Vulnerability Curves for Partial Damage to Wooden Buildings for Seismic Asset Risk Assessment

Abstract

This study developed a building vulnerability curve for partial damage to wooden buildings in order to improve the accuracy of economic seismic risk assessment. In constructing the building fragility curve, municipal-level damage ratio data published by the General Insurance Rating Organization of Japan were utilized. Specifically, the building fragility curve for “minor damage”, based on disaster certificates, was adjusted using the municipal-level damage ratio data. Using the vulnerability curve for minor damage, building losses from the Tokyo Metropolitan Earthquake were calculated to be approximately ￥22.2 trillion. Of this total, building losses attributable to minor damage were estimated to exceed ￥6.7 trillion. These results demonstrate that even minor building damage significantly impacts the monetary value of building loss risk.