Centrifugal modelling of subway-induced vibration

In a congested urban situation between subway lines and facilities requiring noise and vibration free conditions, it is necessary to estimate the propagated subway-induced vibration. The attenuation characteristics of subway-induced vibration in the ground may not be fully understood because of a number of influencing factors, and it is appropriate to investigate the attenuation under a clear ground condition with known boundary conditions. This paper describes the development of a centrifugal model test system, simulating the subway-induced vibration, experimental results, including contour of vibration acceleration level and comparisons between experimental observations and field measurements. It was found that the attenuation of subway-induced vibration in the ground becomes larger as frequency becomes higher. Bomitz’s formula is applied to estimate the attenuation and it was found that the values of material damping coefficient α are almost the same in the acceleration level of 15 to 62 g, which are consistent with those obtained by field measurements at 14 sites in and around the Tokyo area.