DIR Île de France – Detailed inspection of the A86 – Belle-Rive tunnel

The Belle-rive tunnel is located on the A86 motorway between Nanterre and Rueil in the Hauts de Seine department (department number 92). As part of their task to ensure the tunnels’ fire-resistance, Bouygues was required by DIR IF to carry out a complete assessment of the health of the structures in order to prevent possible changes in the structure that may call into doubt the use of fire sheets, and to have a comprehensive account of the condition of the walls to be covered, and therefore rendered invisible.

4 A 86

Client & Project Manager



The detailed inspection also included the inspection of the inner surface of a hydraulic concrete structure and a concrete beam bridge adjoining the tunnel. Simultaneous inspection of the positioning of the concrete reinforcements and coatings of the beams in the RATP (the Paris public transport operator) structure by LERM.

  • Open underpass type tunnel (Tunnel de type Portique ouvert double (POD),
  • 2 unidirectional tubes
  • Length of covered section of the Belle Rive tunnel: 736 m
  • 3 lanes per tube

Mission of Diades

3 A86

Diades carried out a periodical detailed inspection of:

  • the inside and outside of the Bellerive tunnel,
  • the equipment,
  • the interior and exterior lane entrances.

The inspection was carried out in the space of three nights per tube (interior and exterior) with the use of a type 2A hydraulic lift. The traffic lanes were closed by the manager. The periodical detailed inspection carried out by DIADES revealed the defects in the structure, and the good behaviour of the concrete over time.

Download the project sheet