Technical specifications

Scope of work

• 2 tunnel tubes
  length: 2,550 m each, internal diameter: 5.80 m
• 6 cross-passages at intervals of 250 m
• 2 stations:
  Serangoon Station, 205 m long
  Woodleigh Station, 210 m long,
  built in an open excavation supported by shoring (soldier piles and timber lagging)
  designed as civil defence shelters, turn-key
• 1 viaduct with 2 separate superstructures with 2 x 3 lanes
  length: 1,750 m, width: 2 x 11.40 m
  using overhead launching system and the free cantilever method for large-span areas
• Contiguous bored pile walls for Braddell Bartley Underpass
  approx. 1 km long, and soldier piles and timber lagging for the excavation of the Upper Paya Lebar Underpass box structure
• extensive roadworks
• 3 pedestrian bridges
• 1 switching substation

Construction method

• TBM tunnelling using 2 EPB shields
• Shield diameter: 6.56 m
• Cross-passages built using NATM techniques with an in-situ concrete inner lining

Geology

• Sand
• Clay
• Granite