Theoretical evaluation of selected back-calculation methods

Abstract EN

Analyzing Falling Weight Deflectometer (FWD) measure- ments is one of the most important problems faced by transportation en- gineers.

Most of the back-calculation programs which use these measure- ments.

do not give unique or similar modulus values for a given pavement system.

The main objectives of this research were: 1 )To conduct a sensitiv- ity analysis of a number of selected back-calculation programs, 2) To deter- mine the ability of these programes to back-calculatc assumed moduli val- ues based on a deflection basin that was calculated using the assumed mod- uli values.

Six back-calculation microcomputer programs were selected and evaluated.

Comparison of the results shows that CHEVDEF and ELSDEF programs are in general more reliable than other programs and can be used to hack-calculate moduli without substantial errors.