2014 年 23 巻 p. 11-20
For the purpose of estimation of population affected by city gas supply disruption in an earthquake disaster, vulnerability factor of low-pressure gas pipelines is defined on the basis of non-earthquake resistant ratio. A functional fragility function in terms of shaking intensity is defined as a logit model with 50% exceedance level at SI=65kine considering the vulnerability factor and standard gas shutoff criteria. A grid cell dataset on population served by city gas supply is also developed based on penetration ratio inside/outside of DID. Observed and estimated population of disruption are compared for three major earthquake disasters during 2004-2011. Precision of estimation is approximately within a factor of two except for some extreme cases.