A geotechnical engineer (infrastructure) is a specialist who investigates and characterises ground conditions to inform the design of infrastructure - roads, embankments, cuttings, retaining walls and bridge foundations. Where a geotechnical engineer working on buildings focuses on foundations and basement structures, the infrastructure geotechnical engineer's primary concerns are slope stability, pavement subgrade, embankment design and ground improvement for highways and civil works. They work closely with the civil engineer to ensure that infrastructure is designed in a way that matches what the ground can safely support.
What they do
- Manage and interpret ground investigation for infrastructure projects
- Carry out slope stability and embankment design
- Assess and specify ground improvement for weak or variable ground
- Provide geotechnical input to retaining wall and bridge foundation design
- Assess drainage conditions and groundwater impacts on roads
- Prepare geotechnical reports for planning and construction
- Investigate existing slopes and landslides near infrastructure
- Specify subgrade treatment for road pavement construction
When you need one
A geotechnical engineer is required for any infrastructure project where ground conditions are a significant design consideration - which includes most highway schemes, embankments and retaining structures.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Ground investigation (per day plus laboratory testing) | £800 - £2,500 / day |
| Geotechnical assessment report | £1,000 - £3,500 |
| Slope stability analysis | £800 - £2,500 |
| Embankment design | £1,500 - £4,000 |
| Ground improvement specification | £800 - £2,000 |
| Retaining wall geotechnical input | £1,000 - £3,000 |
| Hourly rate | £90 - £160 / hr |
Ground investigation costs depend heavily on ground conditions and the number of boreholes or trial pits required. Laboratory testing is typically charged separately. Always agree scope and day rates before investigation commences.
Qualifications to look for
The most common route for infrastructure geotechnical engineers. CEng MICE via the Institution of Civil Engineers covers the ground engineering discipline. Verify at ice.org.uk.
Some geotechnical engineers hold CGeol status via the Geological Society, particularly those with a geology background who have moved into engineering. Verify at geolsoc.org.uk.
How to find a reputable geotechnical engineer
Frequently asked questions
What is slope stability analysis?
Slope stability analysis is an assessment of the likelihood of slope failure under various loading and groundwater conditions - required for embankments, cuttings and existing slopes near development. Modern analysis uses limit equilibrium or finite element methods. The output is a factor of safety against failure which must meet the highway authority's specified minimum.
What is ground improvement?
Ground improvement refers to techniques used to improve the engineering properties of weak ground - including compaction, dynamic compaction, vibro-compaction, stone columns, preloading and reinforcement. It is used where natural ground is insufficiently strong to support infrastructure loads without excessive settlement or bearing failure.
What is a bearing capacity assessment?
A bearing capacity assessment determines the load a soil or rock can safely support without excessive settlement or shear failure. It is fundamental to foundation and pavement design for roads and structures. The assessment uses the results of ground investigation - trial pits, boreholes and laboratory testing - to characterise the ground and calculate allowable bearing pressures.