Geotechnical Drilling Services

QEST is a specialist provider of geotechnical drilling services in Melbourne, Geelong, across Victoria, and interstate including Brisbane, Adelaide and regional Queensland and South Australia. With over two decades of experience, our licensed geotechnical drillers deliver borehole drilling, core drilling, and geotechnical sampling for projects of every size, from residential builds and commercial developments to bridges, roads, tunnels and major infrastructure works.

We are the geotechnical drilling contractor clients call when accurate subsurface data matters. Using modern drilling rigs and proven sampling methodologies, we give engineers, consultants and construction teams the ground-condition data they need to design with confidence and manage geotechnical risk before it becomes a problem on site.

One contact. One coordinated team. One call does it all.

What is geotechnical drilling?

Geotechnical drilling is the process of boring into the ground to collect soil and rock samples that reveal what is beneath a proposed construction site. The samples are tested to determine soil composition, rock structure, groundwater levels, and load-bearing capacity, information that directly informs foundation design, site safety, and construction methodology.

Without accurate geotechnical drilling data, a project is built on assumptions. With it, every design decision is grounded in what is actually under the surface.

Our geotechnical drilling services

QEST offers a complete suite of geotechnical drilling and sampling techniques. The right method depends on ground conditions, project scope, and site access. We will recommend the most appropriate approach for your investigation.

Geotechnical borehole drilling

Standard borehole drilling for subsurface investigation, sampling, and groundwater monitoring. Suitable for the majority of construction and civil engineering projects.

Geotechnical core drilling

Rotary core drilling for the extraction of intact rock and soil cores, ideal where detailed analysis of stratigraphy and rock quality is required.

Auger drilling

Fast, fluid-free auger drilling for soft to medium ground conditions. The preferred method when sample integrity and rapid turnaround are both priorities.

Rotary and wash boring

For harder subsurface materials and deeper investigations where rotary or wash-boring techniques outperform standard auger methods.

Tight access drilling

Specialist drilling rigs configured for confined sites, low-clearance jobs, and inner-city projects where standard equipment cannot reach.

Geotechnical sampling and laboratory liaison

Disturbed and undisturbed sample collection, logged and prepared to industry standard, with coordination through to your nominated laboratory.

Geotechnical drilling vs environmental drilling

The two are often confused. Both involve sampling beneath the surface, but the purpose is different.

Geotechnical drilling investigates the physical and mechanical properties of soil and rock to support construction and foundation design – composition, density, strength, and bearing capacity.

Environmental drilling investigates contamination, collecting soil, water and gas samples to identify pollutants and assess remediation requirements.

QEST delivers both. If you are unsure which your project calls for, get in touch and we will guide the scope.

Service areas

QEST operates Australia-wide from depots in Victoria, Queensland, and South Australia, with crews mobilising to projects across the country. We routinely deliver geotechnical drilling services across:

• Victoria – Melbourne, Geelong, Ballarat, Bendigo and regional Victoria
• Queensland – Brisbane and South East Queensland, regional QLD
• South Australia – Adelaide and regional SA
• Remote and regional Australia on a project-by-project basis

Tight-access urban sites, regional civil projects, and large infrastructure jobs – our fleet and crews are configured to mobilise to the conditions, not the other way around.

Why work with QEST

• 20+ years of geotechnical drilling experience across civil, commercial, residential and major infrastructure projects
• Licensed, qualified drillers with a strong site-safety record
• Modern fleet of drilling rigs, including tight-access machines for restricted sites
• One point of contact from quote to completed report, no managing multiple subcontractors
• Trusted by engineering consultancies, builders, and tier-one civil contractors across Australia

Frequently asked questions

What types of projects require geotechnical drilling?

Geotechnical drilling is required for almost any project that puts load on the ground – residential builds, commercial developments, bridges, roads, tunnels, retaining walls, dam works, and major infrastructure. Anywhere foundation design, slope stability, or subsurface contamination needs to be understood before construction begins.

What factors should be considered when planning a geotechnical drilling project?

Scope and objectives drive the choice of drilling method. Beyond that, the key considerations are ground conditions, site access, depth of investigation, proximity to existing infrastructure, and the type of sample data the engineering team needs. QEST will scope all of this with you before a rig hits the ground.

How accurate is the data from geotechnical drilling?

Highly accurate when the right method is paired with the right site, and when samples are handled and logged to industry standard. QEST’s core drilling and borehole drilling work delivers detailed stratigraphic, geotechnical and groundwater data that engineering teams rely on for foundation design and risk assessment.