Trr No. 1355 Pavement Design, Management, And Performance, pp. 1-7
The results of this studv indicate that material nonlinearities are localized and are important for FWD tests oil flexible pavements where the subgrade is relatively soft or the pavement is thin. In these cases. nonlinear effects increase peak displacements by at least 50%percent under a 20.000-Ib load but are negligible for receivers at 3 ft or more from the source. In general, a FWD test with a load of 2000 Ib or less would not result in any apparent nonlinear effects at anv pavement site. For FWD or rigid pavements or flexible pavcmcnts with a relatively stiff subgrade, nonlinearitics are also less pronounced