Sydney Metro West – CTP PROJECT WIDE .
Concrete surface repairs, structural crack injection and polyurethane injection to treat groundwater ingress in segmentally and cast in-situ lined tunnels, station boxes and cross over caverns.
As part of the Sydney Metro West project, the Central Tunnelling Package (CTP) is being delivered by the Acciona Ferrovial Joint Venture (AFJV). This package involves the construction of twin 11-kilometre tunnels between The Bays and Sydney Olympic Park, along with the bulk excavation of five station boxes located at Sydney Olympic Park, North Strathfield, Burwood North, Five Dock, and The Bays.
AFJV’s scope is focused on excavation and initial structural support, including:
Each of these structures presents critical interface points susceptible to groundwater ingress. These include leakage paths along ground anchors in station boxes, gasket joints between tunnel segments, and waterproofing terminations at junctions between precast tunnels and in-situ cross passages and caverns. Additionally, precast tunnel segments are often damaged during TBM installation, particularly at edges and around segment erector cones formed for vacuum lifting.
Direct Inject has been engaged to perform specialist concrete remediation within station boxes and across the segmentally lined tunnels. Our scope includes repairing spalling and damage around segment edges and erector cones, structural crack injection within the segment intrados, and polyurethane injection to seal leaks originating from ground anchors, gasket joints, and voids within the tunnel annulus grout.
We are also treating active seepage at construction joints within cross passages and at interface zones where cross passages and caverns connect with the main running tunnels. These repairs utilise a combination of polyurethane and acrylic gel injection techniques to ensure long-term structural durability and watertightness.
Our work is taking place during and following TBM operations, often within confined and logistically complex environments, including live transport of tunnel segments and equipment. Direct Inject continues to play an essential role in supporting AFJV in the delivery of this critical infrastructure, contributing to the practical completion of key project milestones through timely, targeted remediation solutions
