Space variable curve bridge multi-body cooperative incremental launching construction method and system

Abstract

The application discloses a kind of space variable curve bridge multi-body cooperative incremental launching construction method and system, belong to bridge engineering technical field.The long distance integral deviation is converted into short section controllable deviation by partitioning hinge, and the multi-span long-association bridge is combined into integral incremental launching using hinge structure, which greatly reduces guide beam and temporary support;The incremental launching equipment with active transverse movement capability is used, and the beam body posture is obtained in real time through Beidou RTK high-precision positioning, combined with design linear lofting, dynamically calculates the theoretical position of web, realizes the automatic alignment of incremental launching equipment and beam body web;During the incremental launching process, based on the spatial rigid body transformation, the local positioning instruction of each jack is calculated according to the real-time posture of the beam body, to ensure the overall linear precision.The application realizes active control and high-precision automatic positioning of transverse deviation, avoids deviation accumulation, and is suitable for complex environments such as bridge operation traffic and ecological protection area, with significant social benefits and broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to a multi-body collaborative jacking construction method and system for spatial variable curve bridges. Background Technology

[0002] Bridge launching is a method of assembling precast beam segments one by one at the bridgehead and then using jacks and other equipment to push them forward along the bridge axis into place. This method has advantages such as not interrupting traffic below the bridge, requiring no large amount of scaffolding, and ensuring construction safety, and is widely used in the construction of bridges spanning rivers, roads, and urban viaducts. Traditional launching technology is mainly used for straight or single-curve bridges. However, when the bridge alignment is a spatial curve, launching faces a fundamental contradiction: the direction of force applied by the launching equipment does not coincide with the bridge's design alignment. Specifically, the launching equipment typically applies thrust in a straight line, while the beam to be launched needs to move along a complex spatial curve to finally be in place. This contradiction leads to the following key technical problems: 1. Deviation between the launching path and the designed beam alignment During long-distance jacking, the beam is forced to move along an approximately straight line, while the design alignment requires the beam to ultimately land on a spatial curve. This inevitably leads to lateral displacement of the beam during jacking, meaning the beam's centerline deviates from the pier's centerline (or temporary pier's centerline). When the displacement is too large, the beam's web may detach from the jacking equipment's support range, causing eccentric stress, localized stress concentration, or even structural instability.

[0003] 2. Misalignment between the jacking equipment and the beam support position The beam typically transfers loads to the launching equipment through its web. On curved sections, the beam needs constant orientation adjustments, causing lateral movement of its web relative to the fixed launching equipment. If this movement exceeds the launching equipment's permissible lateral adjustment range (usually limited by the space at the pier top), it can lead to deflection or misalignment, severely impacting launching safety.

[0004] 3. Traditional segmented jacking requires a large number of guide beams and temporary supports. In conventional jacking construction, to reduce the cantilever length, guide beams are usually installed at the front end of each beam segment, and temporary piers are set up between spans. For multi-span long bridges, if jacking is done segment by segment, guide beams need to be installed and removed for each segment, and temporary supports need to be set up underneath. When the bridge is located above an operating highway, railway, or ecologically sensitive area (such as a water source or nature reserve), setting up temporary piers is often not feasible, and the construction risk is extremely high.

[0005] 4. Sudden changes in local stress when crossing the pier When the joints between beam segments (such as hinge points) pass over piers, the contact area between the bottom of the beam and the jacking equipment changes suddenly due to the gap width and angle between adjacent beam segments, which can easily cause impact and local overload. At the same time, there is a risk of collision at the gaps between beam segments.

[0006] 5. Challenges in multi-point, multi-device collaborative control Long-distance jacking involves the coordinated operation of dozens or even hundreds of jacking devices. Under spatial curvature conditions, the displacement paths of each jacking point differ, and traditional constant-velocity synchronous control cannot meet the requirements. Existing positioning methods mostly rely on manual experience or simple coordinate transformations, which are inefficient, inaccurate, and cannot directly generate equipment control commands.

[0007] While existing technologies employ conventional methods such as multi-point synchronous jacking and guide beam assistance, they lack systematic solutions. For example, conventional lateral correction only passively adjusts after deviation occurs, failing to fundamentally control the generation and accumulation of deviation; fixed connection devices between segments cannot adapt to curve changes; manual adjustment calculations are time-consuming, error-prone, and difficult to achieve closed-loop control throughout the entire process. Therefore, there is an urgent need for a jacking construction method that can actively adapt to changes in spatial curves, effectively control lateral deviation, significantly reduce guide beams and temporary supports, and achieve high-precision automated control. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a multi-body collaborative jacking construction method and system for spatial variable-curve bridges. This method divides the entire bridge into several relatively rotatable segments, connects them using hinges to form a unified jacking system, and utilizes jacking equipment with active lateral movement capabilities and automatic alignment technology based on BeiDou high-precision positioning, combined with a cluster adjustment algorithm for the jacking equipment. This ensures that the centerline of the beam remains close to the designed spatial curve during the jacking process, while simultaneously ensuring that the web of the beam is always aligned with the support center of the jacking equipment. This invention achieves active control and high-precision automatic adjustment of lateral deviation, avoiding deviation accumulation. It is suitable for complex environments such as under-bridge traffic and ecological protection zones, and has significant social benefits and broad application prospects.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a multi-body coordinated jacking construction method for spatial variable curve bridges, comprising the following steps: The entire bridge is divided into several sections of beam body; The first section of the beam is pushed using a jacking device. The next section of the beam is then transported to the assembly platform. A hinged connection structure is installed at the preset position to match and connect with the already pushed beam. The beam is pushed for one section length. This process is repeated until all sections of the beam are pushed to the design position. Before pushing the beam, the jacking device is aligned with the web of the beam. The beam was finally repositioned as a whole, all hinged connections were removed, and the staged beam lowering and permanent support installation were completed.

[0010] As a preferred embodiment of the present invention, the alignment of the adjusting jacking device with the web of the beam includes: The actual position of the beam centerline and the actual position of the launching equipment are obtained. Then, the actual position of the web centerline is obtained by offsetting the geometric parameters of the beam cross section. The actual position of the web centerline is compared with the actual position of the launching equipment to calculate the lateral deviation. The launching equipment is then controlled to actively move laterally to achieve automatic alignment with the web of the beam.

[0011] As a preferred embodiment of the present invention, the method for obtaining the actual position of the beam centerline includes: A positioning device is installed at the center line of each end of the beam in each section to collect the three-dimensional coordinates of the center points at both ends of the beam in real time. Based on the current spatial positions of the two measuring points and the known geometric model of the beam, the actual position of the beam's centerline in the global coordinate system can be calculated.

[0012] As a preferred embodiment of the present invention, the method for obtaining the actual position of the jacking device includes: A distance measuring sensor is installed on each jacking device to measure the relative distance between the jacking device and a known monitoring point on the pier in real time. Combined with the pre-calibrated global coordinates of the monitoring point, the actual position of the jacking device in the global coordinate system is calculated.

[0013] As a preferred technical solution of the present invention, during the jacking process of the beam, the beam's posture is actively adjusted to ensure that the overall shape of the beam always closely approximates the design curve, including: Obtain the three-dimensional coordinates and installation deflection angle of each jacking device in the global coordinate system, as well as the measured coordinates of multiple measuring points on the beam in the current attitude and the theoretical coordinates in the design target attitude; Based on the measured coordinates and theoretical coordinates, the overall translation vector is calculated, and the coordinates of the measured points are decentered. The initial value of the rotation matrix is ​​obtained by using singular value decomposition, and then the optimal rotation matrix is ​​obtained by iterative refinement through Euler angle parameterization and gradient descent. The overall translation vector and the optimal rotation matrix are applied to each jacking device to obtain the target position and global displacement vector of each jacking device in the global coordinate system. Based on the installation offset angle of each jacking device, the global displacement vector is converted into a three-way adjustment command for each jacking device in its local coordinate system, and the adjustment is executed.

[0014] As a preferred technical solution of the present invention, the arrangement of multiple measuring points on the beam is as follows: several characteristic sections are selected along the beam length, and measuring points are arranged on the left, middle and right sides of each section. All measuring points of all sections together constitute a set of measuring points for attitude calculation.

[0015] As a preferred technical solution of the present invention, the method for calculating the overall translation vector is as follows: calculate the centroid of the measured coordinates of the current attitude of all measuring points and the centroid of the theoretical coordinates of the target attitude respectively, and take the difference between the two centroids as the overall translation vector.

[0016] As a preferred technical solution of the present invention, the method of decentralization is as follows: subtract the current centroid from each current posture measured coordinate, and subtract the target centroid from each target posture theoretical coordinate to obtain the decentralized point set.

[0017] As a preferred technical solution of the present invention, the method of solving the initial value of the rotation matrix by singular value decomposition includes: constructing the covariance matrix of the current point set and the target point set after decentralization, performing singular value decomposition on the covariance matrix, calculating the initial value of the rotation matrix based on the decomposition result, and if the determinant of the initial value of the rotation matrix is ​​negative, then correcting it to a rigid body rotation matrix.

[0018] As a preferred technical solution of the present invention, the method for obtaining the optimal rotation matrix through Euler angle parameterization and gradient descent iterative refinement includes: parameterizing the rotation matrix using ZYX Euler angles, defining the loss function as the square of the average Euclidean distance between the current point and the target point after rotation, using the Euler angles corresponding to the initial value of the rotation matrix obtained by singular value decomposition as the initial value of iteration, and iteratively optimizing using the adaptive learning rate momentum gradient descent method until the loss function is less than a preset threshold, or the maximum number of iterations is reached, or the gradient norm is less than the preset threshold multiple times consecutively, thereby obtaining the optimal rotation matrix and the corresponding Euler angles.

[0019] As a preferred technical solution of the present invention, after obtaining the optimal rotation matrix, error closed-loop verification is also performed: the overall translation vector and the optimal rotation matrix are applied to all beam measuring points, the theoretical position of each measuring point after transformation is calculated, and compared with the theoretical coordinates of the target posture, and the global root mean square error and the maximum single-point error are calculated; when any error exceeds the preset engineering allowable error threshold, the system issues a prompt.

[0020] As a preferred technical solution of the present invention, the method for converting the global displacement vector into a three-dimensional adjustment command in a local coordinate system is as follows: construct a local rotation matrix according to the installation deviation angle of each jacking device, multiply the global displacement vector by the transpose of the local rotation matrix to obtain the longitudinal displacement along the jacking direction, the lateral correction amount perpendicular to the jacking direction, and the vertical displacement.

[0021] As a preferred technical solution of the present invention, the output of the three-way adjustment command adopts a three-level output system: the core command layer outputs the number of each jacking device and the local three-way adjustment amount in tabular form; the auxiliary parameter layer outputs the overall translation vector, rotation Euler angle and rotation matrix; and the metadata layer outputs the global root mean square error, the maximum single-point error and data acquisition time information; the output format includes at least one of CSV, TXT and JSON.

[0022] As a preferred technical solution of the present invention, the jacking device is a walking jacking device, which has three-way adjustment functions of vertical jacking, longitudinal jacking, lateral correction and large-range active lateral movement; wherein, the active lateral movement range is ≥ ±500mm, the lateral correction cylinder thrust is ≥ 800kN and the stroke is ≥ 60mm.

[0023] As a preferred technical solution of the present invention, when the gap at the connection of the beam segment passes through the pier, the gap is crossed by increasing the contact area between the jacking device and the beam or by using multiple micro-stroke jacking methods.

[0024] As a preferred technical solution of the present invention, the step of using a jacking device to complete the jacking operation of the first beam segment includes: setting a guide beam at the front end of the first beam segment, setting an upper pier guide section at the front end of the guide beam that is higher than the bottom of the main body of the guide beam, and when the front end of the guide beam approaches the pier, the jacking device on the pier is vertically lifted to contact the upper pier guide section, and the jacking device moves forward to drive the guide beam and the first beam segment to move forward synchronously until the guide beam and the first beam segment are completely on the pier.

[0025] As a preferred technical solution of the present invention, for cases where there are changes in beam height within the same beam section, adjustable height pads are installed on the top of the jacking equipment to keep the bottom of beam sections of different heights at the same horizontal plane during the jacking process. For cases where there is a change in beam height between two adjacent beam segments, a raised pad is added at the root of the hinge connection structure to control the bottom of the two adjacent beam segments to remain on the same horizontal plane during the jacking process.

[0026] As a preferred technical solution of the present invention, before the jacking construction, a step-by-step numerical simulation is performed on the entire jacking process of the bridge to generate the pier height-mileage curve, the lateral deviation-mileage curve of each jacking point, the beam segment gap-mileage curve, and the stress envelope diagram of key working conditions, which serve as the preset control command set for the jacking process.

[0027] Secondly, the present invention provides a multi-body collaborative jacking system for spatially variable-curve bridges to realize the construction method described above, comprising: Multiple hinged connection structures are used to form a connection between adjacent beam sections that can rotate relative to each other and have limited translational motion, and to transmit vertical shear force during the jacking process; Multiple jacking devices are arranged on each pier along the jacking direction, and have the functions of vertical jacking, longitudinal jacking, lateral correction and active lateral movement, which are used to jack the integral beam formed by the hinged connection structure in series. The positioning monitoring module includes a positioning device installed on the beam and a position feedback device installed on the jacking equipment, which is used to acquire the beam's attitude and the spatial position of each jacking equipment in real time. The control system is communicatively connected to the positioning monitoring module and all jacking devices, and the control system includes: The alignment management unit is used to generate the theoretical position of the beam at each launching stage based on the bridge design alignment, and to calculate the theoretical position of the web of each launching device based on the real-time beam posture. The cluster positioning calculation unit is used to solve the overall rigid body transformation parameters based on the deviation between the current posture of the beam and the target posture, and to map the overall rigid body transformation parameters to each jacking device to generate a three-way positioning command for each jacking device in its local coordinate system. The execution control unit is used to control the corresponding jacking device to perform lateral centering, jacking, jacking and correction actions according to the three-way adjustment command; The control system is configured to: before each jacking stroke or after each preset mileage interval, based on the latest positioning monitoring data, drive the jacking equipment to actively move laterally and align with the web of the beam, and during the jacking process or at a preset cycle, call the cluster adjustment calculation unit to dynamically correct the overall posture of the beam, so that the centerline of the beam always approaches the design space curve.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Actively control lateral deviation and ensure support alignment: By setting hinges in sections, the cumulative deviation is decomposed into short-segment controllable deviations. Combined with the jacking equipment with active lateral movement capability and the automatic alignment technology based on Beidou positioning, the deviation between the center line and the design curve of the beam is always controlled within the allowable range during the jacking process. This ensures that the web of the beam is always aligned with the support center of the jacking equipment, fundamentally solving the problem of force eccentricity caused by the non-coincidence of the alignment and path.

[0029] (2) Significantly reduces the number of guide beams and temporary supports, adapting to complex environments: By using hinges to combine multi-span long bridges into a whole for jacking, only guide beams are needed at the beginning and end, eliminating the need to set guide beams at the front end of each segment, and the number of temporary piers is also greatly reduced. This feature makes the present invention particularly suitable for complex environments where the bridge is located under operating highways, railways, ecological protection areas, water sources, etc., where piers cannot be set up, greatly reducing construction risks and interference with existing traffic.

[0030] (3) Automatic alignment by integrating Beidou positioning with design alignment: The attitude of the beam is obtained in real time by using Beidou RTK high-precision positioning. Combined with the design alignment layout, the target position of each jacking device should be aligned with the web is dynamically calculated, and the lateral movement mechanism is automatically controlled to perform alignment. This achieves continuous alignment between the support point and the web during the jacking process, avoiding abnormal force caused by the accumulation of deviation.

[0031] (4) High-precision, fully automatic cluster positioning: The matching jacking equipment cluster positioning algorithm adopts a hybrid optimization strategy of SVD initial estimation + gradient descent fine adjustment, realizing the automatic solution from beam posture to local instructions of individual jacking equipment. It not only utilizes the global analytical capability of SVD to avoid local optima, but also eliminates the influence of measurement noise through gradient descent fine adjustment. The theoretical error can be controlled within 1mm, and the calculation time is in the second level, which greatly improves the level and efficiency of construction digitization and fully meets the requirements of engineering precision control.

[0032] (5) Achieving a smooth transition over piers on curved sections: By increasing the contact area and using micro-stroke crossing technology, the problem of discontinuous force when beam segments pass over piers was solved, eliminating the risk of impact and separation. Gap pre-simulation and real-time monitoring effectively prevented collision accidents.

[0033] (6) High level of intelligence: The monitoring system based on digital twins realizes closed-loop management of perception-analysis-decision-control. The cluster positioning algorithm can automatically calculate the adjustment amount of each jacking device. The cluster control system automatically executes control commands, which greatly reduces manual intervention and improves construction efficiency and safety.

[0034] (7) Promoting the comprehensive upgrade of jacking technology with broad application prospects: This invention breaks through the limitation of existing jacking technology being only applicable to straight lines or single curves, extending its adaptability to multi-span long-distance and large-span bridges with arbitrary complex spatial alignments. The resulting technical system and high-end equipment can solve common engineering construction problems in important channels such as the Yellow River ecological protection area, long bridges across rivers and seas (replacing the high-risk bridge erection machine method), and bridges crossing operational railways. The research results will be directly applied to urban high-constraint environment projects represented by highway reconstruction and expansion, realizing the efficient construction of multi-span long-distance variable curve bridges under extremely limited site conditions, meeting extremely high safety standards (especially for overpasses of operational traffic) and green environmental protection construction requirements, with significant social benefits. At the same time, it promotes the upgrade of jacking technology to less-manned, unmanned intelligent monitoring and collaborative control, enhancing the core competitiveness of enterprises. Attached Figure Description

[0035] Figure 1 This is a process flow diagram of a multi-body collaborative jacking construction method for a spatial variable curve bridge according to the present invention.

[0036] Figure 2 This is a schematic diagram of the connection structure after adding a raised pad at the root of the hinge connection structure of the present invention.

[0037] Figure 3 This is a schematic diagram of the bridge jacking section and hinge design of the present invention.

[0038] Figure 4 This is a schematic diagram of the automatic alignment principle of the abdominal plate based on BeiDou positioning.

[0039] In the diagram: 1. Beam; 2. Hinged connection structure; 201. Pad. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present patent. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present patent.

[0041] This invention addresses the core problems in the jacking construction of spatially variable curve bridges, such as lateral deviation, support misalignment, excessive temporary facilities, abrupt changes in pier stress, and difficulties in cluster control caused by the misalignment of the design alignment and jacking path. It proposes a multi-body collaborative jacking construction method and system. This method transforms long-distance overall deviation into short-segment controllable deviation by using partitioned hinges. It utilizes hinge structures to achieve the overall jacking of multi-span long-connected bridges. Combined with walking-type jacking equipment with active lateral movement capabilities, BeiDou RTK high-precision positioning technology, and a jacking equipment cluster positioning algorithm based on spatial rigid body transformation, it achieves active control of the beam alignment and intelligent construction throughout the entire process.

[0042] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0043] The overall flow of the multi-body collaborative jacking construction method for spatial variable curve bridges of the present invention is as follows: Figure 1 As shown, it mainly includes the following seven core steps: Step 1: Adaptive Partitioning of Spatial Curves Based on Offset Control This step is fundamental to solving the problem of lateral deviation in spatial curve jacking. The core idea is to decompose the long-distance cumulative deviation into multiple short-segment controllable deviations through reasonable partitioning.

[0044] 1.1. Partitioning Principles and Methods Based on the spatial curve characteristics of the bridge, including the horizontal curve radius, transition curve parameters, vertical curve radius, and longitudinal slope changes, finite element software was used to perform step-by-step numerical simulations of the entire bridge jacking process. During the simulation, the maximum lateral deviation of each beam segment 1 under different zoning schemes was calculated to ensure that the maximum lateral deviation within each segment does not exceed the allowable value of the lateral adjustment capacity of the jacking equipment. Zoning should prioritize setting zoning boundaries at points of curve radius change, longitudinal slope change, beam height change, and pier locations. For complex alignment bridges such as S-shaped and M-shaped bridges, hinges can be added within the span to further reduce the length of a single segment and lower the difficulty of deviation control.

[0045] 1.2. Design of Hinged Connection Structure like Figure 2 As shown, a hinged connection structure 2 is installed at the boundary of each section. During the jacking process, the hinged connection structure 2 allows relative rotation and limited translation between adjacent beam sections, while reliably transmitting vertical shear force, thus combining the multi-span long-connected bridge into a single unit for jacking. During the jacking process, the bridge's angle changes are adapted to different jacking conditions, making it suitable for complex and curved jacking routes. After jacking to the desired position, the hinged connection structure is removed, and the beam sections are connected by welding or bolting to form a permanent continuous beam. The hinged connection structure 2 is prior art, and its specific structure is referenced in patent CN121802748A.

[0046] 1.3 Numerical Simulation Pre-analysis Before the jacking operation, a detailed step-by-step numerical simulation of the entire jacking process of the bridge is required to generate the following key control curves and charts as the preset control command set for the jacking process: The pier height-mileage curve is used to guide the adjustment of the pier top pad height at different jacking stages; the lateral deviation-mileage curve at each jacking point is used to predict the lateral deviation trend at each stage; the beam segment gap-mileage curve is used to guide the micro-stroke control when the hinge passes over the pier; the stress envelope diagram of key working conditions includes the stress distribution of the main beam, guide beam, hinge structure and temporary pier; the support reaction force variation curve is used to monitor the load distribution during the jacking process.

[0047] Step 2: Integration and Deployment of the Jacking System and Establishment of BeiDou Positioning Reference 2.1 Selection and Layout of Jacking Equipment Walking-type jacking equipment is installed on the top of each permanent and temporary pier. Each set of equipment has three-way adjustment functions: vertical jacking, longitudinal jacking, lateral correction, and large-range active lateral movement.

[0048] The key performance parameters of the walking-type jacking equipment are as follows: Vertical jacking capacity: determined based on the weight of the beam; Longitudinal jacking capacity: determined based on the jacking force calculation; Lateral correction capacity: Lateral correction cylinder thrust ≥ 800kN, stroke ≥ 60mm; Lateral active lateral movement range ≥ ±500mm, which can be extended to ±1000mm for bridges with large curvatures, achieved through sliding guide rails + lateral movement cylinders, and can automatically adjust its position under no-load conditions; Control accuracy: The three-dimensional displacement control accuracy is ±1mm; The arrangement of the jacking equipment should correspond to the position of the beam web, with one jacking device arranged under each web. The jacking equipment is existing technology, and its specific structure refers to patent CN121853470A.

[0049] 2.2. Deployment of the BeiDou Navigation Satellite System Establish a high-precision positioning and monitoring system based on BeiDou RTK technology to obtain the beam attitude and the position of the jacking equipment in real time.

[0050] The system includes the following components: Base station setup: Fixed reference points are set up on permanent and temporary piers for coordinate system calibration. Beam measuring point layout: A BeiDou RTK rover is installed at the centerline of each end (or key section) of the beam to collect the three-dimensional coordinates of the beam end center points in real time (planar accuracy at the centimeter level, elevation accuracy at the millimeter level). Jacking equipment position feedback: A laser rangefinder is installed on each jacking device to measure the relative distance between the jacking device and known monitoring points on the pier in real time. Combined with the pre-calibrated global coordinates of the monitoring points, the actual position of the jacking device in the global coordinate system is calculated with a measurement accuracy of ±1mm. Communication system: A dual-redundant communication network of fiber optic ring network + wireless bridge is adopted to ensure real-time and reliable transmission of BeiDou data and equipment control commands, with a transmission delay ≤100ms.

[0051] 2.3. Establishment of Spatial Feature Model Establish a spatial feature model in the control system that includes the actuator (jacking device) and the controlled object (beam): Enter the number, installation location, installation angle (i.e., the angle between the pushing direction of the jacking equipment and the global X-axis) and performance parameters of all jacking equipment; import the BIM model of the beam, including geometric dimensions, cross-sectional parameters, web position and design alignment; establish the conversion relationship between the global coordinate system and the local coordinate system of each jacking equipment.

[0052] Step 3: Installation of guide beam and initial jacking 3.1. Guide Beam Design and Installation To reduce the cantilever length and front-end deflection during the initial girder launching, a steel guide beam is installed at the front end of the initial girder. The guide beam employs a variable cross-section box girder structure, such as... Figure 3 As shown.

[0053] A guide section is installed at the front end of the guide beam, with its bottom 500mm higher than the bottom of the main body of the guide beam to compensate for the front deflection of the guide beam under maximum cantilever conditions. The guide section adopts a wedge-shaped design to facilitate the smooth placement of the guide beam on the pier.

[0054] 3.2. Initial beam jacking and guide beam placement on piers After the first beam segment is prefabricated on the assembly platform and the guide beam is installed, the first segment's jacking operation begins. The guide beam is jacked up to the pier in a step-by-step manner, with the specific steps as follows: (1) When the front end of the guide beam is about 1m away from the next pier, stop the jacking; (2) The jacking equipment on the pier is vertically jacked up and contacts the upper pier guide section at the front end of the guide beam; (3) The jacking equipment moves forward longitudinally by one stroke (450mm), driving the guide beam and the first section of the beam forward synchronously; (4) The jacking equipment is lowered vertically so that the guide beam rests on the temporary support structure on the top of the pier; (5) Repeat the above steps until the guide beam and the first section of the beam are completely on the pier.

[0055] During the process of placing the guide beam on the pier, the deflection and stress at the front end of the guide beam should be monitored in real time to ensure that they do not exceed the design allowable values.

[0056] Step 4: Multi-body coordinated cyclic pushing After the first section of the beam is pushed out, the multi-body coordinated cyclic pushing stage begins. The following steps are repeated until all sections of the beam are pushed out to the design position.

[0057] 4.1. Beam segment splicing and hinge installation (1) The next section of the beam is transported to the assembly platform by a beam transport trolley; (2) Use a three-way jacking device to precisely adjust the beam body so that the gap and misalignment between the beam end face and the jacked beam end face meet the design requirements; (3) Install the hinge connection structure at the preset position.

[0058] 4.2. Automatic alignment of the web plate based on BeiDou positioning Before each jacking stroke begins, the jacking equipment is automatically aligned with the web of the beam to ensure that the support center of the jacking equipment is aligned with the center of the web of the beam, thus avoiding eccentric stress. The principle of automatic alignment is as follows: Figure 4 As shown, the specific steps are as follows: (1) The control system receives the three-dimensional coordinates of the center points at both ends of the beam collected by the Beidou RTK rover; (2) Based on the spatial position of the two measuring points at the current moment, and combined with the known geometric model of the beam, calculate the actual position of the center line of the beam in the global coordinate system. (3) Based on the cross-sectional geometric parameters of the beam, offset the center line of the beam to both sides by half the distance between the webs to obtain the actual positions of the center lines of the left and right webs. (4) Obtain the actual position of each jacking device in the global coordinate system using a laser rangefinder; (5) Compare the actual position of the web centerline with the actual position of the jacking equipment and calculate the lateral deviation ΔY; (6) If the lateral deviation exceeds the allowable value, the control system sends a command to the lateral movement mechanism of the jacking equipment to make it move laterally by ΔY under no-load, so as to achieve automatic alignment with the web of the beam. (7) After the alignment is completed, the jacking equipment is lifted vertically to make the beam separate from the temporary support structure and pre-jacke the bottom of the beam.

[0059] After each jacking stroke is completed or every 5m interval, the system automatically re-executes the above alignment process to ensure that the support point is always aligned with the web plate throughout the jacking process.

[0060] 4.3. Multi-body coordinated pushing single stroke After all the jacking devices have completed alignment and pre-jacking, the multi-body coordinated jacking is started: (1) The control system simultaneously sends longitudinal pushing commands to all pushing devices, and each device moves forward synchronously at a preset speed; (2) During the jacking process, the jacking force, displacement and support reaction force of each jacking device are monitored in real time to ensure that each device is subjected to uniform force; (3) When the longitudinal stroke of the jacking equipment reaches the design value, all equipment shall stop jacking simultaneously; (4) The jacking equipment is lowered vertically so that the beam rests on the temporary support structure; (5) Repeat the above steps until the jacking of one section of the beam is completed.

[0061] 4.4. Positioning of the jacking equipment cluster During the jacking process or after each certain number of strokes, it is necessary to dynamically correct the overall posture of the beam to ensure that the overall shape of the beam always closely approximates the design curve. This invention employs a cluster positioning technology for jacking equipment based on spatial rigid body transformation. The specific calculation method is as follows: 4.4.1. Data Acquisition (1) Data collection at the execution level Obtain the three-dimensional coordinates of the left and right jacking devices at each pier position in the global coordinate system. and the direction of the jacking equipment's advance and the overall situation Angle between axes (This refers to the installation offset angle of the jacking equipment, measured in degrees, with the global X-axis as the reference, counterclockwise being positive and clockwise being negative, obtained through total station measurements.) The global coordinate system is defined as follows: X-axis represents the longitudinal direction of the bridge design, Y-axis represents the horizontal direction, and Z-axis represents the vertical direction. This offset angle defines the orientation of the jacking equipment's local coordinate system and is a key parameter for subsequently converting global displacement into recognizable commands.

[0062] (2) Data acquisition at the controlled object level Select one along the beam length (i.e., the longitudinal axis of the beam). The characteristic cross-section should represent the spatial linear and torsional deformation characteristics of the beam. It is typically selected at key sections such as jack support locations, joints between adjacent beam segments, mid-span, or quarter-span points. Each cross-section is marked with a left-side point. ,midpoint Right side point Three measuring points. Record all. Measured coordinates of each measuring point under the current attitude And the theoretical coordinates under the design target attitude. .

[0063] (3) Automatic data verification The system checks the completeness of the input data (not empty, valid values), the consistency of units, and the matching of the number of measurement points (the number of current points and target points must be equal) to ensure the data quality of subsequent calculations.

[0064] Traditional methods often focus only on the coordinates of the beam itself, neglecting the differences in the position and orientation of the jacking equipment positioned above different jacking piers. This invention, for the first time, incorporates the jacking equipment as an independent spatial entity into the computational model, making subsequent overall transformations to local mappings possible and fundamentally solving the problem of the disconnect between the beam's attitude and the jacking equipment's movements. Simultaneously, the cross-sectional layout of the measuring points conforms to the measurement habits of bridge engineering, facilitating rapid on-site data acquisition.

[0065] 4.4.2. Translation-Rotation Decoupling The goal of this step is to solve a rigid body spatial transformation that aligns the current point set with the target point set. This transformation contains six independent components in three-dimensional space: three translations along the X, Y, and Z axes, and three rotations about the X, Y, and Z axes (i.e., six-DOF rigid body motion). Solving for these six parameters directly would involve a highly nonlinear coupled optimization problem, which is computationally complex and physically ambiguous. Therefore, this invention decouples translation and rotation, first solving for the global translation vector independently, and then solving for the rotation matrix separately. This decomposition strategy compresses the original six-dimensional search problem into a three-dimensional rotation space problem, significantly reducing computational complexity and improving robustness; specifically including: (1) Calculate the geometric centroid Current centroid: C C The geometric center of all measurement points in the current attitude. ; Target centroid: C t The geometric center of all measurement points under the target attitude is . ; The centroid is the geometric center of the set of points, which intuitively reflects the average position of the beam in space.

[0066] (2) Solve for the global translation vector ; Global translation vector This vector represents the total amount of movement (longitudinal, lateral, vertical) required for the beam to move from its current position to the target position. Its physical meaning is clear, and this vector will be used in subsequent steps to calculate the global displacement of the jacking equipment.

[0067] (3) Decentralization of point sets ; By translating the two point sets to near their respective centroids, the combined translation and rotation problem is simplified to a pure rotation alignment problem around the origin. This step removes the translation component from the overall transformation, leaving the remaining point set differences consisting only of the rotation component. Thus, subsequent step three focuses solely on solving the pure rotation matrix, eliminating the need to consider translation. Furthermore, subtracting the centroid reduces the numerical coordinates of each point to a relative order of magnitude, avoiding ill-conditioned matrix problems caused by large number calculations.

[0068] 4.4.3. Solving for the rotation matrix The purpose of this step is to find the optimal rotation matrix R. This invention employs a two-layer optimization strategy combining initial estimation using Singular Value Decomposition (SVD) with fine-tuning using gradient descent, balancing global convergence and local accuracy. This operation decouples the translation and rotation components, so only the pure rotation alignment problem needs to be addressed subsequently. The steps include: (1) Global optimal initial value solution based on SVD Construct the covariance matrix of the decentralized point set: ; right Perform singular value decomposition: ; The initial analytical value of the rotation matrix is: ; like (Indicating reflection is involved, which does not conform to rigid body rotation), then it is corrected to: ; Where U and V are the left singular vector matrix and the right singular vector matrix, respectively.

[0069] The SVD method provides a global analytical solution in the least squares sense, avoiding the dependence on initial values ​​in iterative algorithms and ensuring the robustness of the algorithm. This initial value is close to the actual rotation, providing a good starting point for subsequent refinement.

[0070] (2) Local refinement based on gradient descent To further improve accuracy, we need to start from R0 and perform local refinement through iterative optimization, and introduce a loss function L.

[0071] Use the rotation matrix ZYX Euler angles Parameterization: ; The loss function is defined as the squared average Euclidean distance between the current point and the target point after rotation: ; by The corresponding Euler angles are used as initial values, and the adaptive learning rate momentum gradient descent method is used for iterative optimization: ; ; ; Among them, g (k) Let be the gradient direction at step k. Indicates element-wise multiplication, v (k) Let v be the momentum term at the k-th iteration, with an initial value of v. (0) =0; , β This is the momentum coefficient used to accelerate gradient descent convergence (it can be taken as 0.09~0.99). This is the adaptive learning rate at the k-th iteration (dynamically adjusted based on gradient history).

[0072] gradient It can be calculated analytically using the chain rule, for example: ; Iteration termination condition (any one of the following is sufficient): 1) The loss function value is less than a preset threshold; 2) Reach the maximum number of iterations; 3) The gradient norm is less than the threshold multiple times consecutively.

[0073] Finally, the optimal rotation matrix is ​​obtained. and the corresponding Euler angles .

[0074] In solving the rotation matrix, SVD provides a global view to avoid local optima, while gradient descent fine-tunes in the local space to achieve higher accuracy; the two complement each other. Dynamically adjusting the learning rate balances computational efficiency and accuracy, keeping the number of iterations to the hundreds while maintaining precision.

[0075] 4.4.4. Spatial Transformation and Error Closure The purpose of this step is to apply the obtained optimal rotation matrix R to all beam measuring points, calculate the theoretical target position, and evaluate the adjustment accuracy through multi-dimensional error indicators, forming a closed loop of forward transformation and reverse verification.

[0076] Perform a complete rigid body transformation on all beam measuring points: ; Calculate three core error metrics: 1) Global root mean square error ( ): This is used to reflect the overall positioning accuracy.

[0077] 2) Maximum single-point error ( ): It is used to identify local out-of-tolerance risks.

[0078] 3) Directional Error: Calculate the deviation of the normal direction of each cross-section to assess whether the beam is torsion. Specifically, this involves extracting three transformed measurement points belonging to the same cross-section and three target measurement points. For each group of three points, a spatial plane is fitted by solving a system of linear equations to obtain the normal vector of the transformed plane and the normal vector of the target plane. The directional error is defined as the angle between the two normal vectors. This index is used to assess whether the beam is torsion, and the final directional error is the maximum value among all cross-sections.

[0079] Preset engineering allowable error threshold (e.g., 5mm), when or When the threshold is exceeded, the system will automatically prompt the user to check the input data or consider a second adjustment.

[0080] This invention introduces a closed-loop verification mechanism for the first time, ensuring the reliability of calculation results and preventing construction errors caused by measurement mistakes or algorithm malfunctions. Single indicators may mask local problems; this invention provides multi-dimensional error information, offering a comprehensive basis for on-site decision-making. Error data can be output along with the results for quality traceability and process improvement.

[0081] 4.4.5. Generation of Positioning Command for the Pricing Equipment The purpose of this step is to transfer the overall spatial transformation of the beam to each launching device and convert it into local coordinate system commands that can be directly used for device control based on its installation direction.

[0082] (1) Calculation of the target position of the jacking equipment ; Where R is the optimal rotation matrix. This is the current position of the jacking equipment. The target position for the jacking equipment.

[0083] (2) Solving for the global displacement vector ; This vector represents the direction and distance that the pushing device needs to move in the global coordinate system.

[0084] (3) Local coordinate system transformation ; in This refers to the installation offset angle of the jacking device.

[0085] The physical meaning of the output: Displacement along the jacking direction of the jacking equipment (main jacking stroke); : Horizontal displacement perpendicular to the jacking direction (lateral correction amount). Vertical displacement.

[0086] By installing a precise projection of the offset angle, the abstract global displacement is transformed into a local motion that the equipment can recognize. The adjustment amount in the output local coordinate system is the control command for the walking jacking device, eliminating the need for manual secondary calculation and eliminating errors at the source.

[0087] 4.4.6. Result Output The purpose of this step is to deliver the final calculation results in a clear and standardized format, making it easy for users at different levels to use and supporting integration with external systems.

[0088] A three-level output system is adopted: 1) Core command layer: List the number of each jacking device and its local three-way adjustment amount in tabular form. The unit is uniformly millimeters (mm), which can be directly used for construction briefings and equipment input.

[0089] 2) Auxiliary parameter layer: provides the overall translation vector Euler angles of rotation Rotation matrix This is provided for the technical supervisor to review and archive.

[0090] 3) Metadata layer: (Included) Maximum single-point error Information such as data collection time, number of piers, and number of cross-sections is used for quality traceability and process recording.

[0091] Export in multiple formats: 1) CSV: Can be directly imported into the control system of walking jacking equipment to achieve seamless connection between calculation and application.

[0092] 2) TXT: Convenient for document archiving and printing.

[0093] 3) JSON: Supports integration with other information systems (such as BIM and construction management platforms).

[0094] The calculation results can be highlighted on the webpage, and support one-click selection and copying, as well as screenshot saving, making it easy to integrate into construction handover documents. It can also be combined with a 3D visualization module to visualize abstract data.

[0095] The calculation results employ a three-tiered output system to cater to the diverse needs of frontline operations, technical review, and quality management. The versatility of the output results adapts to various application scenarios, enhancing the software's usability and promotional value. Visual aids are used to strengthen user trust and lower the barrier to understanding.

[0096] 4.5. Micro-stroke crossing of the pivot pier When the gap at the connection of beam segments passes through the pier, the contact area between the bottom of the beam and the jacking equipment changes abruptly due to the gap width and angle between adjacent beam segments, which can easily cause impact and local overload. To solve this problem, the following micro-stroke crossing technology is adopted: (1) Install an extended top cap on the jacking equipment to increase the contact area with the bottom of the beam. The contact length should be greater than twice the gap between the beam segments.

[0097] (2) Decompose a single push stroke into multiple micro strokes (e.g., decompose 450mm into 11 micro strokes of about 40mm each).

[0098] (3) After each micro-stroke is completed, the jacking equipment is kept in a vertical jacking state to ensure that the bottom of the beam is always in contact with the jacking equipment.

[0099] (4) Monitor the changes in the gap between beam segments in real time by using a wire displacement sensor. When the gap is about to pass the jacking device, further reduce the micro-stroke length to 10-20mm.

[0100] (5) After the gap has completely passed through the jacking equipment, resume the normal jacking stroke.

[0101] Step 5: Adaptive Adjustment and Linear Dynamic Control of the Rotary Hinge During the jacking process, the hinged connection structure can automatically adapt to changes in the relative rotation angle between adjacent beam segments without manual intervention. At the same time, the monitoring system based on digital twins periodically (e.g., every 10m of jacking) calls the jacking equipment cluster positioning algorithm to calculate the overall correction command based on real-time monitoring data, and actively adjusts the beam posture to ensure that the overall beam shape always closely approximates the design space curve.

[0102] For situations where there are variations in beam height within the same beam segment, adjustable height pads are installed on the top of the jacking equipment to ensure that the bottom of beam segments of different heights remains at the same horizontal level during the jacking process.

[0103] For situations where there is a change in beam height between two adjacent beam segments, a raised support 201 is added at the root of the hinged connection structure to ensure that the bottom of the two adjacent beam segments remains at the same horizontal plane during the jacking process. For example... Figure 2 As shown.

[0104] Step Six: Final Positioning and Beam Placement (1) After all sections of the beam are pushed to the design position, the final overall adjustment and beam lowering operation shall be carried out: (2) The jacking equipment cluster positioning technology was used again for the final overall positioning to precisely adjust the beam to the design position; (3) Install permanent supports and perform precise alignment and fixation; (4) The beams are lowered using a graded synchronous beam lowering method; (5) During the beam lowering process, the reaction force at each support point is monitored in real time, and the reaction force deviation is controlled within ±10%; (6) After the beam is lowered, grouting of the permanent support is carried out. After the strength of the grout reaches the design requirements, the jacking equipment is removed.

[0105] Step 7: Dismantling of temporary facilities Temporary facilities such as guide beams, jacking equipment, lifting platforms, beam transport tracks, temporary bridge piers, and Beidou positioning systems were dismantled in sequence, and the construction site was cleaned up to restore the original environment.

[0106] This invention also provides a multi-body collaborative jacking system for spatial variable curve bridges to realize the above-mentioned construction method, comprising: Multiple hinged connection structures: used to form a connection between adjacent beam sections that can rotate relative to each other and have limited translational motion, and to transmit vertical shear force during the jacking process; Multiple jacking devices: Arranged on each pier along the jacking direction, they have vertical jacking, longitudinal jacking, lateral correction and active lateral movement functions, and are used to jack the integral beam body connected in series by hinged connection structure. Positioning and monitoring module: includes a Beidou RTK positioning device deployed on the beam and a laser ranging sensor deployed on the jacking equipment, used to acquire the beam attitude and the spatial position of each jacking device in real time; Control system: Communicates with the positioning monitoring module and all jacking equipment, including: Linearity Management Unit: Used to generate the theoretical position of the beam at each launching stage based on the bridge design alignment, and to calculate the theoretical position of the web of each launching device based on the real-time beam posture. Cluster positioning calculation unit: It is used to solve the overall rigid body transformation parameters based on the deviation between the current attitude of the beam and the target attitude, and to map the overall rigid body transformation parameters to each jacking device, and generate the three-way positioning command of each jacking device in its local coordinate system; Execution control unit: used to control the corresponding jacking equipment to perform lateral centering, jacking, jacking and correction actions according to the three-way adjustment command; The control system is configured to: before each jacking stroke or after each preset mileage interval, based on the latest positioning monitoring data, drive the jacking equipment to actively move laterally and align with the web of the beam, and during the jacking process or at a preset cycle, call the cluster adjustment calculation unit to dynamically correct the overall posture of the beam, so that the center line of the beam always approaches the design space curve.

[0107] Application Cases In a highway reconstruction and expansion project, a new viaduct with a total length of 3.903 km needs to be built within the central median of the existing highway. The bridge's horizontal alignment is S-shaped, including small-radius circular curves (R=700m), transition curves, and circular curves of various radii; the vertical curves are M-shaped, including longitudinal slopes of +0.5%, -0.5%, +0.977%, and -0.508%. The superstructure is a steel box girder, with a standard girder height of 2.5m, a large-span girder height of 3.6m, a bridge deck width of 33.5m, and a total weight of approximately 70,500 tons. The entire bridge consists of 11 spans.

[0108] The specific implementation of the construction method of this invention is as follows: 1. Sectional Hinge Design: Based on the design alignment and jacking simulation results, the entire bridge is divided into 10 jacking sections, each approximately 360-420m long. One set of hinges is installed between each section, with an additional set of internal hinges added between sections six, seven, eight, nine, and ten, for a total of 13 sets of hinges across the entire bridge. Simulations show that the maximum lateral deviation within each section is 706mm, which is less than the 1m lateral adjustment range allowed by the jacking equipment.

[0109] 2. Configuration of jacking equipment: 174 sets of 800t walking jacking equipment are arranged on the pier top and temporary piers. Each set of equipment has: vertical jacking stroke of 300mm and load of 8000kN; longitudinal jacking stroke of 450mm and load of 800kN; lateral correction stroke of 60mm and thrust of 800kN; and lateral active lateral movement range of ±1000mm.

[0110] 3. BeiDou Positioning System Deployment: A BeiDou RTK rover is installed at the centerline of each end of each steel box girder to collect the three-dimensional coordinates of the girder ends in real time. The sampling frequency is 1Hz, with a plane accuracy of ±10mm and an elevation accuracy of ±20mm. Three fixed reference stations are set up on the permanent and temporary piers, and environmental errors are eliminated through differential technology. All BeiDou data is transmitted to the central control system in real time.

[0111] 4. Automatic alignment of the web plate is achieved. After receiving BeiDou RTK data, the central control system dynamically calculates the actual spatial position of the beam's centerline in the global coordinate system based on the current spatial positions of the two measuring points and the known geometric model of the beam. Then, it shifts to both sides according to the web spacing (11m) to generate the actual theoretical centerlines of the left and right webs.

[0112] The current left-side jacking device is located at section K5+420, with coordinates (100.003, 5.005) as provided by laser ranging. Based on BeiDou measurement data, the system calculates the theoretical centerline position of the left web at this section. The shortest distance from the center point of the jacking device to this theoretical web line is calculated, yielding a lateral offset ΔY = +505mm. The control system immediately sends a command to the lateral movement mechanism of the jacking device, causing it to move 505mm to the left under no-load conditions, aligning the support center with the theoretical web line.

[0113] After the lifting and fitting process begins, the jacking begins. After each stroke or 5m interval, the system recalculates the beam attitude and updates the theoretical line of the web based on the latest Beidou data. It also calculates the shortest distance from each jacking device to the corresponding theoretical line of the web and automatically performs lateral alignment to ensure that the support points are always aligned with the center line of the web throughout the process, thus avoiding the problem of web force eccentricity caused by the accumulation of offset.

[0114] 5. Positioning of the jacking equipment cluster The current jacking stage involves adjusting a large steel beam segment supported by four piers, with one jacking device (jack) positioned on the left and right sides of each pier. Two cross-sections (a total of six measuring points) were taken along the beam length. The following data were obtained (unit: m).

[0115] Table 1 Parameters of the jacking equipment Table 2 Current coordinates of measuring points on the beam Table 3 Coordinates of Target Measurement Points on the Beam Translation-rotation solution: Current centroid ; Target centroid ; Translation vector ; Solving for translation-rotation matrices: SVD initially estimates the rotation matrix (Corresponding to Euler angles approximately (0.002°, 0.008°, 0.005°)); After gradient descent refinement ( The optimal rotation matrix is ​​then obtained: ; Corresponding Euler angles .

[0116] Spatial transformation and error closed loop: Calculate the transformation of all measuring points This meets the engineering accuracy requirements.

[0117] Generating the positioning command for the jacking equipment: Table 4 Output Instructions Result verification: The above instructions were input into the walking-type jacking equipment, and the beam coordinates were remeasured after one adjustment. The actual maximum single-point error was 1mm, which verified the accuracy and reliability of the method.

[0118] 6. Monitoring System Deployment 1) Beidou measurement points: set at both ends of each steel box girder to monitor the geometric attitude in real time.

[0119] 2) Wire displacement sensor: placed at each hinge position to monitor the beam segment spacing and angle in real time.

[0120] 3) Laser rangefinder: Installed on each jacking device to monitor the distance between the device and the top of the pier for position feedback.

[0121] 4) Strain gauges: Placed at key locations such as main beam joints, guide beam roots, and pivot brackets.

[0122] 5) Communication network: Dual redundancy of fiber optic ring network + wireless bridge to ensure reliable data transmission.

[0123] 7. Implementation Results During the bridge's jacking process, the maximum lateral deviation was 680mm, which did not exceed the allowable value. The jacking equipment at each pier was always aligned with the web of the beam through Beidou automatic alignment, and there was no force eccentricity. Only the first and last guide beams were needed, reducing the number of temporary piers by 60% compared to the traditional scheme. The completed bridge alignment met the design and specification requirements, with a maximum alignment deviation of only 8mm. The monitoring system achieved intelligent control throughout the entire process, with accurate early warnings and timely responses.

[0124] This invention successfully solves the problem of lateral deviation control in the jacking construction of spatial variable curve bridges by using core technologies such as partitioned hinge design, active lateral displacement alignment, and cluster adjustment control. It significantly reduces the use of guide beams and temporary supports, improves construction efficiency and safety, and has significant economic and social benefits.

[0125] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A multi-body collaborative jacking construction method for spatial variable curve bridges, characterized in that, Includes the following steps: The entire bridge is divided into several sections of beam body; The first section of the beam is pushed using a jacking device. The next section of the beam is then transported to the assembly platform. A hinged connection structure is installed at the preset position to match and connect with the already pushed beam. The beam is pushed for one section length. This process is repeated until all sections of the beam are pushed to the design position. Before pushing the beam, the jacking device is aligned with the web of the beam. The beam was finally repositioned as a whole, all hinged connections were removed, and the staged beam lowering and permanent support installation were completed.

2. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, The alignment of the adjusting jacking device with the web of the beam includes: The actual position of the beam centerline and the actual position of the launching equipment are obtained. Then, the actual position of the web centerline is obtained by offsetting the geometric parameters of the beam cross section. The actual position of the web centerline is compared with the actual position of the launching equipment to calculate the lateral deviation. The launching equipment is then controlled to actively move laterally to achieve automatic alignment with the web of the beam.

3. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 2, characterized in that, The method for obtaining the actual position of the beam's centerline includes: A positioning device is installed at the center line of each end of the beam in each section to collect the three-dimensional coordinates of the center points at both ends of the beam in real time. Based on the current spatial positions of the two measuring points and the known geometric model of the beam, the actual position of the beam's centerline in the global coordinate system can be calculated.

4. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 2, characterized in that, The method for obtaining the actual position of the jacking device includes: A distance measuring sensor is installed on each jacking device to measure the relative distance between the jacking device and a known monitoring point on the pier in real time. Combined with the pre-calibrated global coordinates of the monitoring point, the actual position of the jacking device in the global coordinate system is calculated.

5. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, During the jacking process, the beam's posture is actively adjusted to ensure that its overall shape consistently approximates the design curve, including: Obtain the three-dimensional coordinates and installation deflection angle of each jacking device in the global coordinate system, as well as the measured coordinates of multiple measuring points on the beam in the current attitude and the theoretical coordinates in the design target attitude; Based on the measured coordinates and theoretical coordinates, the overall translation vector is calculated, and the coordinates of the measured points are decentered. The initial value of the rotation matrix is ​​obtained by using singular value decomposition, and then the optimal rotation matrix is ​​obtained by iterative refinement through Euler angle parameterization and gradient descent. The overall translation vector and the optimal rotation matrix are applied to each jacking device to obtain the target position and global displacement vector of each jacking device in the global coordinate system. Based on the installation offset angle of each jacking device, the global displacement vector is converted into a three-way adjustment command for each jacking device in its local coordinate system, and the adjustment is executed.

6. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The arrangement of multiple measuring points on the beam is as follows: select several characteristic sections along the beam length, and arrange measuring points on the left, middle and right sides of each section. All measuring points on all sections together constitute a set of measuring points for attitude calculation.

7. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The method for calculating the overall translation vector is as follows: calculate the centroid of the measured coordinates of the current attitude of all measuring points and the centroid of the theoretical coordinates of the target attitude, and take the difference between the two centroids as the overall translation vector.

8. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The decentralized processing method is as follows: subtract the current centroid from the measured coordinates of each current posture, and subtract the target centroid from the theoretical coordinates of each target posture to obtain the decentralized point set.

9. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The method for solving the initial value of the rotation matrix using singular value decomposition includes: constructing the covariance matrix of the current point set and the target point set after decentralization, performing singular value decomposition on the covariance matrix, calculating the initial value of the rotation matrix based on the decomposition result, and correcting the initial value of the rotation matrix to a rigid body rotation matrix if the determinant of the initial value of the rotation matrix is ​​negative.

10. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The method for obtaining the optimal rotation matrix through Euler angle parameterization and gradient descent iterative refinement includes: parameterizing the rotation matrix using ZYX Euler angles, defining the loss function as the square of the average Euclidean distance between the current point and the target point after rotation, using the Euler angles corresponding to the initial value of the rotation matrix obtained by singular value decomposition as the initial value of iteration, and iteratively optimizing using the adaptive learning rate momentum gradient descent method until the loss function is less than a preset threshold, or the maximum number of iterations is reached, or the gradient norm is less than the preset threshold multiple times consecutively, thus obtaining the optimal rotation matrix and the corresponding Euler angles.

11. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, After obtaining the optimal rotation matrix, error closed-loop verification is also performed: the overall translation vector and the optimal rotation matrix are applied to all beam measuring points, the theoretical position of each measuring point after transformation is calculated, and compared with the theoretical coordinates of the target posture. The global root mean square error and the maximum single-point error are calculated. When any error exceeds the preset engineering allowable error threshold, the system issues a prompt.

12. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The method for converting the global displacement vector into a three-way adjustment command in the local coordinate system is as follows: construct a local rotation matrix based on the installation deflection angle of each jacking device, multiply the global displacement vector by the transpose of the local rotation matrix to obtain the longitudinal displacement along the jacking direction, the lateral correction amount perpendicular to the jacking direction, and the vertical displacement.

13. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 5, characterized in that, The output of the three-way adjustment command adopts a three-level output system: the core command layer outputs the number of each jacking device and the local three-way adjustment amount in tabular form; the auxiliary parameter layer outputs the overall translation vector, rotation Euler angles and rotation matrix; and the metadata layer outputs the global root mean square error, maximum single-point error and data acquisition time information; the output format includes at least one of CSV, TXT and JSON.

14. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, The jacking device is a walking jacking device, which has three-way adjustment functions: vertical jacking, longitudinal jacking, lateral correction, and large-range active lateral movement; wherein, the active lateral movement range is ≥ ±500mm, and the lateral correction cylinder thrust is ≥ 800kN and the stroke is ≥ 60mm.

15. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, When the gap at the connection of the beam segments passes through the pier, the gap can be crossed by increasing the contact area between the jacking equipment and the beam or by using multiple micro-stroke jacking methods.

16. The multi-body coordinated jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, The method of using a jacking device to complete the jacking operation of the first beam segment includes: setting a guide beam at the front end of the first beam segment, setting an upper pier guide section at the front end of the guide beam that is higher than the bottom of the main body of the guide beam, and when the front end of the guide beam approaches the pier, the jacking device on the pier is vertically lifted to contact the upper pier guide section. The jacking device moves forward, driving the guide beam and the first beam segment to move forward synchronously until the guide beam and the first beam segment are completely on the pier.

17. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, For situations where there are variations in beam height within the same beam section, adjustable height pads are installed on the top of the jacking equipment to ensure that the bottom of beam sections of different heights remains at the same horizontal level during the jacking process. For cases where there is a change in beam height between two adjacent beam segments, a raised pad is added at the root of the hinge connection structure to control the bottom of the two adjacent beam segments to remain on the same horizontal plane during the jacking process.

18. The multi-body collaborative jacking construction method for spatial variable curve bridges according to claim 1, characterized in that, Before the jacking construction, a step-by-step numerical simulation of the entire jacking process of the bridge was carried out to generate the pier height-mileage curve, the lateral deviation-mileage curve of each jacking point, the beam segment gap-mileage curve, and the stress envelope diagram of key working conditions, which served as the preset control command set for the jacking process.

19. A multi-body collaborative jacking system for spatial variable-curve bridges implementing the construction method of any one of claims 1-18, characterized in that, include: Multiple hinged connection structures are used to form a connection between adjacent beam sections that can rotate relative to each other and have limited translational motion, and to transmit vertical shear force during the jacking process; Multiple jacking devices are arranged on each pier along the jacking direction, and have the functions of vertical jacking, longitudinal jacking, lateral correction and active lateral movement, which are used to jack the integral beam formed by the hinged connection structure in series. The positioning monitoring module includes a positioning device installed on the beam and a position feedback device installed on the jacking equipment, which is used to acquire the beam's attitude and the spatial position of each jacking equipment in real time. The control system is communicatively connected to the positioning monitoring module and all jacking devices, and the control system includes: The alignment management unit is used to generate the theoretical position of the beam at each launching stage based on the bridge design alignment, and to calculate the theoretical position of the web of each launching device based on the real-time beam posture. The cluster positioning calculation unit is used to solve the overall rigid body transformation parameters based on the deviation between the current posture of the beam and the target posture, and to map the overall rigid body transformation parameters to each jacking device to generate a three-way positioning command for each jacking device in its local coordinate system. The execution control unit is used to control the corresponding jacking device to perform lateral centering, jacking, jacking and correction actions according to the three-way adjustment command; The control system is configured to: before each jacking stroke or after each preset mileage interval, based on the latest positioning monitoring data, drive the jacking equipment to actively move laterally and align with the web of the beam, and during the jacking process or at a preset cycle, call the cluster adjustment calculation unit to dynamically correct the overall posture of the beam, so that the centerline of the beam always approaches the design space curve.

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