In response to growing demand for the development of more advanced earthquake disaster prevention, the Railway Technical Research Institute (RTRI) has developed a system consisting of facilities for urgent earthquake alarms and operation restart support.
      To estimate earthquake elements more accurately, a seismograph for urgent alarms (Fig. 1) was developed by detecting an earthquake from the initial P-waves using a new algorithm for the urgent earthquake alarm system. Utilizing the railway enterprise's own specific earthquake observations from this system along with JMA's real-time earthquake information (Now-cast earthquake information) can provide timely data on train traffic restrictions when an earthquake occurs.
      The operation restart support system quickly determines which sections require inspection immediately after an earthquake. This system helps to provide earthquake intensity information even in sections where no seismograph is set up. This is done by deriving the intensity distribution along railways from JMA's segmentation-base earthquake intensity estimation (earthquake intensities in approx. 1-km meshes five minutes after an earthquake). A number of estimation methods were also devised for factors such as the natural period of elevated structures, the dominant period of yield acceleration and earthquake motion, and a simplified estimation method of elevated structure damage rank from maximum acceleration (Fig. 2). A prototype of this damage estimation system was built incorporating the above methods.
      A continuous running test is now underway using a prototype system built in the RTRI (Fig. 3).