Earthquakes can cause significant damage to liquefied gas terminals, a critical part of lifeline facilities of energy supply networks, failure of which may lead to loss of hazardous material, explosion, environmental contamination, loss of functionality and disruption of business. To date, seismic risk analysis of such facilities mainly focuses at component level, with the inherent dynamic interaction between the supporting structure and non-structural components not receiving the merited attention. In the present study, the seismic performance of an actual facility comprising of a piping system and a reinforced concrete (RC) supporting structure is analyzed through a finite element model in the nonlinear regime, both as coupled and decoupled case. Plastic strains are used as engineering demand parameters (EDP) to define leakage limit state for pipes. Since the RC pipe rack supporting structure is designed for low seismic loads, shear is recognized as the predominant failure mode. The same components are then analyzed in unison, considering coupling due to dynamic interaction. Fragility functions are estimated for both cases using multiple stripe analysis. A set of strong ground motions artificially generated using the specific barrier model, are employed for developing fragility curves. They are expressed with peak ground acceleration (PGA) as an intensity measure. Statistical estimation of the parameters of fragility functions are based on maximum likelihood method. It is inferred that in the decoupled case, pipes show higher vulnerability at lower PGA, at higher PGA pipe rack can fail suddenly resulting in total failure of the system. Moreover, in coupled case the fragility of the pipes and RC rack changes substantially because of the piping system boundary conditions. Thus, concluding that the risk estimation could be erroneous if dynamic interaction is neglected.

中文翻译：

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考虑组件动态相互作用的液化天然气子厂地震脆性分析

地震会严重损坏液化气终端设备，这是能源供应网络生命线设施的重要组成部分，其故障可能导致危险材料损失，爆炸，环境污染，功能丧失和业务中断。迄今为止，此类设施的地震风险分析主要集中在组件级别，而支撑结构和非结构组件之间的固有动态相互作用并未引起人们的关注。在本研究中，通过有限元模型在耦合和分离情况下的非线性状态下，分析了由管道系统和钢筋混凝土（RC）支撑结构组成的实际设施的抗震性能。塑性应变用作工程需求参数（EDP），以定义管道的泄漏极限状态。由于RC管架支撑结构设计用于低地震载荷，因此剪切被认为是主要的破坏模式。考虑到由于动态相互作用而产生的耦合，然后统一分析相同的组件。使用多条带分析估计两种情况的易碎性函数。使用特定的障碍模型人工生成的一组强烈的地面运动被用于绘制易碎性曲线。它们用峰值地面加速度（PGA）表示为强度度量。易损性函数参数的统计估计基于最大似然法。可以推断，在分离的情况下，管道在较低的PGA中显示出较高的脆弱性，在较高的PGA管架上可能会突然失效，从而导致系统完全失效。此外，在耦合情况下，由于管道系统的边界条件，管道和RC机架的脆性会发生很大变化。因此，可以得出结论，如果忽略了动态交互，则风险估计可能是错误的。