Super Dense Real-Time Monitoring of Earthquakes for a City Gas Network in Japan

To cope with earthquake-related secondary disasters, city gas utilities in Japan have promoted several countermeasures in the last two decades. Tokyo Gas Co. introduced an earthquake monitoring and rapid damage assessment system, SIGNAL, with 331 SIsensors in 1994, as well as installing automated shutoff valves and intelligent meters. After the 1995 Kobe Earthquake, the earthquake monitoring system is further being strengthened by introducing new SI-sensors to all the 3,700 district regulators in greater Tokyo area. A new seismic monitoring and damage assessment system named SUPREME is now under construction using the seismic information from the new SI-sensors and an enhanced GIS. This paper overviews the recent advances in the seismic safety of city gas supply systems in Japan.