地震動シミュレーションにより評価した地震動強さのバラツキ
地震危険度解析技術の高度化に向けて
本研究では，過去に日本で発生した内陸地殻内地震のすべり分布を用いて特性化震源モデルの統計的特性を評価し，この結果に基づき統計的グリーン関数法を用いた地震動シミュレーションを行うことで，断層パラメータのバラツキが最大加速度のバラツキ特性に与える影響を評価した。特に，アスペリティ分布と破壊開始点位置が応答スペクトルのバラツキに与える影響を中心に評価を行った。また，他の断層パラメータのバラツキの影響についても簡易的に評価し，距離減衰式の回帰誤差との比較を行った。
| キーワード： | 最大加速度，バラツキ，地殻内地震，震源特性，統計的グリーン関数法 |
＊１ 技術センター 建築技術研究所 防災研究室
Variability in Simulated Earthquake Ground Motion Intensity
Toward Greater Sophistication in Seismic Hazard Analysis
In this paper, the variability in simulated peak ground acceleration due to uncertainty in the source characteristics for a shallow crustal earthquake was investigated. Firstly, finite fault models of the past crustal earthquakes in Japan were compiled and statistically investigated. Secondly, ground motions were simulated at several receivers for several events using the stochastic green's function approach, where events are defined as the combination of an asperity distribution and a hypocenter location. Then, the variability in peak ground acceleration was evaluated at each receiver. Finally, effects of other source parameters were estimated so as to compare them with the errors in an attenuation relationship. The total variance estimated for a particular distance was compared with the errors in the attenuation relationship.
| Keywords: | peak ground acceleration, variability, crustal earthquake, fault characteristics, stochastic Green's function |
*1 Disaster Prevention Research Section, Building Engineering Research Institute, Technology Center
