Roadworks and hydraulic reconfiguration works related to the rationalisation of SP No. 1 “Aurelia” in the section between the entrance to S. Corona Hospital (Via Pinee) and Pietra Ligure railway station (Piazza Gramsci) – Lot 2.

Project objective

The intervention aims to improve safety and rationalise the SP 1 “Aurelia” road node between the entrance to S. Corona Hospital (Via Pinee) and the Pietra Ligure railway station, addressing traffic criticalities and the hydraulic risk associated with the Rio Ranzi. The project reorganises flows in a strategic area for connections to the A10 tollgate and the hospital, historically congested due to reduced cross-sections and lack of channelisation, and integrates roadway works with hydraulic upgrades to ensure no overtopping of the watercourse along the urban reach.

Main works

Roundabouts
The intervention provides for the construction of two roundabouts (A and B) connected by a new road section, sized to separate and discharge traffic flows towards the Aurelia, the A10 tollgate and S. Corona Hospital, with construction stages designed to maintain traffic circulation and pedestrian routes.

Rio Ranzi underpass – SP 1 box culvert
The Rio Ranzi underpass will be built by means of a reinforced-concrete box culvert (L = 74 m, clear span 12.50 m, soffit at constant elevation), with temporary Berlin-type shoring walls on micropiles and waterproofing with geocomposite. Excavation, demolition and construction of the reinforced-concrete structure are planned in sections in order to limit interactions with adjacent buildings and ensure excavation stability.

Retaining walls on the right and left orographic banks
Downstream of the box culvert, reinforced-concrete walls are planned on both banks of the Rio Ranzi. On the right bank, the wall will be built in successive sections with temporary Berlin-type shoring to protect nearby buildings (former Red Cross area) and the RFI corridor downstream; on the left bank, the wall is integrated with a rear micropile wall to ensure containment of the embankment and the safety of the foundations of the existing buildings.

Executive lots and construction phasing
Given the strategic importance of the node and the traffic issues that occur during specific periods of the year, three separate executive lots have been envisaged (Roundabout B and hydraulic regulation; hydraulic regulation and finishes between the roundabouts; reconstruction of the underpass, bank walls and Roundabout A), structured into phases to ensure two-way traffic, site accesses and reduced interference with utilities.