Abstract
It was the first time for Shinkansen trains on business to derail at the time of the 2004 Niigataken-Chustsu Earthquake. Because various prior measures were effective and it was fortunately, the derailment caused no disaster. One of the countermeasures against earthquake disaster for Shinkansen, the early earthquake detection system has been installed to reduce the level of the disaster as possible. At the time of this earthquake, Compact UrEDAS for Joetsu Shinkansen make alarm one second after P wave detection at the epicentral area, and all trains around epicenter were urgent stopped. Although it was less than three seconds for the derailed train from the alarm to severe earthquake motion begins, the alarm decreased the possibility to run the possible damaged area more than 130m and to rush of the opposite train in the derailed area. Compact UrEDAS demonstrated that it is effective enough even for the earthquake just below as concerned. Moreover from the analysis of the derailment situation, main portion of derailment was caused by the large relative displacement between the specific viaducts. It was assumed that high frictional heat was caused by the derailed vehicle bodies slid on the rail after the earthquake as body landing, and the transformation and breaking the rail occurred just after the train running.
