Mount Barker Interchange Upgrade – South Australia

Roadside scene with maintenance trucks and workers fixing traffic signals near a bridge, green grass and tall trees in the background.

Project Type: Geotechnical Site Investigation – Major Transport Infrastructure

Client: Private construction company

Overview

TERRATECH was engaged to undertake a comprehensive geotechnical investigation to support the Mount Barker Interchange Upgrade, a high-profile, multi-million-dollar Department for Infrastructure and Transport (DIT) project. The works support duplication of the existing overpass bridge, pavement upgrades to on- and off-ramps, and installation of new Variable Message Sign (VMS) structures along the South Eastern Freeway.

The investigation was undertaken to provide reliable factual geotechnical data for detailed design across bridge abutments, road alignments, and sign foundations. The scope included shallow and deep borehole drilling, in-situ testing, and an extensive program of laboratory soil, rock and pavement testing, delivered within a live freeway environment.

Key Challenges

  • Delivering reliable, high-quality geotechnical data to support a high-profile, multi-million-dollar DIT upgrade

  • Characterising complex subsurface conditions, including variable fill, residual soils, and transitions to weathered and competent rock beneath critical structures

  • Maintaining investigation efficiency and safety within a live traffic interchange environment

Outcome

TERRATECH delivered a high-quality, multi-disciplinary geotechnical investigation combining soil, rock, pavement, and geochemical testing to support this complex transport infrastructure upgrade. Clear factual reporting, efficient field delivery, and robust subsurface characterisation enabled confident foundation and pavement design while minimising construction risk, safety exposure, and program impacts on this critical section of the South Eastern Freeway.

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