Construction of HATS stage 1 deep shafts in Hong Kong special administrative region (SAR), China

Shafts play an essential part in the construction, operation and maintenance of tunnels and deep underground structures but are rarely given exclusive prominence in technical publications. The aim of this paper is to summarise the experiences gained in Hong Kong SAR during the construction of the Harbour Area Treatment Scheme (HATS) Stage 1 works where seventeen shafts were constructed. The function of the shafts varied from providing construction access to the tunnel works to conveying sewage to and from the tunnel system. The excavated diameters of these shafts range between 2.5 and 50 m. At a maximum depth over 150 m these are the deepest shafts below sea level in Hong Kong SAR at present. All shafts were located in reclaimed land and in close proximity to the sea. The upper shafts in soils and weak rock were constructed by diaphragm walling method and the lower shafts in rock by mainly drilling and blasting. Raise boring and blind shaft drilling methods were also employed. The upper shafts and permanent shaft linings were designed using conventional methods and the primary support selection for the lower shaft was based on Barton's (1974) 'Q' system. Settlement, water level monitoring and inclinometer measurements were undertaken during excavation to confirm the design assumptions. During construction several difficulties were met that had to be overcome. All shafts with the exception of one were successfully excavated and completed. This paper addresses the key design and construction issues and the difficulties that were encountered which may be common for deep shafts constructed in an urban setting near coastlines. (A). "Reprinted with permission from Elsevier". For the covering abstract see ITRD E124500.

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  • Authors:
    • PAKIANATHAN, L J
    • KWONG, A K
    • MCLEARIE, D D
    • NG, W K
  • Publication Date: 2004-7

Language

  • English

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Filing Info

  • Accession Number: 01011639
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 19 2005 3:22PM