Vibration Induced by Subway Trains: Open-Trench Mitigation Analysis in the Time and Frequency Domains

Wenbo Yang,Juan Wang,Ran Yuan

doi:10.1155/2018/1879392

Wenbo Yang, Juan Wang + Show 1 more

Open Access

https://doi.org/10.1155/2018/1879392

Copy DOI

Abstract

In this paper, we analyse the mitigation effects of open trenches on the vibrations induced by subway trains. The study is performed by using both physical model tests and numerical simulations. The effectiveness is evaluated by calculating the frequency response function (FRF) and the vibration acceleration peak (VAP) in both time and frequency domains. The experimental and numerical results demonstrate that the open trench has clear effects on the dynamic soil response. Both time and frequency domain results suggest that the dynamic response of the soils beyond the open trenches could be significantly affected, due to the existence of the open trench. According to the frequency domain analysis, the inclusion of open trenches could effectively reduce the soil response in a higher frequency range. Due to reflection effects at the boundaries of the trench, an amplification of the soil response in front of the open trench is observed. Parametric study by means of numerical simulations is also performed. The width of the open trench demonstrates negligible effects on the dynamic soil response, whilst the trench depth exhibits a large influence on the trench isolation performance. With an increase in the trench depth, the isolation performance is significantly improved. It is concluded that the open trenches perform well as an isolation barrier, in mitigating the vibration induced by subway trains.

Highlights

We analyse the mitigation effects of open trenches on the vibrations induced by subway trains. e study is performed by using both physical model tests and numerical simulations. e effectiveness is evaluated by calculating the frequency response function (FRF) and the vibration acceleration peak (VAP) in both time and frequency domains. e experimental and numerical results demonstrate that the open trench has clear effects on the dynamic soil response
At the fixed frequency of 200 Hz, the amplitude of the attenuation of A14 is 68%. is result demonstrates that the open trench efficiently isolates the vibration isolation, and Woods [15] has concluded that a reduction of 0.25 should be considered as “effective.” e reason for this observation is that the open trench can interrupt the path in the soil along which the vibration is propagating, so it can effectively reduce the dynamic response of the soil behind the trench
Both physical modelling and numerical simulations were performed to analyse the isolation performance of open trenches on the subway train-induced vibrations. e conclusions can be drawn as below: (i) Experimental and numerical results were compared for cases with or without an open trench subjected to different vibration loads

Summary

Introduction

We analyse the mitigation effects of open trenches on the vibrations induced by subway trains. e study is performed by using both physical model tests and numerical simulations. e effectiveness is evaluated by calculating the frequency response function (FRF) and the vibration acceleration peak (VAP) in both time and frequency domains. e experimental and numerical results demonstrate that the open trench has clear effects on the dynamic soil response. Both physical model tests and numerical simulations are used to evaluate the effectiveness of open trenches for mitigating the vibrations induced by subway trains.

Results

Conclusion