2D and 3D Physical Modelling of Current and Wave Interactions for Rock Berm Design

The return period conditions tested were based on combined wave orbital velocities at the bed and steady currents, which were both simulated in the MHL (Manly Hydraulics Laboratory) 2D flume. The 2D testing utilised model scales of 1:35 and 1:40 and the 3D testing utilised a scale of 1:35. In addition to optimising the rock grading, the influence of rock cover height was also investigated during the tests.

Both regular waves and Pierson-Moskowitz spectra were utilised in the testing. This paper describes the test conditions and the scaling effects that would influence model results, particularly under 2D conditions. In the 3D testing the importance of accurately replicating bathymetry and an adjoining trench is discussed.