Plate Bearing Test

The Plate Bearing Test, also known as the Plate Loading Test, is an in-situ test in which a known load is applied to a steel plate placed on the ground. It is used to determine the ultimate bearing capacity, immediate settlement of the ground, modulus of subgrade reaction and California Bearing Ratio (CBR). The plate bearing test is essential for working platforms, crane outrigger pads, piling mats and some temporary structures, helping to ensure safety and stability.

If you require modulus of subgrade reaction and CBR testing for the design of roads, pavements, car parks, etc., please visit our California Bearing Ratio (CBR) Test page.

Sub Surface provides Plate Bearing Tests nationwide, as described in BS1377: Part 9: 1990: Soils for Civil Engineering Purposes. We offer a professional service with fast mobilisation and quick turnaround results to meet project demands.

Plate Bearing Testing in Liverpool, Merseyside

Plate Load Test at a Wind Farm in Rochdale, Greater Manchester

Performing a Plate Bearing Test

Plate Bearing Tests are carried out on the existing ground surface or on a pre-prepared working platform to assess its capacity to withstand a known pressure, such as a crane or piling rig.

The steps involved in the plate bearing test are as follows:

Site Preparation: The working platform should be constructed, compacted and levelled before Sub Surface’s arrival on site, and the test area must be cleared.
Test Preparation: A thin bed of sand is placed on the ground at each test location to fill in any surface voids
Plate Placement: A circular steel plate, usually between 300mm and 600mm in diameter, is placed on the ground to be tested. Sub Surface will advise on the plate diameter needed based on the loading requirements.
Load Application: A load is applied to the plate in increments using a hydraulic cylinder and jack beneath a minimum 13 tonne tracked excavator. The load increments are determined based on the known maximum working pressure of the crane outriggers, piling rig or temporary structure in kilopascals (kPa).
Settlement Measurement: The settlement of the ground is recorded at each load increment until the settlement has stabilised.
Test Completion: The load is increased at regular intervals until it reaches the required test pressure, where possible, or until failure occurs.

Subject to site conditions and loading requirements, Sub Surface can typically undertake between four and eight Plate Bearing Tests per day. We offer fast mobilisation and a professional, reliable, and competitively priced service nationwide.

Plate Bearing Test near Penrith, Cumbria

Plate Bearing Test for a Piling Platform in Birmingham, West Midlands

The Importance of a Plate Bearing Test

Plate Bearing Tests play a crucial role in construction and civil engineering by ensuring ground stability and safety for working platforms and temporary structures. These tests help assess the bearing capacity and settlement characteristics of the ground, providing essential data for informed decision making.

Key Benefits of Plate Bearing Tests:

Ensures Ground Stability – Prevents ground failure such as bearing capacity failure, excessive settlement and subsidence by verifying the ground or working platform can support the intended pressure.
Enhances safety – Reduces the risk of accidents caused by bearing capacity failure and excessive settlements, protecting both personnel and equipment.
Optimises Design and Construction – Provides accurate data to determine the required thickness of subbase for working platforms, improving efficiency and reducing unnecessary material costs and waste.
Mitigates Project Delays and Costly Repairs – Identifies potential ground issues early, preventing unexpected failures that could lead to costly delays.
Compliance with Industry Standards – Meeting legal and engineering requirements, and ensuring adherence to regulations such as:
- BS1377: Part 9: 1990 – Methods for test for soils for civil engineering purposes (in-situ tests),
- BRE 470 – Working platforms for tracked plant
- Eurocode 7 (BS EN 1997-2) – Geotechnical design (ground investigation and testing).

The Importance of Plate Bearing Tests - Piling Mat Failure

When to Perform Plate Bearing Tests

Plate Bearing Tests should be considered at the following stages:

Before Working Platform Construction: To assess the suitability of the subgrade and determine the required thickness of the well-graded gravel subbase for optimum design.
After Working Platform Construction: To verify the suitability of the constructed working platform.
After significant weather changes: The stability of the working platform can be affected by severe weather, such as heavy rainfall and frost.
Change of construction equipment: Higher loading capacities may be required that were not initially tested for.
Periodically: If the working platform is to remain in place for reuse, it should be tested periodically to ensure that it is still suitable.

Request a Quote

We are happy to assist if you have any questions regarding Plate Bearing Tests or if you would like a quote. Please do not hesitate to contact your Regional Sub Surface Office.

Other In-situ Tests and Services: CBR Testing, Percolation and Soakaway Tests, Ground Investigation

Plate Bearing Test FAQs

Do I need a Plate Bearing Test or a California Bearing Ratio (CBR) Test?

A Plate Bearing Test is used to determine the ultimate bearing capacity and immediate settlement of the ground for working platforms, crane outrigger pads and piling mats. A CBR Test is used in the design of roads, pavements, car parks, etc. If this is what you need, please visit our CBR Test page.

How long does a Plate Bearing Test take?

A Plate Bearing Test takes a minimum of 45 minutes. However, the actual time depends on the ground conditions encountered on site and the loading requirements. We can usually carry out between four and eight in a day.

How quickly will I receive the results of a Plate Bearing Test?

Depending on the amount of tests conducted, the results can usually be made available the next working day.

What equipment is needed for a Plate Bearing Test?

A circular steel plate (usually 300mm, 450mm or 600mm in diameter depending on the loading requirements), a hydraulic cylinder and jack, dial gauges and a minimum 13 tonne tracked excavator are needed to perform a Plate Bearing Test.

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