Sydney Metro - Western Sydney Airport - TBM temporary works

The construction engineering and temporary works team from CIMIC Group's EIC Activities was engaged to deliver the design works supporting the tunnel boring machines (TBMs) and back-up gantries for the Sydney Metro - Western Sydney Airport, Station Boxes and Tunnelling works.

About the project

CPB Contractors (also a CIMIC Group company), in joint venture with Ghella, was selected by the NSW Government to deliver the Sydney Metro – Western Sydney Airport, Station Boxes and Tunnelling works.

The new metro railway runs from St Marys through to the Western Sydney International (Nancy-Bird Walton) Airport and the Western Sydney Aerotropolis. It will provide a public transport service to the new airport and make a lasting economic contribution to Sydney’s west.

It involves the design and construction of 9.8 kilometres of twin tunnels and excavations for five stations at St Marys, Orchard Hills, Airport Business Park, Airport Terminal and Aerotropolis, and service facilities at Bringelly and Claremont Meadows.

EIC Activities' involvement

EIC Activities was engaged from concept stage to detailed design stage to deliver the design works supporting the TBM and back-up gantries while launching, traversing through open excavations, and for breakthrough.

EIC designed the steelwork supporting the TBM and back-up gantries for their interface with the five station boxes and two shafts.

Detailed designs were delivered for the thrust frames to support TBM launch thrust loads, steel runners for the TBM traverse and back-up gantry traverse, concrete blind ring supports, breakthrough stop-thrust brackets, TBM antiroll brackets for launching and other supporting steelwork.

Site-specific solutions were developed such as for the steel runners supporting the back-up gantry wheel bogies, allowing the steelwork to be installed in a retracted position prior to the TBM passing and extended to support the back-up gantry, as well as a precast concrete option.

Foundations 

EIC also designed the supporting foundations and slabs tailored to the relevant station boxes and shafts and site-specific ground conditions, including stressed ground anchors and micropiles for the tension forces of the launch frame.

The Airport Business Park dive foundation included the integration of a tower crane foundation.

At Orchard Hills, a bespoke steel platform was designed to allow the TBM to be assembled off the tunnel axis line and pushed laterally using hydraulic struts.