BS 5930 and Eurocode 7 require reliable hydraulic conductivity data before any deep excavation or foundation design in Aberdeen. The city's geology, dominated by the Aberdeen Pluton—a massive Devonian granite body—creates highly variable permeability conditions. Intact granite has negligible primary permeability. However, the weathered zone, jointing patterns, and fault-related fracturing can transmit significant groundwater flow. Standard lab tests on small samples miss these features entirely. Field permeability tests, specifically the Lefranc test for soils and the Lugeon test for rock, measure hydraulic conductivity in situ at the scale that matters for engineering. Our team has applied these tests across projects in Aberdeen, from the harbour redevelopment to residential schemes on the city's western periphery. Understanding how water moves through the ground is not optional here. It dictates dewatering system design, cut-off wall depth, and grouting requirements for structures in the River Dee and River Don corridors. For sites with deep granular deposits, we often combine permeability testing with CPT soundings to correlate hydraulic behaviour with stratigraphy without sample disturbance.
Packaged in situ tests measure hydraulic conductivity at the scale of rock mass defects—something no lab permeameter can replicate.
Our approach and scope
Site-specific factors
Aberdeen's development history has placed increasing pressure on sites with challenging groundwater conditions. The city expanded westward onto glacial till overlying granite, and the harbour area sits on reclaimed land with complex fill and alluvial sequences. In both settings, underestimating ground permeability leads to construction delays, cost overruns, and in worst cases, basal heave or slope instability during excavation. The Lugeon test is particularly critical in Aberdeen's granitic rock because the Lugeon value directly informs grouting decisions. A value above 10 Lu typically signals the need for systematic curtain grouting before excavation. Values between 3 and 10 Lu may require selective treatment. Below 3 Lu, the rock mass is generally considered tight enough for conventional construction. The Lefranc test in overburden soils informs wellpoint and deep-well dewatering design. Ignoring in situ testing and relying on textbook values for 'granite' is a mistake we see repeated in geotechnical reports. Aberdeen's weathered granite behaves more like a heterogeneous granular material than intact rock. Testing at the right depth intervals, with the right method, is the only way to get data that holds up under construction conditions.
Regulatory framework
BS 5930:2015+A1:2020, BS EN 1997-2:2007 (Eurocode 7), ISO 22282-2:2012, BS EN ISO 22475-1:2021
Complementary services
Lugeon Packer Testing in Rock
Five-stage pressure testing in boreholes drilled into weathered or fractured granite. We supply the full BS 5930-compliant test record, Lugeon unit calculation per stage, and a qualitative assessment of rock mass condition including hydraulic fracturing and wash-out behaviour. Suitable for dam foundations, deep basements, and tunnel alignment investigations across Aberdeen's granitic terrain.
Lefranc Testing in Soils
Constant-head and falling-head Lefranc tests in overburden materials including glacial till, alluvial sands, and man-made fill. Test intervals are sealed with pneumatic packers to prevent short-circuiting. Results feed directly into dewatering system design for commercial and residential excavations in the city's river corridors and harbour redevelopment zones.
Typical parameters
Common questions
What is the difference between a Lugeon test and a Lefranc test?
The Lugeon test applies to rock. It pumps water into an isolated section of a borehole at stepped pressures, measuring the rock mass's hydraulic conductivity in Lugeon units. The Lefranc test applies to soils. It can be performed as a constant-head or falling-head test within a borehole or piezometer. In Aberdeen projects, we often run both: Lefranc in the glacial till and weathered zone, Lugeon in the underlying granite.
How much does a field permeability test cost in Aberdeen?
A Lefranc or Lugeon test campaign in Aberdeen typically ranges from £530 to £780 per test interval, depending on depth, access conditions, and the number of intervals per borehole. Mobilisation, drilling support, and reporting are quoted separately. We provide fixed-price proposals after reviewing your site investigation plan.
When is a Lugeon test required instead of a laboratory permeability test?
Laboratory tests on intact rock cores miss the effects of joints, fractures, and weathering. A Lugeon test measures the bulk permeability of the rock mass, including these defects. BS 5930 recommends Lugeon testing when groundwater control is critical for excavation, when grouting may be required, or when rock mass permeability governs foundation design. In Aberdeen's fractured granite, lab tests alone are insufficient for dewatering or grouting design.