FORWARD ANALYSIS OF PORTABLE FWD TEST USING RESILIENT MODULUS OF SUBGRADE

Abstract

 The resilient modulus (Mr) test results are used to evaluate subgrade and roadbeds in pavement structural analysis, which employs the mechanistic-empirical pavement design (MEPD) method. On the other hand, there is a FWD method for evaluating subgrade stiffness using portable FWD in a field. The deflections obtained by both evaluation methods shows different values due to differences in loading speed. It is important to hold the consistency of these evaluation methods in the MEPD. In this study, the portable FWD test and Mr test were performed for a particular subgrade material, and the forward analysis with the multiLayered elastic theory (MLET) and the inverse parabolic load stress distribution was performed to examine the differences in the deflections using the resilient moduli estimated with both methods.

 As a result, it was confirmed that the deflection obtained from the forward analysis and the deflection measured with portable FWD are in good agreement by multiplying the coefficient β that was introduced to consider the loading time to MPED method.