Prediction and mitigation analyses of ground vibrations induced by high speed train with 3-dimensional finite element method and substructure method

Abstract

This paper focuses on the dynamic interactions between a Shinkansen viaduct and the nearby ground when a high speed train is running along the viaduct. Due to the characteristics of the structure-foundation-soil system, a substructure method is employed to divide the global system into two substructures: one consists of the superstructure of track girder and supporting piers, the other consists of the foundation and near ground. Both substructures have continuity conditions at the interfaces, i.e. deformation continuity and force continuity. The superstructures are modeled by 3-dimensional (3-D) beam elements with a structural procedure, while the substructure is analyzed through a pseudo 3-D axisymmetric finite element method. A field test was conducted in the near field of the Shinkansen viaduct to examine the vibration level. The measurement data also help us to understand the wave motion influenced by the geometric properties of the structures and the moving train. Based on the field test results, a thorough interpretation is provided by analyzing both the structures and the soil. Further, computation simulation is conducted to investigate the vibrations in the ground to a wider extent. According to the nature of vibration, a combined countermeasure is proposed which involves the source motion control and the wave propagation obstruction. Satisfactory mitigation is achieved by the combined measure.