Dynamic load plate tests – Calibration Procedure for test equipments in Germany

Abstract

In Germany the dynamic load plate test with the Light Falling Weight
Deflectometer (LFWD) is, beside the static plate load test, standard for testing the bearing
capacity of the subgrade. For testing the bearing capacity of subbase layers the Medium
Falling Weight Deflectometer (MFWD) has been developed. For this several modifications of
the LFWD have been systematically evaluated. The result of this research is an equipment
with a bigger mass and a modified spring assembly. These small modifications allow to keep
the main principle of the test procedure and the calibration procedure. For the calibration of
the LFWD as well as the MFWD an updated calibration procedure has been developed. To
verify this calibration procedure and to evaluate if the calibration centers can handle the
calibration procedure a round robin test has been started in 2012.
The purpose of use related test device selection and its calibration procedure will guarantee
high quality construction control and a wide acceptance.