Development of level-1 PSA method applicable to Japan sodium-cooled fast reactor, 2; Seismic response analysis considering characteristics of the advanced seismic isolation system

JSFRのレベル1PSA手法の開発,2; 高速炉用免震システムの特性を考慮した地震応答解析

皆川 佳祐*; 藤田 聡*; 山口 彰*; 高田 孝*; 栗坂 健一 

Minagawa, Keisuke*; Fujita, Satoshi*; Yamaguchi, Akira*; Takata, Takashi*; Kurisaka, Kenichi

本論文は、免震システムの地震応答解析及び感度解析について述べる。免震システムを構成する積層ゴムは、大きい変位を加えた場合、水平方向においてはハードニング特性を示し、上下方向にはソフトニング特性を示す。そのため、解析では積層ゴムの非線形性を考慮し、水平及び上下方向の非線形性を多直線モデルで表した。質点解析モデルを適用した。まず、積層ゴムの非線形性の建屋応答への影響を調査するために地震応答解析を実施した。次に積層ゴム,オイルダンパ及び建屋のパラメータのばらつきの建屋応答への影響を調査するために、感度解析を実施した。これらの解析の結果、積層ゴムの非線形特性が建屋及び内部設備の応答へ影響を及ぼすことを確認した。

We carried out fundamental seismic response analysis that considers both horizontal and vertical nonlinearity of rubber bearing. In this study, the horizontal nonlinearity was considered independently from vertical response in order to construct accurate nonlinear analytical model of rubber bearing. That is to say, the coupling effect was not considered. Both horizontal and vertical nonlinear characteristics of rubber bearing were explained by multi-linear model. Analytical model of building for horizontal direction consists of 3 mass points that is the isolation layer, lower and upper layer of the building. It for vertical direction consists of 4 mass points, that is ground layer, the isolation layer, lower and upper layer of the building. At first, nonlinear seismic response analysis was executed in order to confirm nonlinear characteristics of analytical model of rubber bearing. Influence of nonlinearity of rubber bearing upon response of building was also investigated by the analysis. After that, sensitivity analysis was executed. Parameters of rubber bearing, oil damper and building were fluctuated, and influence of variation of these parameters upon response of building was investigated.