Research and application of real time evaluation method of shield method tunnel structural health based on automated monitoring data analysis

2021 ◽  
Author(s):  
Chuangfeng Duan
2021 ◽  
Author(s):  
Huaqiang Zhong ◽  
Limin Sun ◽  
José Turmo ◽  
Ye Xia

<p>In recent years, the safety and comfort problems of bridges are not uncommon, and the operating conditions of in-service bridges have received widespread attention. Many large-span key bridges have installed structural health monitoring systems and collected massive amounts of data. Monitoring data is the basis of structural damage identification and performance evaluation, and it is of great significance to analyze and evaluate its quality. This paper takes the acceleration monitoring data of the main girder and arch rib of a long-span arch bridge as the research object, analyzes and summarizes the statistical characteristics of the data, summarizes 6 abnormal data conditions, and proposes a data quality evaluation method of convolutional neural network. This paper conducts frequency statistics on the acceleration vibration amplitude of the bridge in December 2018 in hours. In order to highlight the end effect of frequency statistics, the whole is amplified and used as network input for training and data quality evaluation. The results are good. It provides another new method for structural monitoring data quality evaluation and abnormal data elimination.</p>


2021 ◽  
Author(s):  
Baran Yeter ◽  
Yordan Garbatov ◽  
Carlos Guedes Soares

Abstract The objective of the present study is to perform a systematic data analysis of structural health monitoring data for ageing fixed offshore wind turbine support structures. The life-cycle extension of the first offshore wind farms is under serious consideration since the support structures are still in a condition to be used further. Big data analytics and machine learning techniques can aid to extract useful information from the monitoring data collected during the service life and build models for future predictions of an optimal life-extension. To this end, it is aimed to analyse the big data provided by embedded control systems and non-destructive inspections of ageing offshore wind turbine support structures using pre-processing techniques, including denoising, detrending, and filtering to remove the noise of different nature and seasonality as well as to detect the signal-specific contents affecting the structural integrity in the time and frequency domain. The effectiveness of the Welch method is investigated in terms of dealing with noisy signals in the frequency domain. Besides, the principal component analysis is carried out to reduce the dimensionality of the data and to select the most significant features that are responsible for most of the variance in the structural health monitoring data. Moreover, nonparametric statistical methods are used to test whether the data before noise being added and the data after cleansing the added noise came from the population with the same distribution. Further, permutation (randomisation) testing is performed to predicate that the results of the nonparametric test are statistically significant. The outcome of this study provides refined evidence that enables to feed the condition monitoring data into the training of the deep neural network to be able to discriminate different structural conditions.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Le-Ning Wang

To effectively evaluate the traffic safety risk of urban expressways in real time and ensure their traffic safety and smoothness, a real-time evaluation method of vehicle conflict risk of an urban expressway based on smartphone GPS data was proposed. We screened and processed smartphone GPS data to obtain vehicle behavior data, including acceleration and angular acceleration, and road state data, including average vehicle speed. Urban expressways were divided into four categories, closed straight section, closed curve section, vehicle entry section, and vehicle exit section; the evaluation indexes of abnormal vehicle behavior were established. Based on the improved entropy weight method, the vehicle conflict risk entropy was established to distribute the weight of different types of abnormal behaviors of vehicles. The evaluation system of vehicle conflict risk entropy was applied to the vehicle behavior data. Urban Expressways with more abnormal vehicle behavior were obtained to evaluate the risk of vehicle conflict in real time. The results showed that the easily obtained smartphone GPS data may be effectively used to analyze the abnormal behavior of vehicles, identify vehicle conflict risk points hidden in urban expressways in real time to provide effective methods for batch and dynamic real-time evaluations of vehicle conflict risks on urban expressways, and improve the traffic safety service level of urban expressways.


2021 ◽  
pp. 147592172110350
Author(s):  
Gaoxin Wang ◽  
Jingshu Shao ◽  
Weizhou Xu ◽  
Zhaoxing Dong ◽  
Bin Chen ◽  
...  

Stayed cable is an important prestress-bearing component in cable-stayed bridges, and the cable damage will seriously threaten bridge safety. In this research, the method of real-time quantitative evaluation on cable damage is proposed through monitoring data analysis, correlation analysis, damage evaluation analysis, and validation analysis. Monitoring data analysis shows that temperature has a good linear relationship with girder deflection and cable force. Correlation analysis shows that this relationship is well described by a time-varying multiple linear regression model. In damage evaluation analysis, a new damage index is proposed for real-time quantitative evaluation. Each stay cable has a corresponding damage index, and a large value of damage index indicates a serious damage. The results of experiment and finite element analysis show that the evaluation error of this damage index is very small, which is feasible for real-time quantitative evaluation. This method can provide valuable reference for real-time quantitative evaluation on cable damage of cable-stayed bridges.


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