The Plate Bearing Test (PBT) BS1377-9 is carried out on site by our technician team. The test determines the maximum bearing capacity of the soil and rocks underneath your working area.

What is a Plate Bearing Test?  

The Plate Bearing Test (PBT) BS1377-9 is carried out on site by our technician team. The test determines the maximum bearing capacity of the soil and rocks underneath your working area.

If your project has shallow foundations or a traffic surface, your design engineers will need to know the bearing capacity of the soil underneath. This informs them whether the ground is able to take the anticipated load of a planned temporary or permanent structure. Your test results can then be interpreted by your design team as a design parameter or to confirm the design assumption.

You would normally use a Plate Bearing Test to:

  • Assist in the design of crane and piling mats
  • Calculate the anticipated settlement beneath a given load
  • Determine CBR Value in granular materials (which are not suitable for in-situ CBR tests)
  • Test bases and shallow foundations for temporary buildings or structures.  
PSL on site testing
How a Plate Bearing Test is Performed

Step 1: Our experienced field technicians will attend your site and carry out the test at foundation level or by digging out a shallow pit to the desired depth.

Step 2: A suitable machine is selected to act as a reaction load to provide the load and stresses required. This is usually a JCB, forklift or other construction plant.

Step 3: The loading plate is placed on the ground or in the pit and connected to the reaction load with a load cell. This converts the force exerted and turns it into a measurable electrical output.

Step 4: A hydraulic jack then loads the steel plate onto the required test area.

Step 5: Our technician records the settlement corresponding to each load increment.

Step 6: Your results will be available either the same day or the next working day, depending on the time the test is performed.

Core boring concrete
Plate Size

The size of plate used in a Plate Bearing Test depends on the material type being tested. Before the technician visits your site, they will contact you for a quick discussion to ensure all your testing requirements are able to be completed on the day. Plates come in a range of sizes ranging from 300mm – 720mm in diameter and the one required depends on the following:

  • Thickness of the material being tested
  • Particle size of the material being tested
  • Zone of Influence depth required

If you have any questions or are unsure if your construction plant is heavy enough to provide the reaction load required, please contact our team who will address and concerns before the test is performed. This will help us achieve a smoother service for you and enable us to deliver your results as quickly as possible.

Prosoils Branded Van