Plate Bearing Tests

Plate bearing tests, also known as plate loading tests, are a crucial method for assessing the ultimate bearing capacity of the ground and predicting settlement characteristics under specific loads.

The results are often used for designing temporary working platforms for piling rigs or crane outriggers. However, they are particularly useful for estimating the bearing capacity and confirming adequate compaction of permanent earthworks.

The test involves jacking a plate, typically made of rigid steel and ranging in size from 300 to 720mm in diameter, against a reaction load, often the underside of a track-driven excavator.

During the plate bearing test, the steel plate is loaded incrementally (measuring with a loadcell), and settlements corresponding to each load increment are recorded.

The Modulus of Sub-grade reaction obtained from the test can also be correlated with CBR values, providing additional insights, especially in assessing gravelly materials where a conventional CBR test may not be appropriate.

The data is also sometimes used to derive stiffness properties for settlement calculations, but the depth of influence of a plate load should be considered when the outcome is to be applied to foundations over larger areas.

This makes plate bearing tests invaluable for ensuring ground conditions are properly understood and suitable for the intended development or infrastructure project.