Evaluation of Soil Stiffness Via Non-Destructive Testing
Primary Topic: Pavement Base and Subbase
Description: The principal purposes of this investigation were to measure the structural characteristics of the subgrade and base on a section of US 35 with various NDT devices as the section was being constructed, and to compare the output of these devices in assessing structural conditions and variability. A series of nondestructive tests was conducted using a Nuclear Density Gauge, a Humboldt Stiffness Gauge, a German Plate Load Test, a Falling Weight Deflectometer (FWD), and a Dynamic Cone Penetrometer. All tests except for the German Plate Load test were conducted at 50-foot intervals along the driving lane of a 2000-foot-long test section after the subgrade and base were completed. The German Plate Load test was conducted at 100-foot intervals. Data obtained from these tests were used to compute soil parameters such as stiffness, unit layer load deflection, and layer moduli. The resilient modulus of the subgrade and base were determined in the laboratory according to the SHRP protocol.
FHWA Publication Number:
Publication Year: 2001