Asian Journal of Applied Sciences1996-3343xxxx-xxxxKnowledgia Review10.3923/ajaps.2009.197.210AmeriM. YavariN. ScullionT. 3200923Backcalculating layer moduli, using the deflections
measured by the FWD (Falling Weight Deflectometer) device, is the basis
for structurally evaluating pavements when considering maintenance and
rehabilitation options. Many algorithms have been developed to perform
the backcalculation. Most of them are based on simplified assumptions
such as the elastic behavior of the pavement and static load. These algorithms
use the peak values of loads and deflections recorded by the FWD sensors.
The dynamic analysis, to the contrary, accounts for the dynamic nature
of the load and factors such as material inertia and damping. These algorithms
use as inputs both load and deflection time histories measured by the
FWD. In this research, three software programs, MODULUS 6.0, ELMOD 5.0
and EVERCALC 5.0, were used to do the elasto-static back-analysis and
the DBSID program was employed for the dynamic backcalculation. The FWD
data gathered from different test sites, including the Zanjan-Tabriz,
Eivanekey-Garmsar and Garmsar-Semnan freeways and also Rafsanjan airport
have been used in this evaluation. The results have been compared, the
performance of each program has been evaluated and the best software for
the sites under study is suggested.]]>Everseries User’s Guide,20052005Iran Highway Asphalt Paving Code, No. 234,20002000Fernando, E. and W. Liu,19931993Chua, K.M.,19891989pp: 398-405pp: 398-405Fernando, E. and W. Liu,20022002pp: 159167Lytton, R.L.,19891989pp: 7-35pp: 7-35Matsui, K. and Y. Hachia,20062006Tawfiq, K.,20032003Uzan, J., R.L. Lytton and F.P. Germann,19891989pp: 217-227pp: 217-227Van Cauwelaert, D.R. Alexander, T.D. White and W.R. Barker,19891989pp: 184-187pp: 184-187Westover, T.M. and B. Guzina,20062006William, G.W.,19991999ELMOD 5 Quick Start Manual,20062006Duncan, J.M., C.L. Monismith and E.L. Wilson,1968No. 228,pp: 18-23pp: 18-23