수평적 공간변이 지진에 대한 고속열차-궤도-교량 시스템의 확률 해석

초록

This study extended the pseudo- excitation method (PEM) to investigate the combined influence of spatial effects, such as the wave passage and incoherence effects, of ground motion on the seismic response of a train-track-bridge system (TTBS). The train is modeled as rigid bodies connected by suspensions, and the track and bridge are modeled as finite elements. The rigid wheel/rail contact is considered, and the coupled equation-of-motion of the TTBS is derived. The power spectrum density (PSD) matrix of ground accelerations is established based on the coherency model, and the PSD matrix is then decomposed to construct a series of pseudo-excitations. The PSD of the pseudo-response of the TTBS under pseudo-excitations is used to calculate the standard deviation. In the numerical example, the seismic responses of a 20-span simply supported bridge under a high-speed train are evaluated by the lateral accelerations of the train and bridge. The results show that the incoherence effect is very important to the seismic responses of TTBS. Furthermore, an earthquake with a faster apparent wave speed and a larger peak acceleration can significantly increase the lateral accelerations of the TTBS.

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