Implications of complex axle loading and multiple wheel load interaction in low volume roads

Various highway vehicle axle/wheel arrangements adopted nowadays to accommodate increasing load levels impact flexible pavement response and performance in accordance with different multiple axle/wheel loading scenarios applied in low volume roads. This paper describes a recent three-dimensional (3D) finite element (FE) pavement modeling research effort focused on investigating effects of complex multiple axle/wheel loading scenarios on mechanistic analyses of critical pavement responses and their implications on low volume pavement designs. For this purpose, realistic nonlinear, stress dependent pavement geomaterial modulus models were employed in the base/subbase and subgrade layers of thinly surfaced asphalt pavements. The low volume road sections were next analyzed using a validated 3D FE structural analysis program. Comparisons made between the single wheel superposition and the full 3D loading results proved the need and importance of 3D FE nonlinear analyses of low volume flexible pavements to properly consider both the stress dependent geomaterial modulus behavior and the implications of multiple wheel loads and their interaction.