FLEXIBLE PAVEMENT EVALUATION/DESIGN - PHASE II. FINAL REPORT

This report presents the results of an analytical investigation of a dual-load Falling Weight Deflectometer with load spacing of 24 and 40 in. An elastic layer program "RIGID" was used to evaluate the deflections produced by rigid load plate at different sensor locations. A parametric study was conducted to identify the optimum sensor locations for determination of layer moduli. Additional deflection data were generated for various combinations of layer moduli and layer thicknesses using the optimum sensor locations. A basic power log equation format was used to develop layer moduli prediction equations for regression analyses of sensor deflections and deflection difference between two different sensors. The developed moduli prediction equations appear to be very reliable with errors generally less than 15%. Upper pavement stiffness is easier to predict using the dual load system which produces double bending.