Influence of tire footprint area and pressure distribution on pavement responses

Abstract

For most pavement analyses, it is assumed that the tire load is uniformly applied over a circular area. Also, it is generally assumed that tire inflation and contact pressures are uniform throughout the contact area. Several studies on this topic have shown different non-uniform pressure patterns. Therefore, a full understanding of the interaction between tires and pavement is necessary to obtain more accurate pavement responses. The objective of this study was to evaluate the effects of truck tire contact pressure on pavement responses at different loading conditions. A tire footprint system was used to capture contact pressure patterns statically and dynamically (low speed) at three inflation pressures and three wheel loads. All testing conditions were performed using a Heavy Vehicle Simulator HVS Mark VI with a five-rib tire type 11R22-5. A flexible pavement section instrumented with asphalt strain gauges, pressure cells and multi depth deflectometers was used to measure pavement responses. Measured tire-pavement contact stress data were input into a finite element analysis program to compute pavement responses and compare them to the measured responses. The contact pressure patterns obtained for the five-rib tire indicated that higher pressures were obtained for the inner ribs based on the controlled variables. In general, the results indicated that the contact area decreased for a given load as the inflation pressure was increased. Statistical analysis confirmed that pavement responses were significantly related to tire pressure distribution.