Displacement response waveform restoration of simply supported bridge during train passage using measured acceleration integration based on linear vibration theory

Abstract

This study proposes a method for restoring the displacement waveform during train passage using the acceleration integration based on linear vibration theory and noise cancellation techniques. This method replaces the low-frequency region affected by noise with a linear theoretical solution; however, this method uses the actual measurement data around the natural frequency, where nonlinearities (such as concrete member cracks and the train–bridge interaction) can be observed. The method identifies only the ratio of single axle weight to modal stiffness. Numerical experiments clarify that the method can estimate the maximum displacement of a bridge from acceleration with an error of approximately 5% or less. Improved prediction accuracy can be achieved using the proposed noise cancellation technique not only in the high-speed range but also into the lower-speed ranges as well. Furthermore, the proposed method is applied to acceleration monitoring data, and results show that the displacement waveform can be restored from the acceleration waveform.