Geotechnical Services

Wheal Jane Consultancy has the expertise, experience and equipment to carry out a wide range of geotechnical investigations. Our in-house rigs and plant make Wheal Jane Consultancy a one-stop-shop for site investigation. Our investigation regime can include, but is not limited to;

• Trial pitting (including soakaway testing in accordance with BRE 365 and percolation testing)
• In situ tests, including California Bearing Ratios and Standard Penetration tests)
• Windowless sampling
• Rotary drilling
• Cable percussive drilling
• Groundwater and ground gas monitoring
• Geotechnical laboratory testing
• Factual reporting
• Interpretive reporting, including advice relating to preliminary foundation design, earthworks, excavations, roads/hardstanding design & concrete classification.

We have found that it is to the advantage of our clients to obtain this information as early as possible in the design and procurement stage of their projects. We can attend your site with our plant, or one of our geotechnical engineers can join our client’s groundworks team to work with their own plant and crew.

Some of our commonly requested services include:

• CBR Testing
• Percolation testing
• Infiltration Testing
• Allowable Bearing Capacity
• Depth To Competent Bedrock
• Existing Foundation Inspection

Our Geotechnical services cover Cornwall, Devon and the South West.

Ground conditions represent perhaps the biggest hazard to any construction project. However, a well designed ground investigation specific to the needs of the site can reduce these geotechnical risks, and save money in the long run.

We often use the findings of desk-based studies, as well as the outline development proposals to design a suitable ground investigation employing technics specific to the anticipated geology, topography and available access.

Common methods of intrusive investigation include;
• Trial pitting (including soakaway testing in accordance with BRE 365 and percolation testing)
• Hand Pitting
• In situ tests, including California Bearing Ratio, Plate Bearing Tests and Standard Penetration tests)
• Windowless sampling
• Rotary drilling
• Cable percussive drilling

Plate bearing tests are a relatively quick and easy method of establishing and understanding bearing strength and settlement characteristics of the ground under specific loads.

The tests are carried out in situ, at foundation level and are useful for a variety of applications but particularly, bearing pads, platforms, piling mats and crane outrigger pads.

All such tests are carried out to the BS1377 Part 9 : 1990 standard for ‘Soils for Civil Engineering Purposes’.

The test is carried out using steel plates of various sizes from 300mm to 600mm and a tracked excavator (or similar heavy reaction weight) and hydraulic jack to apply pressure to the plates at regular time intervals. Gauges are used to measure the extent and rate of settlement.

A similar test which is more generally used for roads, car parking and pavements is the Dynamic Cone Penetration (DCP) test which is used to calculate the CBR (California Bearing Ratio) although a mathematical calculation using the plate bearing test results can provide a comparative CBR result.

For more information on UKAS Accredited Plate Bearing tests (and DCP tests) provided by Wheal Jane Consultancy please contact us.

Soakaway tests are undertaken in accordance with BRE Digest 365, and are used to assess the infiltration characteristics of the ground, in order to aid drainage design.

Soakaway tests can be undertaken at varying depths, reflecting the proposed drainage solution, for example permeable paving.

Soakaway tests are often undertaken as part of a Geotechnical or Phase II Site Investigation, and thus contribute to the development of the ground model.