Model testing of a deep water compliant tower.

Laboratory tests were conducted on a 1-to-100 scale model of a compliant offshore tower under deep water conditions. Tests were performed in both regular and irregular waves while measurements of the structure's deck deflection, base shear force, and overturning moment about the base were obtained. Measured values are compared to simplified theory based on a Single Degree of Freedom analysis and, in general, the SDOF analysis is shown to adequately describe the structure's response in regular waves as well as the RMS structural response in random waves. The severe response in random waves are the result of the impulsive nature of the extreme wave loading and are found to be 5 to 6 times the RMS response.