水平及び鉛直地震動を受ける平底円筒貯槽の滑動判定式

本論文では, 水平及び鉛直地震加速度を受けるアンカー構造を有し, かつ底板が浮上らない平底円筒貯槽の滑動の運動方程式を示し, 加速度応答倍率を適用して滑動の判定を行う方法について検討を行った. ここで, 加速度応答倍率の適用は滑動現象にとって最も重要な水平及び鉛直加速度とそれらの応答の同時性を無視することになるので, この点を補うために2つの係数を定義し, 水平及び鉛直加速度とそれらの応答の同時性の効果を滑動判定式に取入れるようにした. そして, それら係数が正規分布で近似される統計的性質を有することを明らかにし, 許容超過確率に基づいて算定した鉛直地震加速度と貯槽の鉛直応答加速度を設計値として用いて滑動の判定ができることを示した. / This paper presents the slip verification method for the tank with the seismic magnification factors of both horizontal and vertical directions. The equation is derived from an analytical model for the tank slip including the effects of anchor straps and the responses to the ground acceleration in both directions. Since an application of the seismic magnification factors for the tank slip verification implicitly neglects the coincidence between the ground acceleration and responses to them which considerably affect tank slip behavior, two coefficients which express their coincidence are determined to compensate for the deficiency. Since relationships of the coincidence to their probability of occurrence are clarified, the design vertical ground acceleration and vertical response acceleration based on the allowable probability of excess are introduced to the slip verification method. The proposed method accurately approximates the slip commencement of the tank.