Distribution of Stresses in Reinforced and Unreinforced Flexible Pavement Layers under Dynamic Load

Abstract

Nowadays, the increasing demand for road transport makes maintenance and repair of road infrastructures key tasks for road engineering. The current experimental work consists of laboratory model experiments to understand the conduct of sand as a subgrade under dynamic load and its effect on the flexible pavement and base layer. Geogrid reinforcement was applied at the interface between the base and subgrade using SS2 type of geogrid. The road layers were exposed to harmonic dynamic load with two load amplitudes 10 and 15 kN and two frequencies 0.5 and 1 Hz. The vertical stresses in the road layers are measured using stress gauge sensor. It revealed that when laying the geogrid between the base course and subgrade and when base course thickness is 150 mm, the stress and displacement decreased with increase in the frequency and load amplitudes. But in the case of reinforcing layer at the center of the base course layer, the displacement decreased with increase in the frequency and loads except for one case when the load was 15 kN and frequency 0.5 Hz. It can be suggested that the maximum vertical displacement increased with the increase of base course thickness for both reinforced and unreinforced base layers. Also, it can be observed that the vertical stress increased by increasing the base course layer-thickness for unreinforced models.