Field measurement and simplified numerical model for vibration response of subway superstructure

The residents near subway lines may be influenced by subway-induced vibration to a large extent. A simplified numerical modelling technique of the subway superstructure with a high-precision Caughey damping was proposed based on finite element software ANSYS in this paper, aiming to simulate the above-ground vibration response related to residents’ comfort under subway operation. Firstly, the two-stage field measurement of “free field-floor slabs of superstructure”, spanning four years, was carried out on a frame structure building above Guangzhou Metro Line 3. The time domain and frequency domain data of the measured vibration were analysed. A simplified numerical finite element (FE) model of the superstructure was then established, in which a high-precision Caughey damping was constructed using seven control frequencies. The comparative analysis of the simulated and measured results of the building verified that the simplified FE model for simulating the subway superstructure’s vibration response worked well and facilitated engineering applications. Additionally, another superstructure model of the shear wall was established by the same method to explore further the difference in the propagation characteristics of subway-induced vibration in the structure of two different forms. Finally, design recommendations for vibration control of subway superstructure were provided.