Construction method of two-segment single-casting for wet joint of double-sided box girder steel-concrete composite beam

Abstract

This invention relates to the field of bridge construction technology, and more particularly to a two-segment, single-cast construction method for wet joints of double-sided box girder steel-concrete composite beams. The method includes determining a cyclic construction scheme; modeling and simulating the cyclic construction scheme to calculate, at least, the maximum compressive stress and corresponding location of the steel box girder and bridge deck under various working conditions, as well as the maximum tensile stress and corresponding location, obtaining a simulation dataset; determining the feasibility of the cyclic construction scheme and determining monitoring parameters; and carrying out construction based on the cyclic construction scheme while monitoring the parameters in real time. This invention, through simultaneous casting of two segments and working condition chain simulation, can effectively reduce the number of cycles, save time consumed by concrete equalization, thereby improving project efficiency and significantly shortening the turnover period of temporary supports. By dynamically capturing the compressive stress concentration of the steel box girder and the peak tensile stress of the bridge deck through multi-working-condition coupled simulation, the risk of structural instability and cracking can be eliminated through parameterized adjustment, ensuring process reliability and bridge quality.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for constructing wet joints of double-sided box girder steel-concrete composite beams by pouring two segments at a time. Background Technology

[0002] In the construction of a large-scale hybrid beam single-tower cable-stayed bridge, the wet joint pouring process of the main span directly affects the quality and schedule of the completed bridge. The steel structure of this section of the bridge includes double-sided steel box main beams and small longitudinal beams distributed in the longitudinal direction of the bridge, as well as steel transverse beams distributed in the transverse direction of the bridge. After the three are connected, the concrete bridge deck is hoisted and the wet joint of the bridge deck is poured.

[0003] While the traditional one-segment-one-cycle wet joint pouring scheme can ensure structural safety, it suffers from low construction efficiency: each segment needs to be hoisted, poured and tensioned independently, and each segment needs time for the concrete to reach the required strength. According to the specifications, it takes 5 to 7 days for the concrete to reach the design strength, which will significantly extend the construction period. This is especially true for large-scale projects with a large main span, where the above defects are more prominent. Summary of the Invention

[0004] This invention provides a two-segment, one-cast construction method for wet joints of double-sided box girder steel-concrete composite beams, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The construction method for wet joints of double-sided box girder steel-concrete composite beams, consisting of two segments poured in one go, includes:

[0007] A cyclic construction scheme is determined, which is used for cyclic construction of wet joints with two segments poured in one go.

[0008] Modeling and simulation were performed based on the aforementioned cyclic construction scheme. The simulation included steel beam hoisting, cable tensioning, synchronous wet joint pouring, and bridge deck tensioning.

[0009] Based on the simulation model, at least the maximum compressive stress and corresponding position of the steel box girder and bridge deck under each working condition are calculated, as well as the maximum tensile stress and corresponding position, to obtain the simulation dataset.

[0010] The feasibility of the cyclic construction scheme is determined by the simulation dataset. If any data in the simulation dataset exceeds the material strength design value, the cyclic construction scheme is adjusted until the feasibility requirements are met. If all data in the simulation dataset meet the material strength design value, the monitoring parameters are determined based on the simulation dataset.

[0011] Construction is carried out based on the aforementioned cyclical construction scheme, and the aforementioned monitoring parameters are monitored in real time.

[0012] Furthermore, the cyclical construction scheme includes:

[0013] The bridge deck crane was moved forward and, once in place, the anchor points were installed.

[0014] The steel box girder, steel crossbeam, and small longitudinal beams of one section are hoisted.

[0015] For the aforementioned segment, the stay cables are installed and the first tensioning is performed;

[0016] After completing the installation of the bridge deck section, the stay cables are tensioned a second time.

[0017] The bridge deck crane was moved forward and, once in place, the anchor points were installed.

[0018] The steel box girder, steel crossbeam, and small longitudinal beams of the second segment are hoisted.

[0019] For the two segments, the stay cables are installed and the first tensioning is performed;

[0020] Complete the installation of the two bridge deck sections;

[0021] Install the reinforcing steel and formwork for the two wet joints, and then pour the concrete for the two sections.

[0022] After the concrete curing of the wet joints has reached the design requirements, the longitudinal and transverse prestressing tensioning of the bridge deck is carried out.

[0023] The two-segment stay cables are tensioned a second time.

[0024] Furthermore, the concrete pouring is completed within 24 hours after the installation of the bridge deck of the two sections.

[0025] Furthermore, in the cyclic construction scheme, the tension data of the stay cable is acquired in real time, and the tension data includes the tension hydraulic pressure data and tension force data of a single steel strand.

[0026] Furthermore, the modeling and simulation include:

[0027] A finite element model was established, using beam elements to simulate the main steel box girder, steel crossbeams and small longitudinal beams, plate elements to simulate the bridge deck, and cable elements to simulate the stay cables.

[0028] A chain of working conditions is generated in the finite element model, including the steel beam hoisting condition, the cable tensioning condition, the wet joint synchronous pouring condition, and the bridge deck tensioning condition;

[0029] The concrete age-strength evolution function is embedded in the synchronous pouring of wet joints and the bridge deck tensioning condition to constrain the timing of prestressing tensioning to meet the real-time strength threshold of concrete. In the synchronous pouring of wet joints condition, a time-varying shrinkage and creep model is defined for the bridge deck concrete, and the additional tensile stress caused by the shrinkage difference between new and old concrete is quantified.

[0030] The simulation of the working condition chain is executed, and the compressive stress and corresponding location data of the steel box girder and bridge deck are output throughout the construction process.

[0031] Furthermore, an asymmetric load compensation unit is implanted at the finite element node at the connection between the main steel box girder and the steel crossbeam, and the stress distribution is dynamically adjusted by reverse displacement load.

[0032] Furthermore, the asymmetric load compensation unit includes:

[0033] A virtual elastic connection component is provided, in the finite element model, in which an elastic connector with adjustable axial stiffness is implanted at the connection node between the main steel box girder and the steel crossbeam, and the stiffness value of the elastic connector is 5% to 8% of the bending stiffness of the steel crossbeam;

[0034] The reverse displacement load module applies a reverse displacement load perpendicular to the axis of the steel beam to the elastic connector, with the load direction pointing to the opposite side of the deformation displacement of the steel box girder.

[0035] The dynamic adjuster adjusts the stiffness of the elastic connector and the value of the reverse displacement load in real time based on the bending moment monitoring value of the steel beam.

[0036] Furthermore, the concrete age-strength evolution function starts timing based on the completion time of wet joint pouring and dynamically outputs real-time strength values ​​according to concrete mix proportion parameters;

[0037] Tensioning operation is permitted only when the real-time concrete strength value output by the concrete age-strength evolution function is higher than 75% of the design strength.

[0038] Furthermore, in the synchronous pouring of the wet joint, the following are included:

[0039] The time-varying shrinkage and creep model is defined to calculate the difference in shrinkage strain between freshly poured concrete and existing concrete;

[0040] An additional tensile stress is generated based on the shrinkage strain difference value, and the additional tensile stress is input into the bridge deck tensioning condition.

[0041] The tension of a single steel strand is increased based on the additional tensile stress.

[0042] Furthermore, when the synchronous pouring condition of the wet joint is started, the time variables of the concrete age-strength evolution function and the time-varying shrinkage and creep model are activated simultaneously.

[0043] In the bridge deck tensioning condition, the tension force is adjusted by applying additional tensile stress in real time based on the same timing variable.

[0044] The technical solution of this invention can achieve the following technical effects:

[0045] This invention effectively reduces the number of cycles and saves time consumed by concrete equalization through dual-segment synchronous casting and working condition chain simulation, thereby improving engineering efficiency. It dynamically captures the compressive stress concentration of the steel box girder and the peak tensile stress of the bridge deck through multi-working condition coupling simulation, and eliminates the risk of structural instability and cracking through parameterized adjustment. In the specific construction process, based on the simulation dataset, high-risk areas are located and monitoring points are set up to ensure the reliability of the process and the quality of the completed bridge. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 A flowchart for the construction method of pouring two segments of wet joint in a double-sided box girder steel-concrete composite beam;

[0048] Figure 2 A flowchart for the cyclical construction plan;

[0049] Figure 3 This is a schematic diagram showing the location of the bridge deck crane;

[0050] Figure 4 This is a schematic diagram showing the positional relationship between the steel box girder, steel crossbeams, small longitudinal beams, bridge deck, wet joints, and stay cables.

[0051] Figure 5 For modeling and simulation flowchart;

[0052] Figure 6 A flowchart for the synchronous pouring of wet joints;

[0053] Figure label:

[0054] 1. Steel box girder; 2. Steel crossbeam; 3. Small longitudinal beam; 4. Bridge deck; 5. Wet joint; 6. Cable stays; 7. Crane. Detailed Implementation

[0055] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0056] Example 1:

[0057] like Figure 1 As shown, the construction method for the wet joint of the double-sided box girder steel-concrete composite beam, consisting of two segments poured in one go, includes:

[0058] A1: Determine the cyclic construction plan. The cyclic construction plan is used for the two-segment pouring cycle construction of wet joints. In specific implementation, the main span is divided into continuous double-segment units according to the bridge span distribution and construction resource conditions.

[0059] A2: Modeling and simulation are performed based on the cyclic construction scheme. The simulation includes steel beam hoisting, cable tensioning, synchronous wet joint pouring, and bridge deck tensioning. Multiple scenarios constitute the scenario driving chain of the cyclic construction scheme, realizing full-scenario coupled simulation. Specifically, the steel beam hoisting scenario applies the self-weight of each steel beam segment and the load of the hoisting equipment; the cable tensioning scenario applies the design cable force and adjusts the beam alignment; the synchronous wet joint pouring scenario synchronously loads the self-weight of the wet joint of the adjacent two segments of cast-in-place concrete and the construction load; and the bridge deck tensioning scenario applies longitudinal and transverse prestress in stages.

[0060] The modeling and simulation in this step can be carried out using finite element analysis software such as ANSYS, MIDAS or ABAQUS. Four types of working conditions are defined according to the construction sequence: steel beam hoisting, cable tensioning, synchronous pouring of wet joints and bridge deck tensioning. The inheritance of mechanical state and superposition of loads between working conditions are realized.

[0061] A3: Based on the simulation model, at least calculate the maximum compressive stress and corresponding location of the steel box girder and bridge deck under each working condition, as well as the maximum tensile stress and corresponding location, and obtain the simulation dataset;

[0062] In the simulation dataset, the maximum compressive stress and corresponding location of the main girder can identify the risk zone of compressive instability in the web of the main girder, such as the connection between the lower flange of the double-sided main girder and the steel crossbeam; the maximum tensile stress and corresponding location of the main girder can locate the potential point of fatigue cracking in the weld, such as the weld between the cable anchor box and the top plate of the main girder; the maximum compressive stress and location of the bridge deck can monitor the risk of local bearing failure, such as the tensioning end pad area of ​​the longitudinal prestressing tendon; the maximum tensile stress and location of the bridge deck can provide early warning of cracking at the interface of the wet joint.

[0063] A4: The feasibility of the cyclic construction scheme is determined by the simulation dataset. If any data in the simulation dataset exceeds the material strength design value, for example, the maximum compressive stress of the steel box girder is greater than 60% of the yield strength, or the maximum tensile stress of the bridge deck is greater than 80% of the real-time tensile strength, the scheme is deemed infeasible. The cyclic construction scheme is then adjusted, specifically by refining the key parameters for each working condition. For example, if the compressive stress at the root of the cantilever of the steel box girder exceeds the standard, the temporary supports are increased or the hoisting speed is reduced, until the feasibility requirements are met. If all data in the simulation dataset meet the material strength design value, the monitoring parameters are determined based on the simulation dataset. The monitoring parameters are specifically the high-risk locations identified in the above steps, such as deploying strain sensors at the wet joint interface.

[0064] A5: Construction is carried out based on a cyclical construction scheme. The construction here must be carried out strictly according to the simulation verification and adjusted working condition parameters to ensure the unity of process safety and efficiency, and to monitor the monitoring parameters in real time.

[0065] In this embodiment, the number of cycles can be effectively reduced by using dual-segment synchronous casting and working condition chain simulation-driven methods, saving time consumed by concrete equalization and improving project efficiency. Multi-working condition coupled simulation can dynamically capture the compressive stress concentration of the steel box girder and the peak tensile stress of the bridge deck, and the risks of structural instability and cracking can be eliminated by parameterized adjustment. In the specific construction process, high-risk areas are located and monitoring points are set up based on the simulation dataset, which can ensure the reliability of the process and the quality of the completed bridge.

[0066] As a preferred embodiment of the above, such as Figures 2-4 As shown, the cyclical construction scheme includes:

[0067] B1: The bridge deck crane 7 moves forward and, after reaching its position, installs and sets anchor points to provide a stable working platform for the hoisting of the double-segment steel beams;

[0068] B2: Hoisting of one section of steel box girder 1, steel crossbeam 2, and small longitudinal beam 3. The intermediate joint of steel crossbeam 2 is welded during the assembly in the back field. After the high-strength bolts of steel box girder 1 are tightened, welding is performed. After the high-strength bolts of steel crossbeam 2 are tightened, the joint between steel box girder 1 and steel crossbeam 2 is welded. Weld inspection is completed before the installation of small longitudinal beam 3 is completed. It is required that all high-strength bolts be tightened on the same day that steel box girder 1, steel crossbeam 2, and small longitudinal beam 3 are hoisted.

[0069] B3: Install cable 6 for one segment and perform the first tensioning; such as Figure 4 As shown, the positional relationship between the steel box girder 1, steel crossbeam 2, small longitudinal beam 3, bridge deck 4, wet joint 5, and stay cables 6 is illustrated.

[0070] B4: Complete the installation of one section of bridge deck 4, and after the installation is completed, perform a second tensioning of the stay cables 6;

[0071] B5: Move the bridge deck crane forward and install the set anchor points after it has been moved into position;

[0072] B6: Hoisting of the two-section steel box girder 1, steel crossbeam 2, and small longitudinal beam 3;

[0073] B7: Install cable 6 for the second segment and perform the first tensioning;

[0074] B8: Complete the installation of the second-section bridge deck 4;

[0075] B9: Install the reinforcing bars and formwork for the two-section wet joint, and then pour the concrete for the two sections.

[0076] B10: After the concrete curing of the wet joints has reached the design requirements, specifically when the concrete strength reaches 90% of the design value, the longitudinal and transverse prestressing of the bridge deck can be performed.

[0077] B11: Perform a second tensioning on the two-segment stay cable 6.

[0078] As a preferred embodiment of the above, in the cyclical construction scheme, concrete pouring is completed within 24 hours after the installation of the two bridge deck sections. After the bridge deck is hoisted into place, its bottom surface is in tight contact with the top plate of the steel beam, at which point the interface cleanliness is at its highest. If the delay exceeds 24 hours, the oxide film at the steel-concrete interface thickens, the bonding strength decreases, and environmental dust contaminates the interface, which also leads to a loss of shear strength in the wet joint. Pouring within 24 hours ensures the shear strength of the interface. In addition, there is a difference in the linear expansion coefficients between the steel beam and the concrete bridge deck. When the temperature difference between day and night is large, the longer the time, the greater the relative displacement between the steel plate and the concrete slab. By controlling the concrete pouring time, cold joints and subsequent water seepage in the wet joint can be avoided.

[0079] During implementation, uneven cable force distribution caused by asynchronous tensioning of multiple steel strands can lead to torsion of the main beam. To solve this problem, as a preferred embodiment, the cyclic construction scheme acquires tension data of the stay cables in real time. The tension data includes tension hydraulic pressure data and tension force data of a single steel strand. Tension hydraulic pressure refers to the pressure value displayed by the pressure gauge of the hydraulic system when tension force is applied to the steel strand by hydraulic jacks during prestressed concrete construction. By comparing the hydraulic pressure and tension curves of a single steel strand in real time, the tension difference between adjacent strands can be dynamically adjusted.

[0080] Example 2:

[0081] This embodiment further optimizes the simulation modeling process based on Embodiment 1, as follows: Figure 5 As shown, the modeling and simulation include:

[0082] S1: Establish a finite element model, using beam elements to simulate the main steel box girder, steel crossbeams and small longitudinal beams, plate elements to simulate the concrete bridge deck, and cable elements to simulate the stay cables; after the modeling is completed, it provides a digital carrier for the calculation of structural mechanical response in subsequent simulations;

[0083] S2: Generate a chain of working conditions in the finite element model, including steel beam hoisting, cable tensioning, wet joint synchronous pouring, and bridge deck tensioning; the specific details of each working condition are as described in the above embodiments and will not be repeated here.

[0084] S31: Embed the concrete age-based strength evolution function in the synchronous pouring of wet joints and the bridge deck tensioning condition to constrain the prestressing tensioning timing to meet the real-time concrete strength threshold. In this step, the synchronous pouring of wet joints and the bridge deck tensioning condition have both physical coupling and construction time-dependent relationships, as detailed below:

[0085] The physical coupling relationship is reflected in the direct bonding between new and old concrete at the wet joint interface. The early strength of the newly poured concrete is low, while the strength of the existing concrete has stabilized. The strength difference between the two makes the interface a weak stress zone. If prestress is applied at this time, it may cause cracks. The construction sequence dependence is reflected in the fact that the concrete age begins to accumulate from the moment of pouring, and the strength increases with the curing time. The tensioning operation must be performed after the concrete strength has reached a safe threshold.

[0086] During implementation, the starting point of strength evolution is determined by the synchronous pouring of wet joints. The subsequent bridge deck tensioning condition requires reading real-time strength values ​​to determine the timing of tensioning. The two are forcibly linked by sharing concrete age data through the embedded concrete age strength evolution function. The concrete age strength evolution function can use existing functions to describe the growth law of concrete compressive strength with curing time, and can be specifically selected from mature models.

[0087] And, S32: Define a time-varying shrinkage and creep model for bridge deck concrete in the synchronous pouring condition of wet joints, and quantify the additional tensile stress caused by the shrinkage difference between new and old concrete; this step outputs the additional stress value caused by the shrinkage difference in real time, providing a basis for adjusting the curing measures. The additional stress result can be input into the subsequent prestressing tensioning condition, thereby correcting the tension force calculation benchmark.

[0088] S4: Perform a work condition chain simulation and output the compressive stress and corresponding location data of the steel box girder and bridge deck throughout the construction process, as well as the tensile stress and corresponding location data. Specifically, load the load step by step according to the S2 sequence and couple the material time-varying response of steps S31 and S32.

[0089] The synchronous pouring process of double-segment wet joints reduces the number of cycles compared to the traditional single-segment process, significantly shortening the construction period. In this embodiment, a simulation process driven by a working condition chain is constructed to dynamically capture the structural response throughout the entire process of steel beam segment hoisting, cable tensioning, synchronous pouring of double-segment wet joints, and graded prestressing tensioning of the bridge deck. This process accurately outputs the compressive stress data of the steel box girder and the tensile stress data of the bridge deck, which can directly guide construction decisions.

[0090] As a preferred embodiment of the above, an asymmetric load compensation unit is implanted at the finite element node at the connection between the main steel box girder and the steel crossbeam, and the stress distribution is dynamically adjusted by reverse displacement load.

[0091] By embedding asymmetric load compensation units in the simulation environment, the stress peak caused by hoisting deviation or load asymmetry can be actively offset at the connection node between the main steel box girder and the steel crossbeam through reverse displacement load, thereby reducing the equivalent stress at the node and avoiding local plastic deformation. After dynamically adjusting the load distribution, the stress gradient change rate in the connection node area can be reduced. After the simulation is completed, compensation can be performed on the solid end through processes such as pre-adjustment of shape and position, dynamic counterweight, and jacking fine adjustment, transforming the simulation intervention into solid structure optimization.

[0092] As a further preferred embodiment of the above, the asymmetric load compensation unit includes:

[0093] In the finite element model, a virtual elastic connection component is installed at the connection node between the main steel box girder and the steel crossbeam. The elastic connection component has an axial stiffness adjustable elastic connector. The stiffness value of the elastic connector is 5% to 8% of the bending stiffness of the steel crossbeam.

[0094] The reverse displacement load module applies a reverse displacement load perpendicular to the axis of the steel beam to the elastic connector, with the load direction pointing to the opposite side of the deformation displacement of the main steel box girder.

[0095] The dynamic regulator adjusts the stiffness of the elastic connector and the value of the reverse displacement load in real time based on the monitored value of the bending moment of the steel beam, thereby reducing the peak stress at the node to within the design allowable range.

[0096] In this preferred embodiment, by implanting virtual elastic connectors, the actual constraint state of the steel nodes can be restored in the simulation, which can reduce the error in the calculation of node stress. Applying a reverse displacement load perpendicular to the axis of the steel beam can directly offset the deformation caused by hoisting deviation, thereby reducing the peak value of node displacement. Based on the bending moment monitoring value, the stiffness and load values ​​can be adjusted in real time to ensure the reasonable range of node stress.

[0097] After the simulation is completed, the actual construction control parameters can be output. For example, the stiffness value of the elastic connector directly corresponds to the selection of the elastic gasket on site, while the reverse displacement load value can be converted into the counterweight installation position command, etc.

[0098] As a preferred embodiment of the above, the concrete age-strength evolution function starts timing at the moment the wet joint is completed, and dynamically outputs real-time strength values ​​based on the concrete mix proportion parameters; tensioning is only allowed when the real-time concrete strength value output by the concrete age-strength evolution function is higher than 75% of the design strength. By using the concrete age-strength evolution function with the completion of the wet joint as the timing starting point, and dynamically outputting real-time strength values ​​that match the mix proportion, the risk of cracks at the interface between new and old concrete is directly avoided, while also avoiding early tension damage caused by insufficient curing; this function synchronizes construction decisions with the actual material performance, reduces blind waiting time, and ensures the safe and efficient implementation of the two-segment synchronous pouring process.

[0099] As a preferred embodiment of the above, such as Figure 6 As shown, the synchronous pouring of wet joints includes:

[0100] C1: Define a time-varying shrinkage and creep model to calculate the difference in shrinkage strain between freshly poured concrete and existing concrete; this step can be achieved using existing technical solutions.

[0101] C2: Generate additional tensile stress based on the shrinkage strain difference and input the additional tensile stress into the bridge deck tensioning condition; as a preferred embodiment, the shrinkage strain difference and the additional tensile stress are defined as a linear relationship, specifically, the additional tensile stress is K times the shrinkage strain difference, and the K value is specifically adjusted according to the concrete grade and ambient temperature. This method can effectively reduce the calculation time and labor cost.

[0102] C3: The tension of a single steel strand is increased based on the additional tensile stress, which can actively compensate for the tensile stress in the weak area caused by the shrinkage difference, directly eliminate the risk of interface cracks, and at the same time avoid the waste of steel strands caused by blindly increasing the overall tension.

[0103] As a preferred embodiment of the above, when the synchronous pouring of the wet joint is started, the timing variables of the concrete age-strength evolution function and the time-varying shrinkage and creep model are activated simultaneously; in the bridge deck tensioning condition, the real-time additional tensile stress is called to correct the tension force based on the same timing variable. By activating the timing start point of the concrete strength evolution and shrinkage and creep model simultaneously, and dynamically correcting the tension force based on a unified time variable, the millisecond-level precise collaborative control of the time-varying parameters throughout the wet joint construction process is achieved.

[0104] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for wet joints of double-sided box girder steel-concrete composite beams, characterized in that: include: A cyclic construction scheme is determined, which is used for cyclic construction of wet joints with two segments poured in one go. Modeling and simulation were performed based on the aforementioned cyclic construction scheme. The simulation included steel beam hoisting, cable tensioning, synchronous wet joint pouring, and bridge deck tensioning. Based on the simulation model, at least the maximum compressive stress and corresponding location of the steel box girder and bridge deck under each working condition should be calculated, as well as the maximum tensile stress and corresponding location, to obtain the simulation dataset. The feasibility of the cyclic construction scheme is determined by the simulation dataset. If any data in the simulation dataset exceeds the material strength design value, the cyclic construction scheme is adjusted until the feasibility requirements are met. If all data in the simulation dataset meet the material strength design value, the monitoring parameters are determined based on the simulation dataset. Construction is carried out based on the aforementioned cyclical construction scheme, and the monitoring parameters are monitored in real time. The modeling and simulation include: A finite element model was established, using beam elements to simulate the main steel box girder, steel crossbeams and small longitudinal beams, plate elements to simulate the bridge deck, and cable elements to simulate the stay cables. A chain of working conditions is generated in the finite element model, including the steel beam hoisting condition, the cable tensioning condition, the wet joint synchronous pouring condition, and the bridge deck tensioning condition; The concrete age-strength evolution function is embedded in the synchronous pouring of wet joints and the bridge deck tensioning condition to constrain the timing of prestressing tensioning to meet the real-time strength threshold of concrete. In the synchronous pouring of wet joints condition, a time-varying shrinkage and creep model is defined for the bridge deck concrete, and the additional tensile stress caused by the shrinkage difference between new and old concrete is quantified. Perform the aforementioned work condition chain simulation and output the compressive stress and corresponding location data of the steel box girder and bridge deck throughout the entire construction process, as well as the tensile stress and corresponding location data. Asymmetric load compensation units are implanted at the finite element nodes at the connection between the main steel box girder and the steel crossbeam to dynamically adjust the stress distribution through reverse displacement load. The asymmetric load compensation unit includes: A virtual elastic connection component is provided, in the finite element model, in which an elastic connector with adjustable axial stiffness is implanted at the connection node between the main steel box girder and the steel crossbeam, and the stiffness value of the elastic connector is 5% to 8% of the bending stiffness of the steel crossbeam; The reverse displacement load module applies a reverse displacement load perpendicular to the axis of the steel beam to the elastic connector, with the load direction pointing to the opposite side of the deformation displacement of the steel box girder. The dynamic adjuster adjusts the stiffness of the elastic connector and the value of the reverse displacement load in real time based on the bending moment monitoring value of the steel beam.

2. The construction method for wet joint of double-sided box girder steel-concrete composite beam with two-segment single-casting as described in claim 1, characterized in that, The cyclical construction scheme includes: The bridge deck crane was moved forward and, once in place, the anchor points were installed. The steel box girder, steel crossbeam, and small longitudinal beams of one section are hoisted. For the aforementioned segment, the stay cables are installed and the first tensioning is performed; After completing the installation of the bridge deck section, the stay cables are tensioned a second time. The bridge deck crane was moved forward and, once in place, the anchor points were installed. The steel box girder, steel crossbeam, and small longitudinal beams of the second segment are hoisted. For the two segments, the stay cables are installed and the first tensioning is performed; Complete the installation of the two bridge deck sections; Install the reinforcing bars and formwork for the two-section wet joint, and then pour the concrete for the two-section wet joint. After the concrete curing of the wet joints has reached the design requirements, the longitudinal and transverse prestressing tensioning of the bridge deck is carried out. The two-segment stay cables are tensioned a second time.

3. The construction method for wet joint of double-sided box girder steel-concrete composite beam with two-segment single-casting as described in claim 2, characterized in that, The concrete pouring was completed within 24 hours after the bridge deck of the two sections was installed.

4. The construction method for two-segment single-casting of wet joints in double-sided box girder steel-concrete composite beams according to claim 2, characterized in that, In the cyclic construction scheme, the tension data of the stay cable is acquired in real time, including the tension hydraulic pressure data and tension force data of a single steel strand.

5. The construction method for two-segment single-casting of wet joints in double-sided box girder steel-concrete composite beams according to claim 1, characterized in that, The concrete age-based strength evolution function starts timing at the moment the wet joint is poured and dynamically outputs real-time strength values ​​based on the concrete mix proportion parameters. Tensioning operation is permitted only when the real-time concrete strength value output by the concrete age-strength evolution function is higher than 75% of the design strength.

6. The construction method for two-segment single-casting of wet joints in double-sided box girder steel-concrete composite beams according to claim 1, characterized in that, In the synchronous pouring of the wet joint, the following are included: The time-varying shrinkage and creep model is defined to calculate the difference in shrinkage strain between freshly poured concrete and existing concrete; An additional tensile stress is generated based on the shrinkage strain difference value, and the additional tensile stress is input into the bridge deck tensioning condition. The tension of a single steel strand is increased based on the additional tensile stress.

7. The construction method for two-segment single-casting of wet joints in double-sided box girder steel-concrete composite beams according to claim 6, characterized in that, When the synchronous pouring condition of the wet joint is started, the time variables of the concrete age strength evolution function and the time-varying shrinkage and creep model are activated simultaneously. In the bridge deck tensioning condition, the tension force is adjusted by applying additional tensile stress in real time based on the same timing variable.

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