Rehabilitation of Sines west breakwater: wave overtopping study

The paper presents an historical perspective on the design, construction, failure and rehabilitation of the west breakwater of the Portuguese harbour of Sines, as well as on the overtopping physical model studies performed to check the effectiveness of the different proposed solutions for its rehabilitation. Studies are now being conducted for Sines Port Authority for the final rehabilitation of the breakwater, with the primary objective of reactivating berth 1 but also to generally improve the shelter and operating conditions within the port. The paper presents the three proposed solutions for the west breakwater and their two-dimensional physical model tests of stability and overtopping carried out in 2008 at Laboratório Nacional de Engenharia Civil (LNEC), Portugal. The paper also illustrates the application of a new version of the non-linear shallow water numerical model, Amazon, and of the methodologies recommended in the EurOtop overtopping manual to study the mean overtopping discharge over the breakwater. The Clash neural network was the only tool applicable to the three proposed solutions, although it tended to underpredict the physical model discharges, mainly for the selected solution 3. There was good agreement between the physical model data and the Amazon results for solutions 1 and 2, although Amazon tended to slightly overpredict the discharges, especially for solution 2. The empirical methods overpredicted these discharges to a great extent, warning of the fact that direct application of these methods is limited to particular structural configurations and wave conditions.