In-Situ Plate Load Testing

While site investigations for most projects consider ground conditions at depth, the strength and variability of the near-surface ground are critical for the cost-effective design of flexible and rigid pavements. Approximate equivalent CBR values can be derived from the modulus of subgrade reaction by use of mathematical relationship. The test involves loading a steel bearing plate onto the subgrade surface to be measured by applying pressure with a hydraulic jack. The resulting surface deflection is read from dial micrometers near the plate edge and the modulus of subgrade reaction is determined.