In conjunction with a number of JR companies and the Japan Railway Construction, Transport and Technology Agency (JRTT), the RTRI is now promoting research and development into a range of derailment prevention measures. These include new derailment preventive guards, vehicle runaway preventive guards, rolling stock guides, rail overturn preventive devices, glued-insulated joint rails and expansion joints. In the development of these measures, the RTRI performed vibration tests to confirm the behavior of rolling stock in earthquakes.
Vibration tests on an actual truck
The RTRI tested a Shinkansen truck to confirm the load working on derailment and on runaway preventive guards when earthquakes occur, and implemented a rolling stock dynamics simulation (Fig. 1). Table 1 shows the conditions of the vibration test using four excitation waveforms.
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A comparison of the test results with those of the rolling stock dynamics simulation showed an approximate correlation between the two (Fig. 2). The vibration test was performed with a subsidy from the Ministry of Land, Infrastructure and Transport.
Example of derailment prevention measures
Rolling stock guides perform the function of preventing derailed vehicles from moving away from the track (Fig. 3). The RTRI has confirmed that these guides can withstand the assumed impact load determined using static loading tests and FEM analysis.
When a Joetsu Shinkansen train derailed in the Niigata Joetsu Area earthquake, derailed wheels hit and broke the ends of a glued-insulated joint rail. In such cases, it is known that derailed vehicles can move away from the track and magnify the damage to wayside areas. The RTRI therefore manufactured a prototype glued-insulated joint rail contoured to reduce the impact load from wheels or truck members on fishplate ends and keep wheels from touching fishplate bolts (Fig. 4).
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