other important projects

North West Rail Link Sídney

Sydney, Australia

This design and build contract in Sydney includes:

  • 15.5km long and 6.17m inner diameter twin tunnels between the existing Epping Station and the new Bella Vista Station.
  • 5 stations with excavation of approx. 180m long and 20m wide: Cherrybrook, Castle Hill, Showground, Norwest and Bella Vista. 
  • 2 service facility shafts at Epping and Cheltenham.
  • 59 cross passages.
  • Crossover cavern in Castle Hill 184m long, 21m wide and 14m high.
  • 2 mined tunnels 300m long each between Epping shaft and existing Epping station.

Approximately 70% of the driven tunnels encounter Hawkesbury Sandstone and Mittagong Formation (transition between sandstone and siltstone), with the remaining length of the tunnel drive within Ashfield Shale (competent siltstone).

Most of the running tunnels have been excavated with 4 Double Shield TBMs 6.99m diameter. The precast concrete segments was delivered from the yard to the TBM by rubber tyre vehicles.

The excavated materials have been transported from the TBM via conveyor belts to the portals. In order to avoid disruptions to the neighbourhood around the sites, all the main and potentially noisy activities during the night have been carried out within noise insulated night sheds, including the spoil stock pile management and the segment loading in the tunnel vehicles.

The cross passages were excavated concurrently to the TBM drive using small excavators. The TBM and cross passages works simultaneously, allowed by the cross passages team working on movable crossing platforms. This provides enough space for the TBM vehicles circulation around the cross passages during construction.

Facts of the project
Length 2 x 13,855 km
Excavation diameter: 6.99 m
Excavation volume: 1,06 MM m³
Inner diameter 6.17 m
Completion year: 2016