Venetian Littoral Waterway: Rehabilitation Works (Italy)

The project concerns the upgrading of the section of waterway between the “Cavallino” lock and the Tagliamento river mouth to make it compatible with the European IV category, and the demolition and reconstruction of the “ponte Spano” vertical-lift bridge in Jesolo (VE).

The rehabilitation of the waterway involves the adjustment of canal depths, the restoration of deteriorated embankments and the functional retrieval of four existing lock structures.

In particular, one of these locks, “Cortellazzo” lock, has to be completely demolished and rebuilt. The remaining three locks (“Revedoli” on the homonymous canal, ”Bevazzana” on the “Nuovo” canal, ”Cavallino” on the Sile river) are subject to restoration works and electro-mechanical system maintenance.

The project includes the provision of a brand-new radio-controlled system for managing the four locks remotely.

The deteriorated embankments to be restored are located in Sile River nearby the Cavallino lock, and along the “Cavetta”, “Saetta-Palangon”, “Revedoli” and “del Morto” canals.

The typical design section used in embankments rehabilitation is made of wooden (either pine or larch) sheet-piling, diameter 14 – 35 cm, length 6 m.

The wood types to be used have been chosen on the basis of durability and eco-compatibility criteria.

The rear side of the piling is composed of pre-cast elements called “burghe” and anti-erosion stone mattresses wrapped in plasticised galvanized metal nets, sewed together to guarantee the resistance of the system. Geo-textile is placed behind the wooden piling in order to hold back the fine soil particles and prevent erosion. Moreover, the stability of the embankment will be increased by the vegetal colonisation that will rapidly develop on the back elements. Nevertheless, the overall stability of the river banks does not rely on the existence of the wooden piling. In fact, even in case of wood deterioration in the long-term, the long service of the new embankment structures is guaranteed.

In the nearby Cavallino lock, on the other hand, the embankment structure is realised by means of concrete sheet-piling.