The article describes the construction of the Santa Lucia Tunnel, under Salerno, and considers the use of soil freezing in one tunnel section in detail. A geological section of ground under Salerno is shown; four types of strata present are volcanic, alluvial deposits, and dolomite (tectonic and non-tectonic in origin). Tunnelling difficulties caused by water are discussed. Water and soil cave-ins from the face were stopped by injection. A hydrological study was prepared. Preference of soil freezing over other techniques is discussed. Low temperature brine circulating in freeze pipes causes water in the voids to freeze, giving sealing and stabilization of the soil. The arrangement of freeze pipes is shown. Frost penetration and mechanical properties of frozen soil are considered. The freeze wall conditions of design and their practical realisation are given. The construction method of calottes with a preliminary lining of steel beams and reinforced gunnite was adopted. Relevant construction data are listed. No settlement of structures on the surface occurred where soil freezing was applied, and the method was cheaper and safer than the chemical injection method. /TRRL/

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  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • Braun, B
    • Macchi, A
  • Publication Date: 1974-4-5

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Filing Info

  • Accession Number: 00261768
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Nov 6 1974 12:00AM