Axle pilot project: semi trailer wheel load measurements

RTA is supporting and monitoring a pilot project for the introduction of 27 tonne quad axle groups on selected routes in NSW. This pilot scheme is comprised of modelling and measurement of applied forces, pavement material responses, equipment performances under the described loads, together with monitoring of actual pavement condition over time. As a part of the broader project, in 2008 RTA engaged ARRB to determine the horizontal and vertical forces imparted on a road surface by the tyres of an A123 vehicle and two A124 configurations using computer simulations. The outputs of this project were used in finite element modelling of the pavement, to compare the relative impact on the pavement by those different configurations. Ultimately, this information may be used to determine access, axle mass limits, and pricing options for quad axle configurations. The intention of the completed experimental study (Dec 2010) was to verify the computer simulated parameters used in the finite element modelling of the pavement damage in the pilot area. The experiment used a single prime mover and a quad axle trailer capable of operating in tri-axle configuration as well. The test was carried out in both tri-axle and quad axle un-laden/laden configurations. A comparison was made with the AutoSim generated wheel loads used to calculate pavement damage and measured wheel loads in the experiment.