地震動予測式の残差の周期間相関に関する理論的検討: 短周期側における相関の反転増大の原因

摘要

In the conventional probabilistic hazard analysis, the uniform hazard spectnim(UHS) is used as Ihe ground motion which is corresponding to probability of exceedance. The feilure probability which is evaluated using UHS is considered to be conservative, because fee inter period correlation of residuals of ground motion prediction equation is not incorporated in UHS. Recently, Baker and ComeD(2005) has proposed Ihe concept of conditional mean spectrum(CMS) which takes account of the correlation of fee residuals of ground motion prediction equation. In fee evaluation of CMS, fee correlation of residuals plays key role. Ordinarily the correlation of residuals decreases as fee ratio of two periods increases, but it is known feat the correlation reversely increases in fee short period range although fee ratio of two periods increases. It has not been clarified yet why fee correlation reversely increases in fee short period range. In this paper, fee theoretical study on fee correlation of residuals of ground motion prediction equation is carried out, and it is shown that reverse increase of correlation of residuals in short period range can be reproduced without assuming any reverse increase of correlation of ground motion itself. The validity of fee presented method is also examined by fee recent strong motions records obtained by K-NET and KiK-net stations.%地震の発生時期や規模を確定的に予測することは一般に困難である。また、震源の規模や位置が知られている場合でも，地廣動の予測にある程度の不確実さが含まれることは避けられない。したがって、構造物の安全性評価では、地震動予測のばらつきを何らかの形で考慮しておく必要がある。