Construction method of large-column transport beam of overpass railway shed

Abstract

This invention discloses a method for constructing bridge beams for railway tunnels using a prefabricated beam assembly method, eliminating the lengthy process of on-site formwork erection and concrete pouring and curing. Through a streamlined process of "vertical beam lifting by gantry crane – longitudinal alignment – ​​beam lowering – flatbed car forward movement," the erection of tunnel beams can be carried out continuously. Simultaneously, relying on railway trains for equipment and beam transfer, the transportation efficiency is far higher than traditional railcar / manual transfer methods, significantly reducing the overall on-site construction period. All construction equipment and beams are transported using existing railway flatbed cars, eliminating the need to construct large temporary transport roads along the railway line and reducing the occupation of surrounding space and facilities. All on-line operations are carried out during maintenance windows, with the entire train returning to the designated station before the end of the window, without interfering with normal operating hours.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, and in particular to a method for constructing bridge beams for large-scale transport across railway tunnels. Background Technology

[0002] The traditional construction of tunnels spanning railways stems from the dual demands for railway operational safety and construction efficiency. In complex terrain and alongside busy railway lines, traditional construction methods face challenges such as long construction periods, high safety risks, and significant disruption to existing lines.

[0003] Early tunnel structures were mostly constructed using cast-in-place construction, requiring the layer-by-layer pouring of structures such as pile foundations, sidewalls, and cover slabs on-site. This method relied heavily on formwork and scaffolding, had a long construction period, and exposed workers to the vicinity of the railway line for extended periods, posing significant safety risks.

[0004] In addition, traditional construction is limited by narrow spaces and transportation difficulties, and materials and equipment often need to be transported by railcar or manually, which is inefficient.

[0005] Therefore, it is necessary to develop a construction method for large-scale train transport and beam erection across railway tunnels to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to design a method for constructing bridge erection for large-scale transport across railway tunnels in order to solve the above-mentioned problems.

[0007] The present invention achieves the above objectives through the following technical solutions: A method for constructing bridge girder erection for large-scale train transport across railway tunnels includes: S1. Install a gantry crane travel rail on the top of the longitudinal beam of the shed; S2. Gantry crane off-site assembly; S4. Gantry crane transportation and hoisting: The gantry crane and the first truck crane are transported to the tunnel construction site via railway tracks, and then the gantry crane is assembled and hoisted onto the gantry crane travel rail by the first truck crane; S5. The crossbeams are transported to the station by a beam transport vehicle. After being lifted by the station's second truck crane, they are placed on a flatbed car on the railway track to complete the beam loading. Finally, the flatbed car is pulled to the tunnel construction site by a drive locomotive. S6. Gantry crane vertical lifting beam; S7, longitudinal displacement beam; S8, lowering the beam; S9. Flatbed car moves forward; As the beam lifting progresses, the flatbed car moves forward step by step, aligning the crossbeam to the beam lifting position, until the crossbeam on the flatbed car is lifted. Then the flatbed car returns to the station to load the beam and move it down in a cycle until the crossbeam is installed. S10, the first truck crane lifts the gantry crane onto the flatbed truck, which is then disassembled and towed away.

[0008] Specifically, step S1 includes: pre-embedding steel bars above the longitudinal beam of the shed, placing the gantry crane travel rail on top of the longitudinal beam of the shed, and locking and fixing the travel rail with the steel bars.

[0009] Specifically, step S2 includes: assembling the two main beams, four legs, and two lower crossbeams of the gantry crane off-site, and then installing the gantry crane trolley frame, electric hoist, and lifting gear.

[0010] Furthermore, step S3 is set after step S2. Step S3 includes: conducting a trial lift of the gantry crane under simulated on-site working conditions: using lime to mark out the railway line, longitudinal beams, beam storage area and crane position to simulate the construction site conditions; first, lift the crossbeam 20cm above the original ground and stabilize for 1 minute, then lift the crossbeam 1 meter above the original ground and stabilize for 1 minute, turn the crossbeam 90 degrees on-site and stabilize for 1 minute, then lift it to the gantry crane's maximum lifting height and stabilize for 1 minute, and then test the maximum traveling speed of the gantry crane in normal lifting condition.

[0011] Specifically, in step S4, when transporting the gantry crane, the main beam is erected symmetrically, and one outrigger is symmetrically loaded on each side of the horizontal center line under the main beam, so that the overall center projection of the cargo is located at the intersection of the longitudinal and transverse center lines of the flatbed truck floor; each outrigger is leveled and stabilized with square timber, and square timber is squeezed around the outrigger to prevent longitudinal and transverse movement of the square timber; the main beam outriggers are nailed to the flatbed truck floor with round steel nails; two strands of steel wire rope are used to pull a figure-eight shape on each side of the main beam and tied to the T-shaped iron or support groove on the side of the flatbed truck.

[0012] Specifically, in step S4, when transporting the truck crane, the truck crane is loaded evenly and symmetrically so that the projected center of gravity of the truck crane is located at the intersection of the longitudinal and transverse center lines of the flatbed floor; the front and rear ends of the front wheels and the front and rear ends of the rear wheel assembly of the truck crane are each secured with triangular blocks and nailed to the flatbed floor; triangular blocks are placed on the inside of the rear wheel assembly of the truck crane, and after approaching the tires, they are nailed to the flatbed floor with brass nails; square timbers are placed under the outriggers of the crane and pressed down, and each square timber is nailed to the flatbed floor with four brass nails; through the front axle of the truck crane, two strands of steel wire rope are used to pull a figure-eight shape on each side; through the front and rear axles of the rear wheel assembly of the truck crane, two strands of steel wire rope are used to pull a figure-eight shape on each side, and tied to the T-shaped iron or support groove on the side of the flatbed truck; the boom hook of the truck crane is secured to the body of the flatbed truck with four strands of steel wire rope.

[0013] Specifically, in step S5, when loading, reinforcing, and transporting the crossbeams at the station, each flatbed truck is loaded with two crossbeams of the same specifications. The crossbeams are placed on horizontal support timbers so that the total center of gravity projection of the crossbeams is located on the longitudinal center line of the flatbed truck floor, and the weight difference between the two ends of the flatbed truck does not exceed 2t. One horizontal support timber is placed symmetrically on each side of the horizontal center line of the flatbed truck and nailed to the flatbed truck floor with round steel nails. The crossbeams are tightened with diagonal supports on both sides to prevent them from tilting laterally. Square timbers are used to squeeze the diagonal supports and horizontal support timbers together and nailed to the horizontal support timbers with round steel nails. Wooden blocks are placed on both sides of the crossbeam retaining wall and nailed to the flatbed truck floor with round steel nails. Two strands of steel wire rope are passed through the lifting ring at the top of the crossbeam and tied to the T-shaped iron or support groove on the side of the flatbed truck for reinforcement.

[0014] Specifically, step S6 includes: binding guy ropes to the crossbeam to prevent it from swaying; aligning the gantry crane longitudinally and installing the lifting points of the crossbeam to be erected on the corresponding lifting holes of the gantry crane lifting tool; lifting the crossbeam, and when erecting the crossbeam on a curved section, first lift the crossbeam on the inner side of the curve, and then lift the crossbeam on the outer side of the curve; after the crossbeam is lifted off the flatbed truck, first move it laterally away from the contact wire to ensure that the horizontal distance between the crossbeam and the contact wire is greater than 80cm, and then perform vertical lifting.

[0015] Further, step S7 includes: confirming that there is no abnormality in the hoisting mechanism of the gantry crane, pulling the guy rope connected to one end of the crossbeam to turn the crossbeam 90°, and then moving the crossbeam longitudinally by the gantry crane to align it. During the longitudinal movement, the guy ropes are pulled on both sides of one end of the crossbeam to prevent the crossbeam from rotating.

[0016] Furthermore, in step S8: when lowering the beam, the beam remains horizontal, with a front-to-back height difference of less than 200 mm and a left-to-right height difference of less than 20 mm.

[0017] The beneficial effects of this invention are as follows: Significantly shortening the construction cycle and improving beam erection efficiency: This method adopts a prefabricated beam assembly erection mode, replacing the traditional cast-in-place construction process, eliminating the long cycle of on-site formwork erection and concrete pouring and curing. Through a streamlined process of "vertical beam lifting by gantry crane - longitudinal alignment - beam lowering - flatbed truck forward movement," the erection of tunnel beams can be carried out continuously; at the same time, relying on railway trains to complete the transfer of equipment and beams, the transportation efficiency is far higher than the traditional railcar / manual transfer method, significantly reducing the overall on-site construction period.

[0018] To reduce on-site safety risks and minimize personnel exposure time near railway lines: The assembly and simulated trial lifting of the gantry crane are all completed off-site. Only the core processes of lifting and beam erection are carried out near the railway line during maintenance windows, significantly reducing the exposure time of workers near the railway operating line. The entire process of lifting, longitudinally moving, and lowering beams is mainly carried out by mechanized gantry crane operations, supplemented by protective measures such as guy rope beam stabilization, lifting the inner beam first and then the outer beam on curved sections, and staged lifting and stopping. These measures can effectively avoid risks such as beam swaying and flatbed truck overturning, reducing the safety hazards of manual operations.

[0019] To minimize disruption to existing railway operations: all construction equipment and beams are transported using existing railway flatbed wagons, eliminating the need for large temporary transport access roads along the railway line and reducing the occupation of surrounding space and facilities; all on-line operations are carried out during maintenance windows, with the entire wagon returning to the designated station before the windows end, without interfering with normal operating hours; during beam lifting operations, the beams are first moved laterally away from the overhead contact line to ensure a safe horizontal distance from the contact line, avoiding contact with railway contact line facilities and minimizing the impact on existing line operations.

[0020] Overcoming the limitations of narrow sites and reducing the construction area: This method relies on existing railway lines to complete the direct transportation of equipment and beams, without the need to build additional land transportation channels from off-site to the construction site, which is suitable for narrow construction site conditions next to railways; at the same time, there is no need to set up a large beam storage area or equipment assembly area on site. The beams and equipment are transported directly to the work surface by railway, and only the space for gantry crane travel and operation needs to be reserved on site, which greatly reduces the construction area and reduces the cost of site acquisition and temporary facility layout.

[0021] Simplify construction equipment configuration and reduce overall project costs: This method makes full use of the existing railway transportation capacity and existing equipment such as flatbed trucks, without the need to build an additional professional bridge erection and transportation system. The core construction equipment is only gantry cranes and truck cranes, which are simple to configure and highly versatile. At the same time, the "off-site prefabrication + on-site assembly" model reduces the investment in turnover materials such as formwork and supports, thereby reducing the overall construction cost. Attached Figure Description

[0022] Figure 1 This is a layout diagram of the components of a gantry crane; where A is the front view and B is the side view. Figure 2 This is a layout diagram for the reinforcement and transport of goods by a gantry crane flatbed truck; where A is the front view and B is the side view. Figure 3 This is a layout diagram for the reinforcement and transport of a flatbed truck using a first-class truck crane; where A is the front view and B is the side view. Figure 4 This is a plan view of the first truck crane used for hoisting and installing the gantry crane according to the present invention; Figure 5This is an elevation layout diagram of the first truck crane lifting gantry crane of the present invention; Figure 6 This is a plan view of the lifting beam of the 25t truck crane (second truck crane) in the freight yard of this invention; Figure 7 This is a cross-sectional view of the lifting beam of the 25t truck crane (second truck crane) in the freight yard of this invention; Figure 8 This is a diagram showing the reinforcement arrangement for transporting the crossbeam flatbed truck according to the present invention; where A is the front view and B is the side view. Figure 9 This is a construction plan layout diagram of the gantry crane lifting beam of the present invention; Figure 10 This is an elevation layout diagram of the gantry crane lifting beam construction of the present invention.

[0023] Labeling instructions: 1-Gantry crane, 2-First truck crane, 3-Flatbed truck, 4-Longitudinal beam of the tunnel, 5-Traveling rail, 6-Crossbeam, 7-Main beam, 8-Outrigger, 9-Lower crossbeam, 10-Trolley frame, 11-Wire rope, 12-Triangle stop, 13-Square timber, 14-Horizontal pad, 15-Diagonal support, 16-Stop timber, 17-Guest rope. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0029] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] A method for constructing bridge girder erection for large-scale train transport across railway tunnels includes: S1, such as Figure 1 and 5 As shown, the traveling rail 5 of the gantry crane 1 is installed on the top of the longitudinal beam of the shed. Before the beam erection begins, the construction of the longitudinal beam 4 of the shed needs to be completed, and steel bars are pre-embedded above the longitudinal beam 4 of the shed with a spacing of 60cm. The traveling rail 5 of the gantry crane 1 is placed on the top of the longitudinal beam of the shed, and the steel bars lock and fix the traveling rail 5. The installation of the traveling rail 5 of the gantry crane 1 needs to be completed within the skylight point. The traveling rail 5 of the gantry crane 1 uses P24 steel rails.

[0032] S2, such as Figure 1 As shown, gantry crane 1 is assembled off-site. Off-site, the two main beams 7, four outriggers 8, and two lower crossbeams 9 of gantry crane 1 are assembled, followed by the installation of the gantry crane 1 trolley frame 10, electric hoist, and lifting gear. Gantry crane 11 has a rated lifting capacity of 12t and a span adjustable within a range of 10.565m. Its external dimensions are 11m × 2.4m × 4.0m. The lifting speed is 3.5m / min, and the moving speed is 10m / min. The total weight of gantry crane 11 is 5.4t. S3. Gantry crane 1 was tested under simulated on-site conditions: The railway line, longitudinal beams, beam storage area, and crane position were marked out with lime to simulate the construction site conditions; First, the crossbeam 6 was raised 20cm above the original ground and stabilized for 1 minute, then the crossbeam 6 was raised 1 meter above the original ground and stabilized for 1 minute. The crossbeam 6 was then turned 90 degrees on-site and stabilized for 1 minute, then raised to the maximum lifting height of gantry crane 1 and stabilized for 1 minute. Gantry crane 1 was then allowed to travel under normal lifting conditions, and the maximum travel speed was tested.

[0033] S4, such as Figure 2-5 As shown, the gantry crane 1 is transported and hoisted; the gantry crane 1 and the first truck crane 2 are transported to the tunnel construction site via railway tracks, and then the first truck crane 2 assembles and hoists the gantry crane 1 onto the gantry crane 1 travel rail 5; When transporting the gantry crane 1, the main beam 7 is erected symmetrically. One support leg 8 is symmetrically loaded on each side of the horizontal center line under the main beam 7, so that the total center projection of the cargo is located at the intersection of the longitudinal and transverse center lines of the flatbed truck 3 floor. Each support leg 8 is leveled and stabilized with square timber 13, and square timber 13 is squeezed around the support leg 8 to prevent the square timber 13 from moving longitudinally or laterally. The support legs 8 of the main beam 7 are nailed to the floor of the flatbed truck 3 with round steel nails. Two strands of steel wire rope 11 are used to pull an eight-shaped rope on each side of the main beam 7 and tied to the T-shaped iron or support groove on the side of the flatbed truck 3.

[0034] When transporting the truck crane, load the truck crane evenly and symmetrically so that the center of gravity of the truck crane is located at the intersection of the longitudinal and transverse center lines of the flatbed truck 3 floor. The front and rear ends of the truck crane's front wheels and the front and rear ends of the rear wheel assembly are each secured with triangular blocks 12 and nailed to the floor of the flatbed truck 3. Triangular blocks 12 are placed on the inside of the truck crane's rear wheel assembly and nailed to the floor of the flatbed truck 3 with brass nails near the tires. Square timbers 13 are placed under the crane's outriggers 8 and pressed down, with each square timber 13 nailed to the floor of the flatbed truck 3 with four brass nails. Through the front axle of the truck crane, two strands of steel wire rope 11 are used to pull a figure-eight shape on each side. Through the front and rear axles of the truck crane's rear wheel assembly, two strands of steel wire rope 11 are used to pull a figure-eight shape on each side and are tied to the T-shaped iron or support groove on the side of the flatbed truck 3. The hook of the truck crane's boom is secured to the body of the flatbed truck 3 with four strands of steel wire rope 11.

[0035] Note: For gantry crane 1 used in large-scale train transport, flatbed truck 3 with a length of 14.3m should be used; for truck crane used in large-scale train transport, flatbed truck 3 with a length of 16.5m should be used.

[0036] During the installation of gantry crane 1, it is assembled using a truck crane at the nearest location outside the designated skylight. After assembly, it is loaded and secured on the flatbed truck 3. After loading and securing, the power supply arm of the contact network is de-energized within the skylight, the contact network is adjusted, and the guy ropes 17 are tied to gantry crane 1. Then, the truck crane is used to lift and position the gantry crane 1 as a whole. After the installation of gantry crane 1, it is run unloaded and returned. During this period, professional technicians check the braking and limit measures of gantry crane 1. After the inspection and testing are completed, normal operation can begin.

[0037] S5, such as Figure 6-9 As shown, the crossbeam 6 is transported to the station by a beam transport vehicle. After being lifted by the station's second truck crane (25t truck crane), it is placed on the flatbed car 3 on the railway track to complete the beam loading. Finally, the flatbed car 3 is pulled to the tunnel construction site by a drive locomotive. After the crossbeam 6 is loaded, according to the dispatch order, the flatbed car 3 needs to be on standby at the station before 3 o'clock (before the start of the track maintenance window). According to the dispatch order, within the time window, it is pulled by the drive locomotive to the construction site to complete the hoisting and installation of the gantry crane 1.

[0038] When loading, reinforcing, and transporting the crossbeams 6 at the station, two crossbeams 6 are loaded sequentially on each flatbed 3. The two crossbeams 6 are of the same specification and are placed on horizontal blocks 14 so that the total center of gravity projection of the crossbeams 6 is located on the longitudinal center line of the flatbed 3 floor. The weight difference between the two ends of the flatbed 3 does not exceed 2t. One horizontal block 14 is placed symmetrically on each side of the transverse center line of the flatbed 3 and nailed to the floor of the flatbed 3 with round steel nails. The crossbeams 6 are tightened on both sides with diagonal supports 15 to prevent them from tilting laterally. The contact points between the diagonal supports 15 and the horizontal blocks 14 are squeezed with square timbers 13 and nailed to the horizontal blocks 14 with round steel nails. A retaining block 16 is placed on each side of the crossbeam 6 retaining wall and nailed to the floor of the flatbed 3 with round steel nails. Two strands of steel wire rope 11 are passed through the lifting ring at the top of the crossbeam 6 and tied to the T-shaped iron or support groove on the side of the flatbed 3 for reinforcement.

[0039] S6, such as Figure 10 As shown, gantry crane 1 lifts the beam vertically; guy ropes 17 are tied to the crossbeam 6 to prevent it from swaying; gantry crane 1 moves longitudinally to align, and the lifting points of the crossbeam 6 to be erected are installed on the corresponding lifting holes of the lifting tool of gantry crane 1; when lifting the crossbeam 6, when erecting the beam on the curved section, the inner side of the curve crossbeam 6 is lifted first, and then the outer side of the curve crossbeam 6 is lifted; after the crossbeam 6 is lifted off the flatbed truck 3, it is first moved laterally away from the contact wire to ensure that the horizontal distance between the crossbeam 6 and the contact wire is greater than 80cm, and then it is lifted vertically.

[0040] S7. Longitudinal moving beam: After confirming that there are no abnormalities in the hoisting mechanism of the gantry crane 1, pull the guy rope 17 connected to one end of the crossbeam 6 to turn the crossbeam 6 90°, and then move the crossbeam 6 longitudinally by the gantry crane 1 to align it. During the longitudinal movement, pull the guy rope 17 on both sides of one end of the crossbeam 6 to prevent the crossbeam 6 from rotating.

[0041] S8. Lowering the beam; When lowering the beam, the crossbeam 6 should remain horizontal, with a front-to-back height difference of less than 200 mm and a left-to-right height difference of less than 20 mm.

[0042] S9. Flatbed trolley 3 moves forward; as the beam lifting progresses, flatbed trolley 3 gradually moves forward, aligning the crossbeam 6 to the beam lifting position. If there are overhead contact wire cantilever arms and anchoring equipment, the gantry crane 1 will travel over the contact wire equipment, increasing its travel distance. Before the entire train is completed, the whole train returns to the designated station. After the track maintenance window ends, the train will be requested to return to the beam loading station for beam loading. After each flatbed trolley 3 has lifted the crossbeam 6, the flatbed trolley 3 returns to the station for beam loading and continues the downward cycle until the crossbeam 6 is installed. S10. Finally, the first truck crane 2 lifts the gantry crane 1 onto the flatbed truck 3, and after disassembly and assembly, it is pulled away.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for constructing bridge erection for large-scale train transport across railway tunnels, characterized in that, include: S1. Install a gantry crane travel rail on the top of the longitudinal beam of the shed; S2. Gantry crane off-site assembly; S4. Gantry crane transportation and hoisting; The gantry crane and the first truck crane are transported to the tunnel construction site via railway tracks, and then the gantry crane is assembled and hoisted onto the gantry crane travel rail by the first truck crane. S5. The crossbeams are transported to the station by a beam transport vehicle. After being lifted by the station's second truck crane, they are placed on a flatbed car on the railway track to complete the beam loading. Finally, the flatbed car is pulled to the tunnel construction site by a drive locomotive. S6. Gantry crane vertical lifting beam; S7, longitudinal displacement beam; S8, lowering the beam; S9. Flatbed car moves forward; As the beam lifting progresses, the flatbed car moves forward step by step, aligning the crossbeam to the beam lifting position, until the crossbeam on the flatbed car is lifted. Then the flatbed car returns to the station to load the beam and move it down in a cycle until the crossbeam is installed. S10, the first truck crane lifts the gantry crane onto the flatbed truck, which is then disassembled and towed away.

2. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 1, characterized in that, Step S1 includes: pre-embedding steel bars above the longitudinal beam of the shed, placing the gantry crane travel rail on top of the longitudinal beam of the shed, and locking and fixing the travel rail with the steel bars.

3. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 2, characterized in that, Step S2 includes: assembling the two main beams, four legs, and two lower crossbeams of the gantry crane off-site, and then installing the gantry crane trolley frame, electric hoist, and lifting gear.

4. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 3, characterized in that, Step S2 is followed by step S3, which includes: conducting a trial lift of the gantry crane under simulated on-site conditions: using lime to mark out the railway line, longitudinal beams, beam storage area, and crane position to simulate the construction site conditions; first, lifting the crossbeam 20cm above the original ground level and stabilizing it for 1 minute, then lifting the crossbeam 1 meter above the original ground level and stabilizing it for 1 minute, turning the crossbeam 90 degrees on-site and stabilizing it for 1 minute, then lifting it to the gantry crane's maximum lifting height and stabilizing it for 1 minute, and then testing the maximum travel speed of the gantry crane under normal lifting conditions.

5. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 4, characterized in that, In step S4, when transporting the gantry crane, the main beam is erected symmetrically, and one outrigger is symmetrically loaded on each side of the horizontal center line under the main beam, so that the overall center projection of the cargo is located at the intersection of the longitudinal and transverse center lines of the flatbed truck floor; each outrigger is leveled and stabilized with square timber, and square timber is squeezed around the outrigger to prevent longitudinal and transverse movement of the square timber; the main beam outriggers are nailed to the flatbed truck floor with round steel nails; two strands of steel wire rope are used to pull a figure-eight shape on each side of the main beam and tied to the T-shaped iron or support groove on the side of the flatbed truck.

6. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 5, characterized in that, In step S4, when transporting the truck crane, the truck crane is loaded evenly and symmetrically so that the projected center of gravity of the truck crane is located at the intersection of the longitudinal and transverse center lines of the flatbed floor. The front and rear ends of the front wheels and the front and rear ends of the rear wheel assembly of the truck crane are secured with triangular blocks and nailed to the floor of the flatbed. Triangular blocks are placed on the inside of the rear wheel assembly of the truck crane and nailed to the floor of the flatbed with brass nails near the tires. Square timbers are placed under the outriggers of the crane and pressed down, and each piece of square timber is nailed to the floor of the flatbed with four brass nails. Through the front axle of the truck crane, two strands of steel wire rope are used to pull a figure-eight shape on each side. Through the front and rear axles of the rear wheel assembly of the truck crane, two strands of steel wire rope are used to pull a figure-eight shape on each side and tie it to the T-shaped iron or support groove on the side of the flatbed. The boom hook of the truck crane is secured to the body of the flatbed with four strands of steel wire rope.

7. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 1, characterized in that, In step S5, during the loading, reinforcement, and transportation of the crossbeams at the station, two crossbeams of the same specification are loaded onto each flatbed car. The crossbeams are placed on horizontal support timbers so that the total center of gravity projection of the crossbeams is located on the longitudinal center line of the flatbed car floor, and the weight difference between the two ends of the flatbed car does not exceed 2t. One horizontal support timber is placed symmetrically on each side of the horizontal center line of the flatbed car and nailed to the flatbed car floor with round steel nails. The crossbeams are tightened with diagonal supports on both sides to prevent them from tilting laterally. Square timbers are used to squeeze the diagonal supports and horizontal support timbers together and nailed to the horizontal support timbers with round steel nails. Wooden blocks are placed on both sides of the crossbeam retaining wall and nailed to the flatbed car floor with round steel nails. Two strands of steel wire rope are passed through the lifting ring at the top of the crossbeam and tied to the T-shaped iron or support groove on the side of the flatbed car for reinforcement.

8. The method for constructing a large-scale train transport and beam erection project across a railway tunnel according to claim 1, characterized in that, Step S6 includes: binding guy ropes to the crossbeam to prevent it from swaying; aligning the gantry crane longitudinally and installing the lifting points of the crossbeam to be erected on the corresponding lifting holes of the gantry crane lifting tool; lifting the crossbeam, and when erecting the crossbeam on a curved section, first lift the crossbeam on the inner side of the curve, and then lift the crossbeam on the outer side of the curve; after the crossbeam is lifted off the flatbed truck, first move it laterally away from the contact wire to ensure that the horizontal distance between the crossbeam and the contact wire is greater than 80cm, and then perform vertical lifting.

9. A method for constructing a large-scale train transport and beam erection system over a railway tunnel according to claim 8, characterized in that, Step S7 includes: confirming that there are no abnormalities in the hoisting mechanism of the gantry crane, pulling the guy rope connected to one end of the crossbeam to rotate the crossbeam 90°, and then moving the crossbeam longitudinally by the gantry crane to align it. During the longitudinal movement, the guy ropes are pulled on both sides of one end of the crossbeam to prevent the crossbeam from rotating.

10. A method for constructing a large-scale train transport and beam erection system over a railway tunnel according to claim 9, characterized in that, In step S8: When lowering the beam, the beam should be kept horizontal, with a front-to-back height difference of less than 200 mm and a left-to-right height difference of less than 20 mm.

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