Performance Assessment of Bridge Modal Frequency Identification Using High-Rate GNSS

Identification of dynamic model frequencies is a critical step in bridge health monitoring. This paper assesses the performance of bridge modal frequency identification based on 50-Hz GNSS displacements of the Sanchaji bridge at Changsha. In the experiment, the Chebyshev filter is used to remove the long-period static component caused by the static displacement and multipath effect, and the ensemble empirical mode decomposition method is used to reduce the influence of random noise on the positioning results. Compared with the results of finite element modeling and accelerometer, using the high-rate GNSS displacement information can accurately identify the first three modal frequencies of Sanchaji bridge, and the difference is less than 5%.