点击次数：

论文类型：期刊论文

发表时间：2020-04-01

发表刊物：INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS

收录刊物：SCIE

卷号：20

期号：4

ISSN号：0219-4554

关键字：Train-track-bridge system; wheel-rail contact; subset simulation; earthquake; dynamic reliability

摘要：The increasing use of bridges in high-speed railway (HSR) lines raises the possibility of train derailment on bridges under seismic excitations. In this paper, the influence of random multi-point earthquakes on the safe running of a train on a long-span bridge is studied in terms of the dynamic reliability, considering spatial seismic effects, and randomness of ground motions and train locations. The equations of motion for the train and the track/bridge as time-invariant subsystems under earthquakes are established, separately. The two subsystems are connected via the wheel-rail interface, for which a nonlinear contact model and detachment are considered. The time-history samples of nonstationary multi-point random earthquakes considering wave passage effects and incoherence effects are generated by the autoregressive moving average (ARMA) model. The ground motions are imposed on the bridge support points in terms of displacement and velocity. The train location at the time of earthquake is considered a uniformly distributed random variable. The running safety reliability of a train moving on a long-span bridge under earthquakes is determined by combining subset simulation (SS) with a prediction-based iterative solution method. Under different seismic components, train speeds, apparent seismic wave velocities and seismic intensities, the most unfavorable train location intervals are determined, which provides a reference for the safety performance assessment of trains traveling on bridges under earthquakes. Numerical results show that the influence of the lateral seismic component on the wheel derailment coefficient (WDC) is greater than the vertical seismic component, and the earthquake that occurs before the train's arrival at 70% length of the bridge will significantly reduce its running safety.