On-site geotechnical testing to the
Construction and Engineering industries.
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Services / Plate Bearing Tests
Plate bearing tests offer a cost-effective, reliable, rapid assessment of ground strength.
The tests are particularly suited to determining the strength of ground for temporary structures such as crane pads, as well as spread foundations for building slabs, wind turbines, electrical sub stations etc.
- Crane Pads – A Plate Bearing Test will mimic the load of your crane outrigger, establishing the suitability of the crane pad prior to arrival of the crane. This provides reassurance to the constructor of the pad, demonstrates safety for the crane operators, and provides certification for insurers.
- Building Foundations – Plate Bearing Tests can be used to establish / confirm the strength of the ground for raft or spread foundations. The testing can provide reassurance if assumptions have been made about ground bearing pressure.
- Wind Turbines – Most suppliers of small or medium sized turbines will supply a standard foundation design for use with that turbine. A Plate Bearing Test will confirm the strength of the ground, and will therefore confirm the suitability of the standard foundation design. This avoids the need for costly bespoke foundation design work on most sites.
- Roads / Hardstanding – Plate tests (in particular the 150 mm diameter plate) can be used to simulate the static load of a vehicle. Larger plates can be used to calculate an equivalent California Bearing Ratio (CBR) value.
- Tanks, Bio-digesters & Rigid Structures – The Plate Bearing Test is particularly useful when constructing tanks, bio-digesters or other rigid structures where cracking caused by movement cannot be tolerated. The test can be used to calculate the modulus of subgrade reaction (springiness) of the soil beneath the tank, to allow suitable remedial measures to be designed.
How It Works
Our plate test site teams have access to a full suite of plates:
- 150 mm plate – Suitable for concrete / bound hardstanding or for modelling point loads.
- 300 mm plate – For clayey / fine grained soils.
- 450 mm plate – For coarse grained soils and for modelling spread loads.
- 600 mm plate* – For very coarse grained soils and for modelling spread loads.
*600 mm diameter plate is only carried as required. It requires a two-man crew due to its weight.
Our plate test site teams carry equipment suitable for testing up to 400 kN/m2 or 40 tonnes / m2 on a 450 mm diameter plate. Higher loads can be tested with additional notice.
Accuracy is essential! - Geotest always use a fully calibrated load cell to monitor pressure on the plate. This is far superior to a calibrated pressure system which can vary significantly over time.
PBTs - Supermarket, Cornwall
Plate Bearing Tests (PBTs) being carried out for a raft foundation at a supermarket in Cornwall. Testing was carried out for a private developer and used to obtain Ground Bearing Pressure and an indication of settlement.
PBTs - Dockyard, Cornwall
Plate Bearing Tests (PBTs) were carried out at a dockyard in Cornwall. Testing was carried out by the dockyard owner to establish the maximum safe lifting loads in a number of locations around the dockyard, for the cranes that frequently visit the site. The testing was undertaken to establish the ground bearing pressure on site.
Crane Pad Testing - Dockyard, Cornwall
Plate Bearing Tests (PBTs) being carried out at a dockyard in Cornwall for a luxury yacht manufacturer. The testing was required prior to lifting the mast onto the largest single-masted yacht in The World! The crane operator was present during the testing (supplying a crane for kentledge). The testing was required to establish the size of spreader plates required beneath each crane outrigger to prevent the maximum safe bearing pressure from being exceeded.
Anaerobic Digestion Plant, Devon
Work to install the base of an Anaerobic Digestion Tank following Plate Bearing Tests (PBTs) to establish the Modulus of Subgrade Reaction on the ground. This enabled the engineer, a national renewable energy company, to design a sufficient layer of stone to prevent movement in the base of the tank.
PBTs - Wind Turbine Base, Berkshire
Close view of a Plate Bearing Test (PBT) in Berkshire. This setup was using a 300 mm diameter plate, to assess ground bearing pressure for a Wind Turbine.
Plate Bearing Tests, Kent
Close up view of a Plate Bearing Test (PBT) in Kent. This setup was using a 300 mm dimeter plate, to assess the safety of a crane pad prior to lifting.
Modulus of subgrade reaction
Installation of clean gravel beneath a proposed Anaerobic Digestion Tank in Devon, following plate bearing tests to establish the modulus of subgrade reaction. This enabled the engineered to establish the thickness of stone required for the project.
Plate Bearing Tests - Hampshire
Plate Bearing Tests being set up in Hampshire for a major reinforced plastics company. The testing was carried out at various points in the yard to establish the strength of the ground, and therefore the maximum load that a crane could safely lift. Geotest were also able to make recommendations on ways of preventing degradation to the concrete yard.
Anaerobic Digestion Plant, Devon
Installation of clean gravel beneath a proposed Anaerobic Digestion Tank in Devon, following plate bearing tests to establish the modulus of subgrade reaction. This enabled the engineer to establish the thickness of stone required for the project.
Wind Farm Repowering, Cornwall
Plate Bearing Tests (PBTs) being carried out at a wind farm in Cornwall for a repowering project. The client was a national renewable energy company. Testing comprised carrying out a series of Plate Bearing tests in the base of trial pits.
Crane Pad Testing, Cornwall
Plate Bearing Tests being carried out directly from a crane in Cornwall. This testing was carried out on a construction site prior to lifting heavy steel beams into a building undergoing refurbishment. The testing established that the ground was sufficiently strong to be able to support the crane during the lift.
PBTs - Wind Turbine Foundations
Plate Bearing Tests being carried out at a wind farm in Cornwall to establish the suitability of a crane pad prior to lifting and replacing the Nacelle. The testing was required by the crane operator to ensure that the ground was safe prior to lifting.
Plate Bearing Test Setup
Close up view of the Plate Bearing Test (PBT) setup, before the excavator was moved into position. Testing was carried out for a proposed wind turbine. Initial testing had been carried out on the base of the foundation, to confirm ground bearing pressure. A second phase of testing was then carried out on the crane pad prior to lifting the components into place, to establish that the ground was suitable for the lift.
