DECOUPLING FE METHOD TO SIMULATE THE ENVIRONMENTAL VIBRATION CAUSED BY URBAN RAIL TRAFFIC

In this paper, the decoupling finite element method is used to calculate the surface environmental vibration caused by urban rail traffic. Two-steps are defined to simulate environmental vibration induced by urban rail transit. In the first step, the train-track system is simplified as a series of subsystems. Taking into account the track irregularity spectrum, each subgrade reaction under ballast block is calculated when a train moves on the track. All the forces constitute the point source array to simulate the source. In the second step, the foundation is simulated as isotropic layered media, combined with artificial boundary conditions in the calculation border region, using the decoupling finite element method to calculate the surface environmental vibration. The simulation result is compared with those from field observation in Beijing, China. The result is quite close to the field observation data, and provides a good foundation for further study on environmental vibration impact to buildings and human beings.