Volume 34, Issue 6 (November 2006)
Multi-Depth Deflectometer Dynamic Response Measurements under Simulated New Generation Aircraft Gear Loading
In this paper, the comparative effect of dual-tridem (Boeing 777) and dual-tandem (Boeing 747) gear trafficking is studied on the Multi-Depth Deflectometer (MDD) responses of two medium-strength subgrade flexible test sections at the National Airport Pavement Test Facility (NAPTF). Using the MDD response-time histories and in-depth displacements obtained under repeated traffic loading, the results were investigated in terms of rebound (recovered) and residual (unrecovered) displacements in the pavement and in the subgrade. The resilient behavior of the NAPTF flexible pavement sections were characterized by analyzing the MDD rebound response data. The results showed that the rebound surface displacements were significantly influenced by changes in asphalt concrete surface layer temperature. Analysis of transverse distributions of MDD rebound surface displacements revealed multiple-wheel load interaction effects. In general both the rebound and residual (and hence the maximum total) displacements are approximately equivalent for both the dual-tridem and dual-tandem gears.