Abstract Summary
Abstract. Train-induced vibration is a growing concern in China for tracks in close proximity to buildings, in particular, for over track building in metro depots. Over-track buildings generally include heavy transfer structures due to irregular spacings between ground columns in between the tracks. Ground-borne vibration transmits up the ground columns into the transfer structures then into over-track buildings where residents may experience feelable vibration at levels above those permitted by codes for human comfort and at levels that are potentially excessive in laboratories and manufacturing plants with sensitive equipment. Predictions of train-induced vibration levels are needed for comparison with serviceability limits. An analytical prediction method based on impedance modeling of building components has been developed that accounts for transmission through the transfer structures in the buildings. It includes impedance expressions that characterize the vibration transmission in structural components including columns, beams, and floors. Train-induced ground vibration generates axial wave transmission in ground columns, which transmits bending waves into the horizontal transfer structures, and then axial waves in the over-track building columns and bending in its floors. Model predictions closely matched measured levels in a metro depot in Shenzhen, China. The model was used to assess the potential effectiveness of reducing vibration transmission into the over track building by a heavy, high impedance, blocking floor at lower elevation.
