A combined method for high-speed rail seismic monitoring and early warning

The ground motion characteristics include the strength, frequency spectrum and duration time. In China, the PGA (peak ground acceleration) is commonly used in determination of whether an earthquake warning is necessary when the high-speed train is on the rail. This method has not given an earthquake early warning time, and it only considers the strength factor of an earthquake, so the system may release an alarm for the near and small earthquakes which are no destructive. The new alarm method reconciles the timeliness and stability. It issues a P wave warning when the system receives seismic wave first, which will make the train to decelerate. Then, the system will confirm whether the P wave alarm is correct using the joint alarm result of CAV (cumulative absolute velocity) and PGA, and then take measures according to the result. The new method eliminates the interference from the near and small earthquakes, as well as the large and far earthquakes, and ensures the safety of the train when it is subjected to earthquakes. In this paper, we use seismic data to simulate the combined alarm of CAV and PGA, and then obtain the cumulative time of CAV and the time interval between CAV and PGA. Finally, we compare the new method with the double-station, earthquake monitoring alarm method which is currently used on China's high-speed rail, and find the new alarm method is better in the aspect of alarm timeliness.