Location:

Tripoli, Libya

Client:

Libyan Port and Maritime Transport Authority

Year:

1997 – ongoing

Description:

Tripoli harbour, one of the major ports of Libya, is protected by a main breakwater of 4.7 km length. This breakwater, running parallel to the coast and situated in water depths up to 12 m, was hit by two severe storms in 1981. They inflicted extensive damage over approximately half of its length, both to the parapet walls and to the primary armour layer (Tetrapods).

The re-design, prepared by consultant in the period 1981 – 1984 was not implemented for various reasons. Faced by increasing threat to the harbour, LMPA asked in 1997 to reconsider the 1982 redesign.

The project started with a detailed survey of the present breakwater and seabed situation, together with an update of the design (wave) data. After developing several possible design modifications it was chosen to adopt a new Accropode primary armour layer in combination with an extended under water berm at the seaside. Along the first stage of the breakwater where a landfill is present a stone filled canal was designed at the harbour side in order to tackle the venting and overtopping problem. The chosen design modification was finally optimised using small scale physical model tests, which resulted in the final design. The project was concluded with the revision of the 1982 tender documents, including tender drawings, specifications, bill of quantities and cost estimate.