Effects of Axle Load, Suspension System, Vehicle Speed and Pavement Condition on Dynamic Loads

This work aims at quantifying the effects of traffic loading factors and pavement roughness on dynamic loads of trucks. It is used the computer program TruckSim to accomplish the simulations, which was developed at the UMTRI (The University of Michigan Transportation Research Institute) and it is based on mathematical models of vehicles and the longitudinal profile of pavements. It is presented a factorial simulation considering the following factors: axle type (steering axle, single axle, and tandem axle), axle load (legal limits in Brazil, plus and minus 20%), suspension system, vehicle speed (70, 90, and 110 km/h) and pavement condition (in terms of roughness: 1.6, 3.5 and 4.4 IRI). The effect of dynamic loads relatively to the static condition is quantified by similarly to the load equivalence factor concept. This paper presents statistic models for the estimation of dynamic loads, which highlight the importance of pavement roughness and vehicle speed on the dynamic loads supported by the highway infrastructure.