Research on the input ground motion and analysis of the floating-roofed oil storage tanks

在2003年的德立树8.0级地震中，由于长时间的地震动，在Tomakomai的许多储油罐受到严重的晃动破坏。本文研究了储油罐浮顶的长周期地震动特征和响应，以期减轻未来大地震对储油罐浮顶的破坏。得到的主要结果如下：1)对多立树地震及其两次大余震期间Yufutsu平原K-net记录的水平平原地面速度轨道进行了检验，发现Tomakomai地面运动具有多方向性，这可能是由于地下结构的三维非均质性造成的。2)在Tomakomai IDEMITSU炼油厂现场处理强震加速度图，得到了非常大的PSV （h=0.5%）值。3)为了用简化的半经验方法获得长周期谱水平，对K . More udo（1989）提出的预测方法进行了检验，并利用K-net Tomakomai站点附近的多处tokachio -oki地震余震记录，发现该站点的站点放大系数大于以前的值（Zama,1998）。4)通过Sakai等人的线性化流体-弹性振动分析，在考虑单层和双层弹性浮顶存在的情况下，对浮顶晃动行为进行了详细研究。我们进行了参数化研究，以明确哪些参数对浮桥内的应力影响最大。5)为了防止甲板浮桥的屈曲，我们通过ABAQUS定量地检查了在浮桥中间歇性放置的加强筋和橡胶的影响（一种隔离方法；Sakai和Inoue，2005），其中我们包括几何和材料非线性。6)通过分析浮顶与所含液体的相互作用振动，提出并检验了TLCD浮顶晃动振动控制方法（Sakai et al.,1989）。少

During 2003 Tokachi-oki earthquake (M=8.0), many oil storage tanks in Tomakomai were damaged severely by sloshing due to long-period ground motion. In this research, we investigated the characteristics of the long-period ground motion and responses of the floating roofs of the oil tanks in order to mitigate such damages by future large earthquakes. The main results obtained are as follows:1) We examined the orbits of the ground velocities in the horizontal plain obtained by the K-net records in Yufutsu plain during the Tokachi-oki earthquake and its two large aftershocks, and found that the multi-directionality of ground motions at Tomakomai which is probably due to the 3-D heterogeneity of the underground structure.2) We processed the strong-motion accelerogram on the premises of IDEMITSU refinery at Tomakomai, and obtained very large PSV (h=0.5%) values.3) To obtain the long-period spectral level by the simplified semi-empirical method, we examined the prediction method proposed by K … More udo (1989) using many aftershock records of Tokachi-oki earthquake at around the K-net Tomakomai site, and suggested that the site amplification factor at the site is larger than the previous value (Zama,1998).4) Through the linearized fluid-elastic vibration analysis developed by Sakai et al., we investigated in detail the floating -roof sloshing behaviors taking into consideration of the existence of the elastic floating-roofs with single-deck type and double deck type. We conducted the parametric study to clarify which parameter affects mostly to the stresses in the pontoon.5) To prevent the buckling of the pontoon of the deck, we examined quantitatively the effects of the stiffeners and the rubber placed intermittently in the pontoon (a kind of isolation method ; Sakai and Inoue,2005) by ABAQUS, where we included geometrical and material nonlinearity.6) We proposed and examined a vibration control method of floating-roof sloshing by TLCD (Sakai et al.,1989) through the analysis of the interactive vibration between a floating-roof and contained liquid. Less