Challenges in Structural Engineering Design and Analysis of Offshore Plants Under Probabilistic Vapor Cloud Explosion Loads

Hydrocarbon gas explosion is one of the critical hazards resulting in huge environmental impact as well as loss of valuable assets and lives as observed from the historical disasters in the oil and gas industry. In response to these events, stronger international rules and regulations have been made to ensure safety of these structures. Hence, considerable effort has been devoted to quantify accidental design loads for flammable gas based on probabilistic approaches which requires extensive computational fluid dynamic simulations. Also, demand for 3D nonlinear dynamic finite element structural simulations has increased significantly with rapid progress in computer performance. Some of the major issues and difficulties in structural design and evaluation for probabilistic design loads are discussed in this paper. Uncertainties in explosion hazard analysis which cause large variations in probabilistic explosion responses are reviewed. Some gaps between provisions for design load estimation based on probabilistic approaches versus current structural design and analysis schemes are compared. Finally, it is concluded that there is an urgent need for reliable guidelines for risk-based structural design and simulation for probabilistic explosion design loads.