Review of fire-related assessment damage of steel off shore structures

Abstract

Fixed offshore structures are continuously exposed to risk of hydrocarbon fire or cellulosic fire. Hydrocarbon fire generally causes more detrimental effect than cellulosic fire because the rapid increment of temperature gives little response time for people to evacuate the location or to put off the fire. Metallography tests have demonstrated that steel structures continuously exposed to temperature escalation from fires will lose their mechanical properties such as yield strength, tensile strength, toughness, hardenability and elastic modulus. Thus, to understand the structural response during fire, structural integrity assessment with revised steel mechanical properties is advised to be performed. The outcome of the analysis helps to identify the hotspots of the steel structures due to the fire and allow the investigation team to further perform detailed inspection and proposed structural repair to reinstate the integrity of the steel structures. This introductory paper reviews a procedure to appraise structures after a fire incident with the objective of filling the gap of the absence of standard assessment procedure. The procedure is based on experience encounters and proposals of practising engineers and utilizes basic engineering mechanics and materials science. The procedure is not a standard operating procedure but should be employed by engineers to emphasise and reiterate the need of a rigid standard.