Plate Load Tests are performed to determine the stress–deformation behavior of compacted soils, road subbase layers and base courses. The deformation moduli (Ev1 and Ev2) are determined from the test results, while the Ev2/Ev1 ratio is used to evaluate the quality of compaction. During the test, loads are applied incrementally to a rigid loading plate by means of a hydraulic jack through two loading cycles consisting of the first and second loading–unloading sequences.
A loaded truck or tracked construction equipment with sufficient reaction capacity is used as the reaction system for transferring the hydraulic jack loads to the ground. At each loading stage, vertical settlements are measured using three dial gauges positioned around the rigid plate at 120° intervals. The average of the three measurements is taken as the settlement value corresponding to each load increment and is used to establish the load–deformation curve.
