Ashton House

67 Compton Road



Plate Bearing Testing

The plate bearing (or loading) test is used to determine the vertical deformation and strength characteristics of an in-situ soil by measuring the force and amount of penetration with time when a rigid plate is directed to penetrate the soil, without it being subject to sample disturbance.  The results obtained can then be used to determine the ultimate bearing capacity and modulus of subgrade reaction (k) of the mass ground and also an estimate of its California Bearing Ratio (CBR).  The test method is usually carried out at the ground surface or in shallow pits or trenches.


GIS carry out the test in accordance with Clause 4.1 of BS 1377: Part 9: 1990, normally using the dead weight of a mechanical excavator to provide the kentledge and reaction load necessary for the test.  Various plate sizes can be used ranging from 150 mm to 600 mm diameter, depending on the composition and depth of the soil being tested and the size of the reaction load required.


The load on the centre of the plate is normally applied in five increments, with settlement readings taken at 30 sec to 1 min intervals until detectable deflection of the plate has stopped.  After the final loading increment, the pressure on the plate is released and the movement of the plate allowed to recover before a final residual settlement value is recorded.   Included on the test report given to the client is the calculated k and CBR values and data presented in graphical form giving the bearing pressure and final plate settlement at the end of each load increment and the deformation and time elapsed from the start of each load increment.





For more information about plate bearing testing, call us today on:

01902 717 653