Characteristics Analysis And Reliability Calculation Based On Long-term Bridge Health Monitoring Data

Under the comprehensive function of load and natural environment, the bearing capacityof the important bridge bearing component will be different degrees attenuation over time.The direct performance is that the bridge component will occur tiny fractures, which affect thenormal use of the bridge. In order to master the bridge health, we adopt long-term healthmonitoring system to monitor the real-time status of bridges. And with the accumulatedmonitoring data year by year, how to explore effective information on the collected data, andthen applied them in the actual state of bridge design, maintenance and evaluation become aworth exploring research problems.In this paper, on the basis of a large amount data accumulation, it can be used to analyzeinformation contained in the data by combining the measurements of bridge health monitoringwith the related numerical calculation methods.(1) Firstly, engineering background of the bridge and a Long-Term Health MonitoringSystem used on this bridge is introduced. The variation of temperature and strain on differentsection is summed up. Combining with statistical method, the measured strain data werepreprocessed. Combined with the analysis of concrete bridge data, it can be found that thetemperature difference inside of concrete bridge is significantly higher than the temperaturedifference inside of the steel bridge.(2)Secondly, it can be obtained by FFT transform that the steel box girder bridgemeasured temperature data and strain data contain the same mainly frequency,12hours and24hours. Extract the amplitude of different frequency to discuss the changes on longitudinaldistribution.(3)Then, the noise ingredients contained in the measured temperature data can be filteredout by wavelet analysis. It can be confirmed that strain component validation which have thesame frequency as temperature is caused by the daily temperature changes. The proportion oftemperature stress caused by steel box girder temperature field and concrete box girder wasinvestigated. The temperature effects on concrete bridge section of different locations are verydifferent, but the temperature-induced strain takes a small part of the total; while thetemperature effect of steel bridge section is more balanced overall. Temperature strain takes alarge part of the total composition. Strain effects caused by day temperature effects accountedfor more than50%of the overall.(4) Finally, introduced the real-time data into the reliability assessment. Using a second-order moment method and Monte-Carlo method based on original data sampling andfitting data sampling to realize double calculation. The applicability and accuracy of a secondorder moment method for computing reliability of the measured data can be inspected bycomparing the calculated results.