Deformation features of a long-span arch bridge based on long-term monitoring data

The bridge deformation is a key parameter when assessing the condition of the bridge. The geometric con-figurations of the deck profile in a cable- stayed bridge are the major items in estimating the loading conditions of the bridges. Any deviation of the deck profile implies a change of force condition in the whole bridge. The Jiubao Bridge is a newly constructed bridge in China with a total length of 1855 m. To completely under-stand the behaviors of the bridge, a permanent SHM system, which is composed of the sensor subsystem, the data acquisition and transmission subsystem, the data management subsystem, and the condition evaluation subsystem, is installed on the bridge. The vertical displacements of bridge deck are monitored by the pressure transmitter sensors, whose sampling period is set to 10 seconds. The longitudinal displacements at the end of the three-span arch bridge are measured by the magnetostrictive displacement transducers (MDTs), whose sampling period is also set to 10 seconds. By using these data, the daily and monthly fluctuations of displacements are investigated. Following that, the statistical features of the structural deformation are extracted. The results indicate that both the vertical displacement and longitudinal displacement has strong relationship with the structural temperature. Furthermore, the vertical displacement shows nonlinear correlation with the structural temperature, and the longitudinal displacement shows linear correlation with the structural temperature. The results are expected to provide reference values for bridge evaluation and design.