2024 Volume 3 Issue 1 Pages 40-47
In this study, as a method for evaluating the soundness of the granular base directly from the FWD deflection shape, we focused on the granular base compressive strain prediction equation shown in the NCHRP report. Then, the accuracy of the NCHRP’s prediction formula was using the FWD survey results on the national highway was verified, and based on the FWD operating conditions in Japan, a new prediction equation establish method was examined. As a result, it was found that the prediction equation of NCHRP tends to deviate from analytical results of FWD using the multilayered elasticity theory (MLET). In addition, the MLET analysis results based on the FWD operating conditions in Japan were used to formulate the compressive strain prediction equation and the temperature correction equation, and the threshold for the compressive strain soundness evaluation was shown.