Keiichi Goto

Seismic Train-Running Safety on Structures

In this study, using the analysis program DIASTARS III that is able to take into account the dynamic interaction between railway vehicles and railway structures, we conducted seismic train-running analysis on a model line that is about 4.8 km long. And we identified the relative weak structures of seismic train-running safety in the model line.

Effect of Dynamic Interaction between Railway Vehicle and Structure on Seismic Response of Structure

The conventional seismic standard specifies that the seismic inertia force of trains is modelled as the rigid mass which has the upper limit force of 30% of the train weight on insufficient grounds. However, train actions on railway structures during earthquakes have not been identified, although actual train vehicles are the complicated vibration system. The object of this paper is to quantify dynamic interactions between train vehicles and structures during earthquakes, and to develop a reasonable train action model. Numerical simulations clarified that the dynamic interaction consisting on the creep force and the contact force between wheels and rails changes depending on response level. Additionally, the displacement response of heavy structures, such as RC structures can be evaluated without considering the effect of the dynamic interaction, and that of light structures, such as steel bridges of open floor type, should be evaluated with considering the effect of the dynamic interaction.

Experimental Study on Contact Force between a Train Wheel and a Prestressed Concrete Sleeper

This paper describes the static and the impact experiments using a wheel shaped contact shoe and prestressed concrete sleepers (PC sleeper) to simulate the phenomenon that train wheels are expected to collide with PC sleepers when a railway vehicle is derailed by a large-scale earthquake. These experiments clarified the following items: firstly, the maximum force obtained in the static and the impact experiments were almost equal except for the case of loading at the edge side in the longer direction of the sleeper. Secondary, regarding fracture mode, it became clear that flexure fracture, delamination fracture or shear fracture could be classified, not by the loading method but by the loading position. Thirdly, regarding contact stiffness, it differs according to the loading method and loading position.