During a routine inspection of an offshore platform corrosion damage was discovered at various welds connecting horizontal braces to the pontoon. One of the horizontal braces was found to be completely separated from the pontoon with a gap of up to 1.5 inches. Our immediate tasks were to investigate the safety of the structure and to identify the cause(s) of the damage.
Our engineering team developed computer models to analyze the structure for various configurations. Several design conditions were considered. Our analysis indicated that the horizontal brace broke due to a combination of factors. We recommended removing the damaged braces as the remaining structure has the capacity to resist its design loads, sandbagging around the diagonal braces to minimize erosion and reduce the likelihood of structure resonance with the current, and performing an annual inspection to confirm the integrity of the remaining structural members.