Runup on columns in large waves

Runup is known to cause damage to deck plates in the vicinity of the columns of semi-submersibles. Previous studies have related the extent of the runup to the kinetic energy of the wave crest particle motion, However, these studies have been limited in the wave heights which were used. In this study, wave runup on vertical cylinders is investigated with the use of video cameras, The waves are generated in a narrow wave flume and are representative of storm waves in the North Sea. Wave period and wave height are used as the independent variables and the extent of the runup is compared to the kinetic energy calculated from high order wave theory, It is shown that even high order wave theory is insufficient to calculate the extent of the runup, and that the measured values exceed the calculated values by about one third over a wide range of conditions.