断層モデル地震波群を用いた建物の機能損傷評価の効率化手法の適用

Application of an efficient evaluation method for predicting building function loss using ground motions with fault models

五十嵐 さやか*; 坂本 成弘*; 宇賀田 健*; 西田 明美  ; 高田 毅士*  

Igarashi, Sayaka*; Sakamoto, Shigehiro*; Ugata, Takeshi*; Nishida, Akemi; Takada, Tsuyoshi*

断層モデル地震波群を用いた建物の確率論的リスク評価の実適用に向けて、地震波群作成に関する効率化手法について検討してきた。効率化手法は、断層モデル地震波群を用いて評価した建物の機能損傷確率を「機能損傷確率順に並べた場合」と「地震波群の地震動強さ順に並べた場合」の差の標準偏差が最も小さい地震動強さ指標(すなわち、建物機能損傷と最も相関が高い指標)をハザード評価の指標として選定することによって、建物機能損傷への影響度の大きい震源に焦点を当てて、地震波群を作成しようとするものである。本報では、適切な指標を選定するのにどの程度の地震波数が必要かを検討するとともに、断層モデル地震波群を用いた地震リスク評価の全体フローを示す。

The authors have investigated an efficient method for generating ground motions based on fault models detecting the optimal seismic intensity index which has good correlation with the seismic risk of the building. This method is based on the examination of the errors of generated ground-motions which are ordered by the damage probabilities of the system or by their seismic intensity indices. In this study, the errors were evaluated for some cases of an equipment system which has different weak equipment components in order to validate the method. As a result, the smallest error was obtained to the expected seismic intensity index of each system, and the validity of the proposed method was confirmed. The authors also indicated the workflow to conduct the seismic risk assessment for arbitrary building utilized the ground motions based on fault models.