Abstract
One of the complaints due to traffic vibrations generated from highway bridges is a low-frequency sound. The authors focused on this phenomenon to analyze the occurrence and the component where the low-frequency sound is generated. Analyzed vibration modes were vertical primary mode, which has a lot of measured cases, and higher-order vibration mode, which includes the vibration of the out-of-plane of the lower floor slab. Bridges considered for the study were the multiple girders and the two main-girder. By analyzing the measurement data on vibration and low frequency sound, the frequency band to cause complaint has been revealed. In addition, the vibration mode of the bridge corresponds to the frequency band causing complaints were analyzed. Furthermore, by analyzing the relationship between the vehicle position and the low-frequency sound, differences were found in the causes of each frequency. Then, a numerical analysis using a 3D FEM model was conducted to reproduce the analysis results from the measured data. It was possible to grasp the vibration distribution shape generating complaints and the general behavior of the bridges.
