Abstract
In 2000, the South Dakota Department of Transportation sponsored a research study to evaluate the impact of off-road vehicles on flexible pavements. This project included field pavement responses measured under a variety of loading and environmental conditions. The objective of this investigation is to validate the applicability of the three-dimensional moving load analysis (3D-MOVE) pavement response model before attempting to generate a database of important pavement responses for representative pavements in South Dakota. The validation investigation adopted here addressed both the development of appropriate contact stress distribution for bulky off-road vehicle tires and comparison of computed and measured pavement responses. The field testing consisted of one relatively thin and one relatively thick flexible pavement tested under three types of empty and loaded off-road vehicles. Each pavement section was instrumented with pressure cells, deflection gages, and strain gages at the bottom of the asphalt–concrete layer. The field testing was undertaken during multiple seasons, representing different environmental and material conditions. The extent of good comparison between the computed and measured pavement response values under a variety of loading and pavement structural and material conditions support the applicability of the procedures adopted in the paper to evaluate flexible pavement responses from typical off-road farm vehicle loading.