Probabilistic analysis of high-speed train safety on bridges under stochastic near-fault pulse-type ground motions

The safety of high-speed railway trains running on bridges during stochastic near-fault pulse-type earthquakes is of utmost importance in designing railway bridges. This paper presents an efficient and feasible approach for analyzing the train-bridge coupling system (TBCS) during random near-fault ground motions using the number theory method with dimensionality reduction (NTM-DR). The method's validity is demonstrated through Monte Carlo simulations, which calculate the probabilistic maximum of the system response and the derailment coefficient under various conditions, such as different bridge heights, seismic intensities, and train speeds. Additionally, the response sensitivity to changes in seismic randomness is discussed by comparing it with the deterministic maximum. The results show that the proposed method achieves high accuracy and efficiency in analyzing the TBCS under random near-fault earthquakes. The ratio between the probabilistic and deterministic maximum is consistently above 1.3, highlighting the significance of considering earthquake randomness.