RELIABILITY REASSESSMENT OF A JACKET PLATFORM WITH GAS SEEPAGE IN THE SOUTH CHINA SEA

摘要

A structural reliability analysis is carried out on a jacket platform in 75 m water depth, in the South China Sea. A platform collapse failure mode is considered, with emphasis on uncertain soil conditions around the pile foundations, due to gas seepage while the platform has been in service. Random environmental conditions due to wind, waves and current are taken into account, based on observed data. Allowance for the short duration of environmental measurements is included and has a marked effect on the results. Two response surfaces are applied in the reliability calculation, to model the loads and the system capacity.