Assessment of Dynamic Interaction between In-Pavement Light Fixtures and Aircraft Wheel Load through Accelerated Pavement Testing

Failure of in-pavement light fixtures prompted the Port Authority of New York and New Jersey (PANYNJ) to conduct an in-depth evaluation of the in- service light fixtures in their jurisdiction followed by an instrumentation study. For the study, the L-868B light fixture bases were instrumented with four horizontal and four vertical strain gauges. The Federal Aviation Administration (FAA) embarked on a study in 2019 to replicate and verify PANYNJ results using four different configurations of L-850 light fixtures and corresponding bases with the same instrumentation configuration. A total of eight fixtures with varying combinations of spacer rings, studs, and extension were embedded and instrumented in a conventional flexible pavement test bed. The installed fixtures were subjected to impulse, static, and dynamic loading conditions. This paper summarizes the interaction between light fixtures and slow- rolling aircraft wheel load in terms of observed strains. Following a predefined lateral wander, the test items were trafficked at five different incremental load levels using a 3D-gear traversing bidirectionally at a consistent speed of 4 km/h (2.5 mph). Variations in strains along the two axial directions were examined against the nine different wander tracks. The transition of polarity in base strains with loading distance indicated a larger zone of influence than that from the direct impact of the moving wheel loads on the fixtures.