Vibration transmissions and predictions within low-rise buildings above throat area in the metro depot

Abstract

Train-induced feelable vibrations can bring side effects to people living or working in the building, as well as to operation of precise equipment. As massive construction of over-track buildings above metro depots prevails in megacities, impacts from train-induced feelable vibration take more concern. Four standard-designed 4-story steel-framed offices above the throat area in the Qianhai metro depot in Shenzhen, China, are studied in this research. The field measurements were conducted to investigate the influences of track alignment and track location in the throat area on vibration responses of over-track buildings. Detailed vibration analyses using the finite element method have been conducted. Train-induced floor vibration assessments on human comfort are carried out based on a total of 54 train pass-bys operated in the morning and evening and on different tracks. It can be found that the track alignment primarily affected the higher frequency components of train-induced vibrations, where curved trackinduced vibrations have larger amplitudes. The variance of train-induced building vibrations among pass-bys on different track locations was reduced compared with that of ground vibrations because of the averaging effects caused by multiple transmitting paths within the massive platform and stiff transfer structures. Train-induced acceleration levels at mid-floor can be 20–25 dB larger than those near columns at floor resonance frequencies which are dependent on the structural design. This research gives a comprehensive insight into train-induced vibrations within low-rise steel-framed buildings above the throat area in the metro depot, which is a valuable reference for assessments before the construction of future similar over-track communities.