Bridge incremental launching construction early warning control method and system

Abstract

The invention discloses a bridge incremental launching construction early warning control method and system, and relates to the technical field of bridge construction. The method comprises the steps that a finite element model of the whole bridge incremental launching construction process is established, construction stages are divided, simulation analysis is conducted, and theoretical values of incremental launching construction of all the stages are obtained; determining an early warning threshold value corresponding to each stage based on the theoretical value; in the pushing process, actual monitoring values of all construction stages are collected in real time; and comparing the actual value of the same stage with an early warning threshold value, and generating an early warning instruction according to a comparison result to control incremental launching construction. The system comprises corresponding modules. Finite element simulation prediction is combined with field real-time monitoring, intelligent early warning and automatic control, a'prediction-monitoring-control 'closed loop is formed, the problems that in the prior art, simulation and monitoring are disjointed, early warning is lagged, and control is not intelligent are solved, and the method is suitable for large-scale popularization and application. Advanced early warning and active intervention of structure safety risks in the incremental launching construction process are achieved.

Description

Technical Field

[0001] This application relates to the field of bridge construction technology, specifically to a method and system for early warning and control during bridge jacking construction. Background Technology

[0002] Bridge launching is an advanced bridge erection technique, particularly suitable for crossing deep valleys, rivers, or busy traffic routes. However, launching is a time-varying process, with the bridge structure constantly changing, resulting in complex internal forces and alignment. Risks include exceeding structural stress limits and excessive alignment deviations. Currently, on-site monitoring relies heavily on post-construction analysis of collected data by technicians, which suffers from response delays and strong subjectivity, making it difficult to effectively prevent accidents in a timely manner. While finite element simulation technology is widely used in construction simulations, it is typically limited to guiding preliminary plans and lacks strong linkage with on-site construction control, failing to form a real-time closed loop of "prediction-monitoring-control." Therefore, there is an urgent need for a technical solution that combines the predictive capabilities of simulation analysis with the real-time control capabilities of on-site construction to achieve intelligent and proactive safety protection during the launching process.

[0003] For example, the Chinese invention patent with publication number "CN112797962B" entitled "Monitoring Structure and Method for the Incremental Launching Construction of Prestressed Concrete Continuous Beam Bridge" discloses a monitoring structure and method for bridge incremental launching construction. It uses a central station, reflectors, and inclinometers arranged at the pre-launch support, the end of the guide beam, etc., to measure the support displacement and guide beam displacement in real time, thereby improving the safety and quality control level of the incremental launching construction process.

[0004] While this monitoring method can improve the accuracy of bridge jacking construction to some extent, there are still many areas for improvement: First, the method mainly focuses on the displacement monitoring of the bearings and guide beams, and there is still room for improvement in the comprehensive real-time monitoring and early warning logic integration of internal structural stress, deformation and staged construction status; Second, its monitoring system and method have not yet formed a complete integrated process of "theoretical analysis - real-time monitoring - automatic feedback control" in terms of achieving real-time comparison with finite element simulation results and closed-loop linkage control with execution equipment, such as automatically sending control commands (such as stopping jacking) based on early warning results. Summary of the Invention

[0005] The purpose of this application is to address the shortcomings of the aforementioned background technology and to provide a method and system for early warning and control during bridge jacking construction.

[0006] The technical solution of this application is: a method for early warning and control during bridge jacking construction, comprising, A finite element model of the entire bridge jacking construction process was established, the construction stages were divided and simulation analysis was conducted to obtain the theoretical values ​​of jacking construction under each construction stage. The corresponding early warning threshold is determined based on the theoretical value of each construction stage; During the jacking process, actual values ​​at each construction stage are collected in real time; The actual monitoring values ​​at the same construction stage are compared with the corresponding early warning thresholds, and an early warning instruction is generated based on the comparison results, so as to control the jacking construction according to the early warning instruction.

[0007] According to the bridge jacking construction early warning and control method provided in this application, the method for establishing a finite element model of the entire bridge jacking construction process includes: using a spatial beam grid model to simulate the main beam, discretizing the single-box single-cell box girder into longitudinal beam elements and transverse virtual beam elements; and using solid elements to establish a local refined model for the connection area between the guide beam and the main beam, as well as the connection area between the main beam and the temporary pier and the permanent pier.

[0008] According to the bridge jacking construction early warning and control method provided in this application, the method of dividing the construction stages includes: dividing the bridge jacking construction into multiple continuous construction stages according to the construction sequence, such as guide beam installation, beam segment assembly, step-by-step jacking, arch rib lifting, closure segment construction, system conversion and bridge deck paving.

[0009] According to the bridge jacking construction early warning and control method provided in this application, the method for obtaining the theoretical value of jacking construction at each construction stage includes: based on the whole bridge finite element model, simulating the main beam with beam elements under the consideration of prestressing, establishing models of all temporary piers and permanent piers, and setting the boundary conditions of temporary piers and permanent piers as elastic supports; simulating the entire bridge jacking construction process according to the designed jacking step length, calculating and extracting the longitudinal and transverse elevation difference of the main beam, the vertical displacement of the front end, the transverse offset of the centerline of the main beam, the foundation settlement of the temporary piers, the support reaction force of the temporary piers, the stress of the key section of the main beam, the jacking displacement difference of the jacking jacks, and the maximum value of the equilibrium state of the main beam at each construction stage, and taking the maximum value as the theoretical value.

[0010] According to the bridge jacking construction early warning control method provided in this application, the method for determining the corresponding early warning threshold based on the theoretical value of the jacking construction in each construction stage includes: for each monitoring indicator, taking the smaller value between its theoretical value and the allowable value of the relevant design specification, multiplying it by a safety factor to obtain the early warning threshold of the indicator in the construction stage, wherein the safety factor is less than 1.

[0011] According to the bridge jacking construction early warning and control method provided in this application, the method for real-time acquisition of actual values ​​of jacking construction at each construction stage includes: The actual values ​​of the longitudinal and transverse elevation differences of the main beam are calculated by measuring the coordinates of the preset observation points on the main beam. The actual values ​​of the vertical displacement at the front end of the main beam and the lateral offset of the centerline of the main beam are measured by displacement sensors. The actual settlement of the temporary pier foundation was measured using monitoring points. The actual value of the temporary pier support reaction force is obtained by measuring and converting the pressure sensor. The actual stress values ​​of key sections of the main beam were measured using strain gauges. By comparing the lifting displacement of each jack, the actual value of the difference in jacking displacement is obtained; The tilt angle of the main beam is measured by an inclination sensor to obtain the actual value of the main beam's equilibrium state.

[0012] According to the bridge jacking construction early warning control method provided in this application, the method for formulating early warning instructions based on comparison includes: setting a first-level early warning value and a second-level early warning value that are less than the early warning threshold, wherein the first-level early warning value is less than the second-level early warning value; if the monitored actual value does not exceed the first-level early warning value, no early warning instruction is generated; if the monitored actual value exceeds the first-level early warning value but does not exceed the second-level early warning value, a first-level early warning instruction is generated to provide an early warning prompt; if the monitored actual value exceeds the second-level early warning value, a second-level early warning instruction is generated, wherein the second-level early warning instruction is used to trigger the jacking equipment to stop.

[0013] According to the bridge jacking construction early warning control method provided in this application, the first-level early warning command is used to trigger a warning prompt, and the second-level early warning command is used to trigger mandatory control actions, including stopping the machine.

[0014] This application also relates to a bridge jacking construction early warning control system, which operates according to the aforementioned bridge jacking construction early warning control method, including... The model building module is used to create a finite element model of the entire bridge launching construction process; The theoretical value acquisition module is used to divide the entire process of bridge jacking construction into multiple construction stages and perform simulation analysis to obtain the theoretical value of jacking construction under each construction stage. The early warning threshold acquisition module is used to determine the corresponding early warning threshold based on the theoretical value of the jacking construction under each construction stage; The actual value acquisition module is used to collect the actual values ​​of the jacking construction at each construction stage in real time during the jacking process; The comparison module is used to compare the actual values ​​of the jacking construction under the same construction stage with the early warning threshold; The early warning instruction generation module is used to generate early warning instructions based on the comparison results from the comparison module. The control module is used to control the operation of the jacking equipment based on early warning commands.

[0015] 1. The bridge jacking construction early warning and control method of this application systematically connects multiple technical links that may have been isolated, such as modeling, simulation, threshold setting, data acquisition, and comparative control, to form a logically rigorous and automatically operating early warning and control process. By setting early warning thresholds based on simulation theoretical values, the system can issue early warnings or even directly intervene before problems (such as stress exceeding limits or excessive displacement) actually occur and cause irreversible damage to the structure, thereby significantly reducing the risk of structural damage and instability and ensuring construction continuity and safety. The early warning and control method of this application is a high-level methodology that is not limited to specific bridge types or sensors. It provides a methodological foundation for digital simulation, real-time control, and intelligent early warning technology frameworks, and has broad applicability and scalability. 2. This application uses a spatial beam grid model to simulate the main beam, which can efficiently simulate the overall stress and deformation of the entire bridge during construction with relatively few computational resources. It is suitable for multi-stage and long-term construction simulation. For key parts with complex stress and stress concentration, such as connection areas, solid elements are used to establish local refined models. This can more accurately capture the detailed stress distribution and deformation of these areas and avoid simulation errors that may occur under a single model scale. This hybrid modeling strategy, which uses beam elements as the main component and solid elements as the auxiliary component, ensures that the simulation results can not only meet the needs of the whole bridge analysis, but also provide a high-precision theoretical basis for setting the early warning threshold of key local areas, thereby improving the reliability of the entire early warning system. 3. This application precisely divides the jacking construction into multiple continuous stages from guide beam installation to bridge deck paving, which means that the early warning threshold can be personalized according to the unique stress characteristics of each stage; this makes early warning and control more targeted, avoiding insufficient sensitivity or false alarms that may be caused by using a uniform threshold; it covers all major procedures from start to finish, ensuring uninterrupted early warning and control throughout the entire construction life cycle, and realizing full-process, all-round management of construction safety; 4. The indicators listed in this application (elevation difference, displacement, offset, settlement, support reaction force, stress, displacement difference, equilibrium state) cover three core safety dimensions: geometric deformation, mechanical response, and construction status. This ensures that the early warning system can comprehensively assess structural safety and construction quality from multiple perspectives. It clearly points to core parameters that directly affect structural strength and stability, such as the stress of key sections of the main beam and the support reaction force of temporary piers, as well as operational parameters that directly affect construction synchronization and accuracy, such as the difference in jacking displacement. This focus allows the early warning to be directly linked to the most dangerous factors, improving the effectiveness and engineering value of the early warning. Obtaining the maximum values ​​of these specific indicators as theoretical values ​​provides a direct and reliable data basis for setting specific and quantitative early warning thresholds in the future. 5. This application uses the smaller value between the theoretical value and the allowable value in the design specification as the benchmark, reflecting the prudent principle of combining theory and specifications; it respects scientific calculations while strictly adhering to the mandatory safety baseline of the industry, forming a double guarantee; multiplying by a safety factor less than 1 essentially sets up a safety buffer zone; this places the warning line before the actual danger threshold (theoretical value or specification value), leaving valuable time for taking early warning and intervention measures; it also creates conditions for subsequent implementation of multi-level early warning, allowing for the setting of a more lenient first-level warning value for early alerts; 6. This application specifies the most suitable sensor type for different monitoring indicators (such as strain gauges for stress measurement, tilt sensors for equilibrium measurement, and pressure sensors for support reaction force measurement); this ensures the accuracy and high precision of the collected data; through the coordinated deployment of multiple sensors, a three-dimensional field monitoring network is constructed, which can reliably acquire various actual parameters that completely correspond to the simulation theoretical values ​​in real time, ensuring the data homogeneity and comparability in the comparison process, and providing technical support for achieving real-time acquisition and millisecond-level response; 7. This application avoids excessive intervention through tiered early warning. By setting two levels of warning values, the system can issue a warning when the monitored value is slightly abnormal (Level 1 warning) without interrupting construction. This balances construction efficiency and safety, avoiding frequent shutdowns caused by short-term, minor fluctuations. When the monitored value reaches the more dangerous Level 2 warning threshold, the system automatically generates a shutdown command. This mandatory hardware-level control responds quickly and makes decisive decisions, preventing the escalation of accidents to the greatest extent. It clearly distinguishes between prompts and mandatory control actions, making the entire early warning control logic clear and hierarchical, allowing operators to clearly understand the meaning of different levels of alarms and the measures to be taken. 8. This application also relates to a bridge jacking construction early warning control system. The control system of this application has a clear system architecture by dividing it into modules such as model construction and theoretical value acquisition, which is easy to develop, maintain and expand. It realizes a dual-channel safety architecture, which can be specifically implemented as a dual-channel architecture of software control + hardware emergency stop relay. It greatly improves the fault tolerance and anti-interference performance of the control system, prevents loss of control due to software failure or communication delay, and ensures reliable shutdown in emergency situations. It has high reliability and engineering applicability. The system is the physical and software carrier of the integrated technology framework of digital simulation, real-time control and intelligent early warning, and provides a feasible and operable solution for intelligent construction and digital twin application of large bridges.

[0016] The bridge jacking construction early warning and control method proposed in this application solves the prominent problems of simulation and monitoring disconnect, delayed early warning, and unintelligent control in the existing technology. It realizes intelligent, forward-looking and precise safety management and control of bridge jacking construction and has great promotional value. Attached Figure Description

[0017] Figure 1 The flowchart of the bridge jacking construction early warning and control method in this application. Detailed Implementation

[0018] The embodiments of this application are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] This application relates to an early warning and control method for bridge jacking construction. The early warning and control method of this application includes multiple processes such as modeling, simulation, threshold setting, data acquisition, and comparison control. The entire early warning and control method can issue early warnings or even directly intervene before problems (such as stress exceeding limits or excessive displacement) actually occur and cause irreversible effects on the structure, thereby significantly reducing the risk of structural damage and instability, ensuring the continuity and safety of construction, and solving the prominent problems of simulation and monitoring disconnect, early warning lag, and unintelligent control in the prior art.

[0023] Specifically, such as Figure 1 As shown, a bridge jacking construction early warning and control method of this application includes the following steps: S1. Theoretical Modeling and Simulation Before construction began, finite element analysis software such as MIDAS Civil was used to establish a three-dimensional finite element model of the bridge from the assembly platform to the final placement of the beams. Based on the design drawings and construction plan, the process was divided into multiple continuous construction stages, and static and nonlinear simulation calculations were performed to output the theoretical calculation values ​​of parameters such as stress, displacement, and temporary pier reaction force of the main beam key sections in each stage. S2, Dynamic setting of early warning threshold Based on the theoretical values ​​of each construction stage and each monitoring indicator calculated by the above simulation, and combined with the allowable values ​​of relevant specifications such as the "Technical Specification for Construction of Highway Bridges and Culverts" (JTG / T 3650), the early warning threshold for that indicator at that stage is comprehensively determined; this threshold is pre-input into the early warning control system. S3, Real-time Data Acquisition During the jacking construction process, a sensor network (such as strain gauges, displacement gauges, inclinometers, etc.) pre-deployed in key parts such as the main beam, guide beam, and temporary piers is used to collect real-time data of various monitoring indicators and obtain actual values. S4. Real-time comparison and early warning control The data processing center of the early warning control system automatically compares the real-time actual value collected in step S3 with the early warning threshold preset in step S2 corresponding to the current construction stage. Once the actual value exceeds the early warning threshold, the system immediately generates corresponding early warning instructions (such as audible and visual alarms, screen pop-ups) according to preset logic. For high-level early warnings, the instructions will be directly sent to the jacking pump station control system to trigger control actions such as speed reduction or shutdown.

[0024] The bridge jacking construction early warning control method of this application constructs an online control method that includes prediction, monitoring, decision-making, and control. Traditional jacking construction safety relies on experience-based judgment and post-event verification through offline simulation. This method transforms the offline simulation prediction results (theoretical values) into online monitoring judgment criteria (early warning thresholds) in advance, enabling the monitoring system to have predictive capabilities. The system compares the actual situation on site (actual value) with the theoretical prediction (early warning threshold) in real time, using the difference as the input to trigger control decisions, thereby realizing the transformation from passive monitoring to active intervention.

[0025] The bridge jacking construction early warning and control method of this application integrates discrete simulation analysis and on-site monitoring into a dynamic and collaborative intelligent system, transforming safety control from post-event remediation and manual judgment to pre-event prediction and automatic decision-making. This systematic integration provides the top-level logic and operating platform for the realization of all subsequent refined and intelligent functions.

[0026] In some embodiments of this application, step S1 described above has been optimized. Specifically, the method for establishing a finite element model of the entire bridge jacking construction process in this embodiment includes: S11, Main Girder Global Model A spatial beam grid model is adopted, in which the main beam (taking a single-box single-cell box girder as an example) is discretized into longitudinal beam elements and transverse virtual beam elements to accurately reflect the warping and shear lag effects of the cross section; the top plate, bottom plate and web of the box girder are equivalent to longitudinal beam elements (ridge beams), and transverse virtual beam elements are set to simulate the transverse diaphragms and ensure the deformation coordination of each longitudinal beam, so as to accurately reflect the overall longitudinal and transverse stress characteristics of the box girder; S12, Key Local Model In general-purpose finite element software (such as ANSYS), independent local refined models are established for the connection area between the guide beam and the main beam, and the support area of ​​the main beam at the sliding support at the temporary pier top. Based on the local refined model, stress concentration is accurately calculated. The stress concentration coefficients of key points obtained from the local refined model analysis are fed back and used to correct the theoretical values ​​of the warning thresholds at the corresponding locations in the global model.

[0027] This embodiment constructs a multi-scale simulation combining macroscopic and microscopic perspectives. The spatial beam grid model efficiently simulates the overall response (bending moment, shear force, and displacement) of the entire bridge during construction using fewer elements, solving the computational efficiency problem. Meanwhile, the solid element model is used to refine the modeling of local areas with complex stresses, which can capture details such as local stress concentration, contact nonlinearity, and the risk of weld or concrete cracking that the beam grid model cannot simulate. The combination of the two ensures that the simulation results can guide global safety and provide early warning of local damage.

[0028] The model building method in this embodiment takes into account both computational accuracy and engineering practicality. By using a hybrid modeling strategy, it overcomes the problems of low computational accuracy and low computational efficiency of a single model. This ensures both the feasibility of simulation analysis of the entire construction process under long cycles and multiple working conditions, and the scientific nature and accuracy of early warning information for key parts, thereby improving the reliability of the theoretical foundation of the entire early warning system from the source.

[0029] In some other embodiments of this application, the above-mentioned construction stage division method has been optimized. Specifically, the construction sequence of the entire bridge jacking construction process in this embodiment is divided into the following continuous stages: guide beam installation, beam segment assembly, step-by-step jacking, arch rib lifting, closure segment construction, system conversion and bridge deck paving.

[0030] This embodiment is a dynamic early warning based on the time-varying characteristics of the structural system. During the jacking process of the bridge, the structural system, boundary conditions, and load distribution change drastically over time. A uniform early warning threshold cannot be applied to the entire process. This method identifies the most unfavorable stress state and key risk points unique to each stage by finely dividing the construction stages, thereby tailoring differentiated monitoring priorities and early warning thresholds for each stage. In actual operation, all the above-mentioned construction stages are preset in the early warning control system software; the on-site technical supervisor switches the system to the current construction stage manually on the control interface or by scanning the construction node QR code according to the actual progress; the system then calls up the full set of preset early warning thresholds and monitoring instrument panel interface for that stage.

[0031] The construction stage division method in this embodiment achieves refined and adaptive safety monitoring. It divides the entire jacking construction process into a series of micro-controllable states, enabling the early warning system to use the most appropriate early warning method at each construction stage. This greatly improves the sensitivity and pertinence of the early warning, avoids false alarms and missed alarms, and achieves accurate early warning for bridge jacking construction.

[0032] In a further embodiment of this application, the method for obtaining theoretical values ​​described above is optimized. Specifically, based on the constructed full-bridge finite element model, when simulating the main beam, the tension effect of the prestressed steel strands is considered and simulated as a load or by modifying material properties; the temporary and permanent piers are modeled, and their connection with the main beam is set as an elastic support; the simulation is performed according to the designed jacking step length (e.g., jacking 3 meters per cycle), and the following indicators are calculated and extracted for each construction step, and the maximum value within that stage is taken as the theoretical value of that indicator for that stage: Geometric alignment: longitudinal and transverse elevation differences of the main beam, vertical displacement at the front end, and transverse offset of the centerline of the main beam; Foundation and support: settlement and reaction force of each temporary pier; Structural internal forces: stresses (tension / compression) at key sections such as mid-span and supports of the main beam; Construction parameters: the difference in jacking displacement between the two banks of the jacking jack (synchronicity index); Overall condition: The transverse and longitudinal tilt angles of the main beam (an indicator of equilibrium state to prevent overturning).

[0033] This embodiment conducts a multi-dimensional and comprehensive quantitative simulation of the safety of bridge jacking construction. The selected index group covers four major risk areas: structural safety (stress, support reaction force), construction accuracy (alignment, displacement), external environment (foundation settlement), and equipment status (synchronicity). By simulating and obtaining the theoretical extreme values ​​of these indicators, it is equivalent to conducting a virtual test in advance before the bridge jacking construction, obtaining the safety boundaries of each link in advance, and providing complete and quantitative safety indicators for on-site monitoring.

[0034] During actual construction, before construction begins, the simulation report outputs a list of the theoretical maximum values ​​for the above indicators. During construction, the on-site monitoring plan strictly follows this list to deploy sensors: to monitor the displacement difference of the jacking, a high-precision displacement sensor is installed on each main jack; to monitor the balance state of the main beam, dual-axis tilt sensors are installed at the front end of the guide beam and the rear end of the main beam; the monitoring data is compared in real time with the corresponding items in the list of theoretical maximum values ​​from the simulation.

[0035] The theoretical value acquisition method in this embodiment establishes a systematic and quantifiable safety monitoring indicator system, transforming the previously vague and empirical safety requirements into a series of clear and data-driven monitoring targets. This makes the early warning no longer a single indicator exceeding the limit alarm, but a comprehensive diagnosis of the overall safety status of the construction, greatly improving the scientific nature and operability of safety management.

[0036] In a preferred embodiment of this application, the above-mentioned intelligent setting method for early warning thresholds is optimized. Specifically, for each monitoring indicator, the smaller of its theoretical value and the allowable value in the relevant design specifications is taken, and multiplied by a safety factor to obtain the early warning threshold for that indicator in the construction stage. The safety factor is less than 1. In practical applications, the safety factor can be set to 0.9.

[0037] For example, taking the compressive stress at a critical section of the main beam as an example, the theoretical maximum value of the compressive stress at the critical section of the main beam can be determined using the virtual model calculation method described above. s cal = 14MPa, the allowable value for this steel was obtained by consulting relevant design specifications [such as the "Standard for Design of Steel Structures" (GB50017)]. s y = 16MPa; take the smaller of the two values: s min (14, 16) = 14MPa; Introduce a safety factor. k =0.9 (for important structures, k can be 0.8 or 0.95); the calculated warning threshold is: s warn = 14MPa × 0.9 = 12.6MPa; Similarly, for the theoretical value of the vertical displacement δ at the front end of the main beam... cal =50mm, permissible value according to specifications d y =60mm, then d warn =min(50,60) ×0.9 = 45mm.

[0038] The theoretical value in this embodiment is the smaller of the allowable value in the specification, which constitutes the first double insurance, ensuring that the threshold benchmark meets both the actual calculation and the safety bottom line; multiplying by a safety factor of less than 1 is equivalent to building a buffer wall, adding a warning distance or reaction time to the safety of the jacking construction, so that the system can give an early warning before the real danger occurs.

[0039] In actual operation, on the background configuration page of the early warning control system software, the theoretical value / standard allowable value and the preset safety factor k are entered for each monitoring indicator; the system automatically calculates and generates early warning thresholds at all levels; for example, the first-level early warning value (yellow line) is set as the threshold, and the second-level early warning value (red line) can be set to a value closer to the theoretical value.

[0040] The warning threshold setting method in this embodiment enables the warning system to have foresight and fault tolerance; through the buffer space set by the safety factor, the system realizes the transformation from critical alarm to pre-critical alarm, providing a valuable time window for on-site personnel to judge, make decisions and take preliminary measures, effectively avoiding the risk of directly sliding to the edge of an accident due to system response delay or human judgment error, which is the core technical embodiment of the concept of pre-accident prevention.

[0041] In some embodiments of this application, the above-mentioned construction stage information collection method has been optimized. Specifically, this embodiment involves the following aspects in real-time collection of actual values ​​of jacking construction at each construction stage: 1. Main beam alignment Using a theodolite, four coordinate observation points are set on the bottom surface of the main beam at each temporary pier location. After each stroke of the jacking is completed, the coordinates of the measuring points are measured and the data is collected. The maximum allowable height difference of the main beam without the need to adjust the shims is determined by calculation. If the height difference of the main beam in all directions exceeds the allowable range, construction must be stopped immediately and the shims adjusted. An automated total station is used to measure the three-dimensional coordinates of the preset observation points, and the longitudinal and transverse elevation differences are calculated in real time by software. 2. Displacement and Offset Cable sensors are installed at the front end, rear end, and web of the main beam. During construction, the measured values ​​are cross-compared with the finite element model in real time on the human-machine interface of the main control console. A GNSS receiver and inclinometer are installed at the front end of the guide beam to obtain the absolute vertical displacement and lateral offset values ​​through fusion calculation. 3. Foundation settlement Static levels were installed at the four corners of the temporary pier cap to monitor uneven settlement. Monitoring instruments such as total stations, theodolites, and levels were used to monitor the settlement at a frequency of once every 30 minutes. Two observation points were arranged along the longitudinal direction of the bridge for each jacking device, with the observation points located on the longitudinal beam at the center of the steel support column. At least two horizontal displacement, deformation monitoring, and settlement observation points were arranged along the longitudinal axis of the bridge for each device. The horizontal displacement and deformation data of the column top and the overall column were cross-compared with the finite element model. 4. Support reaction force Pressure sensors are integrated into the hydraulic slides or pressure pads at the top of the temporary pier to directly measure and calculate the support reaction force. The reaction force of the temporary pier is accurately calculated, and the jacking force at each point is determined based on the reaction force. Excessive unbalanced horizontal forces on the temporary pier should be avoided during construction. The support reaction force of the temporary pier is mainly measured by measuring the hydraulic pressure of the equipment, and then indirectly calculated. The pressure sensor measures the pipeline hydraulic pressure P / MPa when the cylinder is working. Specifically, the pipeline hydraulic pressure P can be used to determine... Lifting force and ; 5. Section stress Twelve strain gauges are planned to be arranged on each key control section of the main beam to measure the longitudinal stress of the main beam structure and transmit it to the main controller in real time to sense stress changes in real time. 6. Synchronization of jacking Each jack is equipped with a built-in magnetostrictive displacement sensor, and the control cabinet calculates the displacement difference of each cylinder in real time. After the lifting jack piston extends and lifts the main beam, the pushing jack piston extends and pushes the main beam forward. This process requires displacement synchronization control, pressure equalization control, and lateral adjustment control. In addition to controlling the unified action of all the pushing jacks on the piers, the main control console must also ensure the synchronization of each stroke of all the pushing jacks. The control strategy is as follows: among the horizontal jacking jacks on the same pier, the No. 1 horizontal jacking jack (in actual application, it is not limited to this horizontal jacking jack, and can be selected according to the actual situation) is the active point, which extends the cylinder at a certain speed. The other horizontal jacking jacks are the follow-up points and are compared with the No. 1 horizontal jacking jack. The displacement difference between each horizontal jacking jack and the No. 1 horizontal jacking jack is controlled within the set value. If a horizontal jacking jack extends the cylinder faster, the flow rate of the corresponding proportional valve is reduced, and vice versa. The synchronization control method for the horizontal jacking jacks on different piers is as follows: take the No. 1 horizontal jacking jack on pier No. 1 as the active point, and compare it with the No. 1 horizontal jacking jacks on the other piers. If the jacking cylinder is faster, reduce the flow rate of the corresponding proportional valve, and vice versa, increase the flow rate of the corresponding proportional valve, so as to achieve synchronization of all horizontal jacking jacks. The synchronization accuracy between each pier can be controlled within 5mm, and between the two sides of the same pier can be controlled within 3mm. According to sensitivity analysis, the maximum allowable asynchronous error of the jacking equipment is ≤30mm, and the maximum allowable deviation of the actual system setting is ≤10mm. The vertical jacking jack cylinder retraction does not require synchronous control. Since each jacking jack is equipped with a pressure sensor to monitor load changes, the maximum pressure of each jack and the maximum pressure difference of several jacks on the same pier can be set through the field controller or the panel on the main control console. The computer accurately coordinates the load distribution of the entire system by monitoring the load changes of each jack. If the load of a jack reaches the set maximum pressure or the maximum pressure difference of several jacks on the same pier exceeds the value set by the finite element software, the system will automatically stop and issue a warning. 7. Equilibrium state A dual-axis tilt sensor is installed at the tail of the main beam to directly output tilt angle data; Inclination sensors can also be installed on the sliding boxes of each pier to detect the tilt angle of the main beam in the X and Y directions. Therefore, by setting the maximum tilt angle of each inclination sensor in the X and Y directions, the balance of the main beam can be controlled.

[0042] This embodiment employs optimal sensing technology for specific physical quantities to achieve multi-source information fusion. Different monitoring targets require different sensor principles: strain and pressure sensing are used for mechanical indicators (stress, pressure), optical and hydraulic leveling are used for geometric indicators (displacement, settlement), and angle and displacement sensing are used for state indicators (balance, synchronization). Through the collaborative networking of heterogeneous sensors, a comprehensive, high-frequency field information sensing neural network is constructed to provide real-time, reliable, and diverse data streams for early warning decision-making.

[0043] Before construction, the sensor deployment scheme and wiring are carefully designed based on the monitoring points determined by simulation. All sensor signals are connected to the field data acquisition station through industrial buses (such as CAN, EtherCAT) or wireless transmission modules. The acquisition station performs preliminary filtering, verification and packaging of the data, and sends it to the early warning control server in the central monitoring room through the industrial fiber optic network to complete the data acquisition chain.

[0044] This embodiment constructs a highly reliable and high-precision field data perception layer. Through professional sensor selection and systematic integration and deployment, it ensures that the collected actual values ​​can truly and accurately reflect the structural state and are comparable to the simulated theoretical values. This is the cornerstone for the effective operation of the entire early warning control system, and its millisecond-level response capability makes real-time control possible.

[0045] In other embodiments of this application, the method for generating the warning instruction described above has been optimized. Specifically, this embodiment sets two levels of warning values: a first-level warning value (70% of the warning threshold) and a second-level warning value (90% of the warning threshold) that are less than the warning threshold. Level 1 warning value (yellow line): When the actual monitored value exceeds the Level 1 warning value but does not exceed the Level 2 warning value, the warning command generation module triggers the Level 1 warning command, the sound and light alarm in the control room flashes yellow light, the corresponding data point on the monitoring screen turns yellow and a pop-up prompt appears; Level 2 Warning Value (Red Line): When the actual monitored value exceeds the Level 2 warning value, the system immediately generates a Level 2 warning command; this command is executed simultaneously through two channels: Software control channel: Instructions are sent to the PLC control system of the jacking equipment, and the PLC executes the preset emergency stop program; Hardware direct connection channel: The command simultaneously triggers an independent hardware emergency stop relay, which directly cuts off the power supply to the main motor of the jacking pump station, achieving physical-level forced shutdown; After shutdown, the system enters a locked state, which can only be released by authorized personnel who have investigated the problem on-site and restored the data to normal through manual reset on the control panel.

[0046] This embodiment features a tiered response and fail-safe design. The first-level warning adopts a prompt and manual intervention mode, balancing efficiency and safety in the initial warning stage. The second-level warning adopts an automatic control and dual-channel protection mode to ensure the absolute reliability of control actions in the most dangerous situations. The software and hardware dual channels constitute a redundant safety architecture. Even if the software system crashes or communication is interrupted, the hardware relay can serve as the last line of defense to ensure shutdown, reflecting the fail-safe principle. During the daily meetings for the jacking operation, the meaning and response procedures for the two-level early warning system were clearly explained: In the event of a Level 1 early warning, the monitor reports the situation and the technicians strengthen their observation; in the event of a Level 2 early warning, all personnel are aware that the system will automatically shut down and are prepared with emergency inspection plans; the emergency stop relays are regularly tested for functionality to ensure their reliability. This embodiment achieves the unification of intelligent decision-making and ultra-high reliability execution; hierarchical early warning optimizes human-machine collaboration; and dual-channel emergency control completely solves the failure risk that may exist if relying solely on software, raising the reliability of the control system to a level suitable for life-or-death engineering scenarios.

[0047] This application also relates to a bridge jacking construction early warning control system. The early warning control system of this application operates according to the aforementioned bridge jacking construction early warning control method. Specifically, the early warning control system of this application includes: The model building module is used to create a finite element model of the entire bridge launching construction process; The theoretical value acquisition module is used to divide the entire process of bridge jacking construction into multiple construction stages and perform simulation analysis to obtain the theoretical value of jacking construction under each construction stage. The early warning threshold acquisition module is used to determine the corresponding early warning threshold based on the theoretical value of the jacking construction under each construction stage; The actual value acquisition module is used to collect the actual values ​​of the jacking construction at each construction stage in real time during the jacking process; The comparison module is used to compare the actual values ​​of the jacking construction under the same construction stage with the early warning threshold; The early warning instruction generation module is used to generate early warning instructions based on the comparison results from the comparison module. The control module is used to control the operation of the jacking equipment based on early warning commands.

[0048] The early warning control system of this application encapsulates the methodology into a modular and executable engineering system; each functional module corresponds to a methodological step, and data exchange and instruction transmission are carried out through standard software interfaces and hardware protocols; the system solidifies human experience, theoretical calculations and on-site perception into the software and hardware process, forming a safety officer that can work 24 / 7 without interruption.

[0049] The early warning control system of this application is installed and commissioned as a professional system independent of conventional construction management; during construction, it is operated and maintained by a dedicated monitoring engineer; the system interfaces with the construction management platform (such as a BIM platform) to realize the linkage display of early warning information and construction progress.

[0050] The early warning control system of this application provides an integrated technical solution entity, which integrates the scattered technical points into a user-friendly, stable, and interface-standard dedicated system, greatly reducing the technical implementation threshold and integration complexity. The early warning control system of this application is the carrier for realizing industrial application and promotion, and provides a core functional platform for building digital twins of bridge construction and smart construction sites.

[0051] The actual implementation of the bridge jacking construction early warning and control method of this application includes the following steps: 1. Pre-construction preparation stage Refined Digital Pre-simulation: Based on the above methods, the technical team established a multi-scale finite element model of the entire bridge and finely divided the construction stages; then, according to the set index system, they conducted a full-process simulation analysis and output a detailed report containing the theoretical maximum values ​​of each stage and each monitoring index. Construction and Configuration of Intelligent Early Warning System Deploy the aforementioned early warning and control system hardware and software; According to the simulation report, following the principle of taking the least squares coefficient of the dual benchmarks mentioned above, two levels of early warning thresholds (yellow line and red line) are configured in the system for each indicator and each stage. Based on the monitoring points determined in the simulation report, a sensor network was deployed on-site according to the data acquisition equipment layout plan, and joint debugging and testing with the system acquisition module were completed. According to the hierarchical comparison method, hierarchical early warning logic is set in the system, and the output of the control module is connected to the PLC and hardware emergency stop circuit of the jacking equipment to complete the dual-channel safety test. 2. Construction Implementation Phase Start-up and Phase Management: The jacking construction begins; the site supervisor accurately sets or switches to the current construction phase in the control system; the system automatically loads the complete set of monitoring screens and early warning thresholds corresponding to this phase; Real-time monitoring and intelligent early warning: The system collects various actual data in real time through a sensor network; The comparison module continuously compares the actual data with the threshold of the current stage; Normal situation: All data is below the yellow line, the system only records and displays it, and the push continues continuously; Level 1 Warning: If a certain indicator (such as the reaction force of a temporary pier) touches the yellow line, the system will trigger a Level 1 warning, the yellow light in the control room will flash, and a pop-up window will appear on the screen. The technical supervisor will immediately pay attention to the trend of the data change, analyze the cause, and remind the site staff to pay attention via walkie-talkie, but will not force the system to shut down. Level 2 Early Warning and Automatic Control: If the indicator continues to deteriorate and reaches the red line, the system will immediately trigger a level 2 early warning; the early warning command generation module will simultaneously send emergency stop commands to the software PLC and hardware relays; the jacking equipment will quickly and reliably stop operation under dual-channel protection; the on-site red light will illuminate and the alarm will sound continuously; Emergency Response and Closed-Loop Processing: After shutdown, construction personnel check relevant parts according to the plan (such as the settlement of the temporary pier and whether the supporting structure is abnormal); engineers quickly diagnose the root cause of the problem by combining early warning data, on-site inspection results and simulation models; after taking measures (such as adjusting the jacking posture and fine-tuning the pier top elevation), the monitoring data falls back to the safe range; authorized personnel confirm and reset on the control system to remove the alarm and shutdown lockout, and construction safety is restored.

[0052] The bridge jacking construction early warning and control method proposed in this application realizes intelligent management of the entire process, which enables digital twin pre-simulation to guide actual construction, real-time data to drive intelligent decision-making, hierarchical early warning to ensure efficiency, and dual-channel control to ensure safety. It transforms the traditional open-loop, passive construction mode into a closed-loop, proactive intelligent control mode, which significantly improves the safety, accuracy and reliability of jacking construction. It is a model of the deep integration of modern information technology and bridge construction technology.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A method for early warning and control during bridge jacking construction, characterized in that, include, A finite element model of the entire bridge jacking construction process was established, the construction stages were divided and simulation analysis was conducted to obtain the theoretical values ​​of jacking construction under each construction stage. The corresponding early warning threshold is determined based on the theoretical value of each construction stage; During the jacking process, actual values ​​at each construction stage are collected in real time; The actual monitoring values ​​at the same construction stage are compared with the corresponding early warning thresholds, and an early warning instruction is generated based on the comparison results, so as to control the jacking construction according to the early warning instruction.

2. The bridge jacking construction early warning and control method according to claim 1, characterized in that, The method for establishing a finite element model of the entire bridge launching construction process includes: using a spatial beam grid model to simulate the main beam, discretizing the single-box single-cell box girder into longitudinal beam elements and transverse virtual beam elements; and using solid elements to establish a local refined model for the connection area between the guide beam and the main beam, as well as the connection area between the main beam and the temporary and permanent piers.

3. The bridge jacking construction early warning and control method according to claim 2, characterized in that, The method for dividing the construction phases includes dividing the bridge jacking construction into multiple continuous construction phases according to the construction sequence, such as guide beam installation, beam segment assembly, step-by-step jacking, arch rib lifting, closure segment construction, system conversion, and bridge deck paving.

4. The bridge jacking construction early warning and control method according to claim 3, characterized in that, The method for obtaining the theoretical values ​​of the jacking construction at each construction stage includes: based on the finite element model of the whole bridge, simulating the main beam with beam elements under the consideration of prestressing, establishing models of all temporary and permanent piers, and setting the boundary conditions of the temporary and permanent piers as elastic supports; simulating the entire bridge jacking construction process according to the designed jacking step length, calculating and extracting the longitudinal and transverse elevation difference of the main beam, the vertical displacement at the front end, the transverse offset of the centerline of the main beam, the foundation settlement of the temporary piers, the support reaction force of the temporary piers, the stress of the key section of the main beam, the jacking displacement difference of the jacking jacks, and the maximum value of the equilibrium state of the main beam at each construction stage, and taking the maximum value as the theoretical value.

5. The bridge jacking construction early warning and control method according to claim 4, characterized in that, The method for determining the corresponding early warning threshold based on the theoretical value of the jacking construction at each construction stage includes: for each monitoring indicator, taking the smaller value between its theoretical value and the allowable value of the relevant design specifications, multiplying it by a safety factor to obtain the early warning threshold of the indicator at that construction stage, wherein the safety factor is less than 1.

6. The bridge jacking construction early warning and control method according to claim 5, characterized in that, The method for real-time acquisition of actual values ​​of the jacking construction at each construction stage includes: The actual values ​​of the longitudinal and transverse elevation differences of the main beam are calculated by measuring the coordinates of the preset observation points on the main beam. The actual values ​​of the vertical displacement at the front end of the main beam and the lateral offset of the centerline of the main beam are measured by displacement sensors. The actual settlement of the temporary pier foundation was measured using monitoring points. The actual value of the temporary pier support reaction force is obtained by measuring and converting the pressure sensor. The actual stress values ​​of key sections of the main beam were measured using strain gauges. By comparing the lifting displacement of each jack, the actual value of the difference in jacking displacement is obtained; The tilt angle of the main beam is measured by an inclination sensor to obtain the actual value of the main beam's equilibrium state.

7. The bridge jacking construction early warning and control method according to claim 1, characterized in that, The method for generating early warning commands based on comparison results includes: setting a first-level early warning value and a second-level early warning value that are less than the early warning threshold, wherein the first-level early warning value is less than the second-level early warning value; if the monitored actual value does not exceed the first-level early warning value, no early warning command is generated; if the monitored actual value exceeds the first-level early warning value but does not exceed the second-level early warning value, a first-level early warning command is generated to provide an early warning; if the monitored actual value exceeds the second-level early warning value, a second-level early warning command is generated, wherein the second-level early warning command is used to trigger the shutdown of the jacking equipment.

8. The bridge jacking construction early warning and control method according to claim 7, characterized in that, The first-level warning command is used to trigger an alert, and the second-level warning command is used to trigger mandatory control actions, including shutdown.

9. A bridge jacking construction early warning control system, characterized in that, The control system operates according to the bridge jacking construction early warning control method as described in any one of claims 1 to 8, including, The model building module is used to create a finite element model of the entire bridge launching construction process; The theoretical value acquisition module is used to divide the entire process of bridge jacking construction into multiple construction stages and perform simulation analysis to obtain the theoretical value of jacking construction under each construction stage. The early warning threshold acquisition module is used to determine the corresponding early warning threshold based on the theoretical value of the jacking construction under each construction stage; The actual value acquisition module is used to collect the actual values ​​of the jacking construction at each construction stage in real time during the jacking process; The comparison module is used to compare the actual values ​​of the jacking construction under the same construction stage with the early warning threshold; The early warning instruction generation module is used to generate early warning instructions based on the comparison results from the comparison module. The control module is used to control the operation of the jacking equipment based on early warning commands.

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