Method, system and device for calculating pre-camber of continuous rigid frame aqueduct midspan and medium

Abstract

The application provides a continuous rigid frame aqueduct midspan pre-camber calculation method, system, equipment and medium, and relates to the technical field of hydraulic engineering, and the method comprises the steps of: dividing the continuous rigid frame aqueduct into a plurality of cantilever beam segments, and constructing a finite element mechanics model of the continuous rigid frame aqueduct based on the cantilever beam segments; theoretically predicting the stress and deflection of each construction stage of the continuous rigid frame aqueduct according to the model, to obtain corresponding stress theoretical values and deflection theoretical values; and establishing a comprehensive objective function according to the stress theoretical values, the deflection theoretical values, and stress actual values and deflection actual values; iteratively inverting the comprehensive objective function to obtain key parameters; and then determining the pre-camber values of each calculation node in the finite element mechanics model. The application establishes a finite element mechanics model, introduces the measured stress and deflection data in the construction process, constructs a comprehensive objective function for iterative inversion, dynamically corrects the key parameters of the model, and thus effectively improves the pre-camber calculation accuracy.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and more specifically, to a method, system, equipment, and medium for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct. Background Technology

[0002] As a type of hydraulic engineering canal structure, the continuous rigid frame aqueduct effectively reduces its self-weight and ensures longitudinal bending stiffness and lateral torsional stiffness through the rigid connection technology between the upper aqueduct structure and the lower supports. In the construction of continuous rigid frame aqueducts, the pre-camber, as a key factor affecting the aqueduct's closure accuracy, the completed bridge alignment, and long-term performance, directly determines the accuracy of the formwork elevation. Since there is no industry-specific system standard for continuous rigid frame aqueducts, the setting of the pre-camber mainly refers to relevant theories and standards for highway engineering.

[0003] In related technologies, the load characteristics of continuous rigid frame aqueducts and highway bridges differ fundamentally. Highway bridges experience random vehicle loads, while continuous rigid frame aqueducts are under full load for most of their service life, operating at their design flow rate. Therefore, relying solely on highway engineering theories and standards for pre-camber analysis and simulation cannot accurately reflect the load characteristics of hydraulic aqueducts, leading to significant discrepancies between calculated pre-camber and actual requirements. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the accuracy of pre-camber calculation.

[0005] To address the aforementioned problems, this invention provides a method, system, equipment, and medium for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct.

[0006] In a first aspect, the present invention provides a method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct, comprising:

[0007] The continuous rigid frame aqueduct is divided into multiple cantilever beam segments, and a finite element mechanical model of the continuous rigid frame aqueduct is constructed based on the cantilever beam segments.

[0008] Based on the finite element mechanical model, the stress and deflection of each construction stage of the continuous rigid frame aqueduct are theoretically predicted, and the theoretical stress and deflection values ​​of each construction stage are obtained.

[0009] Obtain the actual stress and deflection values ​​during the construction phase, and establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value.

[0010] The key parameters are obtained by iterative inversion using the comprehensive objective function.

[0011] Based on the key parameters, the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model is determined.

[0012] Optionally, the step of dividing the continuous rigid frame aqueduct into multiple cantilever beam segments and constructing a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments includes:

[0013] Based on the construction drawings and design parameters of the continuous rigid frame aqueduct, the continuous rigid frame aqueduct is divided into multiple cantilever beam segments;

[0014] Each cantilever beam segment is discretized into corresponding beam elements through finite element analysis;

[0015] The connection points between the beam elements are used as the calculation nodes to construct the finite element mechanical model.

[0016] Optionally, the step of theoretically predicting the stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, and obtaining the theoretical stress and deflection values ​​for each construction stage, includes:

[0017] The construction stages are divided according to each cantilever beam segment in the finite element mechanical model, including the formwork erection stage, the concrete pouring stage, and the prestressing tensioning stage.

[0018] Based on the finite element mechanical model, the mechanical response of each construction stage under the action of structural self-weight and prestressed load is simulated to obtain the construction conditions of each construction stage.

[0019] Based on the construction conditions of the construction stage, determine the theoretical stress value and theoretical deflection value of each calculation node in the construction stage.

[0020] Optionally, obtaining the actual stress and deflection values ​​during the construction stage includes:

[0021] By monitoring the stress and deflection at preset stress and deflection points respectively set on the continuous rigid frame aqueduct, the actual stress and deflection values ​​during the construction stage are obtained.

[0022] The stress gauge and the displacement gauge are positioned at locations consistent with the corresponding calculation nodes in the finite element mechanical model.

[0023] Optionally, establishing a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value includes:

[0024] For each calculation node, the stress deviation ratio is determined based on the theoretical stress value and the actual stress value, and the deflection deviation ratio is determined based on the theoretical deflection value and the actual deflection value.

[0025] The absolute values ​​of the stress deviation ratio and the deflection deviation ratio corresponding to each calculation node are summed together with the number of preset stress measurement points and the number of preset deflection measurement points to generate the comprehensive objective function.

[0026] Optionally, the step of iteratively inverting the comprehensive objective function to obtain key parameters includes:

[0027] Set the error threshold for the comprehensive objective function;

[0028] Using the aforementioned error threshold as a constraint, the prestressed tendon loss parameters and material mechanical parameters are corrected to obtain the corrected prestressed tendon loss parameters and material mechanical parameters.

[0029] Substitute the corrected prestress loss parameters and material mechanics parameters into the finite element mechanical model to update the theoretical stress value and the theoretical deflection value of the calculation node corresponding to each construction stage;

[0030] Based on the updated theoretical stress value and the theoretical deflection value, combined with the actual stress value and the actual deflection value, the error value of the comprehensive objective function is determined;

[0031] If the error value is greater than the error threshold, then return to the step of correcting the prestressed tendon loss parameters and material mechanical parameters with the error threshold as a constraint, until the error value is less than the error threshold;

[0032] If the error value is less than or equal to the error threshold, then the prestress loss parameter and the material mechanical parameter corresponding to the error value that finally satisfies the error threshold are taken as the key parameters.

[0033] Optionally, determining the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model based on the key parameters includes:

[0034] Based on the prestress loss parameters and the material mechanical parameters, combined with the stiffness reduction factor, the long-term growth factor of dead / live load and the long-term growth factor of prestress, the construction precamber of each calculation node is determined;

[0035] The finite element mechanical model is updated by the prestress loss parameters and material mechanical parameters to determine the flow conditions and long-term shrinkage and creep of the continuous rigid frame aqueduct.

[0036] Based on the cosine distribution law, the pre-camber of each calculation node is determined according to the flow conditions and the long-term shrinkage and creep.

[0037] The construction pre-camber of each calculation node is superimposed with the completed bridge pre-camber to obtain the total mid-span pre-camber value of each calculation node.

[0038] Secondly, the continuous rigid frame aqueduct mid-span pre-camber calculation system of the present invention includes:

[0039] A modeling unit is used to divide a continuous rigid frame aqueduct into multiple cantilever beam segments and to construct a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments.

[0040] The prediction unit is used to perform theoretical prediction of stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, and to obtain the theoretical stress value and theoretical deflection value for each construction stage.

[0041] The function establishment unit is used to obtain the actual stress value and actual deflection value during the construction stage, and to establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value.

[0042] An iterative unit is used to perform iterative inversion through the comprehensive objective function to obtain key parameters;

[0043] The data acquisition unit is used to determine the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model based on the key parameters.

[0044] Thirdly, the electronic device of the present invention includes: a processor and a memory, the memory being used to store a computer program;

[0045] When the computer program is loaded by the processor, it causes the processor to execute the above-described method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct.

[0046] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct.

[0047] The present invention relates to a method, system, equipment, and medium for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct. By establishing a finite element mechanical model that matches the structure and construction stage of the continuous rigid frame aqueduct, and introducing measured stress and deflection data from the construction stage, a comprehensive objective function is constructed for parameter inversion. This effectively corrects the deviation between the theoretical model and the actual situation. The present invention fully considers the actual mechanical behavior and deformation characteristics of the aqueduct structure during construction, thereby significantly improving the accuracy of pre-camber prediction and ensuring that the closure accuracy of the aqueduct and the bridge alignment meet the design requirements.

[0048] Traditional methods rely heavily on highway bridge theories and standards, failing to reflect the typical hydraulic load characteristic of aqueducts operating under full load throughout their service life. This invention establishes a dedicated finite element mechanical model for aqueducts, realistically simulating their load distribution and transmission mechanisms. This allows for a more accurate calculation of pre-camber in accordance with the actual stress state of the aqueduct. Furthermore, by collecting actual stress and deflection values ​​in stages and comparing them with theoretical predictions, a comprehensive objective function is established for iterative inversion. This dynamically identifies and corrects key design parameters such as concrete elastic modulus, shrinkage and creep coefficients, and prestress loss. This process achieves controllable optimization throughout the entire construction cycle, forming a closed-loop control system of theory-measurement-feedback-correction, thus improving the predictability and controllability of the construction process.

[0049] In summary, this invention establishes a finite element mechanical model that matches the continuous rigid frame aqueduct structure and construction stage, incorporates measured stress and deflection data during construction, constructs a comprehensive objective function for iterative inversion, and dynamically corrects key model parameters, thereby effectively improving the accuracy of pre-camber calculation. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating the method for calculating the pre-camber of the middle span in a continuous rigid frame aqueduct according to an embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of the finite element mechanical model of the continuous rigid frame aqueduct in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the pre-camber of each node before the mid-span jacking closure in an embodiment of the present invention.

[0053] Figure 4 This is a schematic diagram of the pre-camber of each node of the bridge before the mid-span jacking closure in an embodiment of the present invention.

[0054] Figure 5 This is a schematic diagram of the pre-excavation height distribution across each node in a continuous rigid frame aqueduct according to an embodiment of the present invention.

[0055] Figure 6This is a schematic diagram of the structure of the mid-span pre-camber calculation system for a continuous rigid frame aqueduct in an embodiment of the present invention;

[0056] Figure 7 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention. Detailed Implementation

[0057] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0058] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0059] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0060] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0061] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0062] Combination Figure 1 As shown, this embodiment of the invention provides a method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct, including:

[0063] The continuous rigid frame aqueduct is divided into multiple cantilever beam segments, and a finite element mechanical model of the continuous rigid frame aqueduct is constructed based on the cantilever beam segments.

[0064] Specifically, based on the construction drawings, construction plan, and key parameters such as concrete unit weight, elastic modulus, shrinkage and creep coefficient, and prestress loss measured through parallel tests, the aqueduct is divided into multiple cantilever beam segments along the longitudinal direction. Corresponding two-dimensional or three-dimensional beam element mechanical models are established using finite element software such as MIDAS, thereby providing an accurate numerical calculation basis for subsequent stage analysis.

[0065] For example, combined Figure 2 As shown, based on the construction drawings and design parameters measured by parallel tests conducted by the monitoring unit, the entire aqueduct is divided into multiple cantilever beam segments according to the construction plan. For example, based on the construction drawings and design parameters measured by parallel tests conducted by the monitoring unit, such as concrete unit weight, strength, shrinkage and creep coefficient, elastic modulus, and prestressing tendon loss, and according to the construction plan, the entire aqueduct structure is divided longitudinally into multiple cantilever beam segments. The division criteria typically include: dividing the aqueduct longitudinally based on its span, cross-sectional shape, prestressing arrangement, and construction technology (such as the cantilever casting method using hanging baskets). The bridge is divided into several segments; the length of each cantilever beam segment is generally 3 to 5 meters, with the specific length determined based on the length of the formwork, the capacity of a single concrete pour, and the prestressing tensioning process. Each segment corresponds to a construction cycle, including three main stages: formwork erection, pouring, and tensioning. Taking a continuous rigid frame aqueduct with a mid-span of 120 meters as an example, if symmetrical cantilever construction is adopted, each cantilever can be divided into approximately 15 segments, each approximately 4 meters long, for a total of approximately 30 construction beam segments. Each segment corresponds to one or more beam elements in the finite element mechanical model, facilitating stage-by-stage stress and deformation analysis. Taking a certain aqueduct as an example, a three-dimensional finite element mechanical model is established using MIDAS as follows: Figure 2 As shown, each segment is discretized into a beam element model, and the entire bridge is divided into 122 beam elements and 131 nodes. The trough body material is C55 concrete, and the trough piers are C40 concrete.

[0066] Based on the finite element mechanical model, the stress and deflection of each construction stage of the continuous rigid frame aqueduct are theoretically predicted, and the theoretical stress and deflection values ​​of each construction stage are obtained.

[0067] Specifically, in the finite element mechanical model, each cantilever beam segment is further subdivided into three typical construction stages for simulation: moving the formwork forward, pouring concrete, and tensioning prestressing tendons. The synchronous construction and closure process of each T-structure is simulated according to the actual construction sequence. Based on this, the stress and deflection values ​​of each node under each construction stage are predicted theoretically, forming a comparable theoretical benchmark.

[0068] Obtain the actual stress and deflection values ​​during the construction phase, and establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value.

[0069] Specifically, by embedding stress gauges and displacement gauges at key locations within the aqueduct, the actual stress and deflection values ​​at corresponding construction stages are monitored simultaneously during construction. This yields measured data reflecting the true mechanical state of the structure, which is then used for comparison and correction with theoretical values. Furthermore, to overcome the shortcomings of traditional single-parameter correction, this embodiment establishes a dual-parameter comprehensive objective function that simultaneously considers stress and deflection errors. With the objective function value approaching zero as the optimization goal, key parameters such as elastic modulus, prestress loss, and shrinkage / creep coefficient are continuously corrected through iterative inversion until the error between the calculated and measured values ​​meets the set standard (e.g., f < 0.01), making the model parameters more closely match the actual engineering situation.

[0070] In a preferred embodiment of the present invention, the comprehensive objective function f is established according to formula (1):

[0071] , formula (1);

[0072] In the formula, , The measuring points are respectively under static loading conditions. j Measured and finite element analysis values ​​of deflection at the location; , For static loading conditions, measuring points j Measured stress values ​​and finite element calculation values ​​at the location, m、n These represent the number of measurement points for deflection and stress under static conditions, respectively.

[0073] The key parameters are obtained by iterative inversion using the comprehensive objective function.

[0074] Specifically, based on the parameters corrected by inversion, the precamber of the i-th node is calculated using formula (2). This formula comprehensively covers the deflection caused by factors such as the self-weight of the cast and uncast beam segments, prestress, shrinkage and creep, formwork deformation, temperature, construction load, and system transformation. A stiffness reduction factor and a long-term growth factor are introduced for correction, thus accurately reflecting the cumulative deformation during construction. Formula (2) is as follows:

[0075] , formula (2);

[0076] in, Indicates the pre-camber of the i-th node during construction, in mm; This represents the stiffness reduction factor, with a value of 0.95. This represents the long-term growth factor of dead / live loads. When using concrete below C40, the value is 1.60; when using concrete between C40 and C80, the value is 1.45 to 1.35. For intermediate strength grades, linear interpolation can be used, and for C55, the value is 1.413. This indicates that the prestressing force of the prestressed steel bars should be reduced by all prestress losses, and the long-term growth factor is taken as 2.0. To calculate the cumulative deflection value (in mm) of the beam segment poured before node i in construction stage and in subsequent stages; Formula (3); where the superscript 1 indicates the influence of the structure's self-weight. express Similarly, the deflection of the beam segment already cast before the node under its own weight is also considered. +1、 +2 and so on also indicate nodes, and each node corresponds to a pouring section. This indicates the influence value of the deflection caused by the self-weight of the subsequent beam segment to be poured; These are the values ​​for early shrinkage and creep, the effect of formwork deformation, temperature correction, deflection caused by construction load, and deflection (mm) caused by system transformation and secondary dead load. A key feature is that the pre-cast beam segment has already undergone its own weight deformation and no longer affects the subsequently cast segments. To calculate the cumulative deflection (in mm) of the point affected by the longitudinal prestressing tensioning of the cast beam segment during the construction phase and in subsequent phases; where, Formula (4), where the superscript 2 indicates the effect of prestressing. This represents the deflection of the prestressed beam segment cast before node i under tension. This indicates the influence value of deflection after prestressing tensioning of subsequent beam segments.

[0077] Based on the key parameters, the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model is determined.

[0078] Specifically, considering the load characteristics during the operation of the aqueduct, the variable load in the calculation of the precamber of the highway bridge is reduced to the full-distribution design flow load. The completed bridge state (including 10-year shrinkage and creep) is modeled according to the modified parameters, and the precamber of the completed bridge is calculated according to formula (5). This formula distributes the deflection caused by the design flow according to the cosine curve, reflecting the deformation characteristics of the aqueduct under the action of a long-term full-distribution water load. Finally, the construction precamber and the completed bridge precamber of the same node are superimposed according to formula (6) to obtain the total precamber value of the mid-span of the node, thereby providing a direct and scientific basis for determining the formwork elevation of each beam segment, ensuring that the construction closure accuracy and the completed bridge alignment meet the design requirements.

[0079] In this process, the pre-camber of the bridge is calculated and allocated according to the adjusted parameter correction model, taking into account the design flow conditions after the aqueduct is completed and the shrinkage and creep over 10 years. Formula (5); where, The deflection, in mm, is the deflection caused by the design flow rate acting on the i-th node. The span of the aqueduct is mm; x represents the distance from the i-th node to the support point, mm; further, the total pre-camber of node i at each construction stage is calculated according to formula (6): Formula (6) in which, For the first i Total precamber of the node, mm.

[0080] The method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct in this embodiment establishes a finite element mechanical model that matches the structure and construction stage of the continuous rigid frame aqueduct, and introduces measured stress and deflection data from the construction stage. It constructs a comprehensive objective function for parameter inversion, which can effectively correct the deviation between the theoretical model and the actual situation. This invention fully considers the actual mechanical behavior and deformation characteristics of the aqueduct structure during construction, thereby significantly improving the accuracy of pre-camber prediction and ensuring that the closure accuracy of the aqueduct and the bridge alignment meet the design requirements.

[0081] Traditional methods rely heavily on highway bridge theories and standards, failing to reflect the typical hydraulic load characteristic of aqueducts operating under full load throughout their service life. This embodiment establishes a dedicated finite element mechanical model for the aqueduct, realistically simulating its load distribution and transmission mechanism. This allows for a more accurate calculation of the pre-camber to reflect the actual stress state of the aqueduct. By collecting actual stress and deflection values ​​in stages and comparing them with theoretical predictions, a comprehensive objective function is established for iterative inversion. This allows for the dynamic identification and correction of key design parameters such as concrete elastic modulus, shrinkage and creep coefficients, and prestress loss. This process achieves controllable optimization throughout the entire construction cycle, forming a closed-loop control system of theory-measurement-feedback-correction, thus improving the predictability and controllability of the construction process.

[0082] In summary, this embodiment establishes a finite element mechanical model that matches the continuous rigid frame aqueduct structure and construction stage, incorporates measured stress and deflection data during construction, constructs a comprehensive objective function for iterative inversion, and dynamically corrects key model parameters, thereby effectively improving the accuracy of pre-camber calculation.

[0083] Optionally, the step of dividing the continuous rigid frame aqueduct into multiple cantilever beam segments and constructing a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments includes:

[0084] Based on the construction drawings and design parameters of the continuous rigid frame aqueduct, the continuous rigid frame aqueduct is divided into multiple cantilever beam segments;

[0085] Each cantilever beam segment is discretized into corresponding beam elements through finite element analysis;

[0086] The connection points between the beam elements are used as the calculation nodes to construct the finite element mechanical model.

[0087] Specifically, based on the construction drawings of the continuous rigid frame aqueduct and the design parameters obtained by the monitoring unit through parallel tests, such as concrete unit weight, elastic modulus, shrinkage and creep coefficient, and prestress loss, the entire aqueduct structure is divided longitudinally into multiple independent cantilever beam segments according to the established cantilever casting construction plan. Figure 2 As shown, this provides clear geometric and physical partitioning for subsequent refined modeling. Furthermore, using finite element analysis software such as MIDAS, each cantilever beam segment is further discretized into multiple beam elements. For example, in one embodiment, the entire bridge is discretized into 122 beam elements. Each beam element is assigned corresponding section properties and material constitutive relations based on its location and material properties, such as C55 concrete in the channel body and C40 concrete in the piers, thereby accurately representing the mechanical behavior of the structure numerically. The connection endpoints between the discretized beam elements and key structural parts, such as supports, mid-span, and variable cross-sections, are set as calculation nodes. All nodes are interconnected through element stiffness matrices, ultimately forming a complete two-dimensional or three-dimensional finite element mechanical model containing 131 nodes. This model serves as the basic calculation framework for all subsequent construction stage simulations, theoretical predictions, and parameter inversions.

[0088] In this optional embodiment, the aqueduct is divided into multiple cantilever beam segments based on the construction drawings and measured design parameters. Each beam segment is discretized into beam elements with clear material and cross-sectional properties using the finite element method. Finally, the connection points of the elements are used as calculation nodes to form a complete mechanical model. This constructs a high-fidelity numerical model that can accurately reflect the actual geometry and material properties of the structure and completely simulate the mechanical transmission path during construction. This lays a solid foundation for subsequent reliable stage simulation, theoretical prediction, and parameter inversion.

[0089] Optionally, the step of theoretically predicting the stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, and obtaining the theoretical stress and deflection values ​​for each construction stage, includes:

[0090] The construction stages are divided according to each cantilever beam segment in the finite element mechanical model, including the formwork erection stage, the concrete pouring stage, and the prestressing tensioning stage.

[0091] Based on the finite element mechanical model, the mechanical response of each construction stage under the action of structural self-weight and prestressed load is simulated to obtain the construction conditions of each construction stage.

[0092] Based on the construction conditions of the construction stage, determine the theoretical stress value and theoretical deflection value of each calculation node in the construction stage.

[0093] Specifically, each cantilever beam segment is further subdivided into three standard construction stages: first, the formwork erection stage, i.e., the forward positioning of the hanging basket; second, the concrete pouring stage; and finally, the prestressing tensioning stage. Based on the actual construction sequence, such as simultaneous construction of each T-structure and closure of the side spans before the middle span, corresponding elements and loads are sequentially activated or deactivated in the finite element model to simulate a complete, phased construction process. Based on the established finite element model, static simulations are performed on the mechanical behavior of each construction stage under specific load combinations, mainly including the newly added structural self-weight, applied prestress, and temporary construction loads. Detailed construction conditions for each stage are generated, allowing for the calculation of the overall and local mechanical responses of the model under each condition. By extracting the calculation results from the finite element software under the aforementioned construction conditions, the theoretical values ​​of axial stress, bending stress, and vertical displacement are directly obtained for each preset calculation node in the model, corresponding to the key sections of the beam segment in the corresponding stage. This forms a complete and quantifiable sequence of stage deformation and internal force prediction data, providing a benchmark for subsequent comparison with measured values.

[0094] In this optional embodiment, each cantilever beam segment is finely divided into three typical construction stages: formwork erection, concrete pouring, and prestressing tensioning. The mechanical response of each stage under the combined action of structural self-weight and prestressing load is simulated sequentially in the finite element mechanical model. This achieves high-precision theoretical prediction of the stress and deformation evolution path of the structure throughout the construction process and provides a detailed sequence of theoretical stress and deflection values ​​for each calculation node. This forms the basis for subsequent comparison with measured data, identification of model deviations, and initiation of parameter inversion correction. It effectively supports the key transformation of pre-camber calculation from static theoretical analysis to dynamic construction adaptability.

[0095] Optionally, obtaining the actual stress and deflection values ​​during the construction stage includes:

[0096] By monitoring the stress and deflection at preset stress and deflection points respectively set on the continuous rigid frame aqueduct, the actual stress and deflection values ​​during the construction stage are obtained.

[0097] The stress gauge and the displacement gauge are positioned at locations consistent with the corresponding calculation nodes in the finite element mechanical model.

[0098] Specifically, according to the pre-established construction monitoring plan, stress gauges and displacement gauges are pre-embedded or installed at multiple key sections of the aqueduct structure, such as the root of the cantilever, the mid-span, and near the closure section, forming a network of pre-set stress measurement points and pre-set deflection measurement points covering the main stress areas, thereby providing a hardware foundation for obtaining the actual mechanical state of the structure during construction.

[0099] During actual construction, whenever construction progresses to a predefined stage, such as the completion of concrete pouring or prestressing tensioning of a certain segment, the monitoring data from stress gauges and displacement gauges at the corresponding preset measuring points are synchronously read through the data acquisition system. This directly obtains the actual stress and deflection values ​​at each measuring point during that construction stage. The actual values ​​obtained from the monitoring are synchronously recorded and correlated with the theoretical stress and deflection values ​​calculated by the finite element mechanical model for the corresponding stage and node, forming data pairs for subsequent comparative analysis. This provides accurate measured data input for establishing a comprehensive objective function and initiating parameter inversion.

[0100] In this embodiment, to ensure the homogeneity and comparability of the data upon which subsequent parameter inversion depends, in the collaborative design before construction, based on the three-dimensional coordinates of the calculation nodes predefined in the key cross-section of the structure by the finite element mechanical model, sensors are precisely deployed and installed at the exact corresponding geometric positions of the actual aqueduct structure. This establishes a precise positional mapping relationship between the physical space and the numerical model, thereby ensuring that the theoretical value of a certain calculation node output from the finite element mechanical model and the measured value read from the corresponding sensor at the site represent the mechanical response of the same point on the structure at the same construction stage.

[0101] In this optional embodiment, by systematically deploying a network of stress gauges and displacement gauges at key locations of the aqueduct structure, real-time, in-situ measurements of the actual mechanical response of the structure at each construction stage are achieved. This obtains actual stress and deflection values ​​that directly reflect the combined effects of material properties, construction techniques, and environmental factors, providing an objective and accurate basis of measured data for reliable comparison with theoretical predictions. This effectively overcomes the model bias problem that may exist if theoretical calculations are relied upon alone.

[0102] Optionally, establishing a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value includes:

[0103] For each calculation node, the stress deviation ratio is determined based on the theoretical stress value and the actual stress value, and the deflection deviation ratio is determined based on the theoretical deflection value and the actual deflection value.

[0104] The absolute values ​​of the stress deviation ratio and the deflection deviation ratio corresponding to each calculation node are summed together with the number of preset stress measurement points and the number of preset deflection measurement points to generate the comprehensive objective function.

[0105] Specifically, after obtaining the theoretical stress value, theoretical deflection value, and corresponding actual stress value and actual deflection value for each measuring point at each construction stage, the relative deviation between the theoretical value and the measured value for each measuring point is first calculated. That is, the ratio of theoretical value - measured value to measured value is used to determine the stress deviation ratio and the deflection deviation ratio, thereby quantifying the degree of deviation between the theoretical prediction and the actual situation for each measuring point. At the same time, considering the differences in response at different locations of the structure, the stress deviation ratio of all preset stress measuring points (m in total) and the deflection deviation ratio of all preset deflection measuring points (n in total) are calculated according to the above formula (1). ,in, The stress deviation ratio mentioned above, The deflection deviation ratios mentioned above are summed after taking the absolute values ​​of the deviation ratios at each measuring point, thus aggregating the error information scattered across various measuring points into a single overall error index. The objective function f generated through the above steps directly represents the comprehensive difference between the overall output of the current finite element mechanical model and the measured response of the structure. This establishes a mathematical relationship that unifies and quantifies multi-type, multi-location monitoring data into an iteratively optimized objective, providing a clear convergence criterion for subsequent automatic inversion of driving parameters.

[0106] In this optional embodiment, by establishing a comprehensive objective function that simultaneously integrates the deviations of two key measured data types—stress and deflection—the traditional single-parameter independent correction method is elevated to an optimization framework for multi-parameter collaborative inversion. This effectively overcomes the model distortion problem that may occur due to the one-sidedness of data when correcting solely based on stress or deflection. The comprehensive objective function, by aggregating the absolute deviation ratios of all measuring points and using near-zero as the optimization objective, provides a quantitative and comprehensive convergence judgment basis for the parameter inversion process. This significantly improves the reliability and overall accuracy of iterative correction of key parameters such as elastic modulus and prestress loss, thus laying a solid analytical foundation for the subsequent accurate calculation of pre-camber.

[0107] Optionally, the step of iteratively inverting the comprehensive objective function to obtain key parameters includes:

[0108] Set the error threshold for the comprehensive objective function;

[0109] Using the aforementioned error threshold as a constraint, the prestressed tendon loss parameters and material mechanical parameters are corrected to obtain the corrected prestressed tendon loss parameters and material mechanical parameters.

[0110] Substitute the corrected prestress loss parameters and material mechanics parameters into the finite element mechanical model to update the theoretical stress value and the theoretical deflection value of the calculation node corresponding to each construction stage;

[0111] Based on the updated theoretical stress value and the theoretical deflection value, combined with the actual stress value and the actual deflection value, the error value of the comprehensive objective function is determined;

[0112] If the error value is greater than the error threshold, then return to the step of correcting the prestressed tendon loss parameters and material mechanical parameters with the error threshold as a constraint, until the error value is less than the error threshold;

[0113] If the error value is less than or equal to the error threshold, then the prestress loss parameter and the material mechanical parameter corresponding to the error value that finally satisfies the error threshold are taken as the key parameters.

[0114] Specifically, the error threshold of the comprehensive objective function is set to a minimum value approaching zero. For example, in practical implementation, an error value f < 0.01 is used as a constraint condition. This serves as a quantitative standard for judging whether the parameter inversion has converged, ensuring that the prediction accuracy of the corrected model meets engineering requirements. Using this error threshold as a constraint, adjustment coefficients are introduced to correct prestressed tendon loss parameters in the initial finite element mechanical model, such as the percentage loss after tensioning of straight and curved tendons, and material mechanical parameters, such as the elastic modulus of concrete and the shrinkage and creep coefficient. These coefficients are adjusted through trial calculations or optimization algorithms to make the parameter values ​​more consistent with the actual conditions reflected by the measured data.

[0115] For example, in Table 1 below, the elastic modulus of block 2 is adjusted from 3.55e4 MPa to 3.37e4 MPa. As shown in Table 1, during the pre-camber analysis of the continuous rigid frame aqueduct, the results of iterative inversion and correction of key design parameters are obtained by comparing measured data with theoretical models. Specifically: The loss after straight-line tensioning represents the percentage of prestress loss caused by factors such as anchor deformation and prestressing tendon retraction after tensioning of the straight-line prestressing tendons; the loss after curved-beam tensioning represents the percentage of prestress loss caused by factors such as friction and anchorage after tensioning of the curved-beam prestressing tendons; the elastic modulus of block 2 refers to the elastic modulus of the concrete used in a beam segment (block 2) in the aqueduct structure, reflecting the material's ability to resist elastic deformation. The initial value represents the theoretical parameter value selected during the design stage or based on experience. The adjustment coefficient represents the parameter correction coefficient obtained by inversion calculation through a comprehensive objective function based on measured stress and deflection data during the construction stage. The corrected value represents the parameter value obtained by multiplying the initial value by the adjustment coefficient, which better reflects the actual engineering situation. The tension loss for straight sections was slightly adjusted from 7.4% to 7.5% (adjustment factor 1.02), a minor change. The tension loss for curved bundles was increased from 12.4% to 13.6% (adjustment factor 1.1), indicating that actual frictional losses were greater than originally expected. The elastic modulus of block 2 was adjusted from... Downgraded to (Adjustment coefficient 0.95) indicates that the actual concrete stiffness is slightly lower than the original design value. Through correction, the key parameters in the model are closer to the actual construction performance, thereby significantly improving the prediction accuracy of the finite element mechanical model for structural behavior, and laying a reliable foundation for the subsequent accurate calculation of the pre-camber of the construction and the pre-camber of the completed bridge. The corrected prestress loss parameters and material mechanical parameters are re-input into the finite element mechanical model, such as the MIDAS model, to update the load and material properties of each construction stage, and the construction stage simulation is rerun to obtain the updated theoretical stress and deflection values ​​for each calculation node. Based on the updated theoretical stress and deflection values ​​and the actual stress and deflection values ​​obtained by actual measurement, they are substituted into the above formula (1) of the comprehensive objective function for calculation to determine the error value corresponding to the current parameter set and evaluate the degree of agreement between the model prediction and the measured data.

[0116] Table 1 Parameter Correction Results

[0117]

[0118] If the calculated error value is greater than the preset error threshold (e.g., f≥0.01), then based on the current error analysis, the prestress loss or material parameters are further fine-tuned, and the process of updating the model and calculation error is repeated to form an iterative cycle. When the iterative calculation makes the error value of the comprehensive objective function less than or equal to the preset error threshold, the model is considered to have reached sufficient accuracy. At this point, the iteration stops, and the prestress loss parameters and material mechanical parameters used in the final iteration, as shown in Table 1 (corrected loss percentage and elastic modulus), are determined as the key parameters obtained from the inversion and used for the accurate calculation of the subsequent pre-camber.

[0119] In this optional embodiment, by setting a clear error threshold and constructing an automated iterative inversion process of calculation-comparison-correction, a systematic and quantitative dynamic correction of prestress loss and material mechanical parameters is realized. This process enables the finite element mechanical model to continuously self-calibrate based on actual construction data until its comprehensive output error converges to the permissible range. This fundamentally overcomes the model distortion problem caused by relying on experience to select fixed parameters in traditional methods, and finally obtains a set of key parameters that closely matches the actual situation of a specific project, providing a reliable and adaptive core input for the accurate calculation of the pre-camber of the completed bridge during subsequent construction.

[0120] Optionally, determining the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model based on the key parameters includes:

[0121] Based on the prestress loss parameters and the material mechanical parameters, combined with the stiffness reduction factor, the long-term growth factor of dead / live load and the long-term growth factor of prestress, the construction precamber of each calculation node is determined;

[0122] The finite element mechanical model is updated by the prestress loss parameters and material mechanical parameters to determine the flow conditions and long-term shrinkage and creep of the continuous rigid frame aqueduct.

[0123] Based on the cosine distribution law, the pre-camber of each calculation node is determined according to the flow conditions and the long-term shrinkage and creep.

[0124] The construction pre-camber of each calculation node is superimposed with the completed bridge pre-camber to obtain the total mid-span pre-camber value of each calculation node.

[0125] Specifically, based on the prestress loss parameters and material mechanical parameters obtained from the inversion (such as the corrected elastic modulus of 3.37e4 MPa, prestress loss of 7.5% and 13.6% in Table 1), the construction camber of each calculation node is calculated by substituting them into formula (2). This formula comprehensively considers various factors such as the self-weight of the cast and uncast beam segments, the cumulative deflection caused by prestress, the deformation of the hanging basket, temperature, and construction load. The calculation results are corrected by introducing the stiffness reduction factor k1 (0.95), the long-term growth factor of dead / live load k2 (1.413 for C55 concrete), and the long-term growth factor of prestress k3 (2.0). Finally, the results are obtained as follows: Figure 3 The pre-camber values ​​distributed along the beam segment are shown. The finite element mechanical model is updated using the corrected prestress loss and material parameters (such as shrinkage and creep coefficients) to simulate the condition of full load with a continuous design flow (such as 75 m³ / s) after the aqueduct is built, and the state after the concrete shrinkage and creep effect for up to 10 years is considered. Mechanical analysis is performed to obtain the long-term deformation of the structure under this condition. Based on the deflection results obtained from the above flow condition and long-term shrinkage and creep analysis, the pre-camber of each node is calculated using the above formula (5). This formula is based on the deflection value under the design flow, multiplied by the coefficient considering the long-term effect, and the pre-camber value is distributed to different positions within the span according to the cosine curve law of (1-cos(2πx / L)) (x is the distance from the support point, L is the span), thus obtaining the following results. Figure 4 The pre-camber distribution of the completed bridge, as shown, conforms to the stress characteristics of full water load. The construction pre-camber calculated by formula (2) and the completed bridge pre-camber calculated by formula (5) for the same calculation node are algebraically superimposed. The total mid-span pre-camber value of that node is obtained according to formula (6), thus forming the distribution as shown. Figure 5 The final pre-camber setting curve shown provides a direct and complete basis for determining the formwork elevation of each beam segment.

[0126] In one embodiment of the present invention, based on the construction drawings and design parameters measured by parallel tests conducted by the monitoring unit, the entire aqueduct is divided into multiple cantilever beam segments according to the construction plan. Taking a certain aqueduct as an example, a three-dimensional finite element mechanical model is established using MIDAS, as follows: Figure 2As shown, each segment is discretized into a beam element model, and the entire bridge is divided into 122 beam elements and 131 nodes. The material of the trough body is C55 concrete and the trough piers are C40 concrete. The entire bridge construction process is divided into 57 construction stages, and each cantilever beam segment is divided into 3 construction stages: formwork construction (i.e., moving the hanging basket forward), concrete pouring construction, and tensioning of prestressing tendons construction; each "T" structure is constructed simultaneously, with the side spans on both sides closed first, and the middle span pushed and closed later. The stress and deformation of the construction beam segment are calculated. The stress and deflection of the corresponding construction stage are monitored, and the objective function is established according to the formula. The parameters such as elastic modulus and prestressing tendon loss are further reasonably adjusted according to the error f < 0.01 as the constraint condition. The stress and deformation of the construction beam segment are recalculated iteratively until the error standard is met. The corrected elastic modulus, prestressing tendon loss and other parameters are referred to Table 1 above. According to the corrected parameters, modeling calculation is carried out, and the construction pre-camber of each node is calculated according to the above formula (3). The design flow rate after the aqueduct is completed is 75m³. 3 / s, while considering the completion of shrinkage and creep over 10 years, modeling analysis is carried out. Based on the deflection in the analysis results, the pre-camber of the currently poured beam segment is calculated and allocated according to the above formula (4), such as Figure 4 The diagram shows the pre-camber of each node before the mid-span jacking closure. The two results are superimposed, and the total pre-camber of each node before jacking closure is calculated according to the above formula (5), as shown below. Figure 5 As shown.

[0127] In this optional embodiment, by substituting the key parameters obtained from the inversion into a specialized formula for calculating the pre-camber of the constructed and completed bridge, a coordinated and refined calculation of the complex time-varying effects during the construction phase, including all construction loads, prestress losses, and the characteristics of long-term growth and persistent full-coverage water loads during the operation phase, is achieved. The pre-camber of the completed bridge is scientifically allocated according to the cosine distribution law, and the total pre-camber value of each node is finally obtained by superposition. This forms a pre-camber setting method that can accurately reflect the dynamic deformation during the construction process and fully match the load characteristics during the service period of the aqueduct, fundamentally ensuring the closure accuracy, bridge alignment, and long-term safe service performance of the aqueduct.

[0128] Combination Figure 6 As shown, this embodiment of the invention also provides a system for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct, comprising:

[0129] A modeling unit is used to divide a continuous rigid frame aqueduct into multiple cantilever beam segments and to construct a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments.

[0130] The prediction unit is used to perform theoretical prediction of stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, and to obtain the theoretical stress value and theoretical deflection value for each construction stage.

[0131] The function establishment unit is used to obtain the actual stress value and actual deflection value during the construction stage, and to establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value.

[0132] An iterative unit is used to perform iterative inversion through the comprehensive objective function to obtain key parameters;

[0133] The data acquisition unit is used to determine the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model based on the key parameters.

[0134] The advantages of the continuous rigid frame aqueduct mid-span precamber calculation system of the present invention compared with the prior art are the same as those of the above-mentioned continuous rigid frame aqueduct mid-span precamber calculation method compared with the prior art, and will not be repeated here.

[0135] Combination Figure 7 As shown, an embodiment of the present invention also provides an electronic device, including: a processor and a memory, wherein the memory is used to store a computer program;

[0136] When the computer program is loaded by the processor, it causes the processor to execute the above-described method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct.

[0137] The electronic device of the present invention has the same advantages over the prior art as the above-mentioned method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct, and will not be repeated here.

[0138] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct.

[0139] The computer-readable storage medium system of the present invention has the same advantages over the prior art as the above-mentioned method for calculating the pre-camber of the middle span of a continuous rigid frame aqueduct, and will not be repeated here.

[0140] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct, characterized in that, include: The continuous rigid frame aqueduct is divided into multiple cantilever beam segments, and a finite element mechanical model of the continuous rigid frame aqueduct is constructed based on the cantilever beam segments. Based on the finite element mechanical model, the stress and deflection of each construction stage of the continuous rigid frame aqueduct are theoretically predicted, and the theoretical stress and deflection values ​​of each construction stage are obtained. Obtain the actual stress and deflection values ​​during the construction phase, and establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value; including: for each calculation node, determining the stress deviation ratio based on the theoretical stress value and the actual stress value, and determining the deflection deviation ratio based on the theoretical deflection value and the actual deflection value; summing the absolute values ​​of the stress deviation ratio and the deflection deviation ratio corresponding to each calculation node, combined with the number of preset stress measurement points and preset deflection measurement points, to generate the comprehensive objective function; The key parameters are obtained through iterative inversion using the comprehensive objective function, including: setting an error threshold for the comprehensive objective function; using the error threshold as a constraint to correct the prestressing tendon loss parameters and material mechanics parameters, obtaining corrected prestressing loss parameters and material mechanics parameters; substituting the corrected prestressing loss parameters and material mechanics parameters into the finite element mechanical model to update the theoretical stress values ​​and theoretical deflection values ​​of the calculation nodes corresponding to each construction stage; determining the error value of the comprehensive objective function based on the updated theoretical stress values ​​and theoretical deflection values, combined with the actual stress values ​​and actual deflection values; if the error value is greater than the error threshold, returning to the step of correcting the prestressing tendon loss parameters and material mechanics parameters using the error threshold as a constraint, until the error value is less than the error threshold; if the error value is less than or equal to the error threshold, the prestressing loss parameters and material mechanics parameters corresponding to the error value that finally satisfies the error threshold are taken as the key parameters. Based on the key parameters, the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model is determined, including: determining the construction pre-camber of each calculation node based on the prestress loss parameters and the material mechanics parameters, combined with the stiffness reduction factor, the long-term growth factor of dead / live load, and the long-term growth factor of prestress; updating the finite element mechanical model through the prestress loss parameters and the material mechanics parameters to determine the flow conditions and long-term shrinkage and creep of the continuous rigid frame aqueduct; determining the completed bridge pre-camber of each calculation node based on the cosine distribution law, according to the flow conditions and the long-term shrinkage and creep; and superimposing the construction pre-camber of each calculation node with the completed bridge pre-camber to obtain the total pre-camber value of the mid-span of each calculation node.

2. The method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct according to claim 1, characterized in that, The process of dividing the continuous rigid frame aqueduct into multiple cantilever beam segments and constructing a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments includes: Based on the construction drawings and design parameters of the continuous rigid frame aqueduct, the continuous rigid frame aqueduct is divided into multiple cantilever beam segments; Each cantilever beam segment is discretized into corresponding beam elements through finite element analysis; The connection points between the beam elements are used as the calculation nodes to construct the finite element mechanical model.

3. The method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct according to claim 1, characterized in that, The step involves theoretically predicting the stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, obtaining the theoretical stress and deflection values ​​for each construction stage, including: The construction stages are divided according to each cantilever beam segment in the finite element mechanical model, including the formwork erection stage, the concrete pouring stage, and the prestressing tensioning stage. Based on the finite element mechanical model, the mechanical response of each construction stage under the action of structural self-weight and prestressed load is simulated to obtain the construction conditions of each construction stage. Based on the construction conditions of the construction stage, determine the theoretical stress value and theoretical deflection value of each calculation node in the construction stage.

4. The method for calculating the pre-camber of the mid-span of a continuous rigid frame aqueduct according to claim 1, characterized in that, Obtaining the actual stress and deflection values ​​during the construction stage includes: By monitoring the stress and deflection at preset stress and deflection points respectively set on the continuous rigid frame aqueduct, the actual stress and deflection values ​​during the construction stage are obtained. The stress gauge and the displacement gauge are positioned at locations consistent with the corresponding calculation nodes in the finite element mechanical model.

5. A calculation system for the pre-camber of the mid-span of a continuous rigid frame aqueduct, characterized in that, include: A modeling unit is used to divide a continuous rigid frame aqueduct into multiple cantilever beam segments and to construct a finite element mechanical model of the continuous rigid frame aqueduct based on the cantilever beam segments. The prediction unit is used to perform theoretical prediction of stress and deflection for each construction stage of the continuous rigid frame aqueduct based on the finite element mechanical model, and to obtain the theoretical stress value and theoretical deflection value for each construction stage. A function establishment unit is used to obtain the actual stress and deflection values ​​during the construction stage, and to establish a comprehensive objective function based on the theoretical stress value, the theoretical deflection value, the actual stress value, and the actual deflection value. This includes: for each calculation node, determining the stress deviation ratio based on the theoretical stress value and the actual stress value, and determining the deflection deviation ratio based on the theoretical deflection value and the actual deflection value; summing the absolute values ​​of the stress deviation ratio and the deflection deviation ratio corresponding to each calculation node, combined with the number of preset stress measurement points and preset deflection measurement points, to generate the comprehensive objective function. An iterative unit is used to perform iterative inversion through the comprehensive objective function to obtain key parameters; including: setting an error threshold for the comprehensive objective function; using the error threshold as a constraint to correct the prestressing tendon loss parameters and material mechanics parameters, obtaining corrected prestressing loss parameters and material mechanics parameters; substituting the corrected prestressing loss parameters and material mechanics parameters into the finite element mechanical model, updating the theoretical stress value and the theoretical deflection value of the calculation node corresponding to each construction stage; determining the error value of the comprehensive objective function based on the updated theoretical stress value and the theoretical deflection value, combined with the actual stress value and the actual deflection value; if the error value is greater than the error threshold, returning to the step of correcting the prestressing tendon loss parameters and material mechanics parameters using the error threshold as a constraint, until the error value is less than the error threshold; if the error value is less than or equal to the error threshold, then the prestressing loss parameters and material mechanics parameters corresponding to the error value that finally satisfies the error threshold are taken as the key parameters; The data acquisition unit is used to determine the total pre-camber value of the mid-span of each calculation node in the finite element mechanical model based on the key parameters; including: determining the construction pre-camber of each calculation node based on the prestress loss parameters and the material mechanics parameters, combined with the stiffness reduction factor, the long-term growth factor of dead / live load and the long-term growth factor of prestress; updating the finite element mechanical model through the prestress loss parameters and the material mechanics parameters to determine the flow conditions and long-term shrinkage and creep of the continuous rigid frame aqueduct; determining the completed bridge pre-camber of each calculation node based on the cosine distribution law and the flow conditions and the long-term shrinkage and creep; and superimposing the construction pre-camber of each calculation node with the completed bridge pre-camber to obtain the total pre-camber value of the mid-span of each calculation node.

6. An electronic device, characterized in that, include: Processor and memory, the memory being used to store computer programs; When the computer program is loaded by the processor, it causes the processor to execute the method for calculating the pre-camber of the middle span of a continuous rigid frame aqueduct as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the pre-camber of the middle span of a continuous rigid frame aqueduct as described in any one of claims 1-4.

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