Pouyan PressReliability Engineering and Resilience2821-07272220201201Derrick-Supported Flare-Stacks Seismic Fragility Assessment: A Case Study11613566010.22115/rer.2021.283929.1040ENBijan SayyafZadehDepartment of Civil Engineering, Faculty of Engineering, University of Qom, Qom, Iran0000-0002-1647-9541Saeedeh KouhestaniDepartment of Civil Engineering, Faculty of Engineering, University of Qom, Qom, Iran0000-0003-4696-2523Mahdi SharifiDepartment of Civil Engineering, Faculty of Engineering, University of Qom, Qom, Iran0000-0001-8166-1668Journal Article20210501Today oil, gas and petrochemical plants risk mitigation and management due to various aspects such as energy supply, financial implications, life loss and repairs has become a primary concern. One of the approaches that can be used for risk assessment of such these plants which are composed of different types of equipment and structures that have different responses and consequences is the probabilistic analysis. Flare is a process equipment that is widely used in oil, gas and petrochemical plants and depending on the height and type of lateral stability is categorized into self-supported, guy-supported and derrick-supported. In this article seismic behavior of a derrick-supported flare is investigated using finite element method and incremental dynamic analysis as a case study. For this purpose, various limit states were considered and for each of them a fragility curve is calculated and also presented with statistical parameters. The results showed that in ordinary seismic intensities there is no significant seismic demand on the investigated structure but in the range of rare intensities that can trigger technological disasters, there is probability of failure and consequently escalating the disaster.Pouyan PressReliability Engineering and Resilience2821-07272220201201A Study of Nonlinear Behavior of Multistoried Structure for Repeated Earthquake172913565910.22115/rer.2021.284552.1041ENSachin PopatPatilAssistant Professor, Civil Engineering Department, Sanjay Ghodawat University, Kolhapur, India0000-0002-1157-8014Jagadish GKoriProfessor and Head of the Department of Civil Engineering, Government Engineering College, Haveri-581101, Karnataka, IndiaJournal Article20210503According to current practices in earthquake engineering, and as per guidelines of codes the multistoried structures are analyzed and designed only for a single, rare design earthquake. In reality, most of the locations are affected by multiple earthquakes within short time intervals, also the repeated earthquake effect is ignored. The repeated earthquake affects the strength and stiffness degradation of the structure. In this paper4-, 8-, 12-, 16-storey structures are investigated under repeated earthquakes. The Time history analysis is performed with single, double, and triple earthquake events for calculating drift, displacement, and ductility. The result shows that the drift, displacement, and ductility demand increase with compared to a single earthquake. This research focuses on the study of the effect of a single and repeated earthquake on the multistoried structure and damage identification can be found using deformation in building frame or in frame element with the formation of plastic hinges. The default hinge properties are assigned to elements of structure and the study is carried out to find the location, formation of plastic hinges, and plastic hinge rotation due to repeated earthquake and this study is used to strengthening the element strength. This paper studies the interstory drift ratio and displacement under aftershocks of an earthquake and remedial measures are suggested to strengthen the structure capacity.