Posted by: admin November 11, 2015

PROJECT DESCRIPTION:

Design and construction of an 87 m long pipe-jacked, hydrostatic tunnel to carry 6 x 132kV circuit cables through water-charged soil beneath Burrows Road to an Energy Australia/Transgrid Substation. The scope of works included intensive geotechnical and environmental investigations to inform detailed design, service location identification through potholing, design and shoring of the launching and receiving pits, tunnel boring, pipe-jacked lining, and fitting out of the pits to act as permanent access facilities for Transgrid maintenance staff.

Complex Challenges:

The entire tunnel lies below the ground water table adjacent to the Alexandria Canal, demanding innovative methods using hydrophilic crystals mixed with Bentonite to control groundwater seepage. Traffic management and staging of materials deliveries were also critical, due to the very tight site conditions, which provided little space for storage of materials awaiting installation.

Posted by: admin

PROJECT DESCRIPTION:

Design and construction of a 2400mm diameter by 120m long pipe jacked tunnel, including fit out with stainless steel cable support brackets. The scope of works included construction of 8m x 8m x 8m deep cable pit which into which stainless steel access ladders and platforms were installed for continuing use by maintenance crews.

Complex Challenges:

The tunnel is located beneath railway lines and roads and has strict settlement and environmental monitoring requirements. Modifications to Abergeldie’s EPBM tunnel boring machine were required to suit the dimensions specified for the tunnel, and to address local soil conditions.