A Field Test of Track Stiffness and Vibration in Metro Lines

In order to reduce the vibration impact induced by urban rail transit on surrounding environment, a variety of vibration reduction tracks are used in Beijing metro lines, such as low-vibration track (LVT), floating slab track (FST), ladder sleeper track (LST) and elastic fastener track (EFT). A field test was carried out to investigate the vibration reduction effects of LVT and normal fastener track (NFT) was selected as reference. The wheel-rail force and rail displacement were measured to calculate the dynamic track stiffness. The rail acceleration and slab acceleration were measured, and then the frequency domain analysis was conducted to obtain the vibration acceleration level. It can be concluded that the track stiffness of LVT is about half of the stiffness of NFT, and LVT reduces the accelerations of rail and slab significantly. The field test results would be helpful for the dynamic evaluation and design optimization of vibration reduction track structures in metro lines.

Keywords:

field test , stiffness , vibration acceleration level , low-vibration , metro