SOFT GROUND NATM IN HONG KONG

This article describes the construction of the 3.7km long Tai Lam twin tunnels in the Country Park Section of the Route 3 Expressway in Hong Kong. Each tunnel will carry three highway lanes, and have a cross-sectional area of 333m squared. The tunnels are mostly being excavated through granite and granitic rock, though 60m is through completely weathered granite soil. The analysis of the tunnels in the portal zone presented a complex series of interaction problems, generated by variable geometries and excavation and support sequencing. The design problem was further complicated by time-dependent aspects of primary support and ground loadings. The analysis was simplified by using an idealised plane strain tunnel model at one representative location. The final scheme, adopted for construction, comprised excavation and primary support, executed in five stages using the 'central wall' method. Instrumentation schedules and locations with associated monitoring programmes were prepared with the contractor, to: (1) warn of potentially damaging or dangerous ground movements and prepare contingency plans for them in good time; and (2) provide data to recalibrate the design models to reassess their validity. Tunnel excavation began in late 1995.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09568700
• Corporate Authors:

  THE MINING JOURNAL LTD

  60 WORSHIP STREET
  LONDON,   United Kingdom  EC2A 2HD
• Authors:
  • FREW, B
• Publication Date: 1996-11

Language

• English

Media Info

• Pagination: p. 399,401
• Serial:
  • WORLD TUNNELLING AND SUBSURFACE EXCAVATION
  • Volume: 9
  • Issue Number: 9
  • Publisher: THE MINING JOURNAL LTD
  • ISSN: 0956-8700

Subject/Index Terms

• TRT Terms: Construction management; Continuous structures; Design; Excavation; Excavations; Freeways; Loads; Mathematical models; Measuring instruments; Shape; Surveillance; Tunnels
• Geographic Terms: Hong Kong (China)
• ITRD Terms: 6155: Apparatus (measuring); 3666: Construction method; 9006: Continuous; 9011: Design (overall design); 5155: Excavation (process); 8131: Hong Kong; 5567: Load; 6473: Mathematical model; 2752: Motorway; 9073: Shape; 9101: Surveillance; 3374: Tunnel
• Subject Areas: Bridges and other structures; Construction; Design; Highways;

Filing Info

• Accession Number: 00735337
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Apr 29 1997 12:00AM