WAVE INDUCED SET UP, MARINA DI PISA, ITALY

For background see…..

PDF Link:

Pranzini & Farrell_ICS_2004.pdf

The Problem!

Aerial photo shows shoreline asymmetry at mouth of the Arno River near Pisa, Italy. Southern section is fortified/stabilized using engineered structuresat Marina di Pisa; Northern section lies in a National Park and is rapidly eroding.

Study Site

Stable

Eroding

Nourished beaches - bounded by small groins - using gravel sized marble from local quarries

‘Back – To – The – Beach’

Aerial photo shows section of shoreline renourishment using local marble; Theadjacent shoreline comprises of seawall with no useable beach. This test site was to check the feasibility of constructing a series of gravel beaches for recreation.Note the series offshore breakwaters.

A. Current shoreline configuration of a shoreline section at Marina di Pisa, Italy. A total of 5km of hard structures have been constructed to defend 2.5km of coastline.

B. Artist rendering of shoreline configuration for proposed project (Aminti et al., 2001). The semicircular park bordering the coastline is visible in both pictures for reference.

A. B.

Too much engineering…. Not enough beach.

‘Back – To – The – Beach’

Building the beach

Small groins built up- and downdrift of new beaches to maintain beach shape. Shore parallel breakwaters seen in background.

Gravel-sized marble used in nourishment

Ultimate goal was to build gravel beachesfor recreation and for storm protection.

This would also allow offshore breakwatersto be lowered below mean water level andprovide a more aesthetic environment.

The first storm comes......Overtopping of sea wall occurs from both waves and gravel.

Storm waves pushed newly placed gravel sized marble over sea wall on to the street; later it was surmised that the volume of material used to build the beach was insufficient to absorb the incoming wave energy due to larger storm waves! Street was closed to traffic during and after every large storm.

Seawall location

METHODOLOGY

Pic’s of diving and instruments

RESULTS OF WAVE TRANSFORMATION OVER BREAKWATERS

RESULTS AND CONCLUSIONS