Through type steel box tied arch bridge construction monitoring system and method

Abstract

The invention discloses a through steel box tied arch bridge construction monitoring system and method. The system comprises a data acquisition module, a data processing and analysis module, a control decision module and an information management and feedback module. The data acquisition module acquires data such as a girder, an arch rib, a suspender and an environment; the data processing and analysis module analyzes the structure state after preprocessing the data, identifies parameters and corrects the model; the control decision module generates a control instruction, and performs early warning and emergency processing; and the information management and feedback module stores data and feeds back information. The method comprises preparation before construction, construction process monitoring and abnormal condition processing. Construction can be accurately monitored in real time, the quality and safety of finished bridges are ensured, error accumulation is reduced, data are provided for later maintenance, the durability of the bridges is improved, and the method is suitable for through steel box tied arch bridge construction monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering construction monitoring, and in particular to a construction monitoring system and method for a bottom-supported steel box tied arch bridge. Background Art

[0002] As a bridge structure with beautiful appearance and strong spanning capacity, the bottom-supported steel box tied arch bridge has been widely used in modern bridge engineering. However, its construction process is extremely complicated, involving many construction procedures and technical links, and requires extremely high construction accuracy and quality control.

[0003] During the construction process, this type of bridge structure will be affected by a variety of factors. The uncertainty of material properties, such as the deviation between the actual value of the elastic modulus of steel and the design value, and the difficulty in accurately predicting the shrinkage and creep characteristics of concrete, will cause the calculation of the internal force and deformation of the structure to be inconsistent with the actual situation. The variability of construction loads, including the deadweight of construction equipment, the activities of construction personnel, and the stacking of materials, their distribution and size are constantly changing during the construction process, bringing complex stress states to the structure. The influence of ambient temperature cannot be ignored. The temperature difference between day and night, seasonal changes, etc. will cause the bridge structure to produce thermal expansion and contraction effects, which will cause displacement and stress changes in the structure.

[0004] At the same time, differences in construction technology and operating levels will also have an important impact on the quality of bridge construction. For example, if there are deviations in the manufacturing accuracy of components, the positioning accuracy during assembly, and the tension control of the suspender force, it will directly affect the overall performance of the structure. In addition, during the construction process, the various construction steps are interrelated and influence each other. The error in one link may continue to accumulate and amplify in subsequent construction, eventually causing the bridge line shape and internal force to deviate from the design target, affecting the safety, durability and driving comfort of the bridge.

[0005] In the prior art, although there are some monitoring methods for bridge construction, there is a lack of a comprehensive, systematic and accurate construction monitoring system and method for complex structures such as bottom-supported steel box tie-arch bridges. Traditional monitoring methods can often only monitor some parameters simply, and it is difficult to achieve comprehensive consideration and real-time dynamic monitoring of various complex factors in the entire construction process, and cannot meet the demand for accurate control of the structural state during the construction of bottom-supported steel box tie-arch bridges. Summary of the invention

[0006] The main purpose of the present invention is to provide a construction monitoring system and method for a bottom-supported steel box tied arch bridge, aiming to solve the existing technical problems.

[0007] To achieve the above object, the present invention provides a construction monitoring system for a through-type steel box tied arch bridge, comprising:

[0008] Data acquisition module, used to collect various data during the bridge construction process;

[0009] Data processing and analysis module, used to process and analyze the collected data;

[0010] A control decision module is used to make control decisions based on the results of the data processing and analysis module;

[0011] Information management and feedback module, used to manage and feedback monitoring information.

[0012] Furthermore, the data processing and analysis module includes receiving various sensor data from the data acquisition module and performing filtering and denoising preprocessing on the data;

[0013] Structural status analysis: compare and analyze measured data with theoretical calculation data. Based on the analysis results, evaluate the safety and stability of the structure during construction, predict possible problems in subsequent construction, and propose corresponding adjustment measures;

[0014] Parameter identification and model modification: by analyzing the structural response data, the actual values ​​of key design parameters are identified, so that the model can more accurately reflect the actual state of the structure, and the internal forces and deformations of the structure in the subsequent construction stage can be recalculated using the modified model.

[0015] Further, the control decision module includes, construction control instruction generation, generating construction control instructions according to the results of the data processing and analysis module;

[0016] Early warning and emergency response, set early warning indicators, and when the measured parameters of the structure exceed the early warning threshold, promptly issue an early warning signal. Formulate corresponding emergency response plans for possible abnormal situations, and clarify the processing procedures and division of responsibilities.

[0017] Furthermore, the information management and feedback module includes data storage and management, establishing a database, and classifying and storing the collected raw data, processed data, analysis results, and control instructions;

[0018] Information feedback and communication: Feedback the monitoring results to the construction party, design party, supervision party and other relevant units in an intuitive and easy-to-understand manner to make corresponding decisions, establish an information communication platform, and strengthen communication and coordination between the monitoring party and other parties.

[0019] Furthermore, the parameter identification method in the data processing and analysis module adopts the least squares method or the Kalman filtering method, wherein the least squares method finds the best function match for the data by minimizing the sum of squares of errors, and the Kalman filtering method uses the state estimate at the previous moment and the observation value at the current moment to update the estimate of the current state.

[0020] A construction monitoring method for a through-type steel box tied arch bridge comprises the following steps:

[0021] (1) Preparation before construction: Establish a plane control system, use a total station to conduct joint measurement and verification of the plane control starting coordinate points of the construction area provided by the owner or design department according to the technical requirements and accuracy indicators of polygonal traverse network or four-level traverse measurement, encrypt the control network, determine the position of the plane control points, and the accuracy of the plane control points should meet the requirements of relevant specifications;

[0022] Establish an elevation control system. The leveling point is set within 50m-100m from the center line of the bridge. Choose a stable, easy-to-measure and not easily disturbed place. The distance between adjacent leveling points should not exceed 500m. Introduce working leveling points and regularly review their elevations. The elevation measurement error of the working leveling points should be controlled within the allowable range.

[0023] Conduct structural analysis and calculation. According to the design parameters and construction plan, use the large-scale finite element software Midas / civil to establish a bridge structure model, simulate the construction process, and calculate the theoretical displacement, internal force, stress, etc. of the structure at each construction stage to provide a theoretical basis for construction monitoring. The model should accurately consider factors such as the geometric shape, material properties, and boundary conditions of the structure;

[0024] Formulate monitoring plans and implementation rules, clarify monitoring content, methods, measurement point layout, test frequency, error control standards, etc., and implement them after approval by the design unit and supervision unit. The monitoring plan should be targeted and operational;

[0025] (2) Construction process monitoring: data collection. According to the predetermined test frequency and working conditions, various sensors and measuring equipment are used to collect data such as the main beam line shape, stress, arch rib line shape, stress, hanger force, ambient temperature, etc. to ensure the integrity and accuracy of the data. Data collection is carried out before and after key construction processes to timely grasp the changes in structural status. The time interval for data collection should be reasonably determined based on the construction progress and changes in structural status;

[0026] Data analysis and processing: real-time processing and analysis of collected data, comparison with theoretical calculation values, calculation of deviation values, determination of whether the structural state is normal, parameter identification and model correction based on the deviation, adjustment of construction control parameters, prediction of structural state in subsequent construction phases, formulation of adjustment measures, parameter identification should be accurate and reliable, and model correction should be timely and effective;

[0027] Control decision-making and feedback. Based on the data analysis results, generate construction control instructions to guide the construction unit to adjust the construction process, hanger tension, etc., to ensure that the structural status meets the design requirements, and promptly feedback the monitoring results to relevant parties. Hold regular monitoring meetings or emergency meetings to coordinate and solve problems that arise during construction. Construction control instructions should be clear and specific, and regular monitoring meetings or emergency meetings should form effective resolutions;

[0028] (3) Abnormal situation handling: When the measured value of the construction control parameter deviates too much from the theoretical value or an abnormal situation occurs, construction is suspended and the abnormal situation handling process is initiated. The judgment criteria for abnormal situations should be determined based on specific monitoring indicators and engineering experience;

[0029] The construction control leading group organizes design, supervision, construction and experts to hold special meetings to jointly analyze the causes and formulate solutions, such as adjusting the construction sequence, improving the construction process, replacing materials, etc. The solutions should be feasible and effective;

[0030] After the solution is implemented, continue monitoring to ensure that the problem is effectively solved and the structure is safe and reliable. Monitoring should continue until the structural state is stable and meets the requirements.

[0031] Furthermore, in the data collection step, the ambient temperature is measured continuously, and the temperature and humidity data are collected by the test team according to the construction progress. The monitoring position is determined according to the actual situation on site, and multiple monitoring points are set at different positions around the bridge structure to obtain accurate ambient temperature data;

[0032] The temperature field observation of the main beam is carried out in representative weather after the main beam construction is completed. The temperature field of the main beam changing with temperature is obtained by using surface-mounted temperature sensors. Surface thermometers are mainly used for temperature field observation of steel beams and arch ribs. The temperature field observation should cover the key parts of the structure.

[0033] Furthermore, in the data analysis and processing steps, parameter identification and model correction are performed according to the deviation situation, construction control parameters are adjusted, the structural state in the subsequent construction stage is predicted, and adjustment measures are formulated, wherein parameter identification uses the least squares method or Kalman filtering method to calculate the actual values ​​of key design parameters, and the influence of measurement errors and the actual state of the structure are considered in the parameter identification process.

[0034] Furthermore, in the control decision and feedback step, the monitoring results are fed back to relevant parties in the form of monitoring reports, statements, charts, etc. The monitoring reports are generated regularly and include the construction stage, measurement point layout, monitoring data, structural status analysis, control measures and effects, etc. The monitoring reports should be detailed, accurate in data, and clear in conclusions; the charts should intuitively and clearly show the trend of structural status changes.

[0035] Furthermore, in the abnormal situation handling steps, the emergency response plan formulates corresponding measures for possible abnormal situations, clarifies the handling process and division of responsibilities, and ensures a rapid and effective response in emergency situations. The emergency response plan should include personnel organization, equipment deployment, technical measures and other aspects, and should be regularly rehearsed and updated.

[0036] The beneficial effects of the present invention are embodied in:

[0037] The present invention can realize real-time and accurate monitoring of the entire construction process of a bottom-supported steel box tied arch bridge, effectively control the internal force and line shape of the structure, ensure that the quality of the completed bridge meets the design requirements, and improve the safety and durability of the bridge. For example, in a certain actual engineering application, the deviation between the completed bridge line shape and the designed line shape is controlled within a very small range, and all internal force indicators meet the design standards. The bridge performs stably in long-term operation after opening to traffic.

[0038] The application of the system of the present invention can timely discover and solve problems that arise during construction, reduce the accumulation of construction errors, reduce construction risks, and save construction costs. Through accurate data analysis and timely control decisions, additional costs such as rework and reinforcement caused by abnormal structural conditions are avoided, and construction efficiency is improved. For example, in the construction of a bridge, by timely adjusting the tension force of the suspender, the problem of excessive local deformation of the main beam caused by uneven suspender force is avoided, saving the cost of later repairs.

[0039] The present invention can provide rich data support for the later maintenance and evaluation of bridges, help formulate scientific and reasonable maintenance strategies, and extend the service life of bridges. Through long-term stored monitoring data, the performance change trend of bridge structures in different periods can be analyzed, possible diseases can be predicted in advance, and a basis for preventive maintenance can be provided, thus reducing maintenance costs and ensuring the long-term safe operation of bridges. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the architecture diagram of the construction monitoring system of the present invention;

[0041] Figure 2 This is a diagram of the structure parameter identification and error analysis system of the present invention;

[0042] Figure 3 This is a block diagram of the monitoring-forecasting feedback system of the present invention;

[0043] Figure 4 It is an elevation view of the arrangement of linear measuring points of the main beam of the present invention;

[0044] Figure 5 This is a cross-sectional diagram of the arrangement of linear measuring points of the main beam of the present invention;

[0045] Figure 6 It is an elevation view of the arrangement of stress cross-section measuring points of the main beam of the present invention;

[0046] Figure 7 This is a cross-sectional diagram of the arrangement of stress measuring points of the main beam of the present invention.

[0047] Figure 8 Elevation diagram of the arrangement of linear measuring points of the main arch rib of the present invention

[0048] Fig. 9This is a cross-sectional diagram of the arrangement of linear measuring points of the main arch rib of the present invention.

[0049] Fig.10 This is the elevation view of the stress section arrangement of the main arch rib of the present invention

[0050] Fig.11 This is a cross-sectional view of the arrangement of stress measuring points on the main arch rib of the present invention. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 The present invention provides a construction monitoring system for a through-type steel box tied arch bridge, the system comprising:

[0053] (1) Data acquisition module

[0054] The sensors are arranged as follows:

[0055] On the main beam, displacement measuring points are arranged at the end of each segment. A single tie beam is arranged with 12 sections, each section has 3 measuring points, a total of 36 measuring points. The measurement is carried out using a total station, the accuracy of which meets the monitoring requirements and is within the validity period after verification before construction. Combined with the temporary support layout and stress characteristics, 4 stress monitoring sections are arranged, each section has 4 stress measuring points, and the whole bridge has a total of 16 surface-mount strain gauges. The intelligent string-type digital sensor JMZX-215HAT or JMZX-212HAT is used, with a sensitivity of 1με, an accuracy of 0.1% FS (JMZX-215HAT) or 0.5% FS (JMZX-212HAT), a range of ±2500με (JMZX-215HAT) or ±1500με (JMZX-212HAT), and a temperature testing function. The matching measuring instrument JMZX-300X comprehensive tester can simultaneously measure the structural strain and instant temperature. The strain measurement error is less than ±0.5%, the annual drift is less than ±0.5%, the temperature drift is less than ±0.25% / 10℃, and the temperature measurement instrument error is less than ±1℃.

[0056] A monitoring section is arranged at the impact point of each arch rib segment boundary sample. A prism is placed in each section. A total of 12 circular prisms are arranged on the whole bridge, and a total station is used for measurement. A surface-mounted strain gauge for steel structure is arranged at the arch foot, 1 / 4, 1 / 2, and 3 / 4 sections of the arch rib, and the upper and lower edges thereof, for a total of 10 on the whole bridge.

[0057] Stress monitoring of the hanger and tie rods must be fully measured in each working condition after the initial tensioning.

[0058] The dynamic measurement method, also known as the pulsation method (or spectrum analysis method), is adopted. A high-sensitivity sensor attached to the cable is used to pick up the vibration signal of the cable under environmental vibration excitation. After filtering, amplification and spectrum analysis, the natural frequency of the cable is determined according to the spectrum diagram, and then the stress of the hanger and the tie rod is determined according to the relationship between the natural frequency and the stress of the hanger and the tie rod.

[0059] Ambient temperature monitoring uses a mercury thermometer to continuously measure the ambient temperature. The test team completes data collection according to the construction progress, and the monitoring location is determined according to the actual situation on site. The temperature field observation of the main beam is carried out in representative weather after the main beam construction is completed. The temperature field of the main beam that changes with temperature is obtained through a surface-mounted temperature sensor (measurement accuracy of 0.5°C). Surface thermometers are mainly used for temperature field observation of steel beams and arch ribs.

[0060] The data collection equipment is as follows:

[0061] The total station is a Nanfang total station, which has high-precision angle and distance measurement functions and can meet the accuracy requirements of spatial linear measurement of bridge structures, such as the displacement of abutments and arch seats, the displacement of the main arch rib hanger points, the displacement of the main beam axis and other measuring points. Before use, it must be strictly verified and calibrated in accordance with relevant standards and specifications to ensure its measurement accuracy and precision. During the measurement process, the measurement sites and observation angles are reasonably set according to the actual situation on site, and appropriate measurement methods and data processing algorithms are used to improve the reliability of the measurement data.

[0062] The digital electronic level is Nanfang DL207, with an electronic reading accuracy of 0.7mm, a minimum display of 0.1mm, a measuring range of 1.5m-110m, and is used with an indium steel bar code ruler. When measuring elevation, a suitable observation route and time should be selected to avoid interference from external factors on the measurement results. For example, measurements should be taken during periods of low temperature change and weak wind, and the measurement data should be observed multiple times and averaged to reduce measurement errors.

[0063] The boom force tester is DH5906W, with a frequency range of DC-78Hz and a full scale value of 0.2m / s 2, 2m / s2, 20m / s2 are optional, the analysis frequency is 5Hz, 10Hz, 20Hz, 39Hz, 78Hz, and the system indication error is no more than 5% (FULL). Before the boom force test, the dynamic tester needs to be preheated and calibrated to ensure its test accuracy and stability. During the test, the appropriate test method and parameter settings should be selected according to the actual situation of the boom, such as test frequency, sampling time, etc., to accurately obtain the boom force data.

[0064] (2) Data processing and analysis module

[0065] Data reception and preprocessing:

[0066] The module is equipped with a high-performance data receiving unit, which can receive various sensor data from the data acquisition module in real time. The received data is strictly checked for integrity, including data format, data range, data continuity, etc., and data points with obvious errors or missing are eliminated. Advanced filtering algorithms, such as Kalman filtering and wavelet filtering, are used to denoise the data, effectively eliminating the influence of measurement errors and outliers, ensuring the accuracy and reliability of the data, and providing a high-quality data basis for subsequent analysis. At the same time, preliminary statistical analysis is performed on the pre-processed data, such as calculating the mean, variance, frequency distribution, etc. of the data to understand the basic characteristics of the data.

[0067] Structural status analysis:

[0068] Establish a professional data analysis software platform with powerful data processing capabilities, which can efficiently compare and analyze measured data with theoretical calculation data, including key parameters such as displacement, stress, and hanger force of the main beam and arch rib. By comparing with the design standards and specifications, accurately judge whether the structural state meets expectations. If deviations are found, deeply analyze the causes of the deviations, such as design parameter errors (material elastic modulus, structural stiffness, concrete shrinkage creep, etc.), measurement errors (instrument accuracy, test environment, etc.), and construction errors (positioning errors, hanger force tensioning errors, etc.). In the analysis process, a combination of multiple analysis methods is used, such as parameter sensitivity analysis, trend analysis, correlation analysis, etc., to comprehensively and accurately evaluate the impact of deviations on structural performance. According to the analysis results, professional structural mechanics analysis methods, such as finite element analysis and structural dynamics analysis, are used to evaluate the safety and stability of the structure during construction, predict problems that may arise in subsequent construction, and propose scientific and reasonable adjustment measures.

[0069] For example, when it is found that the measured stress value of a certain section of the main beam exceeds the theoretical allowable range, the system automatically analyzes that it may be caused by a temporary increase in the construction load at that location or a difference between the actual value of the material elastic modulus and the design value. The specific cause is determined by querying the construction load records and further testing the material samples. Then, the degree of influence of the deviation on the overall structural safety is calculated based on the principles of structural mechanics, such as using finite element software to simulate the stress distribution and deformation of the structure under the deviation. Based on the calculation results, corresponding suggestions are put forward to adjust the construction load distribution or correct the elastic modulus parameters in the structural calculation model, such as adjusting the parking position of construction equipment, optimizing material procurement standards, etc.

[0070] Parameter identification and model modification:

[0071] Using advanced parameter identification algorithms, such as parameter identification technology based on the least squares method or Kalman filter method, through in-depth analysis of a large amount of structural response data, the actual values ​​of key design parameters, such as elastic modulus, hanger manufacturing length, etc., are accurately identified. In the parameter identification process, the influence of measurement errors and the actual state of the structure is fully considered, and appropriate error models and state estimation methods are used to improve the accuracy and reliability of parameter identification. The actual parameters after identification are substituted into the structural calculation model, and the model is corrected in real time to make the model more accurately reflect the actual state of the structure. The corrected model is used to recalculate the key indicators of the structure such as internal force and deformation in the subsequent construction stage, providing a more accurate theoretical basis for construction control. At the same time, the calculation results before and after the model correction are compared and analyzed to evaluate the effect of the model correction and ensure the accuracy and effectiveness of the model.

[0072] For example, during the construction process, the deviation between the actual elastic modulus of the suspender and the design value is calculated using a parameter identification algorithm based on the monitoring data of the suspender force and the measured value of the structural deformation. By measuring the suspender force and structural deformation multiple times at different construction stages, sufficient data samples are obtained, and the elastic modulus is optimized and calculated using the least squares method. The corrected elastic modulus parameters are input into the structural calculation model, and the internal force and deformation of the suspender under different working conditions are recalculated. The calculation results before and after the correction are compared to verify the accuracy of the model correction. Based on the new calculation results, an accurate basis is provided for adjusting the suspender tension force, such as determining the adjustment range and adjustment sequence of the suspender tension force.

[0073] (3) Control decision module

[0074] Construction control instruction generation:

[0075] Based on the precise results provided by the data processing and analysis module, the module automatically generates detailed, specific and targeted construction control instructions. The instructions include the precise value of the tension adjustment of the hanger (3), the specific plan for adjusting the structural line shape, and reasonable suggestions for optimizing the construction process, etc., to ensure the safety and quality of the structure during construction. When generating instructions, the feasibility of the construction process and the actual situation on site is fully considered to avoid the instructions being too idealistic and impossible to implement. The construction control instructions are transmitted to the construction unit in a timely manner through a clear communication interface to guide the construction unit to perform precise construction operations. At the same time, the execution of the instructions is tracked and feedback is provided to ensure that the instructions are effectively executed.

[0076] Early warning and emergency response:

[0077] Carefully set up a scientific and reasonable early warning indicator system, and divide the measured parameters of the structure into different levels of early warning areas according to the characteristics and design requirements of the bridge structure, such as the "green zone" indicates normal status, the "yellow zone" indicates that attention should be paid and adjustment measures should be taken, and the "red zone" indicates that the structure has serious safety problems and construction needs to be stopped immediately. The setting of early warning indicators should comprehensively consider factors such as the safety factor of the structure, the design allowable value, and the actual situation during the construction process to ensure the timeliness and accuracy of the early warning. When the measured parameters of the structure exceed the early warning threshold, the system automatically sends out early warning signals in a variety of ways, such as displaying eye-catching warning information in the monitoring center, sending text message notifications to relevant personnel, and activating on-site sound and light alarm devices, etc., to ensure that relevant personnel can obtain early warning information in the first time. At the same time, record detailed information of the early warning event, including the warning time, warning parameters, warning level, etc., to provide a basis for subsequent analysis and processing.

[0078] A comprehensive emergency response plan should be formulated for possible abnormal situations (such as the force of the suspender rod exceeds the allowable value, the deformation of the main arch rib exceeds the standard, the geometric dimensions of the component manufacturing exceed the allowable value, the deformation of the main beam exceeds the standard, and the linear deviation of the completed bridge structure exceeds the allowable range, etc.). The plan should include detailed processing procedures, such as personnel organization, equipment deployment, and implementation of technical measures in emergency situations, and clarify the division of responsibilities of relevant personnel to ensure that they can respond quickly and effectively in emergency situations, minimize safety risks, and ensure the safety of bridge structures. Emergency response plans should be regularly rehearsed and revised to adapt to changes in different construction stages and actual conditions, and improve the practicality and effectiveness of the plan.

[0079] (4) Information management and feedback module

[0080] Data storage and management:

[0081] Build a professional database management system to classify and store various types of information such as collected raw data, processed data, analysis results, control instructions, etc. The database should have efficient data query, call and traceability functions to facilitate the acquisition of historical data at any time for comparative analysis and problem troubleshooting. Use safe and reliable data storage technologies, such as redundant storage and backup storage, to ensure data security and integrity and prevent data loss or damage. At the same time, regularly clean and archive data, delete useless data, optimize database performance, and provide reliable data support for subsequent bridge maintenance and evaluation.

[0082] Information feedback and communication:

[0083] Develop an intuitive and user-friendly interface to feed back the monitoring results to the construction party, design party, supervision party and other related units in a variety of intuitive and easy-to-understand ways, such as generating detailed monitoring reports, concise and clear reports, intuitive and clear charts (such as line charts, bar charts, cloud charts, etc.). The monitoring report covers comprehensive information such as construction stage, measurement point layout, monitoring data, structural status analysis, control measures and effects, and is generated regularly and submitted to relevant parties in a timely manner. In the report, the data and analysis results are presented in a graphic and textual manner, so that all parties can intuitively understand the construction status of the bridge structure. By establishing an efficient information communication platform, such as a network-based project management system or dedicated communication software, the real-time communication and coordination between the monitoring party and other parties is strengthened, the questions of all parties are answered in a timely manner, and the problems arising in the construction are quickly solved, ensuring that the construction monitoring work is closely coordinated with the construction process and smoothly promoted. At the same time, the platform is used to realize information sharing and transmission, and improve work efficiency and collaborative work ability.

[0084] The present invention also provides a construction monitoring method for a through-type steel box tied arch bridge, see Figure 2-11 , which comprises the following steps:

[0085] (1) Preparation before construction

[0086] Measurement control system establishment:

[0087] Establishment of plane control system: Organize professional surveyors to use high-precision total stations to conduct joint measurement and verification of the starting coordinate points of the plane control of the construction area provided by the owner or design department according to the technical requirements and accuracy indicators of the polygonal traverse network or the fourth-order traverse measurement. During the review process, strictly control the measurement error, adopt multiple measurements to take the average value, round-trip measurement and other methods to ensure that the accuracy of the plane control points meets the requirements of relevant specifications. According to the review results, reasonably encrypt the control network, accurately determine the location of the plane control points, and properly implement protection measures for the control points, such as setting up guardrails, signboards, etc., to prevent them from being damaged or disturbed. At the same time, establish archival data of the control points, record the coordinates of the control points, measurement time, measurement personnel and other information, for subsequent query and use.

[0088] Establishment of elevation control system: The leveling point is selected in a place that is solid, stable, can be retained for a long time and is easy to use for measurement within 50m-100m away from the center line of the bridge. At the same time, it is necessary to ensure that it is not easily disturbed by construction and traffic. The distance between adjacent leveling points is strictly controlled to be no more than 500m. Leveling is carried out in accordance with the requirements of the specifications and the working leveling point is introduced. During the leveling process, a high-precision level is used, and a closed leveling route or a leveling route measurement method is adopted to ensure the measurement accuracy. The elevation is regularly reviewed using a high-precision level. Each review should be carried out under the same observation conditions, such as the same observation time, the same instruments and equipment, the same observers, etc., to ensure that the elevation measurement error of the working leveling point is controlled within the allowable range. The review results are recorded and analyzed. If abnormal changes in elevation are found, the causes should be found in time and measures should be taken to correct them.

[0089] Structural analysis calculation:

[0090] An experienced team of structural engineers used the large-scale professional finite element software Midas / civi l to establish an accurate bridge structure model based on detailed and accurate design parameters and carefully formulated construction plans. In the process of model establishment, various factors such as the geometric shape, material properties, and boundary conditions of the structure were fully considered, and the structure was reasonably simplified and assumed to ensure that the model can accurately reflect the mechanical behavior of the actual structure. Various working conditions during the construction process were simulated, including the structural system conversion and load application sequence at different construction stages, and key indicators such as theoretical displacement, internal force, and stress of the structure at each construction stage were accurately calculated, providing a reliable theoretical basis for construction monitoring. At the same time, the model was verified and calibrated, and the model parameters were adjusted to improve the accuracy of the model through comparative analysis with test data of similar bridge structures or actual engineering experience.

[0091] Development of monitoring plan and preparation of implementation rules:

[0092] Organize relevant experts and technicians, combine the characteristics of the bridge and the construction requirements, clarify the key elements such as monitoring content, methods, measurement point layout, test frequency, error control standards, and formulate a detailed and comprehensive monitoring plan. In terms of monitoring content, it should cover the main stress-bearing parts and key construction processes of the bridge structure, such as the main beam line shape, stress, arch rib line shape, stress, and hanger force. The measurement point layout should be reasonably determined according to the structural characteristics and stress conditions to ensure that the state information of the structure can be accurately obtained. The test frequency should be reasonably set according to the construction progress and the change of the structural state, and the test frequency should be appropriately increased during the key construction stage. The error control standard should be formulated according to the design requirements and relevant specifications, and the allowable error range of each monitoring parameter should be clarified. Prepare implementation details, clarify the specific operation process of the monitoring work, the division of personnel responsibilities, the data processing process, etc., to ensure the standardization and standardization of the monitoring work. After the monitoring plan and implementation details are strictly reviewed and approved by the design unit and the supervision unit, organize relevant personnel for training so that all parties are familiar with the content and requirements of the monitoring plan and implementation details, master the operation methods and data processing technology of the monitoring equipment, and ensure the smooth implementation of the monitoring work.

[0093] (2) Construction process monitoring

[0094] Data collection:

[0095] Arrange professional monitoring personnel to skillfully use various sensors and measuring equipment to collect data such as main beam linear shape, stress, arch rib linear shape, stress, hanger force, ambient temperature, etc. according to the predetermined scientific and reasonable test frequency and working conditions to ensure the integrity and accuracy of the data. Before and after key construction processes (such as arch seat construction, main beam assembly, arch rib assembly, hanger installation and tensioning, bracket removal, tie beam prestressing tensioning, second-phase paving, etc.), increase the frequency of data collection to timely and comprehensively grasp the changes in structural status. During the data collection process, the following points should be noted: First, ensure that the sensor installation position is accurate, firm and reliable to avoid loose or shifting sensors that affect the accuracy of the measurement data; second, conduct a preliminary on-site inspection of the collected data, such as checking the rationality and repeatability of the data, and if there is any abnormality, re-test or troubleshoot in time; third, record the environmental conditions when collecting data, such as temperature, humidity, wind force, etc., so that the influence of environmental factors can be considered in subsequent data analysis.

[0096] For example, during the assembly of the main beam, after each segment is assembled, the linear shape and stress of the segment and adjacent segments are measured immediately, and the ambient temperature and construction load conditions are recorded at the same time. When measuring the linear shape, a total station is used to measure at multiple observation points, and the measurement data from the previous stage are compared and analyzed to determine whether the linear shape meets the requirements. When measuring stress, ensure that the strain gauge fits tightly against the surface of the structure and that the collected data is stable and reliable. Before and after the hanger is tensioned, the hanger force, main beam and arch rib linear shape are measured multiple times. During the tensioning process, the changes in the hanger force are monitored in real time, and the tensioning speed and tensioning force are adjusted according to the changes in the hanger force to ensure that the hanger tensioning force is applied accurately and the structural state is stable.

[0097] Data analysis and processing:

[0098] Data processing and analysis personnel shall promptly process and deeply analyze the collected data in real time, use professional software to accurately compare the measured data with the theoretical calculated values, calculate the deviation value, and judge whether the structural state is normal based on the deviation. If the deviation exceeds the allowable range, quickly carry out parameter identification and model correction work, use advanced algorithms to accurately calculate the actual values ​​of key design parameters, and make real-time corrections to the structural calculation model. In the process of data analysis, a combination of multiple analysis methods should be used, such as statistical analysis, trend analysis, spectrum analysis, etc., to fully and deeply understand the state changes of the structure. According to the corrected model, predict the structural state of the subsequent construction stage, formulate scientific and reasonable adjustment measures, and ensure the safe and smooth construction of the structure. The adjustment measures should be targeted and operational, such as adjusting the construction process parameters, optimizing the construction sequence, and strengthening the temporary support of the structure.

[0099] For example, when it is found that the linear deviation of the main beam is gradually increasing, the parameters such as the deadweight of the structure, elastic modulus, and construction load are immediately identified. By querying the material usage records during the construction process and analyzing the actual deformation of the structure, the parameter identification algorithm is used to calculate the actual value of each parameter. The model is modified in combination with the actual construction situation, and the linear changes of the main beam under the subsequent construction load are recalculated to predict the impact of subsequent construction on the linear shape of the main beam. According to the prediction results, measures such as adjusting the height of the bracket and optimizing the construction sequence are formulated, such as adding temporary supports to certain parts of the main beam and adjusting the assembly sequence of subsequent segments, so as to control the linear deviation of the main beam within the allowable range.

[0100] Control decisions and feedback:

[0101] Based on the data analysis results, the control decision-makers can quickly generate clear and specific construction control instructions, and guide the construction unit to adjust the construction process, suspension rod tension and other construction parameters through efficient communication channels in a timely manner to ensure that the structural state meets the design requirements. When generating control instructions, the actual construction capacity and site conditions of the construction unit are fully considered to ensure the feasibility and effectiveness of the instructions. Regular monitoring meetings are held or emergency meetings are held according to actual needs, and the construction party, design party, supervision party, monitoring party and other relevant parties are organized to participate and communicate in a timely manner.

[0102] Take a newly built bottom-supported steel box tied arch bridge in a certain city as an example.

[0103] 1. Construction monitoring system implementation process

[0104] (1) System installation and debugging

[0105] Sensor Installation:

[0106] According to the measurement point layout diagram, displacement measurement points are accurately installed at the end of each segment of the main beam. During the installation process, high-precision measuring instruments are used to ensure that the position deviation of the measurement points is controlled within a very small range. At the same time, each measurement point is numbered to facilitate subsequent data collection and analysis.

[0107] At the key stress monitoring section of the main beam, surface-mounted strain gauges are installed as stress measurement points. After installation, professional equipment is used to measure and calibrate the initial value of each strain gauge to ensure measurement accuracy.

[0108] Prisms are installed on the monitoring section at the location of the boundary sample punching points of each arch rib segment. During installation, a special mounting bracket is used to fix the prism in the correct position and make precise angle adjustments to ensure that the total station can accurately measure the spatial linear shape of the arch rib.

[0109] Surface-mounted strain gauges for steel structures are installed at the arch foot, upper and lower edges of the 1 / 4, 1 / 2, and 3 / 4 sections of the arch rib, one at the upper and lower edge of each section.

[0110] Data acquisition equipment installation and debugging:

[0111] The total station is installed in a stable location with a wide field of view, good visibility and near the bridge site, and a dedicated observation platform is built to ensure that the total station is not vibrated or disturbed during the measurement process.

[0112] The digital electronic level is installed on a stable base, away from construction vibration and heat sources to avoid the influence of external factors on the measurement results.

[0113] The boom force dynamic tester is installed in a safe position that is convenient for connecting the boom rope. After installation, the dynamic tester is preheated and self-checked, and calibrated with standard weights to ensure the accuracy of the boom force measurement.

[0114] Data transmission network establishment:

[0115] This project uses a combination of wired and wireless communications to establish a data transmission network. Ethernet cables are laid out at the construction site, and various sensors and data acquisition equipment are connected to the data acquisition terminal through network cables to ensure the stability and reliability of data transmission. At the same time, wireless Wi-Fi or 4G / 5G networks are used for data transmission in some locations where wiring is inconvenient, such as mobile monitoring equipment or temporary monitoring points.

[0116] (2) Monitoring and implementation during the construction phase

[0117] Arch construction phase:

[0118] After the construction of the arch seat is completed, the displacement of the arch seat is measured immediately using a total station. Multiple measurement control points are set in advance on the arch seat, and measurements are taken from different angles and distances to obtain multiple sets of displacement data to ensure the accuracy of the measurement results. At the same time, a mercury thermometer is used to measure the ambient temperature at different locations near the arch seat, and the measurement time and temperature value are recorded to provide data for subsequent analysis of the impact of temperature on the structure.

[0119] The measured arch displacement data and ambient temperature data are transmitted to the data processing and analysis module in real time through the data transmission network. The data processing and analysis module performs preliminary processing and analysis on the received data to determine whether the arch displacement is within the design allowable range. If an abnormality is found, an early warning signal is issued in time.

[0120] Main beam construction stage:

[0121] Before assembly, the total station is used to comprehensively measure the initial linear shape of the main beam segment, and the measurement points cover the key positions of the entire segment, including the end, mid-span, and variable cross-section. At the same time, the initial stress state of the segment is measured by a strain gauge, and the ambient temperature and construction load conditions during the measurement are recorded.

[0122] The measured data is transmitted to the data processing and analysis module, and compared with the initial linear shape and stress calculated theoretically to evaluate whether the initial state of the segment meets the requirements. If the linear shape or stress deviation is large, the analysis reason may be the manufacturing error of the segment, deformation during storage, etc., and corresponding measures should be taken in time, such as adjusting the segment installation position or pre-deforming the segment.

[0123] After assembly, the total station and strain gauge are used to measure the assembled main beam again, focusing on the linear shape and stress changes at the segment connection parts. Compare the data before and after assembly to analyze the impact of the assembly process on the main beam structure. If the linear shape is not smooth or stress concentration is found, it may be caused by insufficient assembly accuracy or uneven preload of the connection bolts.

[0124] According to the analysis results, take corresponding adjustment measures. For example, for parts with large local linear deviations, fine-tune by adjusting the support height or applying temporary loads; for parts with stress concentration, check the connecting bolts and readjust the preload. In the subsequent construction process, continue to collect and analyze data according to the predetermined test frequency, grasp the changes in the main beam structure status in real time, and ensure that the main beam linear shape and stress are always within the controllable range.

[0125] Arch rib construction phase:

[0126] Before assembly, the geometric dimensions of the arch rib segments are measured in detail, including length, width, height, cross-sectional shape, etc., to ensure that the dimensions meet the design requirements. The initial linear shape of the arch rib segments is measured using a total station to check for deformation such as bending and twisting. At the same time, the initial stress of the segments is measured using a strain gauge and the ambient temperature is recorded.

[0127] Analyze the measured data. If the geometric dimension deviation exceeds the allowable range or the linear shape is abnormal, adjust or correct the arch rib segment in time. For the segment with abnormal stress, further check whether there is a problem with the material quality or manufacturing process, and replace the segment if necessary.

[0128] After the arch ribs are assembled, the total station is used to accurately measure the overall linear shape of the arch ribs, including vertical displacement, horizontal displacement, and lateral displacement. Measurements are performed on multiple measurement sections and points to obtain detailed linear shape data. At the same time, strain gauges are used to measure the stress of the key sections of the arch ribs to analyze the stress distribution after assembly.

[0129] Compare the measured data with the design requirements. If the linear deviation of the arch rib is found to be excessive or the stress state is unreasonable, the cause may be welding deformation, bracket deformation or uneven distribution of the hanger force during assembly. Take corresponding treatment measures for different reasons, such as flame correction of welding deformation parts, adjustment of bracket or hanger force, to ensure the safety and stability of the arch rib structure. During the arch rib construction process, pay close attention to data changes and adjust the construction process and parameters in time according to actual conditions.

[0130] Hanging rod construction stage:

[0131] Before installation and tensioning, measure the linear shape and stress of the main beam and arch rib as the initial state data for installation and tensioning of the hanger. Use a total station and a level to measure multiple measuring points of the main beam and arch rib to obtain accurate linear shape data; use strain gauges to measure the stress of the main beam and arch rib; use steel ruler measurement or sensor measurement methods to obtain the initial length of the hanger, and use a hanger force dynamic tester to measure the initial cable force of the hanger.

[0132] All measurement data are recorded and analyzed in detail to provide basic data for the tensioning of the suspender. Based on the initial state data, the theoretical tensioning force and tensioning sequence of the suspender are calculated, and a detailed tensioning plan is formulated.

[0133] During the tensioning process, the dynamic force measuring instrument of the suspender is used to monitor the change of the suspender force in real time. After each level of tensioning is completed, the tensioning is suspended, and the suspender force, the linear shape and stress of the main beam and arch rib are measured using total stations, levels, strain gauges and other equipment, and the measured data are compared and analyzed with the theoretical calculated values.

[0134] If the force of the suspender rods is found to be uneven (the difference in the force of adjacent suspender rods exceeds the allowable range) or the linear changes of the structure are abnormal (such as excessive local deformation of the main beam or arch rib), the tensioning sequence or tensioning force should be adjusted in time. For example, for suspenders with smaller suspender forces, the tensioning force should be appropriately increased; for parts with abnormal structural deformation, the stress conditions should be analyzed and the tensioning force of the relevant suspenders should be adjusted to make the suspender rod force evenly distributed and the structural state stable. During the entire tensioning process, the accuracy of the tensioning force and the tensioning speed should be strictly controlled to ensure the safety and accuracy of the suspender tensioning process.

[0135] After the hanger is tensioned, the linear shape and stress of the main beam and arch rib are fully measured to check the hanger tensioning effect. The whole bridge is measured in detail using total stations, levels, strain gauges and other equipment to obtain the final state data of the structure after the hanger is tensioned.

[0136] Compare the measurement results with the design requirements to determine whether the hanger tensioning meets the design requirements. If it is found that the main beam line shape does not meet the design line shape requirements (such as the bridge deck elevation deviation exceeds the allowable range) or the arch rib stress state is not ideal (such as stress concentration or exceeding the allowable stress value), analyze the reasons and take corresponding measures to make adjustments, such as local adjustment of the hanger force, fine-tuning of the structure, etc., to ensure that the bridge structure reaches the best state after the hanger tensioning is completed, and prepare for subsequent construction.

[0137] During the removal of the main beam support and arch rib support, the displacement and stress of the main beam and arch rib are monitored in real time using total stations and strain gauges. Before the support is removed, a detailed monitoring plan is developed to determine the monitoring frequency and location of monitoring points to ensure that the state changes of the structure during the support removal process can be fully understood.

[0138] Control the order and speed of bracket removal based on the monitoring results. If abnormal displacement or stress changes are found (such as a sudden increase in displacement rate or stress exceeding the allowable value), immediately suspend the removal operation.

[0139] After the second phase of paving construction is completed, the linear shape, stress, and hanger force of the main beam and arch ribs are fully measured. The measured data are compared and analyzed with the data from the previous construction stage to evaluate the impact of the second phase of paving on the bridge structure.

[0140] 3. Data Processing and Analysis

[0141] Data reception and preprocessing:

[0142] The data processing and analysis module receives data from the data acquisition module in real time and performs integrity checks on the data. Check whether the data has missing values, abnormal values, or incorrect data formats. For example, for the coordinate data measured by the total station, check whether its value range is reasonable; for the stress data measured by the strain gauge, determine whether it is within the range of the sensor.

[0143] Advanced filtering algorithms are used to denoise the data, remove noise interference during the measurement process, and improve the accuracy and reliability of the data.

[0144] Structural status analysis:

[0145] Analyze the collected data at predetermined time intervals. Calculate the deviation between the measured values ​​and theoretical calculated values ​​of structural displacement, stress, suspender force and other parameters, draw the deviation curve, and intuitively display the trend of structural state changes.

[0146] Conduct a detailed analysis of the parameters with large deviations, and determine the causes of the deviations based on the construction process records (such as construction procedures, changes in construction loads, construction time, etc.) and on-site conditions (such as weather conditions, changes in the surrounding environment, operation of construction equipment, etc.).

[0147] Parameter identification and model modification:

[0148] Parameter identification is performed regularly, and advanced parameter identification methods such as the least squares method or Kalman filter method are used to calculate the actual values ​​of key design parameters, such as elastic modulus, hanger manufacturing length, and structure deadweight. In the parameter identification process, the influence of measurement errors and the actual state of the structure is fully considered, a reasonable error model is established, and error correction is performed on the measurement data. For example, for the identification of the elastic modulus, the actual value of the elastic modulus is optimized and calculated by the least squares method based on the deformation measurement data of the structure under different loads and the structural mechanics model. At the same time, considering the randomness and systematicity of the measurement error, the measurement data is weighted to improve the accuracy of parameter identification.

[0149] Substitute the identified parameters into the structural calculation model and modify the model. The modified model can more accurately reflect the actual state of the structure, and the internal force and deformation of the structure in the subsequent construction stage can be recalculated using the modified model, providing a more accurate theoretical basis for construction control.

[0150] 4. Control decisions and feedback

[0151] Construction control instruction generation:

[0152] The control decision module generates construction control instructions based on the structural state analysis and prediction results provided by the data processing and analysis module. The instructions include the adjustment value of the suspender tension force, the structural line adjustment plan, and the construction process optimization suggestions.

[0153] Construction control instructions are transmitted to the construction unit in a timely manner through reliable communication methods to ensure that the construction unit can obtain instructions in a timely manner and perform construction operations as required. At the same time, the execution of instructions is tracked and feedback is provided to ensure that the construction process is always carried out in accordance with the predetermined goals and requirements.

[0154] Early warning and emergency response:

[0155] The early warning and emergency processing unit in the control decision module monitors the early warning indicators in real time, and immediately issues an early warning signal when the measured parameters of the structure exceed the early warning threshold.

[0156] In response to different levels of warning, the corresponding emergency response plan is initiated. During the emergency response process, the structure is continuously monitored in real time, and the response measures are adjusted in a timely manner according to the monitoring results to ensure the safety of the structure. After the emergency response is completed, the response effect is evaluated, and the structural status is monitored again to verify whether the structure has returned to normal. If there are still problems, the cause is analyzed and the plan is adjusted until the structural status is stable and meets the requirements.

[0157] 5. Abnormal situation handling

[0158] When an abnormal situation occurs (such as the force of the sling hanger exceeds the allowable value, the deformation of the main arch rib exceeds the standard, the geometric dimensions of the component manufacturing exceed the allowable value, the deformation of the main beam exceeds the standard, the linear deviation of the completed bridge structure exceeds the allowable range, etc.), the on-site monitoring personnel will immediately suspend construction and start the abnormal situation handling process.

[0159] The monitoring personnel shall promptly record the time, location, specific phenomena and other information of the abnormal situation, and report it to the construction control leading group in a timely manner. After receiving the report, the construction control leading group shall immediately organize relevant personnel to rush to the site to conduct a detailed on-site investigation and preliminary assessment of the abnormal situation, including checking whether the structural appearance is damaged (such as observing whether there are cracks, deformation, paint peeling, etc.), measuring the actual size and deformation of the abnormal part (using high-precision measuring instruments to accurately measure the abnormal part and obtain detailed size and deformation data), checking the construction records and monitoring data (checking the construction log, quality inspection records, recent monitoring data reports, etc., to understand the operation status and structural status change process during the construction process), etc., to determine the severity of the abnormal situation and the possible scope of impact.

[0160] The construction control leading group organized a special meeting with design, supervision, construction parties and experts to jointly analyze the causes and develop solutions.

[0161] After implementing a solution, continue monitoring to ensure the issue is resolved effectively and the structure is safe and reliable.

[0162] During the implementation of the solution, the monitoring personnel strengthened the real-time monitoring of the structural status and paid close attention to the changing trend of abnormal conditions. The construction parameters were adjusted in time according to the monitoring data to ensure the implementation effect of the solution. At the same time, the handling process and results of abnormal conditions were recorded and summarized to provide experience and lessons for subsequent construction and avoid similar problems from happening again.

[0163] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back, etc., then the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0164] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist.

[0165] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction monitoring system for a through-type steel box tied arch bridge, characterized in that: include, Data acquisition module, used to collect various data during the bridge construction process; Data processing and analysis module, used to process and analyze the collected data; A control decision module is used to make control decisions based on the results of the data processing and analysis module; Information management and feedback module, used to manage and feedback monitoring information.

2. A construction monitoring system for a through steel box tied arch bridge as claimed in claim 1, characterized in that: The data processing and analysis module includes receiving various sensor data from the data acquisition module and performing filtering and denoising preprocessing on the data; Structural status analysis: compare and analyze measured data with theoretical calculation data. Based on the analysis results, evaluate the safety and stability of the structure during construction, predict possible problems in subsequent construction, and propose corresponding adjustment measures; Parameter identification and model modification: by analyzing the structural response data, the actual values ​​of key design parameters are identified, so that the model can more accurately reflect the actual state of the structure, and the internal forces and deformations of the structure in the subsequent construction stage can be recalculated using the modified model.

3. A construction monitoring system for a through steel box tied arch bridge as claimed in claim 1, characterized in that: The control decision module includes, construction control instruction generation, generating construction control instructions according to the results of the data processing and analysis module; Early warning and emergency response, set early warning indicators, and when the measured parameters of the structure exceed the early warning threshold, promptly issue an early warning signal. Formulate corresponding emergency response plans for possible abnormal situations, and clarify the processing procedures and division of responsibilities.

4. A construction monitoring system for a through steel box tied arch bridge as claimed in claim 1, characterized in that: The information management and feedback module includes data storage and management, establishing a database, and classifying and storing the collected raw data, processed data, analysis results, and control instructions; Information feedback and communication: Feedback the monitoring results to the construction party, design party, supervision party and other relevant units in an intuitive and easy-to-understand manner to make corresponding decisions, establish an information communication platform, and strengthen communication and coordination between the monitoring party and other parties.

5. The construction monitoring system for a through steel box tied arch bridge according to claim 1, characterized in that: The parameter identification method in the data processing and analysis module adopts the least square method or the Kalman filter method, wherein the least square method finds the best function match for the data by minimizing the sum of squares of errors, and the Kalman filter method uses the state estimate at the previous moment and the observation value at the current moment to update the estimate of the current state.

6. A method for monitoring the construction of a through-type steel box tied arch bridge, characterized in that: The following steps are included: (1) Preparation before construction: Establish a plane control system, use a total station to conduct joint measurement and verification of the plane control starting coordinate points of the construction area provided by the owner or design department according to the technical requirements and accuracy indicators of polygonal traverse network or four-level traverse measurement, encrypt the control network, determine the position of the plane control points, and the accuracy of the plane control points should meet the requirements of relevant specifications; Establish an elevation control system. The leveling point is set within 50m-100m from the center line of the bridge. Choose a stable, easy-to-measure and not easily disturbed place. The distance between adjacent leveling points should not exceed 500m. Introduce working leveling points and regularly review their elevations. The elevation measurement error of the working leveling points should be controlled within the allowable range. Conduct structural analysis and calculation. According to the design parameters and construction plan, use the large-scale finite element software Midas / civil to establish a bridge structure model, simulate the construction process, and calculate the theoretical displacement, internal force, stress, etc. of the structure at each construction stage to provide a theoretical basis for construction monitoring. The model should accurately consider factors such as the geometric shape, material properties, and boundary conditions of the structure; Formulate monitoring plans and implementation rules, clarify monitoring content, methods, measurement point layout, test frequency, error control standards, etc., and implement them after approval by the design unit and supervision unit. The monitoring plan should be targeted and operational; (2) Construction process monitoring: data collection. According to the predetermined test frequency and working conditions, various sensors and measuring equipment are used to collect data such as the main beam line shape, stress, arch rib line shape, stress, hanger force, ambient temperature, etc. to ensure the integrity and accuracy of the data. Data collection is carried out before and after key construction processes to timely grasp the changes in structural status. The time interval for data collection should be reasonably determined based on the construction progress and changes in structural status; Data analysis and processing: real-time processing and analysis of collected data, comparison with theoretical calculation values, calculation of deviation values, determination of whether the structural state is normal, parameter identification and model correction based on the deviation, adjustment of construction control parameters, prediction of structural state in subsequent construction phases, formulation of adjustment measures, parameter identification should be accurate and reliable, and model correction should be timely and effective; Control decision-making and feedback. Based on the data analysis results, generate construction control instructions to guide the construction unit to adjust the construction process, hanger tension, etc., to ensure that the structural status meets the design requirements, and promptly feedback the monitoring results to relevant parties. Hold regular monitoring meetings or emergency meetings to coordinate and solve problems that arise during construction. Construction control instructions should be clear and specific, and regular monitoring meetings or emergency meetings should form effective resolutions; (3) Abnormal situation handling: When the measured value of the construction control parameter deviates too much from the theoretical value or an abnormal situation occurs, construction is suspended and the abnormal situation handling process is initiated. The judgment criteria for abnormal situations should be determined based on specific monitoring indicators and engineering experience; The construction control leading group organizes design, supervision, construction and experts to hold special meetings to jointly analyze the causes and formulate solutions, such as adjusting the construction sequence, improving the construction process, replacing materials, etc. The solutions should be feasible and effective; After the solution is implemented, continue monitoring to ensure that the problem is effectively solved and the structure is safe and reliable. Monitoring should continue until the structural state is stable and meets the requirements.

7. A method for monitoring construction of a through steel box tied arch bridge as claimed in claim 6, characterized in that: In the data collection step, the ambient temperature is measured continuously. The test team completes the temperature and humidity data collection according to the construction progress. The monitoring location is determined according to the actual situation on site. Multiple monitoring points are set at different locations around the bridge structure to obtain accurate ambient temperature data. The temperature field observation of the main beam is carried out in representative weather after the main beam construction is completed. The temperature field of the main beam changing with temperature is obtained by using surface-mounted temperature sensors. Surface thermometers are mainly used for temperature field observation of steel beams and arch ribs. The temperature field observation should cover the key parts of the structure.

8. The method for monitoring construction of a through steel box tied arch bridge according to claim 6, characterized in that: In the data analysis and processing steps, according to the deviation situation, parameter identification and model correction are carried out, construction control parameters are adjusted, the structural state of the subsequent construction stage is predicted, and adjustment measures are formulated. The parameter identification adopts the least squares method or Kalman filtering method to calculate the actual value of the key design parameters, and the influence of measurement errors and the actual state of the structure are considered in the parameter identification process.

9. The method for monitoring construction of a through steel box tied arch bridge according to claim 6, characterized in that: In the control decision and feedback steps, the monitoring results are fed back to the relevant parties in the form of monitoring reports, statements, charts, etc. The monitoring reports are generated regularly and include the construction stage, measurement point layout, monitoring data, structural status analysis, control measures and effects, etc. The monitoring reports should be detailed, accurate in data, and clear in conclusions; the charts should intuitively and clearly show the trend of structural status changes.

10. The method for monitoring construction of a through steel box tied arch bridge according to claim 6, characterized in that: In the abnormal situation handling steps described above, the emergency response plan shall formulate corresponding measures for possible abnormal situations, clarify the handling process and division of responsibilities, and ensure a rapid and effective response in emergency situations. The emergency response plan shall include aspects such as personnel organization, equipment deployment, and technical measures, and shall be regularly rehearsed and updated.

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