Modelling long-term response of coastal structures for the safeguard of the Venetian Lagoon.

Over the last decades, a number of engineering solutions, including both nearshore and offshore structures, have been constructed in order to protect the historical city of Venice (Italy) and the whole Venetian coastal environment from sea storms, high tides and recurrent flooding. In recent years, in the context of the ambitious Mo.S.E. project, new breakwaters were set up in front of the three inlets connecting the Lagoon to the Adriatic Sea. A key issue in the design of such structures is represented by the estimate of both short-term and specially long-term settlements. Field observations as well as laboratory evidence have shown that time-dependent phenomena cannot be assumed as negligible in Venetian sediments, with significant implications on the performances of the coastal defence structures. This paper focuses on the modelling of the long-term response of a breakwater built at the Malamocco inlet, using a FE approach in conjunction with an appropriate constitutive formulation to simulate creep behaviour of soils. Numerical results are compared with settlement measurements obtained from Persistent Scatterer Interferometry.