In tunnelling applications compressed air is used to allow the construction of shafts and tunnels in, or below, permeable waterbearing strata and reduces surface settlement during construction in impermeable soils. In permeable strata the pressure in tunnel workings is that required to balance external hydrostatic pressure at the tunnel invert. In impermeable soils air losses are insignificant and consumption is determined by airlock losses. Compressed air is used in clay tunnelling to exclude water arising from permeable laminations and to prevent surface settlement in weak soils. The article reviews current compressed air equipment available for tunnelling applications. Future developments are likely to provide more cost-effective containerised installations requiring little maintenance. Solid segmental tunnel linings should be designed which can resist shield thrusts, resist full ground loading and also provide an airtight and watertight tunnel structure as soon as the ring has been erected. (TRRL)

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  • Corporate Authors:

    Morgan-Grampian (Professional Press) Limited

    Morgan-Grampian House, Calderwood Street
    London SE18 6QH,   England 
  • Publication Date: 1979-9

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00310584
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jul 22 1980 12:00AM