Structural Soils Accreditation logos - UKAS

State of the art and UKAS accredited geotechnical and materials testing laboratories

Located in Bristol, Castleford and Hemel Hempstead our laboratories are well equipped to perform routine and advanced testing for soil, rock, aggregate and asbestos-contaminated materials. Our laboratories are licensed to handle and test non-UK samples and carry out testing according to BS, BS EN, BS EN ISO, ISRM Suggested Methods and ASTM International test methods. We also work with clients to create bespoke site- or project-specific testing solutions.

Our laboratories are continuously extending the original scope of their accreditation to meet the testing needs of our clients. In addition, they participate yearly in national and international proficiency testing schemes to ensure the delivery of high-quality testing results. Laboratory data deliverables include digital data in both AGS and PDF formats. Our accreditation is limited to those activities described on our current UKAS schedule of accreditation found here.

Laboratory tests

Soil tests

Classification and electrochemical

  • Water content
  • Particle size distribution – sieve and sedimentation analysis
  • Liquid and plastic limits (Atterberg limits)
  • Bulk and dry density
  • Particle density
  • Desiccation – filter paper suction method
  • Electrical and thermal resistivity

Compaction related

  • Dry density/moisture content relationship
    – 2.5 kg and 4.5 kg rammer
    – Vibrating hammer
  • Moisture condition value – one point at natural moisture condition or five-point calibration
  • Chalk crushing value
  • California bearing ratio

Consolidation and swelling

  • Incremental loading
  • Constant rate of strain consolidation
  • Consolidation in a Rowe or triaxial cell
  • Swelling and swelling pressure
  • Swell or collapse

Permeability (constant or falling head)

  • In an oedometer
  • In a hydraulic (Rowe) cell
  • In a triaxial permeability cell

Drained and undrained shear strength

  • Fall cone, laboratory vane, hand vane and Torvane
  • Direct and residual shear strength
    – Small and large shear box
    – Ring shear
  • Unconfined compressive strength
  • Unconsolidated undrained triaxial compression
  • Direct simple shear
  • Cyclic direct simple shear

Effective stress and advanced soil testing

  • Consolidated isotropic or anisotropic, undrained or drained, in triaxial compression or extension
  • Load- or strain-controlled cyclic triaxial strength of soil
  • Resonant column
  • Bender elements
  • Mid-height pore pressure measurements
  • Axial and radial deformation measurements

Durability

  • Erodibility by dispersion method
  • Double hydrometer
  • Crumb test

 

Rock tests

  • Moisture content
  • Porosity and density
  • Point load index
  • Uniaxial and triaxial compressive strength
  • Swelling pressure and strain
  • Direct shear strength
  • Indirect tensile strength
  • Sound wave velocity
  • Elastic parameters (shear and Young’s moduli, Poisson’s ratio)
  • Cerchar abrasivity
  • Slake durability and jar slaking
  • Thermal and electrical resistivity

 

Aggregate tests

  • Water content
  • Particle size distribution
  • Flakiness index
  • Methylene blue
  • Constituents of recycled aggregates
  • Density and water absorption
  • Loose bulk density
  • Resistance to fragmentation
  • Aggregate crushing value
  • Ten per cent fines value
  • Aggregate impact value
  • Magnesium sulphate

 

Unbound and hydraulically bound mixtures

  • Reference density and water content
    – Proctor compaction
    – Vibrating hammer
  • California bearing ratio and swelling
  • Moisture content value Concrete
  • Compressive strength of concrete cores

Supplementary laboratory testing services are offered through Envirolab and RSK Materials and Structures.

Structural Soils Contaminated Sample (RED) Laboratory

The Structural Soils Contaminated Sample (RED) Laboratory may accept asbestos or other fibre-containing soil samples; hydrocarbon or heavy-metal-contaminated soil; biologically inactive but odorous organic soil or soil–sludge mixtures. We cannot accept for testing materials containing radioactive compounds, live munitions or explosives, blood products, human body fluids or animal, pathological or microbiological wastes. The Contaminated Sample (RED) Laboratory testing follows accredited standard test methods.

Frequently Asked Questions – Geotechnical Soil & Rock Testing

1. What materials can be tested at your geotechnical laboratory?

Our geotechnical testing laboratories specialise in the physical and mechanical properties testing of soil, rock, and aggregates.
This includes tests for strength, compressibility, permeability, particle size distribution, and other parameters essential for geotechnical design and construction.

While we are not a chemical laboratory, we can assist with the collection and preparation of samples for external analysis, such as Waste Acceptance Criteria (WAC) testing, when required.

We also have a dedicated laboratory for safely handling and testing asbestos-contaminated materials and in compliance with UK regulations.

2. Which test standards do you follow, and is the testing accredited?

All testing is performed in accordance with British (BS) and European  (BS EN) Standards, as well as other globally recognised test methods (ISO, ISRM, ASTM) or national standards (NF, DK). You can view our full list of accredited tests here.  

3. How do I submit soil or rock samples for testing?

Clients can directly submit samples to our testing laboratories. For bulk or heavy samples, we offer courier collection at additional cost. Sample size, packaging, and handling requirements depend on the type of test being performed. For guidance, contact our team to ensure your samples meet all submission criteria.

 

4. What is the typical turnaround time for soil or rock test results?

Turnaround time varies by test type. For basic classification tests, results are typically delivered within 1 to 2 weeks.
More complex analyses such as triaxial or permeability testing may take longer.
To get an accurate timeline based on your project and testing scope, please contact us directly.

 

5. Do you offer interpretation of test results or engineering advice?

Factual and interpretative reports of the results are handled by our engineering department. Furthermore, our engineers can offer consultation, and provide recommendations tailored to your project’s geotechnical requirements.

 

6. How can I get a quote or speak to someone about my testing project?

You can request a quote for soil or rock testing services by using the contact form on our website, or by emailing us directly at ask@soils.co.uk where our team is happy to discuss your testing requirements, turnaround times, and provide you with a detailed quotation based on your specific project needs.

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Structural Soils is part of the RSK group of companies

The RSK group is a leading integrated environmental, engineering and technical services business offering bespoke end-to-end solutions to a variety of sectors. Headquartered in the UK but with an established presence throughout Europe, Africa, the Middle East, Asia and Australia, RSK helps organisations around the world achieve their business aspirations in a sustainable and efficient manner.