SALERNO-REGGIO CALABRIA MOTORWAY: SAN GIOVANNI TUNNEL
|Client||Salerno – Reggio Calabria S.C.p.A.|
|Services provided||Detailed design;technical assistance during construction|
|Period of execution||2004 - ongoing|
|Construction cost||€ 906,122,582.42|
|KEY FACTS / KEY DATA||
The motorway A3 Salerno - Reggio Calabria -having a total length of about 445 kilometers- is the main arterial expressway between Sicily and the extreme southern Tyrrhenian regions to the large European motorway network in junction with the Corridor 1 that connects Palermo to Berlin.
The lot object of the intervention concerns the stretch among the progressive 393+500 (junction of Gioia Tauro) to the progressive 423+500 (junction of Scilla), for a total of 30 km.
The motorway, built between 1964 and 1972 is a work of great engineering valor (it includes a large number of tunnels and viaducts, including the highest arch-frame bridge in the world, the Sfalassà bridge) but has often shown serious problems because of the tortuous layout and the absence of the emergency lane.
The main objectives of the project are:
- The strengthening and functional adaptation of infrastructure to current standards.
- The improvement of the safety conditions and the average speed through targeted interventions for increasing the driving comfort and visibility, with the upgrading of the roadway plano-altimetry.
- The construction of the emergency shoulder and the safety measures in tunnels and viaducts.
At the tender stage for the Integrated Contract, the final design has been drawn up contributing to its award.
THE PROJECT: CHALLENGES AND SOLUTIONS
The general approach in designing was to achieve the greatest possible savings in territory and, consequently, where possible, to operate with modifications and enlargements of the existing road.
The layout, however, takes place in soils with particularly complex geological conditions and often unforeseeable which required the study of several measures for the consolidation and stabilization of slopes, both in the executive and permanent phase, as well as exceptional measures for the safety of the yards.
Nevertheless, the need to ensure the flow of traffic to and from Sicily, especially in coincidence of mass departures during summer, has created many technical problems to evaluate the most appropriate phases of execution that, in complete safety, would guarantee always a certain level of service for traffic and the simultaneous progress of work.The assignment also includes technical assistance during the construction phase, and it was at this stage that our technicians have clashed with major complications.
In fact, during the implementation of the gallery San Giovanni several technical problems have arisen caused by the difficulties concerning the geomorphological and hydrogeological characteristics of the area, which were promptly faced and resolved.
In correspondence of one of the entrances, the presence of a quiescent landslide reactivated on the occasion of heavy rainfall intensity, has required an adjustment of the detailed design for the safety of the slope during both phases of completion of the excavation, both for the conditions of exercise and seismic. A significant intervention of lightening upstream of the slope has been one of the major contributions to its safety measures.
Provided in collaboration with STONE SpA – STE Srl –SINT Srl –ESSEdI Srl
- Technical and administrative coordination of the design temporary association
- Final design for tendering
- Detailed design of S. Giovanni, Iropo, Quartararo and S. Stefano tunnels
- Design for technical variants to the approved detailed design (S. Giovanni, Iropo and S. Stefano tunnels and Sfalassà and Favazzina viaducts)
- Consulting services and Technical Assistance to General Contractor up to final testing of the works.