T-beam transportation and erection integrated construction method

Abstract

The application discloses a T-beam transportation and erection integrated construction method, and relates to the technical field of bridge construction, which comprises the following steps: supporting two tire-type beam transporters on the bottom surfaces of two ends of a T-beam respectively, wherein the hydraulic lifting system of each beam transporter comprises two groups of independently-controlled hydraulic cylinders, and laser ranging sensors and inclination sensors are arranged; the two beam transporters synchronously transport the T-beam, the longitudinal inclination and the transverse inclination are adjusted according to the measured values of the sensors during the transportation process; the rear wheel group is turned to the direction perpendicular to the longitudinal axis of the T-beam when reaching the rear wheel group, and the beam transporter is synchronously driven in the transverse direction; when the perpendicular distance reaches the beam falling range, the hydraulic system is synchronously lowered to make the T-beam fall on the pier support; if the inclination exceeds the threshold value during the beam falling process, the beam transporter is stopped and the hydraulic system is adjusted; and the support is removed and the beam transporter is driven away. The application can significantly improve the construction efficiency, realize the whole-process active control of the spatial posture of the beam body, improve the positioning accuracy, enhance the construction safety and environmental adaptability, and reduce the dependence on the experience of the operators.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology. More specifically, this invention relates to an integrated construction method for the transportation and erection of T-beams. Background Technology

[0002] T-beams (prestressed concrete T-beams) are widely used superstructure components in highway and railway bridge engineering, possessing advantages such as high section efficiency, mature prefabrication technology, and good economy. With the rapid development of transportation infrastructure construction, bridge engineering is characterized by a large number of bridge spans, complex construction environments, and tight schedules, placing higher demands on the efficiency, accuracy, and safety of T-beam transportation and erection.

[0003] Traditional T-beam construction typically employs a segmented operation mode: prefabrication at the prefabrication yard – transport by beam transport vehicle – erection by bridge erecting machine or gantry crane. Specifically, after the T-beams are prefabricated at the prefabrication yard, they are transported by tire-mounted or rail-mounted beam transport vehicles along construction access roads or existing bridge decks to the vicinity of the span to be erected. Then, the bridge erecting machine lifts, moves, and lowers the beams into place. This mode has several inherent limitations: Firstly, transportation and erection belong to different equipment and processes, requiring a large investment in equipment. The transportation vehicles and bridge erecting machines need to be transferred and connected multiple times, and the process connection takes a long time. Secondly, bridge erecting machines usually require the use of the bridge span to be erected and adjacent bridge spans, which places high demands on the clearance and site conditions under the bridge, and their applicability is limited in complex terrains such as mountainous areas and river crossings. Third, during the transportation and erection of T-beams, there is a lack of control over the spatial posture of the beams, making it difficult to accurately grasp the stress state of the beams. This can easily lead to additional stress or even cracking of the beams due to uneven road surfaces, asynchronous transport vehicles, or misalignment during beam placement.

[0004] Therefore, it is necessary to design a technical solution that can overcome the above-mentioned defects. Summary of the Invention

[0005] One objective of this invention is to provide an integrated construction method for T-beam transportation and erection, which improves construction efficiency, enables full-process active control of the beam's spatial posture, enhances positioning accuracy, strengthens construction safety and environmental adaptability, and reduces reliance on operator experience.

[0006] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, an integrated construction method for transporting and erecting T-beams is provided, comprising: S1: supporting two tire-mounted beam transport vehicles on the bottom surfaces of both ends of a T-beam, each tire-mounted beam transport vehicle's hydraulic lifting system including two independently controlled sets of hydraulic cylinders, the two sets of hydraulic cylinders being supported on the left and right sides of the bottom surface of the T-beam end respectively; lifting the T-beam to the transport height using the hydraulic lifting systems of the two tire-mounted beam transport vehicles, and respectively installing laser rangefinders and tilt sensors on the bottom surfaces of both ends of the T-beam; S2: two tires The girder transport vehicles synchronously transport the T-beams along the transport route to the position between the first and second piers of the bridge span to be erected. During transport, laser rangefinders continuously measure the vertical distance between the bottom surfaces of both ends of the T-beam and the transport road surface. The longitudinal tilt angle of the T-beam is calculated by the difference in the vertical distance between the two ends. The tilt angle sensor continuously measures the lateral tilt angle of the T-beam. When the vertical distance deviates from the set range, or the lateral tilt angle exceeds the set threshold, or the calculated longitudinal tilt angle exceeds the set threshold, the adjustment of the longitudinal tilt angle and vertical distance is achieved by controlling the lifting and lowering of the hydraulic cylinders of the two tire-type girder transport vehicles. The adjustment of the lateral tilt angle is achieved by... The T-beam is raised and lowered at unequal heights by controlling the left and right sets of hydraulic cylinders of the corresponding tire-type beam transport vehicle; S3: After reaching the position, the wheel sets of the two tire-type beam transport vehicles are independently steered to rotate each wheel axle to a direction perpendicular to the longitudinal axis of the T-beam. Then, the two tire-type beam transport vehicles move laterally synchronously, causing the T-beam to move laterally. During the lateral movement, the lateral movement speed of the two tire-type beam transport vehicles remains equal. The laser rangefinder measures the vertical distance between the bottom surfaces of both ends of the T-beam and the top surfaces of the first and second piers in real time; S4: When the vertical distance measured by the laser rangefinder reaches the preset height... When the beam distance is within the specified range, the hydraulic lifting systems of the two tire-mounted beam transport vehicles are simultaneously lowered so that the support pads on the bottom surfaces of both ends of the T-beam fall onto the supports on the top surfaces of the first and second piers, respectively. During the beam lowering process, the tilt sensor measures the lateral tilt angle of the T-beam in real time, and calculates the longitudinal tilt angle of the T-beam in real time by the difference in the vertical distance between the two ends. If the lateral tilt angle exceeds the set threshold or the calculated longitudinal tilt angle exceeds the set threshold, the beam lowering is stopped, and the hydraulic lifting system is used for adjustment; S5: Release the support of the two tire-mounted beam transport vehicles on the T-beam, and drive the two tire-mounted beam transport vehicles away from the bridge span to be erected.

[0007] Furthermore, in S1, two laser rangefinders are installed on the bottom surface of each T-beam end. One laser rangefinder is close to the center line of the web of the T-beam, and the other laser rangefinder is close to the edge of the flange of the T-beam. The tilt sensor is a single-axis tilt sensor, fixed on the transverse centerline of the bottom surface of the T-beam end, and the measurement axis of the single-axis tilt sensor is parallel to the transverse axis of the T-beam. Before lifting the T-beam to the transport height, the vertical distance between the two ends of the T-beam is measured by the two laser rangefinders and the longitudinal tilt angle at both ends of the T-beam is calculated. Then, the overall lifting height of the two tire-type beam transport vehicles is independently adjusted by the hydraulic lifting system to make the calculated longitudinal tilt angle at both ends of the T-beam zero. Then, the measurement value of the laser rangefinder near the center line of the web is used as the main control signal to synchronously lift the two tire-type beam transport vehicles. During the lifting process, the measurement difference between the two laser rangefinders on the bottom surface of the same end is continuously compared. If the difference exceeds the allowable range, it is determined that there is local deformation or foreign object on the bottom surface of the T-beam, and the lifting is stopped for manual inspection.

[0008] Further, in S2, the vertical distance deviation at both ends of the T-beam and the longitudinal tilt angle of the T-beam are first calculated based on the measurements from the two laser rangefinders, and the lateral tilt angle of the T-beam is measured using the tilt angle sensor. Then, adjustments are made according to the following priority: the longitudinal tilt angle is adjusted first to within the threshold value, then the lateral tilt angle is adjusted to within the threshold value, and finally the vertical distance is adjusted to the set range. When adjusting the longitudinal tilt angle, all hydraulic cylinders of the two tire-type beam transport vehicles are controlled to rise and fall synchronously in opposite directions, with the first tire-type beam transport vehicle rising and the second tire-type beam transport vehicle lowering by the same amount of height. When adjusting the lateral tilt angle, the left and right sets of hydraulic cylinders of each tire-type beam transport vehicle are controlled to rise and fall at unequal heights. When adjusting the vertical distance, all hydraulic cylinders of the two tire-type beam transport vehicles are controlled to rise and fall synchronously in the same direction.

[0009] Furthermore, when adjusting the longitudinal tilt angle, lateral tilt angle, or vertical distance, the corresponding hydraulic cylinder adjustment amount is determined based on the absolute value of the longitudinal tilt angle deviation, lateral tilt angle deviation, or vertical distance deviation, and the real-time trend of the deviation. When the absolute value of the deviation is less than the preset no-adjustment dead zone, the adjustment amount is set to zero. When the absolute value of the deviation is greater than or equal to the no-adjustment dead zone and the trend of the deviation is decreasing towards the set threshold, the adjustment amount is calculated by multiplying the deviation by a first proportional coefficient. When the absolute value of the deviation is greater than or equal to the no-adjustment dead zone and the trend of the deviation is increasing away from the set threshold, the adjustment amount is calculated by multiplying the deviation by a second proportional coefficient, where the second proportional coefficient is greater than the first proportional coefficient. When the absolute value of the deviation exceeds the preset emergency adjustment threshold, the adjustment amount is directly taken as the maximum allowable lifting speed of the hydraulic cylinder, and the adjustment is continuously performed at this maximum speed until the deviation drops below the emergency adjustment threshold.

[0010] Furthermore, in S3, during the synchronous lateral movement of the two tire-type beam transport vehicles, based on the real-time vertical distances between the bottom surfaces of both ends of the T-beam and the top surfaces of the first and second piers measured by the laser rangefinder, when the vertical distance at one end is greater than that at the other end, the support height at the end with the larger vertical distance is lowered and the support height at the end with the smaller vertical distance is raised by adjusting all the hydraulic cylinders of the two tire-type beam transport vehicles synchronously, until the difference in vertical distance between the bottom surfaces of the two ends of the T-beam is less than the preset lateral movement vertical distance error threshold; the tilt sensor monitors the lateral tilt angle of the T-beam in real time. If the lateral tilt angle exceeds the preset lateral movement safety threshold, the lateral movement is paused and the hydraulic cylinders on the corresponding side of the two tire-type beam transport vehicles are adjusted to restore the lateral tilt angle of the T-beam to within the safety threshold before continuing the lateral movement.

[0011] Furthermore, in S4, when simultaneously lowering the hydraulic lifting systems of the two tire-mounted beam transport vehicles, the descent speed of all hydraulic cylinders on both tire-mounted beam transport vehicles is dynamically adjusted based on the vertical distance difference between the bottom surfaces of the two ends of the T-beam and the top surfaces of the first and second piers, measured in real time by laser rangefinders. This ensures that the vertical distance difference between the two ends is always less than a preset synchronous beam lowering error threshold. During the beam lowering process, tilt sensors measure the lateral tilt angle of the T-beam in real time, and simultaneously calculate the longitudinal tilt angle and the rate of change of the longitudinal tilt angle of the T-beam in real time using the difference in the vertical distance between the two ends. When the calculated longitudinal tilt angle exceeds the set threshold, the beam lowering stops, and the longitudinal tilt angle of the T-beam is adjusted by raising or lowering all hydraulic cylinders of the two tire-mounted beam transport vehicles until the target threshold is reached. The longitudinal tilt angle is restored to within the threshold. When the calculated rate of change of the longitudinal tilt angle exceeds the set rate threshold, the beam dropping is stopped, and the longitudinal tilt angle of the T-beam is adjusted by raising or lowering all the hydraulic cylinders of the two tire-type beam transport vehicles until the rate of change of the longitudinal tilt angle is restored to within the rate threshold. When the lateral tilt angle exceeds the set threshold, the beam dropping is stopped, and the lateral tilt angle of the T-beam is adjusted by raising or lowering the left and right sets of hydraulic cylinders of the corresponding tire-type beam transport vehicles until the lateral tilt angle is restored to within the threshold. When the rate of change of the lateral tilt angle exceeds the set rate threshold, the beam dropping is stopped, and the lateral tilt angle of the T-beam is adjusted by raising or lowering the left and right sets of hydraulic cylinders of the corresponding tire-type beam transport vehicles until the rate of change of the lateral tilt angle is restored to within the rate threshold.

[0012] Furthermore, in S5, when releasing the support of the T-beam from the two tire-mounted beam transport vehicles, all hydraulic cylinders of one of the tire-mounted beam transport vehicles are first controlled to slowly and synchronously descend. During this process, the tilt sensor continuously measures the lateral tilt angle of the T-beam, and at the same time, the longitudinal tilt angle of the T-beam is calculated through the measurement values ​​of the laser rangefinders at both ends. When the change in the lateral tilt angle or the calculated change in the longitudinal tilt angle exceeds the preset unloading change threshold, the descent is stopped and all hydraulic cylinders of the tire-mounted beam transport vehicle are raised back to the initial support state. After the tilt angle stabilizes, the release is repeated. After the tire-mounted beam transport vehicle is completely released, the support of the other tire-mounted beam transport vehicle is released in the same way. After both tire-mounted beam transport vehicles are completely released, the wheel sets of the two tire-mounted beam transport vehicles are turned to a direction parallel to the longitudinal axis of the T-beam, and then they are driven away from the bridge span to be erected along the transport route in the opposite direction.

[0013] Furthermore, throughout the entire construction process from S1 to S5, the following construction parameters were continuously recorded: all vertical distance data measured by two laser rangefinders, all lateral tilt angle data measured by two tilt sensors, all longitudinal tilt angle data calculated from the vertical distances at both ends, the lifting height and lifting speed of each hydraulic cylinder in the hydraulic lifting system, the longitudinal and lateral travel speeds of the two tire-type beam transport vehicles, the wheel steering angle, and the final vertical distance when the beam was lowered in S4. These construction parameters were then used to generate a construction log in chronological order and transmitted to the remote monitoring platform via a wireless transmission module. The remote monitoring platform then processed the construction parameters from the construction logs of the completed T-beams. Using sample data, the total number of adjustments and the total adjustment range of the hydraulic lifting system during the construction of each T-beam, as well as the deviation between the final vertical distance at the time of beam lowering and the preset theoretical value, are used as comprehensive evaluation indicators. Through multiple linear regression or neural network algorithms, a mapping relationship is established between this comprehensive evaluation indicator and the vertical distance setting range, lateral tilt angle setting threshold, longitudinal tilt angle setting threshold in S2, and the beam lowering synchronization error threshold and tilt angle change rate threshold in S4. With the goal of minimizing the comprehensive evaluation indicator, the optimal values ​​of the vertical distance setting range, lateral tilt angle setting threshold, longitudinal tilt angle setting threshold in S2, and the beam lowering synchronization error threshold and tilt angle change rate threshold in S4 are calculated.

[0014] Furthermore, the construction parameters and corresponding comprehensive evaluation indicators from the construction logs of multiple completed T-beams are used as training samples. The various set ranges and thresholds in S2 and S4 are used as parameters to be optimized. A Gaussian process surrogate model from the parameters to be optimized to the comprehensive evaluation indicators is established using the Bayesian optimization algorithm. Then, the surrogate model is iteratively optimized multiple times through the acquisition function. In each iteration, the parameter combination that maximizes the acquisition function is selected as the candidate parameter combination for the next iteration. The comprehensive evaluation indicators corresponding to the candidate parameter combinations are verified in actual construction. The verification results are updated to the training samples to retrain the surrogate model until the improvement of the comprehensive evaluation indicators is less than the preset convergence threshold, and the optimal parameter combination is finally obtained.

[0015] The present invention has at least the following beneficial effects: This invention integrates the transportation and erection of T-beams, eliminating the need for bridge erecting machines or gantry cranes to lower the beams into place. This eliminates multiple transfer and docking processes between transport vehicles and the bridge erecting machine, reduces the use of large lifting equipment, shortens the construction period, and lowers construction costs. By installing laser rangefinders and tilt sensors on the bottom surfaces of both ends of the T-beam, and cooperating with two independently controlled hydraulic cylinders on the left and right sides of each tire-type beam transport vehicle, the longitudinal tilt angle, lateral tilt angle, and vertical distance between the two ends of the T-beam can be monitored and actively adjusted in real time. During transportation, it can automatically adapt to the longitudinal and transverse slopes of the road surface, eliminating accumulated deviations; during beam lowering, it dynamically adjusts the descent speed at both ends to ensure precise alignment of the bearing pads with the top supports of the piers, avoiding errors caused by traditional manual observation and operation. When the tilt angle or vertical distance exceeds the set threshold, the system automatically stops and reverses the adjustment, effectively preventing the risk of cracking or overturning caused by excessive beam tilt or uneven local stress. Meanwhile, the wheels of the two tire-mounted beam transport vehicles can steer independently, enabling lateral movement and allowing for erection on narrow bridge decks or in complex underpasses, thus broadening the applicability of the construction method. The entire construction process is based on closed-loop control using sensor feedback, with key parameters recorded and traceable, providing data support for similar projects in the future and facilitating the intelligent and standardized construction of bridge superstructures.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1 This is a flowchart of one embodiment of this application. Detailed Implementation

[0018] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as "having," "comprising," and "including" used in the embodiments of this application do not exclude the presence or addition of one or more other elements or combinations thereof. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of components in a specific posture. If the specific posture changes, the directional indication will change accordingly. When an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or may have an intervening element present. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. Descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features.

[0020] It should be noted that the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0021] In one embodiment, an integrated construction method for transporting and erecting T-beams is provided. In this method, the T-beam is a prestressed concrete T-shaped beam with its length as the longitudinal axis and its width as the transverse axis. Before construction, a first pier and a second pier are sequentially installed along the bridge's forward direction for the span to be erected. Supports are pre-installed on the top surfaces of the two piers, and the center line connecting the supports coincides with the longitudinal centerline of the span. The main execution component of the construction method is a construction control system, which is connected to the controllers of two tire-mounted beam transport vehicles, a laser rangefinder, an inclination sensor, and hydraulic cylinders. Step S1 is executed first: the two tire-mounted beam transport vehicles are supported on the bottom surfaces of both ends of the T-beam, ensuring that the longitudinal axis of the T-beam is parallel to the centerline of the subsequent transport route. The hydraulic lifting system of each tire-mounted beam transport vehicle includes two independently controlled sets of hydraulic cylinders. The left cylinder is supported below the left flange of the bottom surface of the T-beam end, and the right cylinder is supported below the right flange. The two sets of cylinders jointly bear the weight of the T-beam at that end. A laser rangefinder and an inclination sensor are respectively installed on the bottom surfaces of both ends of the T-beam. The tilt sensor is fixed on the transverse centerline of the bottom surface, and its measuring axis is parallel to the transverse axis of the T-beam. The T-beam is lifted to the transport height, for example, 25 cm, between 20 cm and 30 cm above the ground, using the hydraulic lifting system of two tire-mounted beam transport vehicles. During lifting, a laser rangefinder measures the vertical distance from the bottom surface of the T-beam to the road surface. The controller calculates the longitudinal tilt angle based on the difference in vertical distance between the two ends, while the tilt sensor directly measures the transverse tilt angle. When either the longitudinal or transverse tilt angle exceeds a preset threshold, correction is achieved by adjusting the hydraulic cylinders of the front and rear beam transport vehicles to synchronously reverse their lifting and lowering positions, or by adjusting the left and right hydraulic cylinders of a single beam transport vehicle to lift and lower positions at unequal heights. Step S2: The two tire-mounted beam transport vehicles travel synchronously along the transport route, keeping the longitudinal axis of the T-beam parallel to the transport route, with the two ends of the T-beam corresponding to the directions of the first and second piers (i.e., the front end of the T-beam points to the first pier, and the rear end points to the second pier). The beam transport vehicles transport the T-beam to the position between the first and second piers of the bridge span to be erected. During transportation, laser rangefinders continuously measure the vertical distance between the bottom surfaces of both ends of the T-beam and the transport road surface, and the controller calculates the longitudinal tilt angle in real time. If the vertical distance deviates from the set range, the lateral tilt angle exceeds the set threshold, or the longitudinal tilt angle exceeds the set threshold, adjustments are made: the deviations in the longitudinal tilt angle and vertical distance are adjusted by synchronously raising and lowering all the hydraulic cylinders of the two beam transport vehicles; the deviation in the lateral tilt angle is adjusted by unequal raising and lowering of the left and right sets of hydraulic cylinders of the corresponding beam transport vehicle. Step S3: When the T-beam reaches the designated longitudinal position between the first and second piers (i.e., the two ends of the T-beam are basically aligned with the support positions of the two piers on the horizontal projection), the controller controls the wheel sets of the two tire-type beam transport vehicles to independently steer, so that the axis of each wheel rotates from the direction originally parallel to the longitudinal axis of the T-beam to the direction perpendicular to the longitudinal axis of the T-beam. After the steering is completed, the two tire-type beam transport vehicles begin to move laterally synchronously, with the direction of travel perpendicular to the original transport direction (i.e., perpendicular to the longitudinal axis of the T-beam).During this lateral movement, the T-beam translates along its lateral axis, causing the bottom surfaces of both ends of the T-beam to gradually move directly above the top surfaces of the first and second piers, respectively. Laser rangefinders measure the vertical distance between the bottom surfaces of the T-beam and the top surfaces of the first and second piers in real time. During the lateral movement, the lateral speeds of the two beam transport vehicles remain equal. Step S4: When the vertical distance measured by the laser rangefinder reaches the preset beam-dropping distance range (e.g., 5 cm to 10 cm), the controller synchronously lowers the hydraulic lifting systems of the two tire-type beam transport vehicles, causing the T-beam to descend vertically. At this time, the support pads on the bottom surfaces of both ends of the T-beam align with and fall onto the supports on the top surfaces of the first and second piers, respectively. During the beam drop, tilt sensors measure the lateral tilt angle of the T-beam in real time, and the controller calculates the longitudinal tilt angle of the T-beam in real time using the difference in the vertical distances between the two ends. If the lateral or longitudinal tilt angle exceeds the set threshold, the beam lowering process is immediately stopped, and adjustments are made via the hydraulic lifting system (lateral tilt angle adjustment uses the corresponding side cylinder, longitudinal tilt angle adjustment uses the front and rear cylinders) before continuing the beam lowering. S5: Once the T-beam is fully positioned and the support pad is reliably in contact with the top surface of the support, the two tire-mounted beam transport vehicles are released from their support. Specifically, this can be achieved by controlling the hydraulic cylinders to continue lowering the beam until it is separated from the bottom surface of the T-beam. Then, the wheels of the two tire-mounted beam transport vehicles are turned back to a direction parallel to the longitudinal axis of the T-beam, and they travel in the opposite direction along the transport route, leaving the span to be erected, thus completing the erection of one T-beam.

[0022] In existing technologies, traditional T-beam erection typically involves first transporting the T-beam longitudinally along the bridge deck or access road to the bridgehead using a beam transport vehicle, then lifting, moving, and lowering the beam using a bridge erecting machine. Since the beam transport vehicle is only responsible for longitudinal transport, while the bridge erecting machine handles lateral movement and beam lowering, there is a transfer connection between the two, and the bridge erecting machine requires pre-laying lateral tracks, occupying bridge deck space. In this embodiment, the T-beam maintains its longitudinal axis parallel to the transport route from transport to lowering. Upon reaching the area between the two piers, the independent steering of the beam transport vehicle's wheel sets directly switches from longitudinal to lateral travel, allowing the T-beam to be moved laterally directly above the piers without the need for a bridge erecting machine. Simultaneously, each of the two beam transport vehicles is equipped with independently controlled hydraulic cylinders, allowing real-time adjustment of the longitudinal and lateral tilt angles based on the road surface slope during transport, preventing accumulated deviations in the beam's posture. During lowering, closed-loop control using laser ranging and tilt sensors ensures synchronous descent and horizontal posture at both ends, guaranteeing precise alignment between the bearing pads and the bearings. Throughout the entire process, the orientation and direction of movement of the T-beams are clear and continuous, eliminating the transfer links of segmented operations and the occupation of the bridge erecting machine, thus improving construction efficiency, attitude control accuracy and safety.

[0023] In one embodiment, based on the above method, two laser rangefinders can be installed on the bottom surface of each T-beam end. One laser rangefinder is located near the centerline of the T-beam web, and the other is located near the edge of the T-beam flange. This arrangement is intended to detect whether there is local deformation or foreign matter on the bottom surface of the T-beam. The tilt sensor is a single-axis tilt sensor, fixed on the transverse centerline of the bottom surface of the T-beam end. The measurement axis of this single-axis tilt sensor is parallel to the transverse axis of the T-beam, so that the sensor is only sensitive to rotation around the longitudinal axis, i.e., the transverse tilt angle, and is not affected by changes in the longitudinal tilt angle. The T-beam is placed with its longitudinal axis parallel to the transport route. Before lifting the T-beam to the transport height, the vertical distance between the two ends of the T-beam is measured using two laser rangefinders, and the longitudinal tilt angle at both ends of the T-beam is calculated. The specific calculation process is as follows: For the same end, the sensor reading near the centerline of the web is recorded as D. web The sensor readings near the wing edge are recorded as D. flange If the absolute value of the difference between the two exceeds, for example, 2 mm, it may indicate that the bottom surface is uneven. For the calculation of the longitudinal inclination angle, sensor readings are used at both ends near the centerline of the web, according to θ = arctan((D front_web -D rear_web The longitudinal tilt angle of the T-beam is calculated as () / L), where L is the horizontal distance between the two measuring points. Then, the overall lifting height of the two tire-mounted beam transport vehicles is independently adjusted via a hydraulic lifting system to bring the calculated longitudinal tilt angle at both ends of the T-beam to zero. For example, if the rear end of the T-beam is lower than the front end, the rear beam transport vehicle is raised or the front beam transport vehicle is lowered. After longitudinal leveling is completed, the measurement value of the laser distance sensor near the center line of the web is used as the main control signal to synchronously lift the two tire-mounted beam transport vehicles. During the lifting process, the measurement difference between the two laser distance sensors on the same bottom surface is continuously compared. If the difference exceeds the allowable range (e.g., 0 to 3 mm), and reaches 4 mm, the system determines that there is local deformation or foreign matter on the bottom surface of the T-beam, such as concrete residue or protruding embedded parts. At this time, the controller stops lifting and issues an alarm signal, and construction personnel manually inspect and clean the area. After cleaning, lifting continues. This multi-point measurement method effectively avoids unstable support or localized stress concentration of the T-beam on the beam transport vehicle due to bottom surface defects.

[0024] In existing technologies, when a beam transport vehicle lifts a T-beam, it typically relies solely on visual inspection by the operator or a simple level to check if the beam is level, failing to detect local defects on the beam's bottom. If there are raised concrete lumps or residual steel strand ends on the bottom surface of the T-beam, the beam will be tilted after lifting, making it highly susceptible to tipping over or damage during transport. This embodiment, by installing two laser rangefinders at each end and comparing their differences, can detect local deformations or foreign objects on the bottom surface in the early stages of lifting, allowing for timely shutdown and inspection. Simultaneously, zeroing the longitudinal tilt angle before lifting ensures the beam remains level throughout the subsequent lifting process, reducing the adjustment burden during transport. This dual detection mechanism improves construction safety.

[0025] In one embodiment, during transportation, the longitudinal axis of the T-beam remains parallel to the transportation route, with the front end pointing towards the first pier and the rear end towards the second pier. The controller first calculates the vertical distance deviation at both ends of the T-beam and the longitudinal tilt angle of the T-beam based on the measurements from two laser rangefinders. The vertical distance deviation can be expressed as the difference between the current vertical distance and the target transportation height (e.g., 25 cm). The longitudinal tilt angle is calculated using the aforementioned arctangent formula. Simultaneously, the lateral tilt angle is directly read from the tilt sensor. The controller then adjusts according to the following priority: first, the longitudinal tilt angle is adjusted to within a threshold value; then, the lateral tilt angle is adjusted to within a threshold value; and finally, the vertical distance is adjusted to the set range. The reason for prioritizing the adjustment of the longitudinal tilt angle is that the longitudinal tilt angle deviation simultaneously affects the stress at both ends of the T-beam and its subsequent alignment with the top surface of the pier, while adjusting the longitudinal tilt angle typically only requires synchronously reversing the lifting and lowering of all the hydraulic cylinders of the front and rear beam transport vehicles, having a smaller impact on the lateral tilt angle. The specific operation for adjusting the longitudinal tilt angle is as follows: Control all hydraulic cylinders of the two tire-mounted beam transporters to synchronously raise and lower in opposite directions. For example, if the front end of the T-beam is lower than the rear end (i.e., the T-beam tilts forward and downward), control all cylinders of the first tire-mounted beam transporter to raise, and control all cylinders of the second tire-mounted beam transporter to lower by the same amount of height. "Same amount" means that the number of centimeters the first vehicle raises is equal to the number of centimeters the second vehicle lowers, thus maintaining the overall height of the T-beam. Once the longitudinal tilt angle enters the threshold range (e.g., ±0.5 degrees), then begin adjusting the lateral tilt angle. When adjusting the lateral tilt angle, control the left and right sets of hydraulic cylinders of each tire-mounted beam transporter to raise and lower at unequal heights. That is, if the T-beam tilts to the left, the left cylinder raises and the right cylinder lowers. After the lateral tilt angle is adjusted to the correct position, finally adjust the vertical distance. When adjusting the vertical distance, control all hydraulic cylinders of the two tire-mounted beam transporters to synchronously raise and lower in the same direction, i.e., all four cylinders raise or lower simultaneously, to adjust the vertical distance between the bottom surface of the T-beam and the road surface to the set range, for example, 23 cm to 27 cm. This priority order can avoid mutual interference during the adjustment process. For example, if the longitudinal and lateral directions are adjusted at the same time, it may cause load fluctuations or attitude coupling in the hydraulic system.

[0026] This embodiment sets a clear adjustment priority: longitudinal, then lateral, and finally vertical distance. This aligns with the physical logic of beam attitude control: the longitudinal tilt angle has the greatest impact and its adjustment method is independent; lateral tilt angle adjustment requires differential adjustment of the left and right hydraulic cylinders, which may slightly affect longitudinal balance but has a minor impact; vertical distance adjustment is the simplest. This hierarchical control strategy enables rapid convergence to the target state, reduces the number of adjustments and total adjustment time, and improves transportation efficiency.

[0027] In one embodiment, when adjusting the longitudinal tilt angle, lateral tilt angle, or vertical distance, the controller determines the corresponding hydraulic cylinder adjustment amount based on the absolute value of the longitudinal tilt angle deviation, lateral tilt angle deviation, or vertical distance deviation, and the real-time trend of these deviations. Taking the longitudinal tilt angle deviation as an example, let its absolute value be |e|. The controller presets a no-adjustment dead zone, optionally 0.1 degrees. When |e| is less than 0.1 degrees, the deviation is considered to be within an acceptable range, and the adjustment amount is set to zero, i.e., no adjustment is performed to avoid frequent small movements of the hydraulic cylinder. When |e| is greater than or equal to 0.1 degrees, the trend of the deviation is further judged. The trend can be obtained by comparing the deviation value at the current sampling time with the deviation value at the previous sampling time. If the current deviation value is less than the previous deviation value, it means that the deviation is decreasing towards the set threshold. At this time, the adjustment amount is calculated by multiplying the deviation amount by a first proportional coefficient, which can be 0.5, i.e., the adjustment amount is 0.5*e. If the current deviation value is greater than the previous deviation value, it indicates that the deviation is increasing and deviating from the set threshold. In this case, the adjustment amount is calculated by multiplying the deviation amount by the second proportional coefficient. The second proportional coefficient is greater than the first proportional coefficient and can be set to 0.8, meaning the adjustment amount is 0.8*e. Using a larger coefficient is to quickly curb the trend of deviation divergence. In addition, the controller also sets an emergency adjustment threshold, optionally 0.5 degrees. When |e| exceeds 0.5 degrees, the adjustment amount is directly taken as the maximum allowable lifting speed of the hydraulic cylinder, for example, lifting 5 centimeters per minute, and is continuously adjusted at this maximum speed until the deviation drops below 0.5 degrees, then switching back to proportional adjustment. This combination of variable coefficient proportional adjustment and emergency adjustment allows for smooth adjustment within the normal range and rapid response when the deviation increases rapidly. During the T-beam transportation and lowering process, the orientation and direction of movement of the T-beam are maintained according to the aforementioned steps, and the adjustment action does not affect the correspondence between the longitudinal axis of the T-beam and the transportation route or pier.

[0028] In existing technologies, hydraulic system control often employs fixed-gain proportional control, which either results in slow response leading to accumulated deviations or large overshoot causing oscillations. This is particularly problematic in beam attitude control, where the large inertia of the T-beam means improper adjustments can cause beam swaying. This embodiment introduces adaptive adjustment based on deviation trends. A small coefficient is used when the deviation tends to decrease to avoid overshoot, while a large coefficient is used when the deviation tends to increase to suppress divergence. An emergency mode is also included to handle larger deviations. This control method requires no complex models, is computationally simple, and is suitable for implementation with embedded controllers, enabling smoother and faster convergence of the T-beam attitude adjustment process.

[0029] In one embodiment, during synchronous lateral movement, the T-beam has turned so that its longitudinal axis is perpendicular to the original transport direction, i.e., the length direction of the T-beam is parallel to the line connecting the piers. At this time, the laser rangefinder measures in real time the vertical distance between the bottom surfaces of both ends of the T-beam and the top surfaces of the first and second piers. Assume the vertical distance from the bottom surface of the front end of the T-beam (originally closer to the first pier) to the top surface of the first pier is H1, and the vertical distance from the bottom surface of the rear end of the T-beam to the top surface of the second pier is H2. If H1 is greater than H2, it indicates that the front end is higher than the top surface of the pier, and the rear end is lower. At this time, the controller adjusts all the hydraulic cylinders of the two tire-type beam transport vehicles to raise and lower synchronously, reducing the support height of the end with the larger vertical distance and increasing the support height of the end with the smaller vertical distance. Specifically, if H1 > H2, all cylinders of the front vehicle are lowered by a certain height (e.g., 1 cm), while all cylinders of the rear vehicle are raised by the same height. This decreases H1 and increases H2 until |H1 - H2| is less than a preset lateral movement vertical distance error threshold, which can optionally be 2 cm. Simultaneously, tilt sensors monitor the lateral tilt angle of the T-beam in real time. Note that during the lateral movement phase, the measurement axis of the lateral tilt angle remains parallel to the lateral axis of the T-beam, i.e., perpendicular to its longitudinal axis. If the lateral tilt angle exceeds a preset lateral movement safety threshold, such as 0.5 degrees, the controller pauses lateral movement and adjusts the hydraulic cylinders on the corresponding side of the two tire-type beam transport vehicles. For example, if the T-beam tilts to the left, the left cylinder of both transport vehicles is simultaneously raised while the right cylinder is lowered, restoring the lateral tilt angle to within the safety threshold before continuing lateral movement. This method of dynamically adjusting the height difference and lateral tilt angle during lateral movement ensures that the T-beam remains parallel to the top surface of the pier during lateral movement, preventing collisions with supports or blocks on the pier due to beam tilting during transport.

[0030] In existing technologies, when using a bridge erecting machine to laterally move T-beams, the lateral track is usually pre-leveled, and the beam's posture remains relatively fixed during the lateral movement. However, when the beam transport vehicle travels directly laterally, the elevation difference between the two ends can easily change due to unevenness in the bridge deck or temporary supports. If no active adjustment is made during the lateral movement, when the T-beam reaches the placement position, one end may have already contacted the support while the other end is still suspended high in the air, causing the beam to twist. This embodiment compares the distances from both ends to the top surface of the piers in real time during lateral movement, actively balances the elevation difference between the two ends by raising and lowering the front and rear beam transport vehicles, and monitors the lateral tilt angle to ensure that the beam maintains a horizontal posture throughout the lateral movement, thereby creating favorable initial conditions for subsequent beam placement.

[0031] In one embodiment, during the synchronous lowering of the hydraulic lifting system for beam lowering, the T-beam is already directly above the first and second piers, its longitudinal axis parallel to the line connecting the two piers, and the end bearing pads aligned with the supports on the top surfaces of the piers. The controller dynamically adjusts the lowering speed of all hydraulic cylinders on the two tire-type beam transport vehicles based on the vertical distance difference between the bottom surfaces of the two ends of the T-beam and the top surfaces of the first and second piers, measured in real-time by laser rangefinders. Let the vertical distance difference between the two ends be ΔH = |H1 - H2|, and the controller presets a synchronous lowering error threshold, optionally 3 mm. If ΔH is less than 3 mm, the same lowering speed can be maintained at both ends; if ΔH is close to or exceeds 3 mm, the controller reduces the lowering speed of the cylinder at the faster lowering end, or increases the speed of the cylinder at the slower lowering end, ensuring that ΔH remains less than 3 mm. Simultaneously, during the beam lowering process, the tilt sensor measures the lateral tilt angle in real-time and calculates the longitudinal tilt angle and the rate of change of the longitudinal tilt angle in real-time using the difference in the vertical distance between the two ends. The longitudinal tilt angle change rate can be obtained by dividing the difference in longitudinal tilt angle calculated from two consecutive samplings by the sampling time interval. When the calculated longitudinal tilt angle exceeds a set threshold (e.g., 0.3 degrees), the controller immediately stops the beam lowering and adjusts the longitudinal tilt angle by raising or lowering all hydraulic cylinders of the two tire-mounted beam transport vehicles until it returns to within the threshold. When the longitudinal tilt angle change rate exceeds a set rate threshold, such as 0.1 degrees per second, the beam lowering also stops and adjustments are made, because excessive angular velocity means that the T-beam may flip rapidly, easily causing impact. For the lateral tilt angle and its change rate, thresholds are also set. When the lateral tilt angle exceeds, for example, 0.2 degrees or the lateral tilt angle change rate exceeds 0.1 degrees per second, the beam lowering stops and is corrected by adjusting the left and right sets of hydraulic cylinders of the corresponding tire-mounted beam transport vehicles. This multi-parameter joint monitoring and dynamic speed adjustment mechanism ensures that the beam lowering process is smooth and controllable.

[0032] In existing technologies, bridge girder lowering typically relies on a winch for slow descent. Operators visually inspect the girder for levelness, and manual adjustments are only made when a tilt is detected, often resulting in a significant angle of inclination. Furthermore, the adjustment process requires repeated lifting. This embodiment, by real-time monitoring of the vertical distance difference between the two ends, the longitudinal tilt angle, the lateral tilt angle, and their rate of change, can proactively adjust the descent speed or pause adjustments when deviations are still small, preventing the accumulation of deviations. In particular, the introduction of the tilt angle change rate as a judgment criterion allows for early detection of instability trends, preventing sudden girder overturning. This refined girder lowering control significantly improves positioning accuracy and construction safety.

[0033] In one embodiment, when the supports of the T-beam are released from the two tire-mounted girder transporters, the T-beam is fully positioned on the pier supports, with its longitudinal axis remaining parallel to the line connecting the piers. The controller first controls all hydraulic cylinders of one of the tire-mounted girder transporters, such as the lead vehicle (the one closer to the first pier), to slowly and synchronously descend. The descent speed can optionally be 1 cm per minute. During this process, the tilt sensor continuously measures the lateral tilt angle of the T-beam, while simultaneously calculating the longitudinal tilt angle of the T-beam using measurements from the laser rangefinders at both ends. When the change in lateral tilt angle exceeds a preset unloading change threshold, such as 0.1 degrees, or the calculated change in longitudinal tilt angle exceeds 0.1 degrees, the controller immediately stops the descent and reverses, raising all hydraulic cylinders of the tire-mounted girder transporter back to the initial supported state. After waiting approximately 5 seconds for the T-beam tilt angle to stabilize, the descent is attempted again. This is done because if the T-beam suddenly tilts upon release of support due to friction or localized adhesion between the T-beam and the transporter, the retraction operation can prevent the T-beam from becoming unstable. After the first tire-mounted girder transporter has completely detached from the bottom surface of the T-beam (for example, when the laser rangefinder shows that the bottom surface of that end is more than 2 cm away from the support surface of the transporter), the support of the other tire-mounted girder transporter is released in the same manner. After both tire-mounted girder transporters are completely released, the controller turns the wheel sets of both tire-mounted girder transporters to a direction parallel to the longitudinal axis of the T-beam, and then drives them away from the bridge span to be erected along the transport route in the opposite direction. This sequential unloading method is safer than simultaneous unloading because one end can detach first while the other end remains supported, preventing the T-beam from undergoing excessive deformation or displacement due to the sudden loss of all support.

[0034] In existing technologies, after the bridge erecting machine lowers the beam, operators usually need to manually unhook the lifting device. Sometimes, due to jamming of the lifting device, it is necessary to knock or shake it, posing a safety hazard. After the beam transport vehicle supports the T-beam in place, if two beam transport vehicles are lowered rapidly at the same time, the T-beam may tilt momentarily due to uneven force on both ends. This embodiment adopts a method of slow descent at one end, monitoring changes in tilt angle, and immediately raising and retrying if an anomaly is detected. This is equivalent to simulating the process of manual "trial unloading," which ensures safety and avoids impact on the T-beam. At the same time, detaching one end first and then the other ensures that one end of the T-beam remains stably supported until it is fully lowered, preventing accidental slippage.

[0035] In one embodiment, throughout the construction process, the control system continuously records the following construction parameters: all vertical distance data measured by two laser rangefinders, all lateral tilt angle data measured by two tilt sensors, all longitudinal tilt angle data calculated from the vertical distances at both ends, the lifting height and lifting speed of each hydraulic cylinder in the hydraulic lifting system, the longitudinal and lateral travel speeds of the two tire-type beam transport vehicles, the wheel set steering angle, and the final vertical distance at the time of beam placement. These parameters are compiled into a construction log in chronological order and transmitted to a remote monitoring platform via a wireless transmission module, such as a 4G DTU or Wi-Fi module. The remote monitoring platform uses the construction parameters from the construction logs of multiple completed T-beams as sample data. The total number of adjustments and the total adjustment range of the hydraulic lifting system during the construction of each T-beam, as well as the deviation of the final vertical distance at the time of beam placement from the preset theoretical value (e.g., the vertical distance corresponding to the support design height), are used as comprehensive evaluation indicators. The total number of adjustments reflects the smoothness of the construction process, the total adjustment range reflects energy consumption, and the final vertical distance deviation reflects the positioning accuracy. Using multiple linear regression or neural network algorithms, a mapping relationship is established between the comprehensive evaluation index and the set range of vertical distance, the set threshold of lateral inclination angle, the set threshold of longitudinal inclination angle, the threshold of beam dropping synchronization error, and the threshold of inclination angle change rate. For example, a three-layer neural network is trained using these thresholds as input features and the comprehensive evaluation index as output. Then, with the goal of minimizing the comprehensive evaluation index, the optimal values ​​of these thresholds are calculated. For example, a set of threshold combinations is found using gradient descent to minimize the predicted value of the comprehensive evaluation index. During data collection, the orientation and movement direction of the T-beams are kept consistent according to the aforementioned steps, ensuring the comparability of construction parameters between different T-beams.

[0036] In existing technologies, construction parameters are typically used only for on-site recording or post-construction archiving, rarely for proactively optimizing process parameters. Threshold settings for each project often rely on engineer experience or conservative values ​​in design specifications, lacking adjustments based on actual construction data. This embodiment collects construction data from multiple T-beams, establishes a mathematical model between comprehensive evaluation indicators and various thresholds, and optimizes the threshold parameters in reverse. This allows subsequent construction to automatically adopt better threshold combinations, thereby reducing the number and magnitude of adjustments and improving beam placement accuracy. As the number of construction projects increases and the sample size accumulates, the optimization results become increasingly accurate, achieving continuous improvement of construction parameters.

[0037] In one embodiment, based on the above optimization method, construction parameters and corresponding comprehensive evaluation indicators from the construction logs of multiple completed T-beams can be used as training samples. Various set ranges and thresholds, such as the lower and upper limits of the vertical distance set range, the lateral tilt angle threshold, the longitudinal tilt angle threshold, the beam drop synchronization error threshold, the longitudinal tilt angle change rate threshold, and the lateral tilt angle change rate threshold, are used as parameters to be optimized. A Gaussian process surrogate model is established using a Bayesian optimization algorithm to transform the parameters to be optimized into the comprehensive evaluation indicators. Bayesian optimization is suitable for scenarios where the objective function evaluation cost is high and the parameter space dimension is moderate. The Gaussian process fits the unknown mapping between parameters and evaluation indicators using a mean function and a covariance function (such as the Matrn kernel function). Then, through a collection function, such as the Expected Improvement (EI) function, multiple iterations are performed on the surrogate model for optimization. In each iteration, the collection function weighs exploration (regions with high uncertainty in the parameter space) and utilization (regions with good predicted values), selecting the parameter combination that maximizes the collection function as the candidate parameter combination for the next iteration. In actual construction, the comprehensive evaluation index corresponding to the candidate parameter combination is verified. The verification results (parameter combination and measured comprehensive evaluation index) are updated to the training samples, and the Gaussian process surrogate model is retrained. This process is repeated iteratively until the improvement of the comprehensive evaluation index is less than the preset convergence threshold, for example, the absolute value of the difference between the evaluation index of two adjacent iterations is less than 0.01. The optimal parameter combination obtained at this point is the threshold setting for the best comprehensive performance under the current construction conditions. In each verification construction, the orientation and movement direction of the T-beam are strictly executed according to the aforementioned steps to ensure the effectiveness of the parameter optimization results.

[0038] This embodiment uses a Gaussian process surrogate model to predict the effects of different parameter combinations and actively selects the most promising parameter combination for verification. As construction progresses, the parameter settings become increasingly reasonable. Compared to manual experience-based adjustments, this method is more systematic and data-driven, and can gradually reduce the adjustment actions of the hydraulic system while ensuring safety, thereby improving the accuracy of beam lowering.

[0039] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. An integrated construction method for T-beam transportation and erection, characterized in that, include: S1: Two tire-mounted beam transport vehicles are supported on the bottom surfaces of both ends of the T-beam. The hydraulic lifting system of each tire-mounted beam transport vehicle includes two independently controlled hydraulic cylinders on the left and right sides, respectively. The hydraulic lifting system of the two tire-mounted beam transport vehicles is used to lift the T-beam to the transport height, and laser rangefinders and tilt sensors are installed on the bottom surfaces of both ends of the T-beam. S2: Two tire-mounted beam transport vehicles synchronously transport the T-beam along the transport route to the position between the first and second piers of the bridge span to be erected. During the transport process, the laser rangefinder continuously measures the vertical distance between the bottom surfaces of both ends of the T-beam and the transport road surface. The longitudinal tilt angle of the T-beam is calculated by the difference between the vertical distances at both ends. The tilt angle sensor continuously measures the lateral tilt angle of the T-beam. When the vertical distance deviates from the set range, or the lateral tilt angle exceeds the set threshold, or the calculated longitudinal tilt angle exceeds the set threshold, the adjustment of the longitudinal tilt angle and vertical distance is achieved by controlling the lifting and lowering of the hydraulic cylinders of the two tire-mounted beam transport vehicles. The adjustment of the lateral tilt angle is achieved by controlling the unequal lifting and lowering of the left and right sets of hydraulic cylinders of the corresponding tire-mounted beam transport vehicles. S3: After reaching the position, the wheel sets of the two tire-type beam transport vehicles are independently steered to rotate each wheel axle to a direction perpendicular to the longitudinal axis of the T-beam. Then, the two tire-type beam transport vehicles move laterally in sync, causing the T-beam to move laterally. During the lateral movement, the lateral speed of the two tire-type beam transport vehicles remains equal. The laser rangefinder measures the vertical distance between the bottom surfaces of both ends of the T-beam and the top surfaces of the first and second piers in real time. S4: When the vertical distance measured by the laser rangefinder reaches the preset beam drop distance range, the hydraulic lifting systems of the two tire-type beam transport vehicles are lowered simultaneously, so that the support pads on the bottom surfaces of both ends of the T-beam fall onto the supports on the top surfaces of the first and second piers, respectively. During the beam drop process, the tilt sensor measures the lateral tilt angle of the T-beam in real time, and calculates the longitudinal tilt angle of the T-beam in real time by the difference in the vertical distance between the two ends. If the lateral tilt angle exceeds the set threshold or the calculated longitudinal tilt angle exceeds the set threshold, the beam drop is stopped, and the hydraulic lifting system is used for adjustment. S5: Remove the supports of the two tire-mounted beam transport vehicles on the T-beam and drive the two tire-mounted beam transport vehicles away from the bridge span to be erected.

2. The integrated construction method for T-beam transportation and erection as described in claim 1, characterized in that, In S1, two laser rangefinders are installed on the bottom surface of each T-beam end. One laser rangefinder is close to the centerline of the web of the T-beam, and the other is close to the edge of the flange of the T-beam. The tilt sensor is a single-axis tilt sensor, fixed on the transverse centerline of the bottom surface of the T-beam end, and the measurement axis of the single-axis tilt sensor is parallel to the transverse axis of the T-beam. Before lifting the T-beam to the transport height, the vertical distance between the two ends of the T-beam is measured by the two laser rangefinders and the longitudinal tilt angle of the two ends of the T-beam is calculated. Then, the overall lifting height of the two tire-type beam transport vehicles is independently adjusted by the hydraulic lifting system to make the calculated longitudinal tilt angle of the two ends of the T-beam zero. Then, the measurement value of the laser rangefinder near the centerline of the web is used as the main control signal to synchronously lift the two tire-type beam transport vehicles. During the lifting process, the measurement difference between the two laser rangefinders on the bottom surface of the same end is continuously compared. If the difference exceeds the allowable range, it is determined that there is local deformation or foreign object on the bottom surface of the T-beam, and the lifting is stopped for manual inspection.

3. The integrated construction method for T-beam transportation and erection as described in claim 1, characterized in that, In S2, the vertical distance deviation at both ends of the T-beam and the longitudinal tilt angle of the T-beam are first calculated based on the measurements from the two laser rangefinders, and the lateral tilt angle of the T-beam is measured using the tilt angle sensor. Then, adjustments are made according to the following priority: first, the longitudinal tilt angle is adjusted to within a threshold value; then, the lateral tilt angle is adjusted to within a threshold value; finally, the vertical distance is adjusted to the set range. When adjusting the longitudinal tilt angle, all hydraulic cylinders of the two tire-mounted beam transport vehicles are controlled to synchronously rise and fall in opposite directions, with the first tire-mounted beam transport vehicle rising and the second tire-mounted beam transport vehicle lowering by the same amount of height. When adjusting the lateral tilt angle, the left and right sets of hydraulic cylinders of each tire-mounted beam transport vehicle are controlled to rise and fall at unequal heights. When adjusting the vertical distance, all hydraulic cylinders of the two tire-mounted beam transport vehicles are controlled to synchronously rise and fall in the same direction.

4. The integrated construction method for T-beam transportation and erection as described in claim 3, characterized in that, When adjusting the longitudinal tilt angle, lateral tilt angle, or vertical distance, the corresponding hydraulic cylinder adjustment amount is determined based on the absolute value of the longitudinal tilt angle deviation, lateral tilt angle deviation, or vertical distance deviation, and the real-time trend of the deviation. When the absolute value of the deviation is less than the preset no-adjustment dead zone, the adjustment amount is set to zero. When the absolute value of the deviation is greater than or equal to the no-adjustment dead zone and the trend of the deviation is decreasing towards the set threshold, the adjustment amount is calculated by multiplying the deviation by a first proportional coefficient. When the absolute value of the deviation is greater than or equal to the no-adjustment dead zone and the trend of the deviation is increasing away from the set threshold, the adjustment amount is calculated by multiplying the deviation by a second proportional coefficient, where the second proportional coefficient is greater than the first proportional coefficient. When the absolute value of the deviation exceeds the preset emergency adjustment threshold, the adjustment amount is directly taken as the maximum allowable lifting speed of the hydraulic cylinder, and the adjustment is continuously performed at this maximum speed until the deviation drops below the emergency adjustment threshold.

5. The integrated construction method for T-beam transportation and erection as described in claim 3, characterized in that, In S3, during the synchronous lateral movement of the two tire-type beam transport vehicles, the vertical distances between the bottom surfaces of both ends of the T-beam and the top surfaces of the first and second piers are measured in real time by laser rangefinders. When the vertical distance at one end is greater than that at the other end, the support height at the end with the larger vertical distance is lowered and the support height at the end with the smaller vertical distance is raised by adjusting all the hydraulic cylinders of the two tire-type beam transport vehicles in sync until the difference in the vertical distance between the bottom surfaces of the two ends of the T-beam is less than the preset lateral movement vertical distance error threshold. The tilt sensor monitors the lateral tilt angle of the T-beam in real time. If the lateral tilt angle exceeds the preset lateral movement safety threshold, the lateral movement is paused and the hydraulic cylinders on the corresponding side of the two tire-type beam transport vehicles are adjusted to restore the lateral tilt angle of the T-beam to within the safety threshold before continuing the lateral movement.

6. The integrated construction method for T-beam transportation and erection as described in claim 3, characterized in that, In S4, when simultaneously lowering the hydraulic lifting systems of the two tire-mounted beam transport vehicles, the descent speed of all hydraulic cylinders on both tire-mounted beam transport vehicles is dynamically adjusted based on the vertical distance differences between the bottom surfaces of the two ends of the T-beam and the top surfaces of the first and second piers, measured in real time by laser rangefinders. This ensures that the vertical distance difference between the two ends is always less than a preset synchronous beam lowering error threshold. During the beam lowering process, tilt sensors measure the lateral tilt angle of the T-beam in real time, and simultaneously calculate the longitudinal tilt angle and the rate of change of the longitudinal tilt angle using the vertical distance difference between the two ends. When the calculated longitudinal tilt angle exceeds the set threshold, the beam lowering stops, and the longitudinal tilt angle of the T-beam is adjusted by raising or lowering all hydraulic cylinders of the two tire-mounted beam transport vehicles until the desired longitudinal tilt angle is reached. The longitudinal tilt angle is restored to within the threshold. When the calculated rate of change of longitudinal tilt angle exceeds the set rate threshold, the beam dropping is stopped, and the longitudinal tilt angle of the T-beam is adjusted by raising or lowering all the hydraulic cylinders of the two tire-type beam transport vehicles until the rate of change of longitudinal tilt angle is restored to within the rate threshold. When the lateral tilt angle exceeds the set threshold, the beam dropping is stopped, and the lateral tilt angle of the T-beam is adjusted by raising or lowering the left and right sets of hydraulic cylinders of the corresponding tire-type beam transport vehicles until the lateral tilt angle is restored to within the threshold. When the rate of change of lateral tilt angle exceeds the set rate threshold, the beam dropping is stopped, and the lateral tilt angle of the T-beam is adjusted by raising or lowering the left and right sets of hydraulic cylinders of the corresponding tire-type beam transport vehicles until the rate of change of lateral tilt angle is restored to within the rate threshold.

7. The integrated construction method for T-beam transportation and erection as described in claim 3, characterized in that, In S5, when releasing the support of the T-beam from the two tire-mounted girder transport vehicles, first control all the hydraulic cylinders of one tire-mounted girder transport vehicle to slowly and synchronously descend. During this process, the tilt sensor continuously measures the lateral tilt angle of the T-beam, and at the same time calculates the longitudinal tilt angle of the T-beam through the measurement values ​​of the laser rangefinders at both ends. When the change in the lateral tilt angle or the calculated change in the longitudinal tilt angle exceeds the preset unloading change threshold, the descent stops and all the hydraulic cylinders of the tire-mounted girder transport vehicle are raised back to the initial support state. After the tilt angle stabilizes, the release is repeated. After the tire-mounted girder transport vehicle is completely released, the support of the other tire-mounted girder transport vehicle is released in the same way. After both tire-mounted girder transport vehicles are completely released, the wheel sets of the two tire-mounted girder transport vehicles are turned to a direction parallel to the longitudinal axis of the T-beam, and then they are driven away from the bridge span to be erected along the transport route in the opposite direction.

8. The integrated construction method for T-beam transportation and erection as described in claim 1, characterized in that, Throughout the construction process from S1 to S5, the following construction parameters were continuously recorded: all vertical distance data measured by two laser rangefinders, all lateral tilt angle data measured by two tilt sensors, all longitudinal tilt angle data calculated from the vertical distances at both ends, the lifting height and lifting speed of each hydraulic cylinder in the hydraulic lifting system, the longitudinal and lateral travel speeds of the two tire-type beam transport vehicles, the wheel steering angle, and the final vertical distance at the completion of beam lowering in S4. These construction parameters were then used to generate a construction log in chronological order and transmitted wirelessly to the remote monitoring platform. The remote monitoring platform used the construction parameters from the construction logs of the completed T-beams as samples. The data, using the total number of adjustments and the total adjustment range of the hydraulic lifting system during the construction of each T-beam, as well as the deviation between the final vertical distance at the completion of beam lowering and the preset theoretical value, are used as comprehensive evaluation indicators. Through multiple linear regression or neural network algorithms, a mapping relationship is established between this comprehensive evaluation indicator and the vertical distance setting range, lateral tilt angle setting threshold, longitudinal tilt angle setting threshold in S2, and the beam lowering synchronization error threshold and tilt angle change rate threshold in S4. With the goal of minimizing the comprehensive evaluation indicator, the optimal values ​​of the vertical distance setting range, lateral tilt angle setting threshold, longitudinal tilt angle setting threshold in S2, and the beam lowering synchronization error threshold and tilt angle change rate threshold in S4 are calculated.

9. The integrated construction method for T-beam transportation and erection as described in claim 8, characterized in that, The construction parameters and corresponding comprehensive evaluation indicators from the construction logs of multiple completed T-beams are used as training samples. The set ranges and thresholds in S2 and S4 are used as parameters to be optimized. A Gaussian process surrogate model from the parameters to be optimized to the comprehensive evaluation indicators is established using the Bayesian optimization algorithm. Then, the surrogate model is iteratively optimized multiple times through the acquisition function. In each iteration, the parameter combination that maximizes the acquisition function is selected as the candidate parameter combination for the next iteration. The comprehensive evaluation indicators corresponding to the candidate parameter combinations are verified in actual construction. The verification results are updated to the training samples to retrain the surrogate model until the improvement of the comprehensive evaluation indicators is less than the preset convergence threshold, and the optimal parameter combination is finally obtained.

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