ABSTRACT
High-speed railways (HSR) are considered a reliable and efficient means of transportation which, combined with the capability of on-schedule attendance, emerges as a very competitive transportation system. These advantages have led to the rapid expansion of highway networks and the growing demand for higher operational speeds. In the design and operation context, HSR bridge dynamic analysis is thought to be a crucial element and, in most applications, the moving load method has been utilized for this purpose. However, for short and medium-span bridges, this method tends to be over-conservative, and the interaction between train and bridge considerably influences the accuracy of the bridge responses. Although several efforts have been dedicated to developing enhanced methodologies for the proper modeling of vehicle-bridge interaction (VBI), only a few studies have considered the uncertainties in material properties, geometry, and loading conditions. The acknowledgment of such uncertainties as an integrating part of the dynamic analysis may enhance the response prediction of the bridge, which enables the understanding of the probability of adverse outcomes due to excessive vertical accelerations of the deck. Loss of interlock among ballast grains, which degrades the rail stability, and the loss of wheel-rail contact, are examples of problematic performances of the bridge in such circumstances. In this study, the dynamic responses of a simply supported bridge are evaluated utilizing a 2-D VBI model, accounting for the influence of the passage of a high-speed train.
