Abstract: Accidents caused by the high-speed train failure will incur great economic losses and negative social impacts. However, existing risk assessment methods of high-speed train do not take the time-varying characteristic of external environment into account during the operating process. To solve this problem, the dynamic loss coefficient is utilized to update the static value with combined action of multiple environmental factors. An assessment method is advanced to evaluate the operational risk of high-speed train. Concretely, first of all, in order to describe the impact of different environmental factors on the loss, the probability distribution models are constructed by using logistic distribution after analyzing the typical environmental factors closely related to the loss. Then, the analytic hierarchy process is introduced to determine the weights of the impact on different environmental factors. Finally, quantitative assessment of the dynamic loss to the high-speed trains could be achieved after considering both the environmental impact weights and probability models. To validate the effectiveness of the proposed method, simulation is carried out on a certain type of high-speed train. The result shows that the proposed method not only meets the needs of high-speed trains for dynamic risk assessment, but also reasonably characterizes the dynamic losses under the combined action of different environmental factors. By considering the influence of real-time external environmental factors to the loss of operational accidents in the quantitative risk assessment of high-speed trains, the proposed method can provide an effective reference index to relevant personnel for the decision-making.

Key words: dynamic loss, environment factor, risk assessment, high-speed train