Sydney Metro West – ETP The Bays .

The Eastern Tunnelling Package (ETP) is a key component of the Sydney Metro West project and is being delivered by the John Holland CPB Contractors Ghella Joint Venture (JCGJV). This package includes the construction of twin 3.5-kilometre tunnels beneath Sydney Harbour, linking The Bays to the Sydney CBD, as well as the bulk excavation of underground stations at Pyrmont and Hunter Street.

JCGJV’s scope covers bulk excavation and primary structural support across several complex underground structures adjacent to Sydney Harbour. The use of specialised slurry Tunnel Boring Machines (TBMs) has been essential, given the highly variable ground conditions and elevated groundwater pressures present throughout the alignment.

Due to the proximity of the works to the Harbour, multiple structural interfaces are vulnerable to groundwater ingress. These include gasket joints in the segmentally lined tunnels and the waterproofing transitions between the precast tunnel sections and cast in-situ cross passages.

Direct Inject has been engaged to provide targeted leak-sealing services within the segmentally lined tunnels and adjacent structures. To date, this has included polyurethane injection to address gasket leakage in the running tunnels between The Bays and Pyrmont. With cross passage excavation progressing steadily, Direct Inject remains ready to support this valued client with additional concrete repair and water stopping services as required.

Works are being undertaken during planned TBM maintenance windows and weekend shutdowns to minimise interface with ongoing tunnel logistics. This approach ensures our workforce can operate safely and efficiently, with minimal disruption to critical TBM segment transport and handling operations.