Analysis of Metro Tunnel Overhead Building Vibration Characteristics

Abstract

Objective In recent years, overhead properties along metro tunnel lines are rapidly developing, making effective use of urban space. However, vibrations caused by metro train operation significantly affect these properties. Due to the complexity of overhead building structures and unclear propagation laws of train vibrations in these buildings, it is necessary to conduct relevant research. Method Based on Ningbo an integrated projected by rail transit and block development, a three-dimensional vibration finite element model of train-tunnel-soil-overhead building is established. Through simulation experiments, the impact of tunnel depth, horizontal distance between the tunnel and overhead buildings, and the number of building floors on vibration propagation is analyzed. Result & Conclusion (1) When the horizontal distance between overhead buildings and vibration sources is within a certain range, the Z vibration level increases with increasing horizontal distance. Once exceeding this range, the Z vibration level decreases significantly with increasing horizontal distance. (2) The vertical propagation law of overhead building vibrations under different numbers of building floors generally shows consistency. On the lower floors, vibrations reach a maximum value first, then decrease with increasing floors, and finally show an amplification trend at the top floors. (3) Through 1/3 octave band analysis, it is observed that during the propagation of overhead building vibrations, the trends of vibration acceleration level distribution at the center frequency of the same floor are similar for different tunnel depths, horizontal distances, and building floors. The main difference lies in the attenuation magnitude in the main frequency band, indicating that the vibrations attenuate in the Z-level frequency mainly band during propagation without altering the distribution range of the main frequency.

Keywords

• metro tunnel
• overhead property
• vehicle-induced vibration
• vibration response