Analysis on environment and building vibration induced by passing trains on bridge structures

Based on train-bridge coupling dynamics and wave motion theories in engineering, three-dimensional finite-element analysis was used to analyze the dynamic characteristics of ground and building vibrations induced by passing trains on bridge structures.The finite-element mesh included moving trains, bridge superstructures, bridge foundations, soil and nearby buildings. A number of finite-element analyses were performed to investigate the propagation of vibration and vibration level in buildings. A wide variety of influence factors were used for this evaluation.The primary influence factors included the vibration source distance, train speed, and soil shear wave velocity. The results indicate as follows: The ground vertical vibration level decreases with increasing distance to vibration source; the ground lateral vibration level increases at first and then decreases similar to the ground vertical vibration; the vibration attenuation at low frequencies is smaller when compared with the attenuation at high frequencies; the predominant frequency of soil shifts to higher frequencies with increasing of train speeds; building vibration levels decrease with increasing of the distance to vibration source, but nonlinearly with the train speed and soil shear wave speed; the lateral vibration level of low buildings is dominated by the first modal shape, but the second and third modal shapes dominate for high-rise buildings.