Borgaro and Falchera interchange overpasses along the Turin Northern Ring Road. Executive Design for installation works of the side safety barriers.

Project objective

The objective of this project is the upgrade of the lateral protection systems of Overpass No. 75 at chainage km 14+018 (Borgaro) and Overpass No. 81 at chainage km 18+004 (Falchera) of the Turin Ring Road motorway system, in relation to changed traffic conditions and to the updated legislation, to increase the safety level of the infrastructure.
The intervention provides for new H4 “bridge-edge” barriers with integrated mesh (anti-throw/anti-climb) and, to ensure compliant installation, the upgrading of the kerbs; to improve durability, deck drainage works, waterproofing of the slabs, reconstruction of the pavement build-up, and replacement/adjustment of joints and deck-end details are included.

Main works

Barriers and kerbs
Removal of existing non-certified barriers and installation of H4 “bridge-edge” barriers with integrated mesh, bolted to new reinforced-concrete kerbs. Installation requires upgrading of the side kerbs: the existing kerbs, which incorporate asbestos-cement conduits, will be dismantled after milling of the entire pavement build-up down to the deck slab, by cutting into 2 m blocks and removing/disposal in compliance through specialist procedures. Upstream and downstream transition sections are provided to connect the new bridge-edge barriers with the embankment-edge barriers. On Overpass 81 (Falchera) the upgrade concerns the SV–PC side (on the MI side the recent system remains).

Waterproofing and pavements
Complete removal of the existing pavement build-up, new deck-slab waterproofing and reconstruction of the pavement layers (base, binder, drainage course), maintaining the design elevations and improving surface water runoff.

Joints and deck-end details
Installation of a new reinforced-rubber expansion joint on the central pier (gap up to 50 mm) with water-collecting flashing; at the abutments, due to the specific slab configuration that overlaps the gravel stopper, which prevents installation of joints, a stainless-steel sheet with an insulating panel and armoured waterproofing membrane will be installed to ensure watertightness and mechanical protection.