Soil Environment Services

Soil Surveys, Soil Investigations, Site Investigations and Environmental Land Surveys

Soil Resistivity Testing – Soil Thermal Resistivity (STR)

Soil resistivity testing, or soil or ground thermal resistivity (soil thermal conductivity or soil thermal diffusivity) testing is required to determine cable design and or trench design prior to cable placement.

Please see our new dedicated website for Soil Thermal Testing

Soil Environment Services Ltd can test the ground prior to or during any site works, within trenches or in our specialised  laboratory. We have been testing soil and backfill to the Energy Networks Association specifications for over 10 years. We test soils, rocks and cable bedding materials such as Cement Bound Sand  and in recent years have worked with some of the biggest cable laying companies on the longest cable routes in the UK. Of critical importance is the accuracy of resistivity measurements both on site and in the essential supporting laboratory assessments. Soil Environment Services Ltd is conducting on-going research in this area to understand the soil physics of the environment in order to deliver highly accurate soil resistivity testing measurements. Please see our information sheet.


Field Testing

Our range of equipment is designed to allow full flexibility with in-field soil resistivity testing.

soil resistivity testing










We have experience working in difficult conditions and are able to tailor the equipment to the site.


soil resistivity survey















Thermal probes can be inserted into rock or gravel on site and these very often occur in the same trench.


thermal soil resistivity


We will assess the specific needs of the project and the environment within which the cable will be operating to provide specific and accurate measurements.

Soil resistivity testing may be carried out in boreholes, test pits or trenches, or we can take cores out of soil, rocks or roads.



Laboratory work

Thermal resistivity, thermal conductivity or thermal diffusivity of soil, rock  or other material, e.g. Cement Bound Sand (CBS)  can be measured in our specialised laboratory and is essential to both support field measurements and assess thermal properties under a range of conditions.  We have our own dedicated fully equipped laboratory set up for thermal testing of soils, rocks, trench back-fill, alternative (non-traditional) back-fill and CBS.  We are currently progressing through the preparation of systems and procedures for a UKAS accreditation application. However, our laboratory soil resistivity testing is only undertaken by experienced consultants who also have a full theoretical understanding of the processes involved with attention to detail at the research scientist level.


soil thermal resistivity testing


Normally we test to and using  the following specifications:


IEEE 1997 Std 442 ENAT 97-1, Version 2  2016

BS EN ISO 8990: 1996

National Grid TS 3.05.07

BS 1377 – Compaction


All laboratory work is overseen by Dr Robin Davies who has a PhD in soil physics (soil stabilisation) and many decades of high quality research laboratory experience for the former British Coal and central government funding agencies. Several recent years of laboratory work have  increasingly been focussed on  undertaking thermal testing for aggregate supply and cable installation companies.


All of our laboratory staff have science degrees, have worked on central government funded science projects which included laboratory work  and have spent a number of recent years undertaking soil resistivity testing /rock thermal testing.



UKAS accredited laboratory verification of the mechanical test procedures can currently be supplied if needed.



If you need CBS testing in the laboratory or field, please call us to discuss your exact requirements as sample treatment prior to testing is crucial.



Quality and Standards

Testing is undertaken by Dr Robin Davies who has 15 years experience in testing the thermal properties of soils, rocks and aggregates and over 30 years experience in testing the physical and mechanical properties of these materials. All work is therefore based on a full theoretical understanding of the processes involved with attention to detail at the research scientist level. We have pioneered new and novel techniques with statistically valid in-house research to deliver test values of the highest standard to meet the requirements of the following specifications.

IEEE 1997 Std 442 ENAT 97-1, Version 2 2016

BS EN 8990:1996

National Grid TS 3.05.07

BS 1377

Full project consultancy experience

We tailor testing parameters to your specifications in order for you to design cable trenching and bedding on a project specific basis.

All testing and outputs are conducted to the highest industry standard and in line with current international specifications.


Recent project examples

OMEXOM Crossaig Substation – Mull of Kintyre

ABB – Caithness to Moray 120MW, 50km on land cable route

National Performance Centre for Sport – Heriot Watt University

INSTALCOM – Sheffield roadway dry mix


Ground testing prior to cable placement. United Utilities – National Grid Feckenham Sub Station 

soil resistivity testing


CBS testing above the cables.  Crossaig Substation – OMEXOM

soil thermal resistivity str


CBS testing during cable pulling.  Crossaig Substation OMEXOM

soil resistivity testing


Bentonite testing within cable ducts.   Caithness-Moray HVDC cable.

bentonite testing


Racebank Windfarm Landfall – Kings Lynn

soil thermal resistivity testing




Contact Dr Robin Davies  to discuss your requirements;


Office – 01661 844827

Mob – 07776474028