Reconstitution of Static Deflections of Suspension Bridge Based on Inclinometer Data

Bridge deflection is a significant index reflecting the rigidity, overall stability, carrying capacity, and seismic performance of bridge structures. However, it is difficult to measure accurately, particularly for large-span bridges with complex deflection curves. Inclinometers are tentatively used in the deflection measurements of highway and railway bridges, and they have been found to be potential high-precision deflection measurement instruments. An effective inclinometer monitoring scheme was designed and used to monitor the static deflections of bridge, and an improved data processing method was proposed through using individual analytical solutions in this study. Based on that, analysis was done to explain why the "5 inclinometers" suggested by previous research is the best choice for the deflection test of the simple supported and the continuous beam bridge, which has not explicitly explained in the previous literature. Through the comparative study of the deflection calculation results of the bridge finite element model, inclinometer is applied to measuring the static deflection of a large-span suspension bridge for the first time, and it is found when the number of the instruments is enough and arrangement of the instrument is reasonable, the deflection of suspension bridge can be tested using inclinometer method. In order to reduce the number of test points and improve the deflection measurement precision, semi-span arrangement scheme of test points is proposed, which is applied in the static deflection test of the Jiangyin Yangtze River Bridge, and the error of static deflections is only 1.13% compared to GPS observations.