Study on Joint Return Period of Wind Speed and Wave Height Considering Lifetime of Platform Structure

Summarize the definition of design return period in existent codes and industry criteria. Joint return periods of different ocean environmental conditions are determined from the view of project life and risk probability. Based on equivalent bivariate maximum entropy distribution, joint design parameters of wave height and wind speed are estimated occurred in some place of Bohai Sea. The calculating results show that even if the return value of each environmental factor, such as wave height or wind speed, is small, their combinations usually lead to larger joint return periods. This will make the investment of ocean platform lower.