Prestress multi-beam cooperative tensioning control method and system for U-shaped aqueduct

Abstract

The invention discloses a U-shaped aqueduct prestress multi-beam cooperative tensioning control method and system. The method comprises the steps that S1, a quantitative derivation model is constructed, based on an aqueduct structural mechanical equilibrium equation, a prestress coupling effect item is introduced for calculation, a prestress coupling matrix is output, and an initial tensioning sequence is derived; the device is simple in structure, and an initial tensioning sequence is deduced by establishing a mechanical equilibrium equation and introducing a coupling effect item; meanwhile, stress / displacement deviation data collected by a monitoring system in real time are fed back to an edge calculation terminal to calculate a control strategy in real time, adjustment is executed by a tensioning device, and therefore a field data closed-loop optimization mechanism is constructed, the tensioning force and sequence can be dynamically corrected, the limitation of a static model is broken through, and the construction efficiency is improved. And a displacement constraint term is introduced as a punishment or control condition in the optimization process, so that deformation overrun of key parts of the structure is effectively prevented, and the precision, safety and intelligent level of prestress construction are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of aqueduct tensioning technology, specifically a method and system for controlling the prestressed multi-bundle coordinated tensioning of a U-shaped aqueduct. Background Technology

[0002] In the construction of U-shaped prestressed aqueducts, prestressing tensioning is the core process to ensure the structural bearing capacity and crack resistance. Due to the complex interaction between longitudinal straight tendons and U-shaped steel tendons, traditional methods relying on experience or static models to preset the tensioning sequence cannot quantify the coupling effect of multiple tendons. That is, the tensioning of one tendon will significantly change the stress state and structural deformation of other tensioned or untensioned tendons. Although the tensioning sequence can be preset by establishing a static finite element model or BIM model, this method, while considering the initial state of the structure to some extent, has two inherent defects: the preset tensioning sequence cannot adapt to the dynamic factors such as the time-varying properties of concrete and environmental temperature changes during construction, and the model is out of sync with the actual working conditions on site; the real-time collected monitoring data such as stress and displacement during construction are only used for simple threshold alarms and fail to drive and dynamically optimize tensioning control parameters (such as tension force and sequence), resulting in a disconnect between the "monitoring" and "control" links, and the prestress distribution ultimately deviates from the theoretical expectation. To address this, a multi-tenon coordinated tensioning control method and system for U-shaped aqueducts is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for controlling the prestressed multi-bundle coordinated tensioning of U-shaped aqueducts, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for controlling the prestressed multi-bundle coordinated tensioning of a U-shaped aqueduct, the method comprising: S1. Construct a quantitative model, based on the mechanical equilibrium equation of the aqueduct structure, introduce the prestress coupling effect term for calculation, output the prestress coupling matrix, and derive the initial tensioning sequence. S2. Perform construction according to the obtained initial tensioning sequence, and collect stress / displacement data in real time through the on-site monitoring system; S3. Input the real-time collected stress / displacement data into the edge computing terminal, and output the control strategy after processing. It also drives the tensioning device to perform adjustments, while simultaneously optimizing the parameters of the quantitative estimation model; S4. Repeat S3 until the actual state of the current tensioning stage meets the predetermined dual-index convergence condition.

[0005] As a further aspect of the present invention: the initial tensioning sequence specifically includes: The objective function is established based on the structural mechanics equilibrium equations, and it satisfies the following expression:

[0006] Where S0 is the initial tensioning sequence. Let be the actual stress of the i-th steel strand. Let the target stress of the i-th steel strand be , The maximum value of the absolute values ​​of the displacement deviations of all critical nodes. This is the displacement weighting coefficient, and its value ranges from 0.2 to 0.5.

[0007] As a further aspect of the present invention: the prestressed coupling effect matrix is ​​calculated based on the following formula:

[0008] Where u and v are positive integers, representing different prestressed steel strands, respectively. Indicates the prestressing coupling coefficient. This represents the concrete stress generated by the u-th prestressed steel strand. This represents the tension force applied to the vth prestressed steel strand.

[0009] As a further aspect of the present invention: a control strategy based on stress and displacement is used to calculate the tension force increment in real time through the following control equation:

[0010] In the formula, where, Let k be the stiffness coefficient of the steel strand. , This is the gain coefficient, and its value ranges from 0.5 to 1.2. Let be the distance from node j to the pivot.

[0011] As a further aspect of the present invention: the dynamic adjustment of the gain coefficient with the age of the concrete specifically includes: In the early stage of concrete Showing an increasing trend It shows a decreasing trend; During the concrete strength stabilization stage Showing a decreasing trend It shows an increasing trend; The cycle of a single adjustment is ≤2 seconds, so as to achieve real-time dynamic response to the tensioning process.

[0012] As a further aspect of the present invention: the actual state during the tensioning stage satisfies the predetermined dual-index convergence condition as follows: ,

[0013] In the formula, For stress, This represents the displacement value.

[0014] A prestressed multi-bundle coordinated tensioning control system for a U-shaped aqueduct includes: The monitoring system is configured to monitor concrete stress / strain and displacement of key nodes in real time. The tensioning control module is used to perform the tensioning operation; An edge computing terminal is configured to calculate the initial tensioning sequence and the tension force increment; The monitoring system and the tensioning control module are both communicatively connected to the edge computing terminal, forming a closed-loop control system.

[0015] As a further aspect of the present invention: the monitoring system uses fiber optic grating sensors as its core, which are deployed at the U-shaped bottom, side walls, and beam top of the aqueduct structure to form a composite monitoring network, and the monitoring accuracy of the fiber optic grating sensors is [missing information]. The data acquisition frequency is no less than 1Hz, and the deployment spacing is 2m. It is equipped with a laser displacement meter with an accuracy of 0.01 mm to monitor the displacement data of key nodes.

[0016] As a further aspect of the present invention: the tension control module has a tension force control accuracy of ±0.5%FS, and the data processing delay of the edge computing terminal is no greater than 100ms.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This application derives the initial tensioning sequence by establishing a mechanical equilibrium equation and introducing a coupling effect term. Simultaneously, it combines the stress / displacement deviation data collected in real time by the monitoring system with the data feedback to the edge computing terminal to calculate and control the strategy in real time. The tensioning device then executes the adjustment, thereby constructing a closed-loop optimization mechanism for on-site data. This mechanism can dynamically correct the tension force and sequence, thus overcoming the limitations of static models. Furthermore, displacement constraint terms are introduced during the optimization process as penalty or control conditions, effectively preventing deformation of key structural components from exceeding limits and significantly improving the accuracy, safety, and intelligence level of prestressed construction. Attached Figure Description

[0018] Figure 1 This is a flowchart of the present invention; Figure 2 This is a detailed flowchart of the present invention; Figure 3 This is a schematic diagram illustrating the optimized control strategy of the present invention; Figure 4 This is a schematic diagram illustrating the closed-loop control process for field data of the present invention; Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-4 In this embodiment of the invention, the prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts includes: S1. Construct a quantitative derivation model. Based on the mechanical equilibrium equations of the aqueduct structure, introduce the prestressing coupling effect term for calculation, output the prestressing coupling matrix, and derive the initial tensioning sequence. Throughout the derivation process: establish the mechanical equilibrium equations of the aqueduct section, introduce the prestressing coupling effect term, and determine the initial tensioning sequence through iterative calculations. The derived initial tensioning sequence is: tension the U-shaped bundles to 40%. The longitudinal bundle is stretched to 100%. U-shaped beam supplemented to 100% .

[0020] S2. Execute the initial tensioning sequence obtained for construction, and collect stress / displacement data in real time through the on-site monitoring system; during the tensioning construction process, as the tensioning state of the prestressed steel strands is constantly changing, the monitoring system synchronously collects stress / displacement data and updates it in real time.

[0021] S3. Input the real-time collected stress / displacement data into the edge computing terminal, and output the control strategy after processing. It also drives the tensioning device to perform adjustments, while simultaneously optimizing and quantitatively estimating the model's parameters; S4. Repeat S3 until the actual state of the current tensioning stage meets the predetermined dual-index convergence condition.

[0022] In this embodiment, the preferred initial tensioning sequence specifically includes: The objective function is established based on the structural mechanics equilibrium equations, and it satisfies the following expression:

[0023] Where S0 is the initial tensioning sequence. Let be the actual stress of the i-th steel strand. Let the target stress of the i-th steel strand be , The maximum value of the absolute values ​​of the displacement deviations of all critical nodes. This is the displacement weighting coefficient, and its value ranges from 0.2 to 0.5.

[0024] In this embodiment, preferably, the prestressed coupling effect matrix is ​​calculated based on the following formula:

[0025] Where u and v are positive integers, representing different prestressed steel strands, respectively. Indicates the prestressing coupling coefficient. This represents the concrete stress generated by the u-th prestressed steel strand. This represents the tension force applied to the vth prestressed steel strand.

[0026] Specifically, the prestressed coupling effect matrix is ​​obtained through the following steps: applying a unit tension force sequentially to each prestressed steel strand v; calculating and recording the stress response value of each prestressed steel strand v under the unit tension force; and assigning the stress response value as a matrix element. This forms a complete coupling effect matrix.

[0027] In this embodiment, the preferred control strategy based on stress and displacement calculates the tension force increment in real time using the following control equation:

[0028] In the formula, where, Let k be the stiffness coefficient of the steel strand. , This is the gain coefficient, and its value ranges from 0.5 to 1.2. Let be the distance from node j to the pivot.

[0029] In this embodiment, preferably, the dynamic adjustment of the gain coefficient with the age of the concrete specifically includes: In the early stage of concrete Showing an increasing trend It shows a decreasing trend; During the concrete strength stabilization stage Showing a decreasing trend It shows an increasing trend; The cycle of a single adjustment is ≤2 seconds to achieve real-time dynamic response to the tensioning process.

[0030] In this embodiment, preferably, the actual state during the tensioning stage satisfies the predetermined dual-index convergence condition as follows: ,

[0031] In the formula, For stress, This represents the displacement value.

[0032] A prestressed multi-bundle coordinated tensioning control system for a U-shaped aqueduct includes: The monitoring system is configured to monitor concrete stress / strain and displacement of key nodes in real time. Specifically, the system uses fiber optic grating sensors as its core, deployed at key mechanical locations such as the U-shaped bottom, side walls, and beam tops of the aqueduct structure, forming a composite monitoring network covering the entire aqueduct structure. The monitoring accuracy of the fiber optic grating sensors is [insert accuracy here]. The data acquisition frequency is no less than 1Hz, and the deployment spacing is 2m. With a range of 0.1m, it can collect stress, strain, and temperature data of the aqueduct structure during the tensioning construction process. Laser displacement gauges with an accuracy of 0.01mm are deployed at key nodes such as mid-span and supports to monitor the displacement data of key nodes. All data collected by the sensors are uploaded to the data fusion center in real time, and after preprocessing, they are output to the edge computing terminal to provide necessary parameters for the control strategy.

[0033] The tension control module is used to perform tensioning operations. Specifically, it acquires the control strategy output by the edge computing terminal and executes the corresponding tensioning operation. The tension control module includes a hydraulic jack and a tension controller. The tension controller acquires the control strategy and drives the hydraulic jack to perform the tensioning action, and makes precise adjustments to the tension force increment. The tension force control accuracy of the tension controller is ±0.5%FS, ensuring that the theoretical calculation value can be accurately converted into the actual force.

[0034] The edge computing terminal is configured to calculate the initial tensioning sequence and the tension force increment. Specifically, it calculates the initial tensioning sequence based on the mechanical equilibrium equation and dynamically calculates the tension force increment based on real-time data fed back by the monitoring system. The total delay of data processing and command calculation is no more than 100ms, ensuring the system's rapid response capability to changes in structural state.

[0035] The monitoring system and tension control module are both connected to the edge computing terminal to form a complete closed-loop control system of monitoring-decision-execution.

[0036] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0037] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A method for controlling the prestressed multi-bundle coordinated tensioning of a U-shaped aqueduct, characterized in that, The method includes: S1. Construct a quantitative model, based on the mechanical equilibrium equation of the aqueduct structure, introduce the prestress coupling effect term for calculation, output the prestress coupling matrix, and derive the initial tensioning sequence. S2. Perform construction according to the obtained initial tensioning sequence, and collect stress / displacement data in real time through the on-site monitoring system; S3. Input the real-time collected stress / displacement data into the edge computing terminal, and output the control strategy after processing. It also drives the tensioning device to perform adjustments, while simultaneously optimizing the parameters of the quantitative estimation model; S4. Repeat S3 until the actual state of the current tensioning stage meets the predetermined dual-index convergence condition.

2. The prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts according to claim 1, characterized in that, The initial tensioning sequence specifically includes: The objective function is established based on the structural mechanics equilibrium equations, and it satisfies the following expression: Where S0 is the initial tensioning sequence. Let be the actual stress of the i-th steel strand. Let the target stress of the i-th steel strand be , The maximum value of the absolute values ​​of the displacement deviations of all critical nodes. This is the displacement weighting coefficient, and its value ranges from 0.2 to 0.

5.

3. The prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts according to claim 2, characterized in that, The prestress coupling effect matrix is ​​calculated based on the following formula: Where u and v are positive integers, representing different prestressed steel strands, respectively. Indicates the prestressing coupling coefficient. This represents the concrete stress generated by the u-th prestressed steel strand. This represents the tension force applied to the vth prestressed steel strand.

4. The prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts according to claim 1, characterized in that, The control strategy based on stress and displacement calculates the tension force increment in real time using the following control equation: In the formula, where, Let k be the stiffness coefficient of the steel strand. , This is the gain coefficient, and its value ranges from 0.5 to 1.

2. Let be the distance from node j to the pivot.

5. The prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts according to claim 4, characterized in that, The dynamic adjustment of the gain coefficient with the age of concrete specifically includes: In the early stage of concrete Showing an increasing trend It shows a decreasing trend; During the concrete strength stabilization stage Showing a decreasing trend It shows an increasing trend; The cycle of a single adjustment is ≤2 seconds, so as to achieve real-time dynamic response to the tensioning process.

6. The prestressed multi-bundle coordinated tensioning control method for U-shaped aqueducts according to claim 1, characterized in that, The actual state during the tensioning stage satisfies the predetermined dual-index convergence condition as follows: ， In the formula, For stress, This represents the displacement value.

7. A U-shaped aqueduct prestressed multi-bundle coordinated tensioning control system for implementing the method of any one of claims 1-6, characterized in that, include: The monitoring system is configured to monitor concrete stress / strain and displacement of key nodes in real time. The tensioning control module is used to perform the tensioning operation; An edge computing terminal is configured to calculate the initial tensioning sequence and the tension force increment; The monitoring system and the tensioning control module are both communicatively connected to the edge computing terminal, forming a closed-loop control system.

8. The U-shaped aqueduct prestressed multi-bundle coordinated tensioning control system according to claim 7, characterized in that, The monitoring system uses fiber optic grating sensors as its core, deployed at the U-shaped bottom, side walls, and beam top of the aqueduct structure to form a composite monitoring network. The monitoring accuracy of the fiber optic grating sensors is [insert accuracy here]. The data acquisition frequency is no less than 1Hz, and the deployment spacing is 2m. It is equipped with a laser displacement meter with an accuracy of 0.01 mm to monitor the displacement data of key nodes.

9. The U-shaped aqueduct prestressed multi-bundle coordinated tensioning control system according to claim 8, characterized in that, The tension control module has a tension control accuracy of ±0.5%FS, and the data processing latency of the edge computing terminal is no more than 100ms.

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