Study of wave disturbance in the harbours of Valletta (Malta)

10 November 2020

Characterising wave disturbance and proposing solutions to protect the natural harbours of Valletta.

The two natural harbours on either side of Valletta, Marsamxett Harbour to the north-west and Grand Harbour to the south-east, have significant heritage interest. They are also deep, steep-sided, rocky and exposed to waves from three different directions (north-west, north-east and east), making protecting them a particularly complex matter. They accommodate pleasure boating, trade, transport, cruise and naval activities, within severely limited space. There is hence an urgent need to improve operability conditions and protect them during winter storms.

3D model: vertical impact of a wave beneath the bridge deck at the level of the abutment | Artelia Hydraulics
3D model: vertical impact of a wave beneath the bridge deck at the level of the abutment

 

In this context, Infrastructure Malta commissioned Artelia to perform comprehensive hydraulic studies to characterise the current situation, define protection scenarios, draw up a preliminary dimensional design of the solution selected, and check the hydraulic performance and stability of the structures on a physical model.

 

 

 

Numerical model: diagram of wave disturbance in Grand Harbour with N75° chop, Tp= 5s | Artelia Hydraulics
Numerical model: diagram of wave disturbance in Grand Harbour with N75° chop, Tp= 5s

 

 

Artelia performed the hydraulic studies (offshore waves and onshore transformation, wave disturbance inside the harbours, and hydrodynamics), proposed protection solutions, assessed the hydraulic performance of the submerged breakwater using a numerical wave flume, produced the conceptual preliminary dimensional design of the proposed structures (overall layout and sections) and validated this design by performing wave flume and wave tank studies at its Hydraulics Laboratory near Grenoble.

 

 

2D wave flume model: waves breaking on the submerged breakwater | Artelia Hydraulics
2D wave flume model: waves breaking on the submerged breakwater

The 3D model in 100-year storm conditions | Artelia Hydraulics
The 3D model in 100-year storm conditions