Stability assessment method for railroad bridges using acceleration and strain in combination

The stability of a railway bridge is mainly governed by level of acceleration, vertical displacement, and twist. While acquiring acceleration is relatively easy task in the data measurement respective, displacement and twist are very challenging due to lack of appropriate sensors. Furthermore, as most existing displacement sensors are confined to measuring single displacement, twist which is obtained from multiple displacements requires instrumentation of multiple displacement sensors, which are costly and laborintensive. To address these issues, this study proposes an indirect multiple displacement estimation method based on the measurement of acceleration and strain; therefore, acceleration, displacements and twist for stability of a railway bridge can be obtained at a time. The proposed method was numerically and experimentally validated. Then, stability evaluation of a railway bridge was then carried out with a high-speed train speeding at three cases: 280km/h, 300km/h and 400km/h. The acceleration, vertical displacement and twist were successfully obtained and compared with the design limit.