The plate bearing test is a simple, effective way to determine the strength of a soil sample. The test measures the amount of force required to push a steel plate down into the soil sample. This force is then used to calculate the CBR of the soil.
There are several factors that affect the CBR calculation, including the plate size and weight, the type of soil, and the degree of compaction. In order to get accurate results, it is important to follow the testing guidelines carefully.
The CBR calculation can be used to help assess the suitability of a site for certain types of construction projects, or to help design foundation systems. By understanding the CBR of your soil, you can make better decisions about how to build on or accommodate that soil.
The plate load test should be carried out in line with the British Standard 1377 1990: Part 9
The test is normally carried out at the foundation level and is applied in five increments with readings taken every minute.
Plate bearing test procedure
- Note test location
- Record plate size used
- Setup plate on level surface
- Setup dial rails and dial gauges on the plate
- Setup hydraulic jack
- Strat test
- Record each pressure test
- Record corresponding settlement
- Record rebound readings
- Reload to maximum
- Record final settlement reading
For loading tests made at the ground level or in an excavation where the bottom is at least five times the plate diameter, the plate settlement modulus EPLT may be calculated from the general equation:
where:
Δp is the selected range of applied contact pressure considered;
Δs is the change in total settlement for the corresponding change in the applied contact pressure Δp including creep settlements;
b is the diameter of the plate;
The results of the test are normally used in the design of temporary structures such as working platforms or piling rigs. Plate bearing tests can also be used for wind farms, airport runways, and many other applications.
If you would like a quote for Plate Bearing Tests or have any questions, please do not hesitate to contact IBX Consultant Engineers for further information.
