Derrick-Supported Flare-Stacks Seismic Fragility Assessment: A Case Study

Abstract

Today 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.