Environmental vibration induced by underground moving metro trains has aroused much attention of the society as more and more subway tunnels are constructed in saturated soft soils in the coastal area of China. Taking the Shanghai metro line 2 for example

response of saturated soft soil layers induced by subway train in the shield tunnel is analyzed by using cyclic mobility constitutive model and water-soil coupled method

including ground surface vibration acceleration and dynamic displacement

as well as the dynamic response of excess pore water pressure(EPWP). The acceleration level of ground surface is adopted to evaluate the intensity of ground surface vibration. Numerical results show that dynamic response of saturated soil is much smaller than that of dry soil

vibration on the ground surface also presents distinct differences in the horizontal direction and vertical direction. As for excess pore water pressure

it diminishes along vertical tunnel axial direction

whereas it increases first and then decreases in the vertical profile several meters away from tunnel center. The results can provide guidance for vibration mitigation design and settlement control measures for nearby structures.