Prediction of building vibration induced by metro trains running in a curved tunnel

Abstract

Curved metro lines currently account for a significant proportion of total route mileage. However, the existing prediction model of environmental vibration only considered the vibration induced by trains running in a straight tunnel. In the present study, a numerical model was proposed to predict the environmental vibration induced by trains running in a curved tunnel. The model was divided into two parts: a train–track coupled model and a tunnel–soil–building finite element model. In the first part, a novel three-dimensional train–curved track coupled model was established and solved in the frequency domain based on the periodic theory. Both vertical and horizontal train loads were calculated by this model. Then, an in situ measurement was performed in the curved tunnel of an operating metro line, and the tunnel vibration responses were obtained and used to calibrate the train–track model. Finally, a case study was selected from Beijing metro line 16, where it is needed to predict and evaluate the environmental impact of vibration from a curved metro line being planned for construction beneath an office building. A three-dimensional tunnel–soil–building finite element model was built, and the building vibrations in vertical and horizontal directions were predicted. The results show that the floor vibrations have peak values of approximately 5.29 and 27.8 Hz, which are exacerbated by the building local mode and the spacing of the rail supports. Below the third floor, the vertical vibration response exceeded the vibration control limit recommended by Chinese national standards. Track solutions for vibration control must be implemented to mitigate the environmental vibrations.