Western Harbour Tunnel – Package 1 .
Polyurethane and acrylic gel injection to treat groundwater ingress through shotcrete lined main carriage way tunnels and ventilation caverns.
Stage 1 of the Western Harbour Tunnel project was awarded as a variation to the Rozelle Interchange contract and is being delivered by the John Holland CPB Contractors Joint Venture. This package focuses on the southern section of the new Western Harbour Tunnel, connecting the Rozelle Interchange to the future harbour crossing.
The scope of Stage 1 includes the construction of approximately 1.7 kilometres of twin tunnels from the Rozelle Interchange to Victoria Road at the base of the Iron Cove Bridge. Similiar to the Rozelle Interchange, the western harbour tunnels are designed as drained structures using rock bolts and a shotcrete lining for primary support. The Project Specification included strict inflow criteria covering limits on total ground water ingress within a specific geographical extents and a zero tolerance policy for drips on the main carriage ways and on mechanical and electrical installations.
Direct Inject had spent two years working with this joint venture client on teh Rozelle Interchange prior to the Western Harbour Tunnel Stage 1 package being awarded. Due to the satisfactory work we had performed at the Interchange we were enagged almost 18 months later to perform the same services in the newely constructed tunnel extensions. The scope included polyurethane injection of the shotcrete lining were high-flow water ingress was observed and to seal leaks causing drips over the main carriageway to meet the strict inflow criteria stipulated in the project specification.
