Background

As part of a major high voltage transmission line project, a large-scale geophysical investigation was undertaken across regional Queensland to support the expansion of essential energy infrastructure.

The project alignment extended across vast and remote areas, intersecting multiple geological provinces and ground conditions. With the growing demand for reliable energy networks, the project required a scalable and efficient approach to understanding subsurface conditions along the full corridor.

The scale of the investigation was a defining factor, with more than 70 sites distributed across hundreds of kilometres. Delivering consistent, high-quality data across this extent was critical to support planning and design of this key energy asset.

Electrical resistivity testing for energy project in Queensland

Objective

To provide a consistent subsurface dataset across a large transmission corridor, supporting the design and delivery of critical energy infrastructure.

Key objectives included:

  • Characterising subsurface conditions along a major energy transmission route
  • Identifying regional trends and variability across different geological zones
  • Supporting efficient planning of follow up geotechnical investigations
Geophysical fieldwork along transmission line alignment in Australia

Methods

A standardised geophysical approach was deployed across more than 70 sites along the transmission alignment to ensure consistency across the entire dataset.

Each location was surveyed using complementary seismic and electrical methods, collected both parallel to and perpendicular to the proposed transmission alignment to improve reliability and identify lateral variability. Survey design and acquisition parameters were carefully controlled to maintain uniformity across all sites, enabling meaningful comparison across the corridor.

The program was delivered over multiple field campaigns, with teams operating across remote environments to efficiently capture data at scale.

MASW shear wave velocity profile for energy transmission project in Queensland
Representative subsurface profiles from orthogonal survey directions, illustrating consistent layering and variability in ground conditions across the alignment.
VES resistivity profile for transmission line investigation in Queensland
Measured and modelled resistivity data showing strong correlation between field observations and inversion results.

Outcome

The project successfully delivered a high quality geophysical dataset across a major energy transmission corridor.

The investigation covered:

  • 70 plus sites along the alignment
  • Hundreds of kilometres of transmission corridor

Multiple geological zones with distinct subsurface conditions

Despite the scale and logistical complexity, the dataset demonstrated strong consistency, allowing for reliable comparison across the entire corridor. Regional trends in subsurface conditions were clearly identified, providing valuable insight into ground variability.

By delivering repeatable, large-scale coverage, the investigation reduced uncertainty in early-stage design and supported more targeted follow up investigations. The outcome was a more efficient pathway toward the delivery of critical energy infrastructure.