Study On Early Warning And Safety Assessment Of Bridge Structure Based On Safety Monitoring Data

Due to insufficient maintenance and vehicle overloading,more and more bridge accidents have happened in China in recent years.Potential risk of bridge structure may not be detected in time using traditional means of bridge safety management.Therefore,in order to get the status of the bridge stucture in real time,conduct effective early warning,assess the safety condition of bridge,and provide reference for subsequent bridge maintenance,it is necessary to use the massive data collected by the safety monitoring system installed on bridge structure.Based on the massive data collected by the real-time safety monitoring system of bridge structure,the data processing method,early warning method and evaluation method of bridge structural safety condition have been studied in this paper.Taking G206 viaduct in Hefei as the actual project background,a set of effective early warning and safety assessment method of bridge structure is established.First,a finite element model of the actual bridge structure has been established and analysed.A response surface-based method using both static and dynamic data has been used to update the finite element model.Based on structural analysis and numerical simulation results,suggestions for the layout of monitoring sensor are put forward.Then,in view of the deflects in the pre-processing of the mass monitoring data,this paper mainly focuses on the problems of the recognition and processing of distortion monitoring data and the extraction of temperature effect in the monitoring data.According to the features of different types of data distortions,a real-time data recognition and processing method based on data variety rate and data trend variety rate is put forward.By verifying this method in the strain monitoring data of G206 viaduct,the effectiveness and reliability of this method in engineering application is proved;As to the extraction of temperature effect in monitoring data,3 real-time separating methods of temperature effect are proposed based on the different sampling frequencies of different monitoring indicators.Monitoring data in a concrete continuous bridge and a cable-stayed bridge have been used to verify the effectiveness of above-mentioned methods.The results show that these simple and efficient methods can be applied to realtime temperature extraction of monitoring data,and laid the foundation for the following early-warning and safety assessment of bridge structure safety monitoring system,as well as the moving load identification of the bridge structure.After the pre-processing of monitoring data is completed,b y analyzing the monitoring data of bridge structure,combined with the updated finite element numerical results,a set of structural safety monit oring and early warning method is set up by setting reasonable warning indicators,threshold and early warning process.Based on analytic hierarchy process(AHP)and the variable weights principle,a safety evaluation method for actual bridge structure is established.