Experimental determination of the hydrodynamic loading on a model of offshore platform in waves and current

This paper reports on extensive wavetank investigations of the hydrodynamic loading on a large scale model of an offshore jacket in waves and current. Two independent series of tests were conducted. In the first series the structure was mounted on the bottom of the tank and tested in regular and irregular waves. In the second series of tests, the model structure was towed by a carriage to simulate a current, first in still water and secondly against regular and irregular waves. This experiment was repeated for different riser configurations, in order to determine wave/current blockage effects. The data collected in the experiment has been systematically analysed to obtain the wave profile, speed of towing, overall loading, water-particle velocities and near field velocities. Maximum wave loads were determined over a period corresponding to seven hours at full scale. Also, base-shear force and overturning moment have equally been assessed in prototype conditions by means of a probabilistic approac