Travelling times between the centre of Rome and the international airport have been reduced considerably by a tunnel, part of a bypass linking the terminal to a ten lane highway. The tunnel was only 3.5m below the highway so that none of its lanes required closing and there was no interference with services. The 100m long bored tunnel section, chosen in preference to the original cut-and-cover plan, has a curved 70m radius alignment and two shallow straight cut-and-cover access ramps. The tunnel runs along the interface between two different soils; the crown and walls in upper fill and the invert in base peaty soils. Some old structures including bridge abutments were encountered during the drive. Jet grouting was chosen to preconsolidate the ground so that it could support the weight of overhead traffic. Standard consolidation treatment was carried out every 6.5m during construction. The columns injected into the crown were reinforced with steel pipes. The face was also spiled for 12m ahead with 15 jet grouting columns reinforced with fibreglass tubes. This precaution was taken to prevent cave-in, limit face deformation and provide support for the column arch at the tunnel border. Poor ground conditions were offset by casting the invert every 3m immediately following excavation. (TRRL)

  • Availability:
  • Corporate Authors:

    Morgan-Grampian (Construction Press) Limited

    Morgan-Grampian House, 30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • RICCI, P
  • Publication Date: 1991-1

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Filing Info

  • Accession Number: 00619953
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Mar 31 1992 12:00AM