Modulus backcalculation method of deflection data based upon FWD and influencing factors;

The deflection criterion of the void under slab of the cement concrete pavement is studied on the basis of the results of several void detective methods in the experimental road.

Based on the elastic foundation model,the deflection rules under the loads of falling weight deflectionmeters(FWD)are comprehensively analyzed,and approximate formulas are obtained accordingly by regression among void scope beneath slab corner,deflection index(defined by deflection ratio of slab corner and slab middle under FWD loads),foundation type and relative stiffness radius of slab.

Based on deflection basin parameters and artificial neural networks(ANNs),this paper presents a methodology for processing dynamic falling weight deflectometer(FWD) measurements to estimate layer module and condition.

Aimed at the problem of error treatment of measured settlement data,the fairing filtration theory is put forward to treat the measured settlement errors.