— Project Description:

The most important structure is a 1.8 km sewage tunnel with an internal diameter of 2,800 mm, to be excavated under populated areas and the main city ring, conveying the total flow to the Wastewater Treatment Plant. There are hydraulic structures at the two portals in order to connect the tunnel to the surface network of waste water; moreover a chamber for permanent access to the tunnel is foreseen. An EPB-Shield type of TBM (CSM BESSAC, Ø=3.10) was foreseen to excavate the tunnel and a universal type of ring (19.0cm thickness) is to form the main lining of the tunnel.

— Description of Services:

• Critical review of the geological context and the available geotechnical parameters; • Temporary and permanent works for the hydraulic structures on the two rivers (Rio Aguilar and Rio Torres); • Forecast of the settlements induced by the tunnel excavation; • Building Risk Assessment related to the settlement forecast; • Plan of advance of TBM (PAT) with definition of the face pressure to be applied in order to minimize the settlements; • Tunnel Design (geometry and reinforcement) and Portals Design (geometry and reinforcement).