Dynamic Responses of a Metro Train-Bridge System under Train-Braking: Field Measurements and Data Analysis

Abstract

This paper focuses on the dynamic responses of a metro train−bridge system under train-braking. Experiments were performed on the elevated Metro Line 21 of Guangzhou (China). A continuous, three-span, rigid-frame bridge (42 m + 65 m + 42 m) and a standard B-type metro train were selected. The acceleration signals were measured at the center-points of the main span and one side-span, and the acceleration signals of the car body and the bogie frame were measured simultaneously. The train−bridge system’s vibration characteristics and any correlations with time and frequency were investigated. The Choi−Williams distribution method and wavelet coherence were introduced to analyze the obtained acceleration signals of the metro train−bridge system. The results showed that the Choi−Williams distribution provided a more explicit understanding of the time−frequency domain. The correlations between different parts of the bridge and the train−bridge system under braking conditions were revealed. The present study provides a series of measured dynamic responses of the metro train−bridge system under train-braking, which could be used as a reference in further investigations.

Keywords

• elevated metro line
• train-bridge system
• acceleration
• choi-williams distribution
• wavelet coherence