Building structure anti-seismic performance monitoring method and system

Abstract

The invention relates to the field of building structure safety detection, and discloses a building structure anti-seismic performance monitoring method and system. The method comprises the following steps: acquiring multi-source response data such as acceleration, displacement, strain and inclination angle; obtaining a structure standard response based on wavelet denoising and standardization processing; adopting a multi-order modal recognition algorithm to extract structural dynamic characteristic parameters; performing structural damage evaluation based on the modal change index, and combining the yield strength, the load index and the displacement margin to calculate the residual bearing capacity of the structure; and finally, outputting an anti-seismic grade early warning signal. The system comprises a structure response acquisition module, a modal identification and damage evaluation module and a residual bearing capacity calculation and early warning module. According to the method, real-time quantitative analysis of the performance of the structure under the earthquake or load effect can be achieved, the evaluation precision is high, the applicability is high, and the wide engineering popularization value is achieved.

Description

Technical Field

[0001] The present invention relates to the field of building structure safety detection, and in particular to a method and system for monitoring the seismic performance of building structures. Background Art

[0002] Traditional monitoring means lack the ability to identify dynamic responses: Most existing building structure safety monitoring uses single sensors such as strain gauges and displacement gauges, which are mainly used for monitoring static loads or long-term settlement trends. It is difficult to effectively capture the high-frequency and transient responses generated under seismic excitation, resulting in the inability to completely restore the dynamic evolution process of structural damage, severely restricting the accuracy of seismic performance assessment.

[0003] The accuracy of modal parameter identification is low, and damage is difficult to quantify: Although some current methods introduce the idea of modal analysis, they mostly rely on traditional frequency domain methods. Under the conditions of noise interference or sparse measurement points, the identification accuracy of modal frequencies, damping ratios, and mode shapes is low, and it is impossible to achieve sensitive detection of early micro-damage, easily resulting in missed or delayed judgments, especially more prominent in long-span structures or complex connection nodes.

[0004] Lack of a quantitative calculation mechanism for seismic remaining capacity: Most existing structural assessment methods use whether there is damage as the judgment criterion, ignoring the non-linear evolution law of the bearing capacity decline of the structure after the action of seismic loads. There is a lack of a comprehensive assessment model that integrates the yield strength, deformation ability, and energy dissipation ability of the structure, and it is impossible to provide a quantitative basis for whether the structure can continue to serve or needs to be evacuated immediately. Summary of the Invention

[0005] In order to achieve the above-mentioned invention purposes, the present invention provides the following technical solutions: A method for monitoring the seismic performance of a building structure, including the following steps: S1. Structural response data acquisition, real-time acquisition of the response data of the building structure under seismic action through multi-type sensors, and the response data includes acceleration data , displacement data , strain data and tilt angle data ; S2. Dynamic feature extraction and modal identification, based on the collected structural response data, using an improved modal parameter identification algorithm to extract the main dynamic characteristic parameters of the building structure under the current working conditions, and the dynamic characteristic parameters include natural frequency , damping ratio , main modal shape ; S3. Calculation and evaluation of seismic damage indicators, comparing the extracted modal feature vectors with historical reference modal parameters to construct the health state index of the building structure and damage index , and then judge the change trend of the seismic performance of the structure under the current working conditions; S4. Deduction and early warning of the remaining bearing capacity of the structure. Using the multi-parameter fusion evolution model and combining with the current health status indicators , the maximum response value and the design strength of structural components , deduce the remaining seismic bearing capacity of the building structure , and generate hierarchical early warning information according to the deduction results .

[0006] Preferably, the step S1 specifically includes: S1(1). Triaxial acceleration sensors, fiber Bragg grating displacement gauges, MEMS tilt sensors and resistance strain gauges are respectively arranged at the key nodes of the structure to collect the response data generated by the building structure during the earthquake excitation process in real time. The response data includes acceleration data , displacement data , strain data and tilt angle data ; S1(2). Set the acquisition frequency range to [100, 500] Hz to meet the capture requirements of the low-order modes of the structure; S1(3). Process the collected original data through the following algorithm and convert it into a standard response data set : ; where is the collected data set , is the mean value of the th group of data, is the standard deviation of the th group of data, is the wavelet denoising function; S1(4). The processed response data forms a multi-dimensional data matrix with the time stamp as the index: ; Preferably, the step S2 specifically includes: S2(1). Based on the data matrix obtained in step S1 , adopt an improved modal parameter identification algorithm to extract the main modal characteristics: ; ; ; where is the natural frequency extraction function, is the damping identification function, is the modal shape identification function, is the natural frequency of the building structure, is the damping ratio of the building structure, is the main modal shape of the building structure; S2(2), forming the modal feature vector by the extracted modal feature parameters : ; wherein, is the number of modal feature parameters.

[0007] Preferably, the step S3 specifically includes: S3(1), comparing the extracted modal feature vector with the historical reference modal parameters to obtain the modal change ratio matrix : ; wherein, the historical reference modal parameters are the stable modal center values obtained by averaging according to the clustering algorithm to ensure robustness, and the calculation formula is: ; wherein, is the modal feature vector of the th group of data; S3(2), comparing the modal change ratio matrix with the standard modal change threshold to represent the damage degree of the structure by constructing the damage index : ; wherein, is the damage index, is the modal change ratio matrix of the th group of data, is the th th group of data's standard modal change threshold, , is the mean value of the historical reference modal parameters , is the standard deviation of the historical reference modal parameters , , which is dynamically adjustable according to the actual allowable error; S3(3), then combining the health state index with the damage index The mapping relationship between the two structures is used to determine the current state of the structure using a fuzzy logic reasoning system: ; in, is the fuzzy logic reasoning function, when When it is <0.98, an early warning is triggered, and it is determined that the seismic performance of the structure under the current working conditions is poor.

[0008] Preferably, the step S4 specifically includes: S4 (1), comprehensively considering the design strength of the structural component according to the current damage state , Maximum response value , Current health status indicators , the residual seismic bearing capacity of the building structure : ; in, is the residual seismic bearing capacity of the building structure, It is the allowable value of the critical response of the structure, which is a fixed threshold and can be queried through the structural material description; S4 (2), combined Set safe load threshold with the structure Compare and determine the current structural status and trigger multi-level warning signals: ; in, It is a graded warning information, corresponding to normal, minor, moderate and severe warnings. Set thresholds for building structural standards.

[0009] The present invention also provides a building structure seismic performance monitoring system, comprising the following modules: Structural response data acquisition module, used to collect multi-dimensional response data of building structures in real time under earthquake excitation; The modal identification and damage assessment module is used to extract modal features and determine damage status based on the collected response data, and generate health status indicators and damage indexes of building structures; The residual bearing capacity calculation and early warning module is used to calculate the residual seismic bearing capacity and generate graded early warning information based on health status indicators, design strength and response data.

[0010] The structural response data acquisition module includes: The sensor deployment unit is used to deploy triaxial acceleration sensors, fiber grating displacement meters, resistance strain gauges and MEMS tilt sensors at key nodes of the building structure to obtain acceleration , displacement ,strain With tilt angle Data A data preprocessing unit for performing wavelet denoising on the collected data, constructing a unified response dataset after standardization and generating a multi-dimensional response matrix based on the time stamp ; ; A sampling control unit for setting the sampling frequency in the range of [100, 500] Hz to meet the frequency domain requirements for extracting the low-order modal characteristics of the structure.

[0011] The modal identification and damage assessment module includes: A modal parameter identification unit that, based on the standard response dataset , uses an improved modal identification algorithm to extract the natural frequency , damping ratio , and main modal shape of the building structure to form a modal feature vector ; A damage index calculation unit that compares the modal feature vector with the historical reference modal parameters to calculate the modal change ratio , and obtains the damage index by comparing it with the standard threshold ; A health status assessment unit that uses a fuzzy logic inference function , combines the damage index , modal change ratio and main modal shape to output a health status indicator , and determines whether to enter the warning state based on this.

[0012] The remaining bearing capacity calculation and warning module includes: A remaining bearing capacity calculation unit that, based on the current damage state, comprehensively considers the design strength of the structural components , maximum response value , and current health status indicator to calculate the remaining seismic bearing capacity of the building structure: A safety threshold determination unit that compares the remaining seismic bearing capacity of the building structure with the set safety threshold to judge the current bearing safety status; A hierarchical warning information generation unit that generates a warning level based on the comparison result, and its value is divided according to the following conditions: ; Advantages of the present invention compared with the prior art: Achieve full-cycle high-precision monitoring of structural response and dynamic damage identification: By integrating multi-source data (acceleration, displacement, strain), it is possible to continuously identify the structural vibration modes, key node responses, and damage evolution paths throughout the earthquake process, breaking through the problem of weak capture ability of traditional monitoring means for earthquake transient responses, and realizing the dynamic assessment of the structural state from undamaged - slightly damaged - severely damaged.

[0013] Construct a quantitative assessment model of seismic performance based on damage indicators: The present invention introduces a comprehensive damage indicator and combines it with a calculation model of the remaining bearing capacity of the structure, which can quantitatively calculate the remaining seismic capacity of the structure in the current state, effectively support subsequent engineering decisions such as whether to continue in service and whether to reinforce, and solve the problem of the lack of quantitative seismic criteria in the prior art.

[0014] Modular system design, strong adaptability, and wide application range: The proposed system adopts a distributed structure combining a sensing integration module, a data acquisition and processing module, and an intelligent decision-making module, and can be widely applied to seismic monitoring of different types of structures such as high-rise buildings, bridges, and tunnels, support remote deployment and dynamic update of algorithm models, and have good scalability and engineering implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic flowchart of the method steps provided by this application; Figure 2 It is a schematic diagram of the system module provided by this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to enable those skilled in the art to better understand the solution of the present invention, 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Refer to Figure 1 , the embodiment of the present invention provides a method for monitoring the seismic performance of a building structure, including the following steps: Step 1: Collect structural response data, and collect in real time the response data of the building structure under earthquake action through multi-type sensors. The response data includes acceleration data , displacement data , strain data , and tilt angle data .

[0018] In Step 1, first, triaxial accelerometers, fiber Bragg grating displacement gauges, MEMS tilt sensors, and resistance strain gauges are respectively installed at multiple key nodes of the building structure to obtain real-time structural response data under seismic excitation, including acceleration data , displacement data , strain data and tilt angle data . Subsequently, the data acquisition frequency of all sensors is uniformly set to 200 Hz to ensure capturing the low-order modal responses of the structure under seismic loads. The original response data collected from each channel are respectively input into the wavelet denoising function , and db4 wavelet basis is used for three-level decomposition and reconstruction to obtain denoised data. Then, normalization standard processing is performed on each type of data: ; where and are respectively the mean and standard deviation of each type of data during this observation period.

[0019] The processed data is stored at intervals of 0.005 s to form a standard response data matrix , as follows: ; Step 2, Dynamic Feature Extraction and Modal Identification. Based on the collected structural response data, an improved modal parameter identification algorithm is used to extract the main dynamic characteristic parameters of the building structure under the current working conditions. The dynamic characteristic parameters include natural frequency , damping ratio , and main modal shape .

[0020] In Step 2, first is input into the improved modal parameter identification algorithm to extract the main modal characteristics of the structure: , and the first three natural frequencies are extracted as 2.1 Hz, 5.4 Hz, and 8.3 Hz respectively; , and the corresponding damping ratios are 2.3%, 2.7%, and 3.0% respectively; , and the modal vectors of each order of main modal vibration shapes are used for subsequent comparison after normalization.

[0021] Subsequently, the modal characteristics are combined into a modal vector: ; where is the number of modal characteristic parameters.

[0022] Step 3: Calculation and evaluation of seismic damage indicators. Compare the extracted modal feature vectors with the historical benchmark modal parameters to construct the health status indicators of the building structure and the damage index , and then judge the change trend of the seismic performance of the structure under the current working conditions.

[0023] In Step 3, first call the modal central value of the structure under the historical stable working conditions in the database as the benchmark modal parameter , and use the following formula to calculate the modal change ratio matrix : ; Among them, the historical benchmark modal parameter is the stable modal central value obtained by averaging according to the clustering algorithm to ensure robustness. The calculation formula is: ; Among them, is the modal feature vector of the th group of data; Subsequently, according to the set standard threshold (k = 2.5), perform differential analysis and calculate the damage index: ; Obtain the current damage index = 2.13, which has reached the preset sensitive detection threshold.

[0024] Finally, combined with the fuzzy logic inference system, input , , to in the inference model. The module formula is: , and output the current health index = 0.91, indicating that the structure is in a warning state, and the system automatically triggers the warning mechanism.

[0025] Step 4: Deduction and warning of the remaining load-bearing capacity of the structure. Use the multi-parameter fusion evolution model, combined with the current health status indicator , the maximum response value and the design strength of the structural components , deduce the remaining seismic load-bearing capacity of the building structure, and generate graded warning information according to the deduction result. In Step 4, considering the current maximum response value = 0.76, the critical response allowable value = 1.0 of the structure given by the material description, and the design strength = 300 MPa of the structural components, calculate the remaining seismic load-bearing capacity: ; where = 0.85, = 0.6, substituting into the calculation gives = 132.5 MPa.

[0026] Finally, compare the remaining seismic bearing capacity with the set safety bearing threshold = 120 MPa, and combine with: ; Judged as a minor warning level, corresponding to the warning information level = 1, automatically send out a yellow signal and generate a structural monitoring report.

[0027] Reference Figure 2 , the embodiment of the present invention provides a building structure seismic performance monitoring system, including the following modules: A structural response data acquisition module, configured to collect multi-dimensional response data of a building structure in real time under the action of seismic excitation.

[0028] In the structural response data acquisition module, first, at key positions such as the beam-column joints, the top and bottom of shear walls, the center and four corners of floors of the building structure, deploy triaxial acceleration sensors, fiber Bragg grating displacement gauges, resistance strain gauges, and MEMS tilt sensors. The corresponding relationship between the numbers of each sensor and the building BIM model is bound to ensure accurate spatial positioning. At the same time, the sensors obtain acceleration displacement strain and tilt angle data in real time. At the same time, the acquisition frequency range is set to [100, 500] Hz, which meets the requirement of capturing the low-order modes of the structure. Subsequently, the data preprocessing unit performs wavelet denoising on the original data to eliminate environmental noise, and normalizes the denoised data according to each dimension, and uniformly converts it into standard response data: , finally, the processed response data is indexed by the timestamp to form a multi-dimensional data matrix: ; A modal identification and damage assessment module, configured to perform modal feature extraction and damage state determination based on the collected response data, and generate a health state index and a damage index of the building structure.

[0029] In the modal identification and damage assessment module, the modal parameter identification unit first receives the processed standard response data set from the structural response data acquisition module , through the embedded improved modal identification algorithm, extract the key modal parameters of the current building structure, including the natural frequency , damping ratio and the main modal shape vector , and combine the above parameters to form a modal feature vector . Subsequently, the damage index calculation unit compares the current modal feature vector with the historical reference modal parameters built into the system component by component, calculates the modal change ratio , and compares it with the set standard threshold to evaluate the amplitude of the structural response change, and calculates the damage index based on this. On this basis, the health status assessment unit calls the fuzzy logic inference function , synthesizes the input damage index , modal change ratio and the main modal shape , conducts fuzzy inference through the preset membership function and rule base, outputs the health status index characterizing the overall health status of the structure, and automatically determines whether the current building structure is in a warning state according to the index value, providing a judgment basis for subsequent bearing capacity calculation and warning classification.

[0030] The remaining bearing capacity calculation and warning module is used to calculate the remaining seismic bearing capacity and generate graded warning information based on the health status index, design strength and response data.

[0031] First, the remaining bearing capacity calculation unit receives the current damage state parameters output by the front-end module, and comprehensively calls the component design strength parameters in the structural design database, as well as the maximum response value recorded during the actual monitoring of the structure. At the same time, combined with the health status index obtained from the current evaluation, the remaining seismic bearing capacity of the building structure in the current state is accurately calculated through the set calculation model. Subsequently, the safety threshold determination unit compares the remaining bearing capacity with the safety threshold pre-set in the system to analyze whether the building structure is in a safe state or has potential risks. When is significantly higher than , the system determines that the structural safety margin is sufficient; if it is close to or lower than the threshold, it is considered that there are different levels of potential safety hazards. Based on the above comparison results, the graded warning information generation unit classifies the current structural state according to the built-in determination rules and generates a warning level , where the early warning level is automatically divided into four levels according to the ratio of the remaining bearing capacity of the structure to the safety threshold, ranging from safe (level 0) to severe early warning (level 3). Finally, the early warning information corresponding to the level is transmitted to the monitoring terminal through the interface for managers to schedule in real time or implement emergency response measures.

[0032] It should be noted that, without conflict, the embodiments and the features and technical solutions in the embodiments in the present invention may be combined with each other.

[0033] Obviously, the embodiments described above are only a part of the embodiments of the present invention, rather than all of them. The drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements on some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present invention in other related technical fields is equally within the scope of the patent protection of the present invention.

Claims

1. A method for monitoring the seismic performance of a building structure, characterized in that, It includes the following steps: S1. Structural response data acquisition: Real-time acquisition of response data of building structures under earthquake action through multi-type sensors. The response data includes acceleration data , displacement data , strain data , and tilt angle data ; S2. Dynamic feature extraction and modal identification. Based on the collected structural response data, use an improved modal parameter identification algorithm to extract the main dynamic characteristic parameters of the building structure under the current working condition. The dynamic characteristic parameters include natural frequency , damping ratio , and main modal shape ; S3. Calculate and evaluate the seismic damage index. Compare the extracted modal feature vectors with the historical reference modal parameters to construct the health status index of the building structure and the damage index , and then judge the changing trend of the seismic performance of the structure under the current working conditions; S4. Deduce and give early warning of the remaining load-bearing capacity of the structure. Using the multi-parameter fusion evolution model, combined with the current health status indicators , the maximum response value and the design strength of structural members , deduce the remaining seismic load-bearing capacity of the building structure , and generate graded early warning information according to the deduction results .

2. The seismic performance monitoring method of a building structure according to claim 1, characterized in that The specific steps of step S1 include: S1(1) Install triaxial acceleration sensors, fiber Bragg grating displacement gauges, MEMS tilt sensors and resistance strain gauges at the key structural nodes respectively to sample the response data generated by the building structure during the earthquake excitation process in real time. The response data includes acceleration data , displacement data , strain data and tilt angle data ; S1(2), the acquisition frequency range is set to [100, 500] Hz, meeting the requirement for capturing the low-order modes of the structure; S1(3), Process the collected raw data through the following algorithm and convert it into a standard response data set : ； Among them, is the set of collected data , is the mean value of the th group of data, is the standard deviation of the th group of data, is the wavelet denoising function; S1(4), the processed response data is indexed by a timestamp to form a multi-dimensional data matrix: 。 3. The method according to claim 1, characterized in that The specific steps of step S2 include: S2(1), based on the data matrix obtained in step S1 , use the improved modal parameter identification algorithm to extract the main modal features: ； ； ； Among them, is the natural frequency extraction function, is the damping identification function, is the modal shape identification function, is the natural frequency of the building structure, is the damping ratio of the building structure, is the main modal shape of the building structure; S2(2), forming a modal feature vector by the extracted modal feature parameters : ； Among them, is the number of modal characteristic parameters.

4. A method for monitoring the seismic performance of a building structure according to claim 1, characterized in that, The specific steps of step S3 include: S3(1)、According to the extracted modal feature vectors and the historical reference modal parameters to make a comparison to obtain a modal change ratio matrix : ； Among them, the historical reference modal parameters are the stable modal center values obtained by averaging according to the clustering algorithm to ensure robustness. The calculation formula is as follows: ； Among them, is the modal eigenvector of the group of data; S3(2), the modal change ratio matrix is compared with the standard modal change threshold to represent the damage degree of the structure by constructing a damage index : ； Among them, is the damage index, is the modal change ratio matrix of the th group of data, is The standard modal change threshold of the first set of data, , is the mean of the historical reference modal parameters , and is the standard deviation of the historical reference modal parameters , which is dynamically adjustable according to the actual allowable error; S3(3), and then combined with the health status indicators and the damage index mapping relationship, use a fuzzy logic inference system to determine the current state of the structure: ； Among them, is a fuzzy logic inference function. When < 0.98, an early warning is triggered, and it is determined that the seismic performance of the structure under the current working conditions is poor.

5. A method for monitoring the seismic performance of a building structure according to claim 1, characterized in that, The specific steps of step S4 include: S4(1)、According to the current damage state, comprehensively consider the design strength of structural members 、The maximum response value 、The current health state index , the remaining seismic bearing capacity of the building structure : ； Among them, is the remaining seismic load-carrying capacity of the building structure, is the allowable value of the critical response of the structure, which is a fixed threshold and can be queried through the structural material description; S4(2), Combine with the structurally set safety load threshold for comparison to determine the current structural status and trigger multi-level warning signals: ； Among them, is the hierarchical warning information, corresponding to normal, minor, medium and severe warnings respectively, is the threshold set for building structure standards.

6. A seismic performance monitoring system for building structures, characterized in that, It includes the following modules: A structural response data acquisition module, which is used to collect multi-dimensional response data of a building structure in real time under the action of seismic excitation; A modal identification and damage assessment module, which is used to extract modal characteristics and determine the damage state based on the collected response data, and generate health state indicators and damage indices of the building structure; A remaining bearing capacity calculation and early warning module, which is used to calculate the remaining seismic bearing capacity and generate hierarchical early warning information based on the health state indicators, design strength and response data.

7. An earthquake resistance performance monitoring system for a building structure according to claim 6, characterized in that, The structural response data acquisition module includes: Sensor layout unit, which is used to layout triaxial acceleration sensors, fiber Bragg grating displacement gauges, resistance strain gauges and MEMS tilt sensors at key nodes of building structures to obtain acceleration , displacement , strain and tilt angle data; A data preprocessing unit for performing wavelet denoising on the collected data, constructing a unified response dataset after standardization , and generating a multi-dimensional response matrix based on timestamps ; Sampling control unit, setting the sampling frequency [100, 500] Hz, meeting the frequency domain requirements for extracting the low-order modal characteristics of the structure.

8. The seismic performance monitoring system for a building structure according to claim 6, wherein, The modal identification and damage assessment module includes: Modal parameter identification unit, based on the standard response data set , uses an improved modal identification algorithm to extract the natural frequency of the building structure , damping ratio , main modal shape , and constitutes a modal feature vector ; Damage index calculation unit, which compares the modal feature vector with the historical reference modal parameters to calculate the modal change ratio , and obtains the damage index by comparing with the standard threshold ; Health status assessment unit, using fuzzy logic inference function , combined with the damage index , modal change ratio and the main modal shape , outputs the health status indicator , and determines whether to enter the warning state accordingly.

9. The seismic performance monitoring system of a building structure according to claim 6, wherein The remaining bearing capacity calculation and early warning module includes: Remaining bearing capacity calculation unit, according to the current damage state, comprehensively considering the design strength of structural members , maximum response value , current health state index , the remaining seismic bearing capacity of the building structure : Safety threshold determination unit, for the remaining seismic bearing capacity of the building structure And the set safety threshold Are compared to judge the current bearing safety status; The graded early warning information generation unit generates an early warning level based on the comparison result , and its value is divided according to the following conditions: 。

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