Full-Bridge Deflected Shape Synchronous Measurement in Bridge Loading Test

Abstract

A loading test can provide valuable insight into the behavior and fundamental characteristics of an existing or new bridge. The full-bridge deflected shape in long-span bridges is an important parameter that evaluates the safety state of a structure. To improve efficiency and reduce labor costs of bridge deflection measurements in a loading test, a measurement system established on hydraulic head principles and optoelectronic liquid-level sensors has been developed. With this system, the deflection of the bridge is converted into an electrical signal through optoelectronic liquid-level sensors, and the liquid-level values of all the sensors can be collected synchronously by a host computer. As a result, the multipoint deflection can be measured so that the full-bridge deflected shape is obtained. The method has been applied to the Caiyuanba Yangtze River Bridge in Chongqing, China, and the results show that the proposed method has apparent advantages in time efficiency and labor costs.