45m prefabricated T-beam double-crane lifting construction method

Abstract

The invention provides a 45m prefabricated T-beam double-crane lifting construction method, which relates to the technical field of bridge engineering, and comprises the following steps: S1, preparation work; s2, trial hoisting: checking and eliminating exceptions; s3, hoisting, arm rotating and walking, wherein a truck crane and a crawler crane are synchronously and slowly hoisted, the truck crane hoists one end of the T-shaped beam to rotate the arm towards the in-place position, the crawler crane hoists the other end of the T-shaped beam to be matched with the arm rotating, meanwhile, the crawler crane walks forwards, the truck crane cooperates with the arm rotating, and the two cranes synchronously rotate the suspension arm to rotate the T-shaped beam to the position above the installation position; and S4, lowering and fixing: slowly lowering the lifting hook, and mounting the T beam in place. By adopting a cooperative mode of a truck crane and a crawler crane, the crawler crane can flexibly walk under a bridge span, a beam transporting vehicle does not need to be driven to a position parallel to the bridge, and the problems that the requirement of a traditional double-crane hoisting site is high, and most construction sites are difficult to adapt are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a method for constructing a 45m precast T-beam using a dual-machine lifting system. Background Technology

[0002] In the field of bridge engineering, as bridge construction develops towards larger spans and heavier loads, the weight and length of precast T-beams continue to increase. For example, the 30m and 40m span T-beams commonly used in large-span highway bridges typically weigh 100-150 tons per beam, far exceeding the conventional lifting capacity of a single crane. Dual-crane lifting technology, by having two cranes work together to share the load, effectively overcomes the lifting capacity limitations of a single crane and reduces the risk of overloading, becoming a key technical means for the hoisting and positioning of large-span T-beams.

[0003] Traditional dual-crane lifting technology has many drawbacks: First, it has stringent site requirements, requiring the beam transport vehicle to be driven parallel to the bridge direction, and the beam transport vehicle must meet the requirements of a turning radius of more than 35m and an ultra-large working area of ​​65m×60m, which is difficult to meet on most sites; Second, when space is limited, temporary land acquisition is required, which increases construction costs and extends the construction period; Third, when using two truck cranes, as the T-beam erection progresses, the working radius of the truck cranes increases, requiring transfer and lifting, resulting in crane relocation, additional crane coordination, and other procedures, doubling the construction period; Fourth, when using two crawler cranes, the lifting point is easily far from the beam end, which does not meet the stress conditions of the T-beam and greatly increases the safety hazards of lifting. Summary of the Invention

[0004] This invention provides a method for constructing 45m precast T-beams using a dual-machine lifting system, in order to solve at least one of the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, this invention discloses a method for constructing a 45m precast T-beam using a dual-machine lifting system, comprising the following steps: S1: Preparations; S2: Trial lifting: Check and eliminate any abnormalities; S3: Lifting, boom rotation, and travel: The truck crane and crawler crane lift slowly and synchronously. The truck crane rotates its boom to the positioning position at one end of the T-beam, while the crawler crane rotates its boom to the other end of the T-beam. At the same time, the crawler crane travels forward and the truck crane rotates its boom in coordination. The two cranes rotate their booms synchronously to move the T-beam above the installation position. S4: Lowering and securing: Slowly lower the hook to install the T-beam into place.

[0006] Preferably, in step S1, the necessary machinery, materials and personnel for lifting are provided, and technical instructions and safety training are given to the workers; obstacles on site are cleared, roadbed plates are laid, and the truck crane is positioned in the designated location; the T-beam is ensured to pass inspection and be in place, and the road is closed to traffic as required. The machinery and equipment include truck cranes, crawler cranes, beam transport vehicles, roadbed plates and slings. All equipment has been inspected and qualified before entering the site.

[0007] Preferably, in step S1, the beam transport vehicle carries the 45m precast T-beam that has passed inspection and travels along the existing newly built roadbed to the designated hoisting area, ensuring that the axis of the T-beam is compatible with the hoisting direction. The hooks of the truck crane and the crawler crane are respectively connected to the preset hoisting points of the T-beam, ready to enter the trial hoisting stage.

[0008] Preferably, in step S2, under the unified command of the signalman, the truck crane and crawler crane synchronously raise the hooks, and when the T-beam is raised to a height of 200mm, the lifting is stopped and held for 5 minutes to check the condition of the crane, outriggers, and wire ropes. If any abnormality is found in the truck crane, crawler crane, outriggers, or wire ropes, the T-beam must be lowered immediately for rectification until the hidden danger is completely eliminated.

[0009] Preferably, in step S4, the hook is slowly lowered, and two installation workers with walkie-talkies on each side work together to place the T-beam in the adjustable range of the design position. The beam is checked by fixing one side and fine-tuning the other side until it meets the design and specification requirements. After acceptance, it is connected and fixed, and the lifting slings are removed after safety is confirmed.

[0010] Preferably, a group of sensing sensors is installed on the truck crane and the crawler crane respectively to acquire first sensing information and second sensing information; the group of sensing sensors includes an attitude sensor group, a load sensor group, an environmental sensor group and a positioning sensor group. Obtain basic parameters for the lifting operation; these parameters include T-beam parameters, truck crane parameters, crawler crane parameters, site parameters, and safety thresholds; the T-beam parameters include span, weight, moment of inertia, and lifting point range; the truck crane parameters include the first rated lifting capacity and the first maximum boom radius; the crawler crane parameters include the second rated lifting capacity and the second maximum boom radius; the site parameters include the boundary coordinates of the lifting area, the coordinates of obstacles, and the track laying range; the safety thresholds include load thresholds, attitude deviation thresholds, wind speed thresholds, and the minimum safe distance between the crane and obstacles. The lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and the basic parameters. The lifting point location and lifting path are sent to the wireless synchronous controllers installed on the truck crane and crawler crane respectively to perform synchronous control operations on the truck crane and crawler crane; the synchronous control operations include lifting speed, boom angle and traveling posture.

[0011] Preferably, the lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and the basic parameters, including: Let the two ends of the T-beam be the origin 0 and the endpoint L. Initially select the distances of the lifting points from point 0 as x1 and x2, where x2>x1, x1≥L1, and L-x2≥L1, and L1 is the minimum value of the lifting point range. Establish a lifting point load distribution mechanism: (F1+F2)·x0 = (x2 - x1)·F2, where F1 is the lifting point load of the truck crane, F2 is the lifting point load of the crawler crane, and x0 is the distance of the T-beam's center of gravity from point 0. Determine the first operating radius of the truck crane and the second operating radius of the crawler crane based on the site parameters; obtain the actual allowable lifting weights Q1' and Q2' under the current radius by querying the equipment performance curves based on the first and second operating radii, and design a lifting redundancy mechanism, where F1≤Q1'×0.9 and F2≤Q2'×0.9; traverse the design lifting point range [L1,L2] to determine the initial selection of lifting point combinations; Based on the initial selection of the lifting point combination, a T-beam model was constructed using the finite element method. The lifting point loads F1 and F2 were used as input loads to calculate the maximum normal stress σmax at the mid-span of the T-beam and the shear stress τmax at the lifting point. The objective is set as the maximum normal stress σmax of the T-beam, with the constraints σmax≤[σ] and τmax≤[τ], where σ is the allowable stress of the T-beam material and τ is the allowable shear stress of the T-beam material. The initial combination of hanging points is used as the initial population, and the target hanging point position is determined by iterative optimization through an adaptive crossover and mutation operator. Construct a path constraint space, input site parameters, safety thresholds, first positioning information (including first sensing information), second positioning information (including second sensing information), and target lifting point location into the path constraint space, determine the path start point, waypoints, and end point, and construct the lifting path.

[0012] Compared with existing technologies, this invention provides a 45m precast T-beam dual-crane lifting construction method, which has the following advantages: It adopts a "truck crane + crawler crane" collaborative mode, allowing the crawler crane to move flexibly under the bridge span. This eliminates the need for the beam transport vehicle to be parallel to the bridge, and avoids the stringent requirements of a turning radius of over 35m and a working area of ​​over 70m. The beam transport vehicle only needs to travel along the existing newly constructed roadbed to the designated area, effectively solving the problems of high site requirements and difficulty in adapting to most construction sites associated with traditional dual-crane lifting methods. Furthermore, it eliminates the need for temporary land acquisition to meet equipment placement requirements, significantly reducing construction costs. By coordinating the movement of the crawler crane and the boom of the truck crane, there is no need to transfer the T-beam, avoiding extra time-consuming procedures and effectively solving the problem of doubling the construction period of traditional methods, thus significantly improving construction efficiency. The lifting point can be precisely set near the T-beam support, which is highly matched with the stress design conditions of the T-beam, effectively avoiding the safety hazards caused by the lifting point being far away from the beam end when two crawler cranes are operating in the traditional way. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the construction process of the present invention; Figure 2 This is a schematic diagram of the construction site layout for the present invention; Figure 3 This is a schematic diagram of the dual-machine lifting operation of the present invention; Figure 4 This is a flowchart of the dual-machine lifting operation of the present invention.

[0014] In the picture: 1. Truck crane; 2. Crawler crane; 3. Beam transport vehicle; 4. T-beam. Detailed Implementation

[0015] 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.

[0016] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., 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.

[0018] Example 1: An embodiment of the present invention provides a method for constructing a 45m precast T-beam using a dual-machine lifting system, such as... Figures 1-4 As shown, it includes the following steps: S1: Preparations; S2: Trial lifting: Check and eliminate any abnormalities; S3: Lifting, boom rotation, and travel: Truck crane 1 and crawler crane 2 lift slowly and synchronously. Truck crane 1 lifts one end of T-beam 4 and rotates its boom towards the installation position. Crawler crane 2 lifts the other end of T-beam 4 and rotates its boom accordingly. At the same time, crawler crane 2 travels forward and truck crane 1 rotates its boom in coordination. The two cranes rotate their booms synchronously to move T-beam 4 above the installation position. S4: Lowering and securing: Slowly lower the hook to install T-beam 4 into place.

[0019] During the trial lifting process in step S2, the truck crane 1 and the crawler crane 2 simultaneously raised the hooks to lift the T-beam 4, and then checked and eliminated any abnormalities.

[0020] The beneficial effects of the above technical solution are as follows: the crawler crane 2 can move forward flexibly without relying on a large area of ​​flat ground or backfill area. Unlike traditional solutions, it does not rely on the turning radius of more than 35m and the extra-large working area of ​​65m×60m required by the beam transport vehicle. It effectively solves the problem of the strict site requirements of traditional dual-machine lifting, and is especially suitable for complex engineering scenarios where the construction area is limited and some areas cannot be backfilled; the transportation of T-beam 4 can be completed along the existing newly built roadbed without the need for temporary land acquisition to open up transportation or lifting sites, saving the costs of temporary land acquisition, earthwork excavation and subsequent reclamation, and significantly reducing construction costs; the coordinated operation of truck crane 1 and crawler crane 2 does not require the transfer and lifting of T-beam 4, avoiding the extra procedures such as crane relocation and the addition of new cranes in the traditional two-truck operation, reducing the time wasted on ineffective operations and significantly improving lifting efficiency.

[0021] Example 2: Based on Example 1 above, as follows Figures 1-4 As shown, in step S1, the necessary mechanical equipment, materials and personnel for lifting are provided, and technical instructions and safety training are given to the operators; obstacles on site are cleared, roadbed plates are laid, and the truck crane 1 is positioned in the designated location; the T-beam 4 is ensured to pass inspection and be in place, and the road is closed to traffic as required. The mechanical equipment includes a truck crane 1, a crawler crane 2, a beam transport vehicle 3, roadbed plates and slings. All equipment has been inspected and qualified before entering the site.

[0022] Preferably, in step S1, the beam transport vehicle 3 carries the 45m precast T-beam that has passed the acceptance test and travels along the existing newly built roadbed to the designated hoisting area to ensure that the axis of the T-beam is compatible with the hoisting direction. The hooks of the truck crane 1 and the crawler crane 2 are respectively connected to the preset hoisting points of the T-beam 4, ready to enter the trial hoisting stage.

[0023] The working principle and beneficial effects of the above technical solution are as follows: the mechanical equipment is inspected and qualified before entering the site, avoiding operation interruption or safety accidents caused by equipment aging or failure; the beam transport vehicle 3 travels along the existing newly built roadbed, without having to meet the requirements of traditional double-machine lifting for beam transport vehicles with a turning radius of more than 35m and a working area of ​​more than 70m, nor is it necessary to temporarily acquire land to open up transportation routes. Combined with the walking advantages of the crawler crane 2, it breaks through the site limitations from the "transportation + hoisting" dual links, and is more adaptable to engineering scenarios with limited construction areas and complex terrain; when transporting, the beam transport vehicle 3 ensures that the T-beam axis is matched with the hoisting direction, and with the precise connection between the hook and the preset hoisting point, it reduces the extra time spent on subsequent hoisting point adjustment and direction calibration, and is safer and more practical.

[0024] Example 3: Based on Examples 1-2 above, as follows... Figures 1-4 As shown, in step S2, under the unified command of the signalman, the truck crane 1 and the crawler crane 2 synchronously raise the hooks, and when the T-beam 4 is raised to a height of 200mm, the lifting is stopped and held for 5 minutes to check the condition of the crane, outriggers, and wire ropes. If any abnormality is found in the truck crane 1, crawler crane 2, outriggers, or wire ropes, the T-beam 4 must be lowered immediately for rectification until the hidden danger is completely eliminated.

[0025] Preferably, in step S4, the hook is slowly lowered, and two installation workers with walkie-talkies on each side work together to place the T-beam 4 in the adjustable range of the design position. The beam is checked by fixing one side and fine-tuning the other side until it meets the design and specification requirements. After acceptance, it is connected and fixed, and the lifting slings are removed after safety is confirmed.

[0026] The working principle and beneficial effects of the above technical solution are as follows: the quantitative standards (200mm height, 5 minutes of static rest) and the closed-loop requirement of "immediate rectification upon discovery of abnormalities" in the trial lifting process can more comprehensively and accurately identify potential hidden dangers in core components such as cranes, outriggers, and wire ropes, and avoid safety accidents caused by non-standard trial lifting. The "one-sided fixing and opposite-side fine-tuning" calibration method, combined with real-time communication and collaboration, can accurately correct minor deviations during the T-beam placement process, ensuring that the beam's plane position, elevation, verticality, and other indicators fully meet design and specification requirements. Compared to traditional extensive installation or single manual calibration, this method significantly improves the T-beam installation accuracy, providing core assurance for the overall structural stability and service life of the bridge.

[0027] Preferably, a group of sensing sensors is installed on the truck crane and the crawler crane respectively to acquire first sensing information and second sensing information; the group of sensing sensors includes an attitude sensor group, a load sensor group, an environmental sensor group and a positioning sensor group. Obtain basic parameters for the lifting operation; these parameters include T-beam parameters, truck crane parameters, crawler crane parameters, site parameters, and safety thresholds; the T-beam parameters include span, weight, moment of inertia, and lifting point range; the truck crane parameters include the first rated lifting capacity and the first maximum boom radius; the crawler crane parameters include the second rated lifting capacity and the second maximum boom radius; the site parameters include the boundary coordinates of the lifting area, the coordinates of obstacles, and the track laying range; the safety thresholds include load thresholds, attitude deviation thresholds, wind speed thresholds, and the minimum safe distance between the crane and obstacles. The lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and the basic parameters. The lifting point location and lifting path are sent to the wireless synchronous controllers installed on the truck crane and crawler crane respectively to perform synchronous control operations on the truck crane and crawler crane; the synchronous control operations include lifting speed, boom angle and traveling posture.

[0028] The working principle of the above technical solution is as follows: Consistent sensor arrays are deployed on both the truck crane and the crawler crane to acquire first and second sensing information. The attitude sensor array includes a MEMS gyroscope and a tilt sensor to collect data on the crane's boom angle, lifting height, and vehicle tilt angle. The load sensor array is a piezoelectric pressure sensor used to capture real-time forces at the lifting points. The environmental sensor array includes wind speed and temperature / humidity sensors to collect environmental data of the work area and mitigate risks from harsh environments. The positioning sensor array includes GPS, BeiDou dual-mode positioning, and a laser rangefinder to acquire the crane's real-time coordinates, relative position to the T-beam, and distance to obstacles, thus building a site space model. This acquires basic parameters for the lifting operation, facilitating the subsequent construction of a constraint system. The lifting point location and lifting path are determined based on the first and second sensing information and the basic parameters. The lifting point location and lifting path are then sent to wireless synchronous controllers installed on the truck crane and crawler crane respectively for synchronous control operations. These synchronous control operations include lifting speed, boom angle, and travel posture.

[0029] The beneficial effects of the above technical solution are as follows: By setting up sensing sensor groups on both the truck crane and the crawler crane, it is easy to obtain comprehensive sensing information, thereby improving decision-making accuracy. The lifting point position and lifting path are accurately determined based on the first sensing information, the second sensing information, and basic parameters. Precise planning of the lifting point position and lifting path avoids rework caused by unreasonable lifting points and path conflicts in traditional lifting operations, thus improving work efficiency. Synchronous control of the truck crane and crawler crane through a wireless synchronous controller improves the safety and accuracy of lifting operations.

[0030] Preferably, the lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and the basic parameters, including: Let the two ends of the T-beam be the origin 0 and the endpoint L. Initially select the distances of the lifting points from point 0 as x1 and x2, where x2>x1, x1≥L1, and L-x2≥L1, and L1 is the minimum value of the lifting point range. Establish a lifting point load distribution mechanism: (F1+F2)·x0 = (x2 - x1)·F2, where F1 is the lifting point load of the truck crane, F2 is the lifting point load of the crawler crane, and x0 is the distance of the T-beam's center of gravity from point 0. Determine the first operating radius of the truck crane and the second operating radius of the crawler crane based on the site parameters; obtain the actual allowable lifting weights Q1' and Q2' under the current radius by querying the equipment performance curves based on the first and second operating radii, and design a lifting redundancy mechanism, where F1≤Q1'×0.9 and F2≤Q2'×0.9; traverse the design lifting point range [L1,L2] to determine the initial selection of lifting point combinations; Based on the initial selection of the lifting point combination, a T-beam model was constructed using the finite element method. The lifting point loads F1 and F2 were used as input loads to calculate the maximum normal stress σmax at the mid-span of the T-beam and the shear stress τmax at the lifting point. The objective is set as the maximum normal stress σmax of the T-beam, with the constraints σmax≤[σ] and τmax≤[τ], where σ is the allowable stress of the T-beam material and τ is the allowable shear stress of the T-beam material. The initial combination of hanging points is used as the initial population, and the target hanging point position is determined by iterative optimization through an adaptive crossover and mutation operator. Construct a path constraint space, input site parameters, safety thresholds, first positioning information (including first sensing information), second positioning information (including second sensing information), and target lifting point location into the path constraint space, determine the path start point, waypoints, and end point, and construct the lifting path.

[0031] The working principle of the above technical solution is as follows: Based on the mechanical balance requirements of the T-beam, a load distribution mechanism for the lifting points is constructed. Taking the two ends of the T-beam as the origin 0 and the end point L, the distances x1 and x2 of the initially selected lifting points from point 0 are clearly defined. Through the load distribution mechanism for the lifting points, the load distribution relationship between the two machines is established. The first operating radius of the truck crane and the second operating radius of the crawler crane are determined based on site parameters. The actual allowable lifting capacity under the current radius is obtained by querying the equipment performance curves based on the first and second operating radii. Based on the lifting redundancy mechanism, a preliminary combination of lifting points is determined. Based on this preliminary combination, a T-beam model is constructed using the finite element method. The lifting point loads F1 and F2 are used as input loads to calculate the maximum normal stress σmax at the mid-span of the T-beam and the shear stress τmax at the lifting point. The maximum normal stress σmax of the T-beam is set as the target, with constraints σmax≤[σ] and τmax≤[τ], where σ is the allowable stress of the T-beam material and τ is the allowable shear stress of the T-beam material. The preliminary combination of lifting points is used as the initial population input to the optimization algorithm. The values ​​of x1 and x2 are dynamically adjusted and iteratively calculated using an adaptive crossover mutation operator until the target lifting point position that satisfies the constraints and minimizes σmax is obtained. This ensures that the lifting point setting is both suitable for dual-machine capacity and meets the stress safety requirements of the T-beam. A path constraint space with multiple constraints is constructed, incorporating site parameters (boundary and obstacle coordinates), safety thresholds (minimum safe distance between the crane and obstacles, etc.), the first positioning information of the truck crane from the first sensing information, the second positioning information of the crawler crane from the second sensing information, and the determined target lifting point position. Based on the path constraint space, key path nodes are identified: the starting point (initial storage position of the T-beam, combined with dual-machine positioning and lifting point position calibration), the waypoint (transition position to avoid obstacles, ensuring that the distance from obstacles meets the safety threshold), and the endpoint (target position for T-beam erection). Ultimately, a collision-free lifting path that is adapted to the dual-machine operating radius and meets the stress requirements of the lifting point is constructed.

[0032] The beneficial effects of the above technical solution are as follows: A dedicated load distribution mechanism establishes a quantitative correlation between the load of the two machines and the location of the lifting points, combined with a 10% lifting redundancy mechanism to avoid equipment overload risks; furthermore, through precise stress calculation using the finite element method and iterative adaptive optimization algorithms, it ensures that the target lifting point not only meets the lifting point range constraints but also minimizes the T-beam σmax and meets the allowable stress requirements of the material, thus improving the stress safety of the T-beam. The path constraint space incorporates multiple key information such as real-time positioning of the two machines, site boundaries, obstacles, and safety thresholds, enabling the constructed path to accurately avoid obstacles and improve the accuracy of path planning.

Claims

1. A method for constructing a 45m precast T-beam using a dual-machine lifting system, characterized in that... Includes the following steps: S1: Preparations; S2: Trial lifting: Check and eliminate any abnormalities; S3: Lifting, boom rotation, and travel: The truck crane (1) and the crawler crane (2) lift slowly and synchronously. The truck crane (1) lifts the T-beam (4) and rotates its boom to the position. The crawler crane (2) lifts the T-beam (4) and rotates its boom to the other end. At the same time, the crawler crane (2) travels forward and the truck crane (1) rotates its boom in coordination. The two cranes rotate their booms synchronously to move the T-beam (4) above the installation position. S4: Lowering and fixing: Slowly lower the hook to install the T-beam (4) into place.

2. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 1, characterized in that, In step S1, the necessary machinery, materials and personnel for lifting are provided, and the operators are given technical instructions and safety training; obstacles on site are cleared, roadbed plates are laid, and the truck crane (1) is positioned in the designated location; the T-beam (4) is inspected and accepted and put in place, and the road is closed to traffic as required; The mechanical equipment includes truck cranes (1), crawler cranes (2), beam transport vehicles (3), roadbed plates and slings. All equipment has been inspected and qualified before entering the site.

3. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 2, characterized in that, In step S1, the beam transport vehicle (3) carries the 45m precast T beam that has passed the acceptance test and travels along the existing newly built roadbed to the designated hoisting area to ensure that the axis of the T beam is compatible with the hoisting direction. The hooks of the truck crane (1) and the crawler crane (2) are respectively connected to the preset hoisting points of the T beam (4) to prepare for the trial hoisting stage.

4. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 1, characterized in that, In step S2, under the unified command of the signalman, the truck crane (1) and the crawler crane (2) simultaneously lift the hooks and stop lifting the T beam (4) when it reaches a height of 200mm and hold it for 5 minutes to check the condition of the crane, outriggers and wire rope. If any abnormality is found in the truck crane (1), crawler crane (2), outriggers or wire rope, the T beam (4) must be lowered immediately for rectification until the hidden danger is completely eliminated.

5. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 1, characterized in that, In step S4, the hook is slowly lowered, and two installation workers with walkie-talkies on each side work together to place the T-beam (4) in the adjustable range of the design position. The beam is checked by fixing one side and fine-tuning the other side until it meets the design and specification requirements. After acceptance, it is connected and fixed. After confirming safety, the lifting slings are removed.

6. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 1, characterized in that, Sensing sensor groups are respectively installed on truck cranes and crawler cranes to acquire first sensing information and second sensing information; the sensing sensor groups include attitude sensor groups, load sensor groups, environmental sensor groups and positioning sensor groups; Obtain basic parameters for the lifting operation; these parameters include T-beam parameters, truck crane parameters, crawler crane parameters, site parameters, and safety thresholds; the T-beam parameters include span, weight, moment of inertia, and lifting point range; the truck crane parameters include the first rated lifting capacity and the first maximum boom radius; the crawler crane parameters include the second rated lifting capacity and the second maximum boom radius; the site parameters include the boundary coordinates of the lifting area, the coordinates of obstacles, and the track laying range; the safety thresholds include load thresholds, attitude deviation thresholds, wind speed thresholds, and the minimum safe distance between the crane and obstacles. The lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and the basic parameters. The lifting point location and lifting path are sent to the wireless synchronous controllers installed on the truck crane and crawler crane respectively to perform synchronous control operations on the truck crane and crawler crane; the synchronous control operations include lifting speed, boom angle and traveling posture.

7. The method for constructing a 45m precast T-beam using a dual-machine lifting system according to claim 6, characterized in that, The lifting point location and lifting path are determined based on the first sensing information, the second sensing information, and basic parameters, including: Let the two ends of the T-beam be the origin 0 and the endpoint L. Initially select the distances of the lifting points from point 0 as x1 and x2, where x2>x1, x1≥L1, and L-x2≥L1, and L1 is the minimum value of the lifting point range. Establish a lifting point load distribution mechanism: (F1+F2)·x0 = (x2 - x1)·F2, where F1 is the lifting point load of the truck crane, F2 is the lifting point load of the crawler crane, and x0 is the distance of the T-beam's center of gravity from point 0. Determine the first operating radius of the truck crane and the second operating radius of the crawler crane based on the site parameters; obtain the actual allowable lifting weights Q1' and Q2' under the current radius by querying the equipment performance curves based on the first and second operating radii, and design a lifting redundancy mechanism, where F1≤Q1'×0.9 and F2≤Q2'×0.9; traverse the design lifting point range [L1,L2] to determine the initial selection of lifting point combinations; Based on the initial selection of the lifting point combination, a T-beam model was constructed using the finite element method. The lifting point loads F1 and F2 were used as input loads to calculate the maximum normal stress σmax at the mid-span of the T-beam and the shear stress τmax at the lifting point. The objective is set as the maximum normal stress σmax of the T-beam, with the constraints σmax≤[σ] and τmax≤[τ], where σ is the allowable stress of the T-beam material and τ is the allowable shear stress of the T-beam material. The initial combination of hanging points is used as the initial population, and the target hanging point position is determined by iterative optimization through adaptive crossover and mutation operators. Construct a path constraint space, input site parameters, safety thresholds, first positioning information (including first sensing information), second positioning information (including second sensing information), and target lifting point location into the path constraint space, determine the path start point, waypoints, and end point, and construct the lifting path.

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