Ground Vibration Caused by Moving Metro Trains

To study ground vibrations caused by metro trains,a three-dimensional dynamic finite element model was derived with simplifications in tracks,tunnels and loads caused by a running train.A train was composed of 8 cars,and its speed was 80 km/h.The ground vibrations were calculated to analyze the influences of elastic modulus of soils and the burial depth of tunnels.Results show that vertical ground vibrations are generally greater than the lateral vibrations in the area vicinity to the central line of the railway,and decrease rapidly with an increase in the distance to the central line.However lateral vibrations of ground may be greater than vertical vibrations, so they should not be neglected in calculation.Ground vibrations decrease as the soil elastic modulus and the burial depth of tunnels increase.