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

Xuhui He,Chenzhi Cai,Yunfeng Zou,Kehui Yu,Xiaojie Zhu

doi:10.3390/s20030735

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.

Highlights

As a result of rapid urbanization, the continuously increasing population and expanding areas of most urban cities are increasing the demand for transportation in cities
Several instantaneous peaks in the time-history data of the bogie frame’s transverse displayed in the time–frequency representation results (TFRs) (Figure 9f). These results indicated that Choi–Williams distribution (CWD) provided better resolution in the acceleration signals (Figure 9b) were obviously displayed in the TFRs (Figure 9f)
This paper investigated the dynamic responses of a metro train–bridge system under train-braking

Summary

Introduction

As a result of rapid urbanization, the continuously increasing population and expanding areas of most urban cities are increasing the demand for transportation in cities. The urban metro system is an effective way of satisfying the need for public transport. Vigorous development of metro systems occurred globally, especially in China. The total length of operating metro lines was about 6000 km throughout 41 cities in China at the end of 2019. Aside from the general underground metro, the elevated metro was widely adopted in recent years in China due to its short construction period and low-cost advantages, especially in cities such as Beijing, Shanghai, and Guangzhou. More and more cities are increasing the maximum operational speeds of metro lines to adapt to the needs of city development

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Conclusion