Case Study on Rail Train-Induced Vibration Reduction at the Metro Depot by Using the Open Trench

With the development of rail transit and the shortage of land utilization, properties above and near metro depots emerge in Chinese major metropolises. Whether the railway-induced vibration will bring discomfort to occupants or malfunction to precise devices is always the concern of stakeholders, designers, occupants, and researchers. In general, there are three main facets to control the train-induced vibrations: from the vibration source, from the wave transmission path, and from the building structure. General vibration mitigation methods include the rubber float-slab track, continuous-wave barrier systems, non-continuous wave barrier systems, wave impedance block, blocking floor, floating floor, etc. This paper mainly focuses on the effectiveness of the open trench in reducing train-induced vibration based on a field test conducted at the throat area of a metro depot of Guangzhou. The results reveal that (a) the vibration attenuation in curve-line segment of the throat area is more than that in straight-line segment, as there being 28–36 dB attenuation in curve-line segment and 22–24 dB attenuation in straight-line segment; (b) higher-frequency components (above 50 Hz) attenuate faster than lower ones and the propagation distance of the former is shorter; (c) the peak frequency induced by trains operating at metro depots lies in 31.5–40 Hz; (d) the effectiveness of the open trench in mitigating horizontal vibration is better than that in reducing vertical vibration. Some suggestions on designing the open trench to reduce railway-induced vibration are also proposed.