South tube of the underground crossing of Toulon (France) East and West cut-and-covers

The completion of the second tube of the underground crossing of Toulon requires the execution of the cut-and-covers on both ends of the main bored tunnel, over about 200 m on the East and West sides.

These trenches are highly constrained by the outlets of the A50 and A57 motorways, which led to designing:

  • on the one hand, a complex phasing of road alternative routing,
  • on the other hand, civil engineering works under a permanent decking bearing on the diaphragm walls, in order to restore the surface traffic lanes as quickly as possible.

The additional construction of 6 staircases (users evacuation and emergency access) on the cut-and-covers (both existing and to be created) is also planned in order to meet the requirements of circular (regulation) 2000-63.

High constraints related with existing structures

As early as the design phase, finite element calculations were used to check the stability of the existing structures of the North tube, as well as of the buildings, during the works.

Terrasol’s achievements:

Full project management:

  • Preliminary design of the engineering structure,
  • Project design,
  • Preparation of the call for tenders for contractors,
  • Works follow-up.
PERIOD :  2003 - 2012
Project Owner : Ministère des Transports, de l'Équipement, du Tourisme et de la Mer
Project Manager : SETEC TPI / TERRASOL
Main specifications :  

Twin-tube – Cross ventilation Cut-and-covers: between 201 and 210 m long Amount of the operation (estimation): 245 M€ excluding VAT (val. 2003)