Cobham Drive crossing – State Highway 1

United Tunneling was engaged to deliver a specialist trenchless crossing beneath State Highway 1 at Cobham Drive. The project involved installing 80 metres of 1500mm concrete jacking pipe at depths of up to 11 metres, using pipe jacking methods supported by sheet piling works.

With a major transport corridor overhead, maintaining traffic flow and minimising disruption were key priorities. Open trench excavation was not a practical option, making pipe jacking the right solution for a safe and controlled underground installation.

Launch and receiving pits were established using sheet piling to provide secure working areas and support excavation at depth. From there, the concrete jacking pipes were installed with precision beneath the highway.

Projects like this highlight the value of trenchless construction on critical infrastructure routes — allowing major underground works to be completed while keeping what happens above ground moving.