A Comparison of Dynamic Soil Models for Backcalculation of Engineering Soil Properties from Falling Weight Deflectometer Data

Abstract

The falling weight deflectometer (FWD) test is one of the most widely used nondestructive tests for backcalculation evaluation of pavement and soil properties. Despite the advantages in accounting for the time-dependent load and responses, the accuracy of evaluating elastic moduli based on dynamic backcalculation analyses is, however, significantly depended on the forward dynamic soil models employed in the backcalculation process. To serve this challenge, a comparison for advantages, limitations and the reliability of different dynamic soil models employed in the backcalculation of engineering soil properties is presented in this paper. Two types of dynamic soil forward models in the FWD backcalculation, namely, dynamic single-degree-offreedom (SDOF) and dynamic half-space models are considered. The study in this paper provides a better understanding of dynamic backcalculation processes which is essential for the development of dynamic backcalculation program and its applications.