A Probabilistic Fracture Mechanics Approach to Offshore Jacket Joint Integrity

Abstract This paper investigates the probability of crack propagation from an initial crack to a critical state in jacket joints using the fracture mechanics method, as outlined in DNVGL-RP-C210. It assesses the criticality of a joint by predicting the duration between crack initiation and rapid crack propagation, leading to fracture. By understanding these dynamics, the study aims to estimate the likelihood and timing of a joint reaching a critical state, which is essential for ensuring structural integrity and safety. The study focuses on Platform A, which has experienced increased water levels due to subsidence, leading to significant fatigue damage. Despite this, inspection records from Flooded-Member-Detection (FMD) and Magnetic-Particle-Inspection (MPI) show no through-thickness cracks. The study aims to identify and prioritize inspections for joints likely to have initiated cracks, ensuring they are addressed before reaching a critical state that could compromise structural integrity.