Fire Fragility Curves for Industrial Steel Pipe-Racks Integrating Demand and Capacity Uncertainties
Fire Fragility Curves for Industrial Steel Pipe-Racks Integrating Demand and Capacity Uncertainties
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DOI：
10.1007/s10694-022-01358-4
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发表时间：
2023-01
期刊：
影响因子：
3.4
通讯作者：
L. Possidente;J. Randaxhe;N. Tondini
中科院分区：
文献类型：
--
作者：
L. Possidente;J. Randaxhe;N. Tondini
本文旨在求出某工业厂房钢管架原型在局部火灾作用下的火灾易损性曲线。特别是，从一个参考案例研究开始，分析中包括了与结构容量和局部火灾的大小有关的不确定性，这些火灾是由储罐或管道上的洞引起的。因此，通过比较四组逐步引入需求和能力不确定性的分析，突出了脆弱性函数推导过程中不确定性的影响。此外，结合云分析(CA)，评估了多条带分析(MSA)用于构建相关的概率火灾需求模型的适用性。将层间漂移率(ISDR)作为工程需求参数(EDP)，通过评估代表局部火灾严重程度的不同相关烈度(IMS)，得到火灾易损性曲线。研究发现，通过在钢的屈服强度中引入不确定性，相对于参考案例研究，可以观察到较低的超过寿命安全和接近倒塌极限状态的概率。此外，进一步的不确定性--用连续的基于物理的火灾直径大小概率函数描述--通过降低超越的概率而影响了概率模型。这些函数为火灾场景提供了更真实的描述，从而能够更好地表示结构漏洞。在这个案例研究中，CA比MSA更适合于火灾易损性曲线的推导。文中对所有的分析结果进行了深入的讨论。
This paper aims at deriving fire fragility curves for a prototype steel pipe-rack in an industrial plant subjected to localised fires. In particular, starting from a reference case study, uncertainties related to the structural capacity and the size of the localised fires caused by a hole in a tank or a hole in a pipe are included in the analyses. Thus, the influence of uncertainties in the derivation of the fragility functions was highlighted by comparing four sets of analyses in which both demand and capacity uncertainties were progressively introduced. Moreover, alongside the cloud analysis (CA), the suitability of the multiple stripe analysis (MSA) to build relevant probabilistic fire demand models was assessed. Fire fragility curves were derived by considering the interstorey drift ratio (ISDR) as engineering demand parameter (EDP) and by assessing different relevant intensity measures (IMs) that represent the severity of localised fires. It was found that by introducing uncertainties in the steel yield strength, lower probabilities to exceed the life safety and the near collapse limit states with respect to the reference case study were observed. Moreover, the inclusion of further uncertainties, described with continuous physically-based probability functions of the size of the fire diameter, affected the probabilistic models by lowering the probability of exceedance. These functions provide a more realistic description of the fire scenario, enabling a better representation of the structural vulnerability. For this case study, the CA exhibited better suitability for the derivation of fire fragility curves than the MSA. All the analysis results are thoroughly discussed in the paper.