The Fusion Of The Long-term Monitoring Data Of Small And Medium Span Bridge Technical Condition Evaluation Method

Based on periodic inspection data and long-term monitoring data collected from a long-term monitoring system which was installed in a simple supported girder bridge, the paper, from the perspective of structural feature of middle and small scaled bridge, brought up an assessment method on how to monitor the technical condition of small and medium scaled girder bridge by blending the data of both periodic inspection and long-term monitoring. The major research results in this paper might be concluded as follows:①To solve the problem caused by incompatibility between long-term monitoring data and artificial test data, the author respectively included strain, mid-span deflection, foundation settlement and crack width monitoring together into the present bridge technical condition assessment standards as disease factor, while, in the mean time, the author also attached data collected from artificial apparent observation and detection.②By introducing and analyzing usage index and K line graph, the author was able to rank and evaluate the above mentioned factors of small and medium bridge.③To prove the rationality and practicability of assessment method, the author not only processed and analyzed daily and weekly data collected from strain, mid-span deflection, foundation settlement and crack width monitoring. But also plot daily and weekly curves and comprehensively took assessment standards and artificial test reports into consideration④By plotting and contrastively analyzing temperature, strain, deflection and crack curve during monitoring period, the author discovered that the main cause for strain changes of simple support bridge is the automobile load, while crack value is majorly under the influence of temperature changes, however, deflection is hardly influenced by temperature.⑤By employing minimum error principle and genetic algorithm, the author optimizing sensor arrangement and calculation of Xin Cun Zhong Bridge, and discovered that long-term monitoring sensor should be fixed to mid-span section while other sensors should be equably and symmetrically arranged.⑥The author also proposed a single warning mechanism, alarm level and alarm indication based on data usage degree and DMI(directional movement indicator) for small and medium bridges. And the practical application on Xin Cun Zhong Bridge further proves the effectiveness and explicitness of this method。...