EXPERIMENTAL RESEARCH ON PORE PRESSURE ATTENUATION IN RUBBLE-MOUND BREAKWATERS

Abstract

The paper describes the pore pressure measurements in a small scale breakwater model performed at Ghent University, Belgium. Two phenomena related to the pore pressure distribution within the breakwater are discussed: the amount of energy dissipation through the armour and filter layer (represented by the 'reference pressure') and the exponential pore pressure attenuation inside the core of the breakwater. The test results are compared with results from literature and with the empirical damping model presented by Burcharth et al. (1999) and Troch (2000). Magnitudes of the reference pressures are found to be strongly dependent on the wave steepness. The pore pressure attenuation obtained from the present experiments shows to be in accordance with the empirical damping model. A suggestion is made for a better prediction of the damping coefficient by eliminating the influence of the wave height in the empirical damping model.