Modularized assembly type construction method for pre-assembly jig frame of steel bridge

Abstract

The invention relates to the technical field of bridge construction, and discloses a steel bridge pre-assembly jig frame modular assembly type construction method which comprises the steps that modular truss units are rapidly assembled through variable constraint connection nodes in an under-constraint mode to form an integral flexible jig frame; global self-adaptive positioning is carried out on the flexible jig frame through closed-loop feedback control by utilizing an active reference hydraulic prop unit, so that the pose and the load state of the flexible jig frame approach target values defined by a three-dimensional digital model at the same time, and high-precision in-position and initial stress elimination are realized; and finally, all nodes are synchronously switched to a rigid locking state, and structural stiffening is completed. According to the invention, state self-verification can be carried out on the stiffened structure so as to quantitatively detect the structural performance of the stiffened structure. According to the method, the construction efficiency and precision are remarkably improved and the mounting quality and safety of the jig frame are ensured through the concept of'flexibility first and then rigidity 'and data-driven closed-loop control.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a modular assembly construction method for pre-assembled steel bridge frames. Background Technology

[0002] In the construction of steel structure bridges, segmental pre-assembly is a crucial process. Its purpose is to assemble factory-manufactured bridge segments on the ground using a high-precision temporary support structure (i.e., a pre-assembly jig), to verify the matching accuracy of the interfaces and ensure the elimination of errors before the formal hoisting and docking at high altitude. The construction quality of this jig, especially the accuracy of the spatial orientation of its support points, directly determines the final alignment and quality of the completed bridge.

[0003] Traditional scaffolding construction methods typically rely on high-precision ground surveying and manual adjustments. Construction workers must use surveying equipment such as total stations to repeatedly measure and adjust the support points of the scaffolding, which is composed of steel sections or rods. This process is tedious, time-consuming, and labor-intensive. Furthermore, due to the cumulative effects of manufacturing tolerances of components, on-site measurement errors, and uneven foundation settlement, it is difficult for all support points to simultaneously achieve the globally consistent high precision requirements.

[0004] More importantly, traditional jigs are typically constructed as statically indeterminate rigid structures during assembly. This assembly method forces even the slightest installation errors to be "absorbed" between components, introducing and leaving behind initial installation stresses of unknown value within the structure. These initial stresses not only affect the jig's own load-bearing capacity and stability but also cause minor deformations, further deviating from the designed orientation and ultimately impacting the pre-assembly quality of the steel bridge. Furthermore, current technology lacks an effective means to quantitatively verify whether the overall structural performance of the jig meets design expectations after its construction and before assembly.

[0005] Achieving rapid and high-precision construction of pre-assembled frames and fundamentally eliminating harmful initial installation stresses has become a pressing technical challenge in this field. Therefore, this invention provides a modular prefabricated construction method for steel bridge pre-assembled frames to address the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a modular prefabricated construction method for steel bridge pre-assembly frames, which solves the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides a modular prefabricated construction method for steel bridge pre-assembly frames, comprising the following steps: In the preparation and model parameterization steps, based on the three-dimensional digital model of the steel bridge segment to be assembled, the target geometric pose of all support points on the formwork is extracted, and the theoretical load that each support point should bear under the self-weight of the formwork is calculated using the model. The target geometric pose may specifically include the three-dimensional coordinates and three-axis attitude angles of each support point; the theoretical load can be calculated by establishing a finite element model of the formwork structure and calculating the support reaction vector of each support point under the condition of applying gravity load. In the flexible rapid assembly step of the jig, multiple active reference hydraulic support units are set up on the construction site, and the superstructure is erected using modular truss units. The modular truss units are connected to each other through variable constraint connection nodes at their ends. During the entire assembly stage, all variable constraint connection nodes are in an under-constrained connection state. This state allows for a preset relative rotational degree of freedom between adjacent modular truss units, and its mechanical function is equivalent to a ball joint connection. This method eliminates the need for high-precision alignment during the assembly process, thereby improving construction efficiency and fundamentally avoiding the generation of initial installation stress, ultimately forming an overall flexible jig structure. In the global adaptive positioning step, the flexible frame structure is automatically adjusted in position through the coordinated action of the active reference hydraulic support units. This step can be further decomposed into two stages: coarse positioning and fine adjustment. In the coarse positioning stage, the current position of each support point is acquired in real time through the sensors configured on each active reference hydraulic support unit and compared with the target geometric position. Through closed-loop feedback control, each unit is driven to move to continuously reduce the position deviation. In the fine adjustment stage, based on the coarse positioning, the real-time load of each support point is further collected and compared with the theoretical load. Through a multi-objective optimization algorithm, a set of optimal position fine adjustment amounts are calculated and executed. This algorithm aims to minimize the weighted sum of the error between the actual load and the theoretical load of all support points and the deviation of the geometric position, thereby achieving precise positioning in both geometry and mechanics. In the structural stiffening step, a synchronization command is issued to all variable constraint connection nodes to switch them from the under-constrained connection state to the rigid locking state, thereby solidifying the flexible frame structure, which is already in a precise pose and zero stress state, into a statically indeterminate high stiffness structure. Following the structural stiffening step, a system state self-verification step is also included. This step involves actively controlling at least one active reference hydraulic strut unit to apply a preset, minute displacement disturbance, and synchronously acquiring global load response changes using sensors from all strut units. Based on the applied displacement disturbance and the acquired load response changes, the experimental stiffness matrix of the current frame structure is solved in reverse using a system identification algorithm.

[0008] Furthermore, the system state self-verification step also includes comparing the calculated experimental stiffness matrix with the theoretical stiffness matrix calculated based on the three-dimensional digital model. When the error between the two is less than the engineering preset threshold, it can be quantitatively confirmed that the installation quality and structural performance of the jig fully meet the design requirements, providing a reliable guarantee for subsequent operations.

[0009] After completing the above steps, the steel bridge segment assembly operation can be carried out, which involves hoisting the steel bridge segments to be assembled onto the support points of the high-rigidity structure, and then connecting and fixing the segments.

[0010] A modular prefabricated construction system for steel bridge pre-assembly frames includes: Multiple active reference hydraulic strut units, each equipped with a six-degree-of-freedom parallel actuator and an integrated multi-dimensional sensor module, are used to perform pose adjustment and state perception. Multiple modular truss units, each with a variable constraint connection node at its end, are used to connect the modular truss units to each other; The system also includes a central control system configured to: store the target geometric pose extracted from the 3D digital model and the calculated theoretical load; control the variable constraint connection nodes to switch between an under-constrained connection state and a rigid locking state; receive real-time pose and load data from the sensors, and generate control commands based on the deviation between the data and the target geometric pose and theoretical load to drive the actuators to perform global adaptive positioning; and after positioning is completed, send synchronization switching commands to all the variable constraint connection nodes to achieve structural stiffening.

[0011] This invention provides a modular prefabricated construction method for steel bridges using pre-assembled jigs. It offers the following advantages: 1. This invention employs an under-constrained connection method with variable constraint connection nodes during the jig assembly stage, making the entire structure flexible. The flexible assembly method eliminates the need for high-precision alignment of each modular truss unit, significantly simplifying the on-site operation process, shortening the construction cycle, and reducing reliance on high-precision measuring equipment and worker skill, thereby greatly improving overall construction efficiency and reducing assembly difficulty.

[0012] 2. This invention utilizes an active reference hydraulic support unit and a central control system to form a closed-loop feedback control system. Through a global adaptive positioning step, the geometric pose of the jig is precisely adjusted to the target state defined by the three-dimensional digital model. By introducing a fine-tuning step based on real-time load feedback, the initial installation stress caused by the accumulation of component tolerances and assembly errors is actively eliminated, ensuring that the jig is in an ideal zero-stress state before curing. This guarantees the final structural quality and load-bearing performance, achieving high-precision global positioning and eliminating initial installation stress.

[0013] 3. This invention innovatively introduces a system state self-verification step after structural stiffening. By actively applying minute displacement disturbances and collecting global load responses, this method can identify the experimental stiffness matrix of the jig and quantitatively compare it with the theoretical stiffness matrix. The self-testing capability provides an objective and reliable non-destructive testing method for the final structural performance of the jig. It can confirm whether the installation quality of bridge segments meets the standards before hoisting, thereby greatly improving the reliability of the construction process and the safety of subsequent operations. It provides a quantitative quality verification method and improves the reliability and safety of construction. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system architecture of the present invention; Figure 2 This is a flowchart of the construction method of the present invention; Figure 3 This is a schematic diagram of the pre-locking load balancing fine-tuning closed-loop control principle of the present invention; Figure 4 This is a partial three-dimensional view of the present invention.

[0015] Among them, 100 is the active reference hydraulic support unit; 110 is the six-degree-of-freedom parallel actuator; 120 is the integrated multi-dimensional sensor module; 130 is the quick-install ground anchor; 200 is the modular truss unit; 210 is the variable constraint connection node; 300 is the central control system; 310 is the model analysis and parameterization module; 320 is the kinematic control module; 330 is the load balancing optimization module; and 340 is the system state self-verification module. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see the appendix Figure 1 - Appendix Figure 4 This invention provides a modular construction system for pre-assembled steel bridge frames, comprising: multiple active reference hydraulic support units 100, multiple modular truss units 200, and a central control system 300. Physically, the modular truss units 200 are erected and fixed on the active reference hydraulic support units 100, forming the main load-bearing body of the frame. In terms of information interaction, sensor data from the active reference hydraulic support units 100 are sent to the central control system 300. After data processing and decision-making, the central control system 300 sends control commands to the active reference hydraulic support units 100 and the modular truss units 200.

[0018] The active reference hydraulic strut unit 100 is an execution and sensing unit that realizes active positioning, attitude adjustment and state perception of the jig. The active reference hydraulic strut unit 100 specifically includes a six-degree-of-freedom parallel actuator 110, an integrated multi-dimensional sensor module 120 and a quick-install ground anchor 130.

[0019] The six-degree-of-freedom parallel actuator 110 is the core mechanism for the active reference hydraulic support unit 100 to achieve pose adjustment. The actuator 110 has a lower platform and an upper platform, which are connected by at least six telescopic hydraulic cylinders. By precisely controlling the extension and retraction length of each hydraulic cylinder, the upper platform can achieve six degrees of freedom of translation and rotation in three-dimensional space, thereby driving the modular truss unit 200 above it to reach any target pose.

[0020] An integrated multidimensional sensor module 120 is fixed to the upper platform of the six-degree-of-freedom parallel actuator 110 and is used to acquire the status information of the active reference hydraulic support unit 100 in real time. The integrated multidimensional sensor module 120 includes: a high-precision spatial positioning sensor for acquiring the absolute position (x, y, z) of the upper platform in the global coordinate system; an inertial measurement unit for acquiring the attitude angles (α, β, γ) of the upper platform; and a multi-axis force sensor for measuring the vertical and lateral loads borne by the upper platform.

[0021] The quick-installation ground anchor 130 is used to establish a quick and stable connection between the active reference hydraulic support unit 100 and the ground of the construction site. The quick-installation ground anchor 130 can be in the form of self-drilling anchor rods or helical piles, etc. Its function is only to provide reliable anchoring reaction force, and there are no special requirements for the flatness of the ground itself.

[0022] Modular truss unit 200 is a standard component constituting the frame load-bearing structure. The connection between modular truss units 200 is achieved through variable constraint connection nodes 210. The variable constraint connection node 210 has a built-in hydraulic locking pin mechanism, which enables it to have two switchable working states: under-constrained state and rigid locking state. In the under-constrained state, the hydraulic locking pin mechanism is in the released position, and the node behaves as a ball joint connection, allowing relative rotation between the connected truss units. In the rigid locking state, the hydraulic locking pin mechanism is driven to the engaged position, completely restricting the rotational degree of freedom of the node, and transforming it into a rigid connection.

[0023] The central control system 300 is the core of the entire construction system for computation and decision-making. Its hardware platform is an industrial control computer, integrating a data acquisition interface, motion control card, and wireless communication module. The central control system 300 deploys several core software functional modules that implement the method of this invention, including: The model parsing and parameterization module 310 is used to import and parse the three-dimensional digital model of steel bridge segments and automatically extract the target pose vectors of all support points. and theoretical load vector ; The kinematic control module 320 has built-in forward and inverse kinematics calculation algorithms for the six-degree-of-freedom parallel actuator 110. Based on the deviation between the target pose and the current pose fed back by the sensor, it calculates the extension length that each hydraulic cylinder needs to achieve in real time and generates corresponding control commands. The load balancing optimization module 330 is used to perform zero-stress fine-tuning during the pre-locking phase, and is used to solve a multi-objective optimization problem to find an optimal set of pose fine-tunings. The objective function of this optimization problem Defined as: ; in: It contains the pose fine-tuning vectors of all support points. A set; Number the support points from 1 to ; For the first Vector function of real-time load readings of sensors at each support point; For the first The target pose vector of each support point; For the first The theoretical load vector of each support point; Let be the square of the Euclidean norm of the vector; and These are preset weighting coefficients for load accuracy and geometric accuracy; The system status self-verification module 340 is used to quantitatively evaluate the structural performance of the frame after it has been rigidified, by applying minute displacement disturbances by controlling a specified six-degree-of-freedom parallel actuator 110. And collect global load response. Based on linear relationship The experimental stiffness matrix of the frame structure was identified by reverse identification. Subsequently, the system state self-verification module 340 calculates the experimental stiffness matrix and the theoretical stiffness matrix using the following formula. Relative error: ; in Let Frobenius norm be the matrix, and this error value will be used as the final criterion for judging whether the installation quality of the jig is up to standard.

[0024] This invention also provides a modular construction method for pre-assembled steel bridge frames, comprising the following steps: S100 involves preparation and model parameterization, specifically: importing the 3D digital model of the steel bridge segment to be assembled into the central control system 300, whereby the central control system 300 automatically analyzes and extracts the target spatial pose and theoretical load parameters of all support points of the formwork. In the S100 preparation and model parameterization stage, the core task is to transform the high-level engineering design blueprint into a precise, quantifiable set of low-level control instructions that can be directly executed by the construction system. All operations in this stage are automatically completed by the model analysis and parameterization module 310 within the central control system 300, including the following steps: S110, extract the target geometric pose parameters. The central control system 300 first imports and loads a pre-established three-dimensional digital model of the steel bridge segment to be assembled, which contains complete geometric and physical attribute information. The model analysis and parameterization module 310 then analyzes the data structure of the model. By identifying preset layers, component labels or specific geometric primitives, it locates all support points in the model used for frame support. For the i-th identified support point, the model analysis and parameterization module 310 calculates and extracts its target spatial pose in the preset global coordinate system. The target spatial pose is defined as a six-dimensional vector. Its specific form is as follows: ; in: These are the coordinates of the center of the support point on the X, Y, and Z axes of the global coordinate system, respectively. The three-axis attitude angles that the flange plane above the support point needs to achieve, such as pitch angle, yaw angle and roll angle defined by Tait-Bryan angle, are used to precisely define its orientation in space. The model analysis and parameterization module 310 repeats this process for all n support points, and finally generates a set containing the target pose vectors of all support points, which serves as the geometric target reference for the subsequent global adaptive positioning stage. S120, calculate the theoretical load parameters. After extracting the geometric parameters, the model analysis and parameterization module 310 calls its embedded finite element analysis engine to calculate the ideal stress state of the frame structure under its own weight. The calculation process is implemented in the following way: The model analysis and parameterization module 310 first constructs the finite element analysis model of the entire frame based on the three-dimensional model of the modular truss unit 200, and assigns the material properties of the model (such as elastic modulus, Poisson's ratio, and material density) to the corresponding units. Subsequently, the model analysis and parameterization module 310 sets all the support point locations extracted in step S110 as fixed constraint boundary conditions for the finite element model. Then, a gravity field is applied as the only external load. After completing the model setup, the finite element analysis engine solves the model and calculates the support reaction force of each fixed constraint boundary condition (i.e., each support point) under the ideal condition of bearing only its own weight. For the i-th support point, the support reaction force is defined as a six-dimensional theoretical load vector. : ; in: These represent the theoretical supporting forces that the support point should bear in the X, Y, and Z directions of the global coordinate system, respectively. The theoretical support torques that the support point should bear around the three axes of the global coordinate system X, Y, and Z are respectively. The model analysis and parameterization module 310 finally generates a set containing the theoretical load vectors of all support points. This set will serve as the mechanical target benchmark for the subsequent zero-stress locking stage.

[0025] S200 involves the flexible and rapid assembly of the jig. Quick-installation ground anchors 130 are deployed at the construction site, and active reference hydraulic support units 100 are installed. Modular truss units 200 are then erected on top of the active reference hydraulic support units 100 using an under-constrained connection method, forming a jig structure in a flexible state. The S200 jig flexible and rapid assembly stage aims to efficiently complete the physical construction of the jig structure. Utilizing the variable constraint characteristics of the structure, the requirements for installation accuracy are temporarily ignored during the assembly process, thereby greatly improving construction efficiency and avoiding the generation of initial installation stress from the source. This includes the following steps: In step S210, the active reference unit is deployed. According to the support point layout plan determined in step S110, the construction personnel install quick-installation ground anchors 130 at the approximate location of the construction site. This step does not have strict requirements on the flatness of the site. The function of the quick-installation ground anchors 130 is only to provide a stable anchor point for the upper structure. Subsequently, the active reference hydraulic support unit 100 is hoisted and fixed on the corresponding quick-installation ground anchors 130. The installation here also does not require precise leveling or centering. S220, perform under-constrained connection of truss unit. After the layout of all active reference hydraulic support units 100 is completed, the upper modular truss unit 200 is erected. In this step, the connection between all modular truss units 200 is achieved through the variable constraint connection node 210 at their ends. Throughout the S200 assembly phase, the central control system 300 pre-sets or instructs the hydraulic locking pin mechanism in all variable constraint connection nodes 210 to remain in the released state. In this released state, the variable constraint connection node 210 exhibits an under-constrained connection method, which is functionally equivalent to a ball joint or universal joint. This under-constrained connection method is the technical basis for realizing the flexible and rapid assembly of the present invention. This ball joint feature allows for a preset range of relative rotational degrees of freedom between adjacent modular truss units 200. Therefore, when hoisting and connecting truss units, construction workers do not need to perform high-precision alignment to complete the insertion and initial tightening of connecting bolts. This connection method fundamentally avoids forced fitting between components due to manufacturing tolerances and installation errors, thereby preventing the generation of initial installation stress inside the jig structure. After completing the S200 stage, the entire jig structure is physically fully connected, but mechanically it is in a flexible, stress-free state, which prepares it for the global adaptive positioning in the subsequent S300 stage.

[0026] S300 executes global adaptive positioning and zero-stress locking, activates the central control system 300, drives all active reference hydraulic support units 100 to move in coordination, adjusts the flexible jig structure to the target spatial pose, and then executes the pre-locking load balancing protocol to minimize the error between the actual load and theoretical load parameters of each support point. In the S300 global adaptive positioning and zero-stress locking stage, through a fully automatic closed-loop control process, the flexible jig structure is precisely adjusted from any initial pose after assembly to a target state with both geometric and mechanical precision, including the following steps: S310, initial state perception and coarse positioning are performed. After the central control system 300 is started, it first sends a status query command to all active reference hydraulic support units 100. The integrated multi-dimensional sensor module 120 on the active reference hydraulic support unit 100 then collects and uploads its current real-time spatial pose. After receiving the current pose of all units, the kinematic control module 320 within the central control system 300 compares it with the target pose extracted in step S110. Compare the results and calculate the pose deviation of each support point. Based on the pose deviation, the kinematic control module 320 uses the inverse kinematic model of its built-in six-degree-of-freedom parallel actuator 110 to calculate the target extension and retraction of each hydraulic cylinder required to eliminate the deviation. Subsequently, the kinematic control module 320 generates control commands and sends them to all active reference hydraulic support units 100, which collaboratively drive their parallel actuators 110 to start moving. This process is a continuous closed-loop feedback control. The system continuously acquires real-time pose, calculates deviation, and adjusts the actuators until the geometric error between the current pose and the target pose of all support points is less than the preset first-level accuracy threshold. During the entire coarse positioning process, because the modular truss units 200 are under-constrained, the upper structure of the frame can deform freely without stress to adapt to the pose adjustment of the lower support points. The load balancing optimization module 330 executes a multi-objective optimization algorithm to find an optimal set of pose fine-tuning. The goal of this optimization process is to minimize the error between the actual and theoretical loads at all support points, while ensuring that the deviation of the geometric position is within a controllable range. : ; in: For the pose fine-tuning vector of all support points to be solved A set; Number the support points from 1 to ; For the first Real-time load measurement vector of a multi-axis force sensor on an active reference hydraulic support unit 100 under a specific orientation; For the first The target pose vector of each support point; The first one calculated in step S120 The theoretical load vector of each support point; Let be the square of the Euclidean norm of the vector; and These are preset non-negative weighting coefficients, used to adjust the relative importance of load balancing accuracy and geometric positioning accuracy in the optimization objective; The load balancing optimization module 330 employs nonlinear optimization algorithms such as Sequential Quadratic Programming (SQP) to solve the problem iteratively. In each iteration, the load balancing optimization module 330 calculates a set of suggested fine-tuning values ​​and drives the actuator to execute these fine-tuning values ​​via the kinematic control module 320. New load readings are then immediately acquired. And re-evaluate the objective function. The value of is determined, and this iterative process continues until the objective function is found. When the value converges to below the preset second-level accuracy threshold, after this step is completed, the frame structure is not only in a precise geometric position, but its internal stress distribution also reaches an equilibrium state that is closest to the ideal design.

[0027] S320 performs pre-locking load balancing fine adjustment. After completing the geometric coarse positioning in S310, the system automatically enters this step. Its purpose is to eliminate potential additional internal stress caused by factors such as structural self-weight and manufacturing tolerances, and to achieve zero-stress locking. This step is led by the load balancing optimization module 330 in the central control system 300.

[0028] In S400, structural stiffening and system state self-verification are performed. After zero-stress locking is completed, all variable constraint connection nodes 210 are synchronously locked, transforming the formwork structure from a flexible state to a rigid state. Then, a stiffness matrix self-testing program is executed. By actively applying disturbances and collecting responses, the experimental stiffness matrix of the formwork structure is identified and compared with the theoretical stiffness matrix to verify the installation quality. In the S400 structural stiffening and system state self-verification stage, the goal is to solidify the formwork from a variable flexible state into a high-stiffness load-bearing structure and to perform a global, quantitative quality confirmation of its final structural performance, including the following steps: In S410, synchronous rigidification locking is performed. After the load balancing fine-tuning in step S320 is completed, the central control system 300 synchronously broadcasts a rigid locking command to the variable constraint connection nodes 210 on all modular truss units 200. Upon receiving the command, the hydraulic locking pin mechanism inside each variable constraint connection node 210 is simultaneously driven, instantly switching the connection mode of the node from an under-constrained ball joint state to a fully constrained rigid locking state. After this process is completed, the entire frame structure is transformed from a flexible system into a mechanically statically indeterminate high-stiffness structure, and its spatial orientation and internal force state are precisely fixed. S420, execute system status self-verification. After the formwork is stiffened and before the bridge segment is hoisted, the system status self-verification module 340 in the central control system 300 is automatically started to execute a stiffness matrix self-test program to verify whether the actual construction status of the formwork meets the design expectations in a non-destructive manner. The specific implementation of this self-testing procedure is as follows: The system state self-verification module 340 first selects one or more active reference hydraulic support units 100 as excitation sources, and through the kinematic control module 320, precisely controls its six-degree-of-freedom parallel actuators 110 to apply one or a series of preset, small displacement disturbances with known amplitude and direction. While applying the disturbance, the system state self-verification module 340 records the load changes measured by the multi-axis force sensors on all n active reference hydraulic support units 100 at high frequency and synchronously through the data acquisition interface, thereby forming a global load response vector. Based on the principle of linear superposition in structural mechanics, there exists a linear relationship between the applied small disturbance and the resulting global load response, defined by the structural stiffness matrix. The system state self-verification module 340 utilizes this relationship and, through a system identification algorithm (e.g., parameter estimation based on least squares), determines the system state based on the input disturbance. and the measured response The experimental stiffness matrix that best fits this input-output relationship is obtained by reverse engineering. The matrix The overall mechanical properties of the currently constructed frame structure were quantitatively characterized. ; Finally, the system state self-verification module 340 will calculate the experimental stiffness matrix. The theoretical stiffness matrix calculated based on the three-dimensional digital model in the S100 stage. A comparison is performed by calculating the relative error between the two: ; in: The experimental stiffness matrix is ​​identified through active excitation and response acquisition; This is the theoretical stiffness matrix derived from the finite element model; The Frobenius norm of a matrix is ​​used to measure the difference between two matrices; this error value... As the final criterion for judging whether the installation quality of the jig is qualified, if this value is less than the preset engineering allowable error threshold... If the error is within acceptable limits, it proves that the installation quality of the jig, the locking status of the nodes, and the overall structural performance all meet the design requirements, and the system status verification is successful. Otherwise, if the error value exceeds the threshold, the system will issue an alarm to prompt the construction personnel to conduct an inspection.

[0029] In S500, steel bridge segment assembly is carried out. After the quality verification of the jig installation is passed, the steel bridge segments are hoisted onto the designated support points of the jig for subsequent assembly operations. During the S500 steel bridge segment assembly stage, the high-quality jig constructed and verified in the aforementioned steps is used to carry out the actual pre-assembly work of the steel bridge segments, including the following steps: In step S510, construction delivery confirmation is performed. After the system status self-verification in step S420 passes, the central control system 300 will generate confirmation information, indicating that the geometric orientation, internal force state, and overall structural stiffness of the jig have all met the design requirements and are ready for delivery. Construction personnel can only proceed with subsequent hoisting operations after confirming this information. S510, the bridge segments are hoisted and positioned. Construction workers operate large lifting equipment to hoist the steel bridge segments to be assembled onto the jig. Since all the support points of the jig have been precisely positioned in the target space posture defined by its three-dimensional digital model through the aforementioned steps, the positioning process of the bridge segments becomes a direct and high-precision alignment operation. The bridge segments are stably placed on the corresponding support points of the jig. S520 involves segmental connection and fixing. After the bridge segments are in place, construction workers can proceed with the connection and fixing of the segments, such as connecting high-strength bolts or welding structural welds. The jig, as a precisely positioned, internally balanced, and rigidly verified load-bearing platform, provides a stable benchmark for the segmental connection work, ensuring the accuracy of the assembly process and the final structural quality after assembly.

[0030] In summary, this invention utilizes a technical approach of "flexible pre-assembly, active precision positioning, and rigid self-verification" to efficiently integrate discrete modular components into an overall structure that meets both geometric and mechanical precision requirements, thereby fully realizing a modular assembly construction method for steel bridge pre-assembly frames.

Claims

1. A modular prefabricated construction method for steel bridge pre-assembly frames, characterized in that, Includes the following steps: a. Preparation and model parameterization: Based on the three-dimensional digital model of the steel bridge segment to be assembled, extract the target geometric pose of all support points and calculate the theoretical load of the support points under the self-weight of the frame. b. Flexible and rapid assembly of the jig: Multiple active reference hydraulic support units 100 are deployed, and multiple modular truss units 200 are connected into a flexible jig structure through variable constraint connection nodes 210 in an under-constrained connection manner. c. Global adaptive positioning: Through the coordinated action of the active reference hydraulic support unit 100, the flexible frame structure is adjusted in position until the actual position and actual load of all support points approach the target geometric position and the theoretical load, respectively. d. Structural stiffening: Synchronously switch all variable constraint connection nodes 210 from the under-constrained connection state to the rigid locking state, so that the flexible frame structure is solidified into a high-stiffness structure.

2. The modular assembly construction method for pre-assembled steel bridge frames according to claim 1, characterized in that, In step a, the three-dimensional coordinates and three-axis attitude angles of each support point are extracted from the three-dimensional digital model to form the target geometric pose; a finite element model of the frame structure is established, and under the condition of applying gravity load, the support reaction force caused by the self-weight of the structure at each support point is calculated to form the theoretical load.

3. The modular assembly construction method for pre-assembled steel bridge frames according to claim 1, characterized in that, In step b, the under-constrained connection is a variable constraint connection node 210 that allows relative rotational freedom between adjacent modular truss units 200 during assembly, and its mechanical function is equivalent to a ball joint connection.

4. The modular assembly construction method for pre-assembled steel bridge frames according to claim 1, characterized in that, Step c includes the following steps: Coarse positioning: The current real-time pose is obtained by the sensor on the active reference hydraulic support unit 100 and compared with the target geometric pose. The active reference hydraulic support unit 100 is driven to move through closed-loop feedback control to reduce the pose deviation. Fine-tuning: After coarse positioning, the current real-time load is obtained by the sensor on the active reference hydraulic support unit 100 and compared with the theoretical load. The pose fine-tuning is calculated and executed by the optimization algorithm to reduce the load deviation.

5. The modular assembly construction method for pre-assembled steel bridge frames according to claim 4, characterized in that, In the fine-tuning step, the goal of the optimization algorithm is to find a set of optimal pose fine-tuning values ​​that minimize the weighted sum of the error between the actual load and the theoretical load of all support points and the deviation of their geometric positions.

6. The modular assembly construction method for pre-assembled steel bridge frames according to claim 1, characterized in that, In step d, after the flexible frame structure is solidified into a high-rigidity structure, the system state is self-verified. A preset small displacement disturbance is applied through at least one active reference hydraulic support unit 100, and the load response change of all active reference hydraulic support units 100 is collected simultaneously. Based on the displacement disturbance and the load response change, the experimental stiffness matrix of the high-rigidity structure is identified.

7. The modular assembly construction method for pre-assembled steel bridge frames according to claim 6, characterized in that, In the system status self-verification step, the experimental stiffness matrix is ​​compared with the theoretical stiffness matrix calculated based on the three-dimensional digital model. When the error between the two is less than a preset threshold, the construction of the jig is confirmed to be qualified.

8. The modular assembly construction method for pre-assembled steel bridge frames according to claim 1, characterized in that, The active reference hydraulic support unit 100 includes a six-degree-of-freedom parallel actuator 110 and an integrated multi-dimensional sensor module 120, which is used to measure the spatial pose and load of the support point in real time.

9. A modular prefabricated construction method for steel bridge pre-assembly frame according to claim 7, characterized in that, After the system status is self-verified, the steel bridge segment assembly operation is carried out. The steel bridge segments to be assembled are hoisted and placed on the support points of the high-rigidity structure, and the connection and fixing operations between the segments are carried out.

10. A modular prefabricated construction system for steel bridge pre-assembly jigs, applied to the modular prefabricated construction method for steel bridge pre-assembly jigs as described in any one of claims 1-9, characterized in that, include: Multiple active reference hydraulic support units 100, each active reference hydraulic support unit 100 is equipped with a six-degree-of-freedom parallel actuator 110 and an integrated multi-dimensional sensor module 120; Multiple modular truss units 200 are provided at their ends with variable constraint connection nodes 210 for connecting the modular truss units 200 to each other; Central control system 300, used for: Store the target geometric pose extracted from the 3D digital model and the calculated theoretical load; Control the variable constraint connection node 210 to switch between an under-constrained connection state and a rigid locking state; The system receives real-time pose and load data from the integrated multi-dimensional sensor module 120, and generates control commands based on the deviation between the data and the target geometric pose and theoretical load to drive the six-degree-of-freedom parallel actuator 110 to perform global adaptive positioning. After positioning is completed, a synchronization switching command is sent to all the variable constraint connection nodes 210 to achieve structural stiffening.

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