Geotechnical Engineering

Geophysical surveys are well suited to projects where understanding subsurface variability between investigation points is critical. This includes linear infrastructure, dams and embankments, foundation investigations, and sites with variable ground conditions, rockhead uncertainty, or potential subsurface hazards.

Yes. Geophysical methods can delineate depth to competent rock and provide insight into material stiffness, hardness and variability relevant to rippability. These results are used to inform excavation planning, plant selection, and earthworks design, and are typically calibrated against borehole or test pit data where available.

The most appropriate method depends on site conditions, target depth, ground type, and project objectives. In many cases, a combination of techniques is used to provide complementary information. Survey design is tailored to each project to ensure the data collected directly supports the required geotechnical outcomes.

Geophysical surveys do not replace intrusive investigations but provide continuous spatial information between them. They can be used prior to intrusive testing to develop an overall site model and guide the targeting of boreholes and test pits. When integrated with these methods, geophysical data improves confidence in subsurface interpretation and helps reduce uncertainty across the site.

Typical requirements include site plans, investigation objectives, known ground conditions, and any existing geotechnical data such as borehole logs or reports. Information on access, services, and site constraints also assists in planning an efficient and targeted survey.

Survey duration depends on site size, access conditions, and the scope of work. Smaller sites can often be completed within one to two days, while larger or more complex investigations may take several days. Reporting timeframes are typically aligned with project requirements.

Deliverables typically include processed geophysical data, interpreted sections or models, and engineering-focused commentary on subsurface conditions. Outputs may include depth to rock mapping, ground models, and integration with existing geotechnical data to support design and decision-making.

Geophysics can help optimise intrusive investigation programs by providing continuous subsurface information across a site. This allows boreholes and test pits to be more strategically targeted, improving efficiency and potentially reducing the overall scope while maintaining confidence in the investigation.

Geophysical data is interpreted alongside borehole logs and CPT results to develop a consistent ground model. This integration improves understanding of layer continuity, material variability, and subsurface features between investigation points, supporting more reliable geotechnical interpretation.

Yes. Many geophysical techniques are well suited to urban and developed environments, including road corridors, industrial sites, and constrained access areas. Surveys can typically be designed to minimise disruption to existing infrastructure, traffic, and site operations.