A metro in Los Angeles has been shown to be more cost effective than existing subways in several US cities. The article discusses the problems needed to be overcome in designing the proposed metro where the majority of the route passes through soft ground favourable for high-speed tunnel boring machines. The main problems anticipated include an area of tar-saturated sands, gassy ground in several locations, strong seismic shaking, the need to cross two potentially active earthquake faults and ground water problems. Proposed methods of remedying these potential problems are outlined. A test pit extending into the bedrock underlying the tar sands is planned to observe the stability of slurry trenches, drilled holes and the seepage of hydrocarbons and water. A fabricated steel lining is being adopted in this area. Sufficient ductility is being incorporated to carry any imposed deformation due to seismic shaking. Continuous steel-lining or the use of crushable material in an over-sized tunnel are being considered as possible methods of crossing an active fault. De-watering by surface wells is a feasible method of combating ground water. (TRRL)

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,    
  • Authors:
    • Proctor, R J
    • Hammond, D G
  • Publication Date: 1985

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 120-125
  • Serial:
    • Underground Space
    • Volume: 9
    • Issue Number: 2-3
    • Publisher: Pergamon Press, Incorporated
    • ISSN: 0362-0565

Subject/Index Terms

Filing Info

  • Accession Number: 00457254
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jul 31 1988 12:00AM