Study on methodology for running safety assessment of trains in seismic design of railway structures

A unique and important task in the seismic design of railway structures is to evaluate the running safety of trains undergoing seismic motion. In the current design practice, however, when compared with the technical advances in the safety assessment of railway structures, the progress in running safety assessment (RSA) of trains is still insufficient, because of the complexity of the problem. In order to develop a practical methodology for the RSA, the dynamic response behavior of railway vehicles is investigated with a simplified analytical model. As a result, a code-type provision based on the concept of energy balance, in which the spectral intensity (SI) is employed as an index for assessment, is proposed in this study. The adequacy of the provision is verified by comparing with the results from rigorous numerical simulation of running vehicles. Moreover, the proposed provision has been applied to the practical design and its applicability has been demonstrated by dealing with different cases, where various types of structures and/or soil profiles are taken into account.