horizontal movement, characterized in that, The system is applied in the construction method for jacking, leveling, and replacing box girders on existing railway lines as described in any one of claims 1 to 9. The system includes: The system construction unit is used to construct a jacking and translation construction system adapted to two working conditions based on the design parameters and working condition characteristics of the existing line beam replacement project. The two working conditions correspond to the existing T-beam removal working condition and the new steel box girder removal working condition, respectively. The slideway construction unit is used to complete the construction of the slideway foundation and track system, and to build a sliding support structure that matches the jacking and translation construction system. The jacking and replacement unit is used to perform jacking and replacement operations on the existing T-beams to be moved out and the new steel box girders to be moved in, so that the beams are removed from the original support structure and locked in the jacking and pressure-holding state. The synchronous jacking unit is used to simultaneously perform the lateral jacking and removal of the existing T-beam and the lateral jacking and removal of the new steel box girder within a preset railway closure window period, and to collect the attitude data of the beam displacement process in real time to generate a beam displacement attitude dataset. The beam-dropping and restoration unit is used to perform correction and beam-dropping operations on the beam after it has been placed in position, based on the beam displacement posture dataset, to complete the support installation and line restoration, and realize the beam replacement construction of the existing line.

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