DESCRIPTION

The rebuilding of La Fenice Theatre in Venice involved complex works in order to achieve new structures and underwater excavations.
The main difficulties were due to several problems:
– the particular location of the theatre, in the middle of Venice
– the presence of high old masonry walls (founded on wooden piles) to be preserved
– the soil profile and the high tide level
A combined solution (called “diaphragmed berlinese”) was chosen:
– steel piles Ø127mm (10mm thick), spaced 40cm, making a structure suitable to support lateral loads.
– plain plastic piles Ø 230 mm placed between steel piles in order to achieve a continuous impervious barrier.
Tubfix type micropiles (with grouted foundation bulb) were designed in order to transfer new structures’s load to the sandy layer lying between -6m and -12m a.s.l., under a soft clayey silty cover.
These steel piles (Ø 101,6 mm and 12,5 mm thick) were also part of “berlinese”.
In situ tests were made in order to optimize the technologies and the operating parameters.
A monitoring system allowed to check the effects of the works on the old structures.
Damages to masonry were prevented by continuous monitoring.
All excavations could be made without water seepage even where the hydraulic head reached its maximum value.