Comparative Analysis of Post-Earthquake Fires in Japan from 1995 to 2017

Post-earthquakes fires are high-consequence events, which may cause extensive damage once occurred. However, their nature has not been fully investigated as they are low-frequency events at the same time. A questionnaire survey was conducted for the fire services that corresponded to post-earthquake fires in their areas of jurisdiction in recent years, and outline data on fires following nine earthquakes was collected. A database containing information on 665 fires following 11 earthquakes in Japan from 1995 to 2017 was constructed by integrating survey data into an existing database of fires following the 1995 Kobe and 2011 Tohoku earthquakes. Through this database, the features of post-earthquake fires were comparatively analyzed from the viewpoint of types and causes of fire, ignition, fire spread in urban areas, firefighting activity, fatalities, and damage to fire safety equipment systems. The result shows that electrical is increasing in proportion in comparison with the earlier earthquakes among several causes of ignition; about 70% of all ignitions following major earthquakes occurred within a day from the shaking; and the average time required for fire engines to discharge water after ignition increased by 8–25 times in comparison with the ordinary cases. Quantitative correlations for the rate of ignition, $$ r $$ , cumulative relative frequency of ignition, $$ f $$ , and virtual travel speed of fire engines, $$ v_{FF} $$ , that can be used for the risk assessment of post-earthquake fires were also developed. This comparative analysis provides a comprehensive perspective on the issues of post-earthquake fires that have formerly been analyzed fragmentally and construct a technical basis for the future studies.