Dynamic Response of Soil Around the Tunnel Under Subway Vibration Loading

Abstract

With the development of urban rail transit construction, the land subsidence, deformation even failure of the subway tunnel and other environmental issues induced by subway vibration have been paid more attention by researchers and engineers recently. The dynamic response of soil under the vibration load is of significance for the safe operation of the subway. In this study, the numerical simulations of soil-tunnel model considering the factors of the model damping and the viscoelastic boundary were conducted. The dynamic response of soil under subway vibration is symmetrically distributed along the vertical centerline of tunnel. The longer the distance to the vibration, the less the effect is. The energy of vibration, which is mainly propagated along the vertical direction and causes the uneven displacement by extruding the soil beside the tunnel, attenuates quickly when spreading in soil. The range of acceleration response of the soil is only about 5 m around the tunnel. The acceleration of soil around the tunnel is superimposed by a series of harmonics with different frequencies and amplitudes. The variations of the amplitude with frequency can be obtained from the acceleration curves by FFT. The dominant frequency of soil under subway vibration is mainly between 5–25 Hz.